Tropical Medicine and Infectious Disease

21 pages, 1847 KB

Open AccessArticle

Development and Validation of an Integrated HIV/STI, and Pregnancy Prevention Programme: Improving Adolescent Sexual Health Outcomes

by Mukovhe Rammela and Lufuno Makhado

Trop. Med. Infect. Dis. 2025, 10(9), 273; https://doi.org/10.3390/tropicalmed10090273 - 22 Sep 2025

Abstract

In developing countries, adolescent girls and young women (AGYW) continue to experience high rates of unintended pregnancy and sexually transmitted infections (STIs), including Human Immunodeficiency Virus (HIV). Several healthcare services are available at the primary level of healthcare to address the sexual and [...] Read more.

In developing countries, adolescent girls and young women (AGYW) continue to experience high rates of unintended pregnancy and sexually transmitted infections (STIs), including Human Immunodeficiency Virus (HIV). Several healthcare services are available at the primary level of healthcare to address the sexual and reproductive needs of adolescents in South Africa. Healthcare providers often face challenges such as limited resources, inadequate funds, and inadequate training, which hinder their ability to provide integrated care. Furthermore, cultural stigma and a lack of privacy prevent adolescents from seeking care. In response to increasing international calls for developing and implementing integrated person-centered care, which addresses both quality and access to care, this paper aims to develop and validate an integrated HIV/STI, and pregnancy prevention program for adolescent girls and young women in the Vhembe District of Limpopo. Multiphase mixed methods were employed in this study. This study consisted of three interconnected phases. As part of phase 1 of this study, a comprehensive literature review was conducted. In phase 2, an empirical study conducted using a concurrent triangulation strategy to collect and analyze both qualitative and quantitative data as a form of confirmation, dis-confirmation, cross-validation or corroboration of the findings. Consequently, a conceptual framework was developed using qualitative and quantitative analysis by merging, comparing, and interpreting the results. The findings of phase 2 interface were analyzed using the Political, Environmental, Social, and Technological (PEST) and Strength, Weakness, Opportunity, and Threat (SWOT) analyses. Additionally, the outcomes of the Logical Framework Analyses (LFA) informed the development of an integrated programme aimed at preventing HIV, STIs, and teenage pregnancy. Several stakeholders and experts (n = 35) were consulted as part of the Reduce the Risk (RTR) Coalition to validate the proposed integrated programme with an average of 94.3% on acceptability, feasibility, and appropriateness. In the Vhembe District of Limpopo province, there has been no published study that has developed an integrated HIV, STIs, and pregnancy prevention programme to improve the sexual health outcomes of adolescent girls and young women. Full article

(This article belongs to the Special Issue HIV Elimination: Addressing Challenges in Vulnerable Populations and Reducing Discrimination)

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14 pages, 4010 KB

Open AccessArticle

Development of a Microfluidic Point-of-Care Platform for HPV Detection Based on Helicase-Dependent Amplification

by Everardo González-González, Elda A. Flores-Contreras, Gerardo de Jesús Trujillo-Rodríguez, Mariana Lizbeth Jiménez-Martínez, Iram P. Rodríguez-Sánchez, Adriana Ancer-Arellano, Salomon Alvarez-Cuevas, Margarita L. Martinez-Fierro, Iván A. Marino-Martínez and Idalia Garza-Veloz

Trop. Med. Infect. Dis. 2025, 10(9), 272; https://doi.org/10.3390/tropicalmed10090272 - 19 Sep 2025

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Abstract

Human papillomavirus (HPV) is the most prevalent sexually transmitted infection worldwide and a leading cause of cervical cancer, accounting for over 300,000 deaths annually, primarily due to high-risk genotypes HPV-16 and HPV-18. Conventional molecular diagnostic methods, such as polymerase chain reaction (PCR), require [...] Read more.

Human papillomavirus (HPV) is the most prevalent sexually transmitted infection worldwide and a leading cause of cervical cancer, accounting for over 300,000 deaths annually, primarily due to high-risk genotypes HPV-16 and HPV-18. Conventional molecular diagnostic methods, such as polymerase chain reaction (PCR), require expensive instrumentation and well-equipped laboratories, which limits their applicability in low-resource or decentralized settings. To address this challenge, the aim of this study was to develop a prototype point-of-care (POC) diagnostic platform based on helicase-dependent amplification (HDA) integrated into a microfluidic device for the specific detection of HPV-16 and HPV-18. The proposed POC platform comprises a disposable poly (methyl methacrylate) (PMMA) microfluidic device, a portable warming mat for isothermal amplification at 65 °C, and a compact electrophoresis chamber for fluorescence-based visualization using SYBR Safe dye, with an approximate total cost of $320 USD. Platform validation was performed on 33 samples, demonstrating amplification of target sequences in less than 60 min with only 20 µL of reaction volume, a limit of detection (LOD) of 15 copies (cp) per reaction, a sensitivity of 95.52%, and a specificity of 100%. This portable and scalable platform constitutes a cost-effective and reliable tool for the detection of HPV, supporting global health initiatives, including those driven by the World Health Organization (WHO), aimed at eliminating cervical cancer as a public health threat, as it can be implemented in decentralized or resource-limited settings. Full article

(This article belongs to the Special Issue Molecular Epidemiology of Human Papillomavirus Infection)

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11 pages, 1043 KB

Open AccessArticle

Seroprevalence and Risk Factor for Canine Tick-Borne Disease in Urban–Rural Area in Ayacucho, Peru

by Jime Rivera Villar, Ivonne Aquino Escalante, Saúl Chuchón Martínez, Rilder Gastelú Quispe, Ruth Huamán de la Cruz, Aide Sandoval Juarez, Giovanna Mendoza Mujica and Nyshon Rojas Palomino

Trop. Med. Infect. Dis. 2025, 10(9), 271; https://doi.org/10.3390/tropicalmed10090271 - 19 Sep 2025

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Abstract

Ehrlichiosis and anaplasmosis are endemic to tropical and subtropical regions and pose significant zoonotic threats to both human and animal health. This study aimed to detect anti-Ehrlichia canis, anti-Borrelia burgdorferi, and anti-Anaplasma antibodies in dogs from the rural–urban [...] Read more.

Ehrlichiosis and anaplasmosis are endemic to tropical and subtropical regions and pose significant zoonotic threats to both human and animal health. This study aimed to detect anti-Ehrlichia canis, anti-Borrelia burgdorferi, and anti-Anaplasma antibodies in dogs from the rural–urban area of Huamanga, Ayacucho. The cross-sectional survey was conducted at the Facultad de Ciencias Biológicas of the Universidad Nacional de San Cristóbal de Huamanga between May and August 2023. Samples were collected via venipuncture, and antibody detection was performed using the immunochromatographic assay Anigen Rapid CaniV-4 kit. Frequencies, percentages, and statistical analyses were conducted using the SPSS^® software package. A total of 107 samples from dogs in the Covadonga Human Settlement were analyzed, comprising 64 (59.8%) males and 43 (40.2%) females. The majority (78.5%) were from mixed-breed dogs, while other dogs breed included Schnauzers, Pekingese, and Pitbulls. Thirty positive samples were identified, with antibodies against Ehrlichia canis (15.9%), Anaplasma phagocytophilum/Anaplasma platys (3.7%), mixed infections of Ehrlichia canis and Anaplasma phagocytophilum/Anaplasma platys (6.5%), and Ehrlichia canis/Borrelia burgdorferi (1.9%) detected, as well as an association between vector exposure and the presence of Ehrlichia canis antibodies. These findings underscore the urgent need for the implementation of integrated control strategies and enhanced surveillance programs targeting tick-borne diseases in high-risk areas, along with targeted educational campaigns to promote responsible pet ownership and preventive measures. Full article

(This article belongs to the Special Issue Emerging Vector-Borne Diseases and Public Health Challenges)

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16 pages, 461 KB

Open AccessArticle

Improved Utilisation and Quality of Blood Culture Services Following Operational Research in a Tertiary Hospital in Ghana

by Rita Sewornu, Emily Boakye-Yiadom, Emmanuel Ativi, Precious Kwablah Kwadzokpui, Bismark Senahey, Helena Owusu, Pruthu Thekkur, Ajay M. V. Kumar and Cornelius C. Dodoo

Trop. Med. Infect. Dis. 2025, 10(9), 270; https://doi.org/10.3390/tropicalmed10090270 - 18 Sep 2025

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Abstract

Operational research (OR) published in 2023 revealed low utilisation and suboptimal quality of blood culture services at a tertiary hospital in Ghana. To address these, several interventions were implemented, including sensitisation of physicians, training of laboratory staff, use of automated incubation systems, and [...] Read more.

Operational research (OR) published in 2023 revealed low utilisation and suboptimal quality of blood culture services at a tertiary hospital in Ghana. To address these, several interventions were implemented, including sensitisation of physicians, training of laboratory staff, use of automated incubation systems, and improved availability of laboratory consumables. To assess the impact of these interventions, we conducted a follow-up study in a cross-section of inpatients (n = 1080) with suspected bloodstream infections (BSI) admitted in 2024. There were three key changes. First, there was a five-fold increase in requests for blood culture from 8% pre-OR to 40% post-OR. Culture requests were more frequent from child health department (63%) and intensive care units (53%) compared to surgery department (15%). Second, there was a reduction in delays: time from hospital admission to culture request was reduced from 2 days to 1 day, and the laboratory turn-around time was reduced from 7 days to 5 days. Third, there was a marginal improvement (p = 0.692) in the quality of blood cultures: diagnostic yield improved from 7% to 10%, and the contamination rate was reduced from 16% to 14%. Achieving universal culture utilisation among eligible patients and lowering contamination rates will require a detailed gap analysis and targeted interventions. Full article

(This article belongs to the Special Issue Field Impact of the SORT IT Initiative on Combating Antimicrobial Resistance Through a One Health Approach in Ghana)

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18 pages, 665 KB

Open AccessCommunication

Agreement Document for the Study of Leishmaniasis from a One Health Approach in Spain

by Joaquina Martín-Sánchez, Jose M. Requena, Montserrat Gállego, Maribel Jiménez, Ricardo Molina, Paul Nguewa, Francisco Morillas-Márquez, José M. Pérez-Victoria, Begoña Monge-Maillo, Manuel Morales-Yuste and Clotilde Marín

Trop. Med. Infect. Dis. 2025, 10(9), 269; https://doi.org/10.3390/tropicalmed10090269 - 18 Sep 2025

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Abstract

Background: Leishmaniasis, a vector-borne disease caused by the parasite Leishmania, is a public health concern in Europe. Although Spain is an endemic country, it lacks a national surveillance network. To address this, the creation of a research and surveillance network is [...] Read more.

Background: Leishmaniasis, a vector-borne disease caused by the parasite Leishmania, is a public health concern in Europe. Although Spain is an endemic country, it lacks a national surveillance network. To address this, the creation of a research and surveillance network is proposed, which would integrate data from various fields and enhance control and public health strategies. Objectives: The first objective is to gather epidemiological data on vectors, reservoirs, and transmission rates in Spain, with a particular focus on the role of dogs and wildlife as primary reservoirs. The plan includes establishing forums, databases, and specialised training programmes. The second objective is to improve case surveillance and reporting by establishing a comprehensive national registry. Implementing molecular diagnostics and bioinformatics tools will aid analysis of retrospective data and tracking of disease evolution. The third objective is to develop a standardised method for the molecular characterisation of Leishmania, using techniques such as PCR and genomic sequencing to detect virulence and resistance patterns. Key actions include collecting isolates, sharing analytical tools and providing genomic training. The fourth objective is to identify new therapeutic targets in response to toxicity and resistance to current treatments by studying specific enzymes (FeSOD, HDAC), metabolic pathways, and natural products. Ultimately, establishing the Leishmaniasis Surveillance Network will support a “One Health” approach and promote interdisciplinary collaboration towards a national control plan. Methods: We created the Working Group on Leishmaniasis funded by the Spanish Society of Tropical Medicine and International Health as a leishmaniasis forum for meetings and discussions on weaknesses and gaps we find in the knowledge and management of the infection based on the background of each academic and healthcare research group. Expected Impact: This study will promote the articulation of a Leishmaniasis Surveillance Network aiming to bring together the main stakeholders in the research and management of leishmaniasis in Spain. Full article

(This article belongs to the Special Issue Leishmaniasis in Europe and the Mediterranean Region)

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16 pages, 1688 KB

Open AccessArticle

Seasonal Distribution of Viral Pneumonia After COVID-19 and the Role of Hematological Markers in Assessing Pneumonia Severity: A Case–Control Study

by Şaban Melih Şimşek and Ayşe Elif Bayar

Trop. Med. Infect. Dis. 2025, 10(9), 268; https://doi.org/10.3390/tropicalmed10090268 - 17 Sep 2025

Viewed by 185

Abstract

Background: Various studies have shown that viral pneumonia pathogens display distinct inflammatory profiles, and hematological indices, such as the Neutrophil/Lymphocyte Ratio (NLR), Lymphocyte/Monocyte Ratio (LMR), and Platelet/Lymphocyte Ratio (PLR), can serve as accessible markers of disease severity. Moreover, the seasonal distribution of respiratory [...] Read more.

Background: Various studies have shown that viral pneumonia pathogens display distinct inflammatory profiles, and hematological indices, such as the Neutrophil/Lymphocyte Ratio (NLR), Lymphocyte/Monocyte Ratio (LMR), and Platelet/Lymphocyte Ratio (PLR), can serve as accessible markers of disease severity. Moreover, the seasonal distribution of respiratory viruses appears to have shifted during the COVID-19 pandemic. Methods: This retrospective case–control study was conducted on patients diagnosed with PCR-confirmed viral pneumonia in the emergency department of a tertiary care center between 1 January and 31 December 2024. The control group comprised age- and sex-matched individuals without viral pneumonia. Subjects with comorbidities or ongoing treatments potentially affecting hematological indices were excluded. Seasonal distribution of viral pathogens was recorded. Hematological and inflammatory parameters at admission—including neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR)—were evaluated. The associations between these biomarkers, Pneumonia Severity Index (PSI) scores, and hospitalization status were statistically analyzed. Results: In this study, it was determined that Influenza A/B was more common in winter (67.3%) and SARS-CoV-2 in summer (70.7%). The relationship between the Pneumonia Severity Index and hemogram parameters was examined in determining the severity of pneumonia. In SARS-CoV-2, leukocyte and neutrophil counts were positively correlated (R: 0.392, p: 0.003; R: 0.466, p: <0.001), while in Influenza A/B, lymphocyte, platelet, and monocyte counts showed a negative correlation (R: −0.402, p: 0.005; R: −0.331, p: 0.021; R: −0.327, p: 0.023). Correlations were found between inflammation parameters and the Pneumonia Severity Index, except for the Lymphocyte/Monocyte Ratio, between SARS-CoV-2 and Influenza A/B (p < 0.05). Conclusions: The seasonal distribution of viral pneumonia pathogens has been revealed following the COVID-19 pandemic. Due to differences in inflammation patterns in viral infections, different leukocyte subgroups have been suggested as biomarkers. Full article

(This article belongs to the Special Issue Respiratory Infectious Disease Epidemiology and Control)

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12 pages, 493 KB

Open AccessArticle

High Rate of Human T-Cell Lymphotropic Virus-2 in Patients with HIV in the Peruvian Amazon

by Silvia Otero-Rodriguez, Martin Casapia-Morales, Carmen de Mendoza, Viviana Pinedo-Cancino, Seyer Mego-Campos, Vicente Soriano, Esperanza Merino and José-Manuel Ramos-Rincón

Trop. Med. Infect. Dis. 2025, 10(9), 267; https://doi.org/10.3390/tropicalmed10090267 - 17 Sep 2025

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Abstract

HTLV-1/2 in people with HIV (PWH) has been little studied in the Peruvian Amazon, an endemic area for both viruses. We aimed to estimate its prevalence and describe the main clinical and epidemiological features of individuals with HTLV-HIV co-existence. We conducted a cross-sectional [...] Read more.

HTLV-1/2 in people with HIV (PWH) has been little studied in the Peruvian Amazon, an endemic area for both viruses. We aimed to estimate its prevalence and describe the main clinical and epidemiological features of individuals with HTLV-HIV co-existence. We conducted a cross-sectional study (October–December 2023) at the Division of Infectious Diseases and Tropical Medicine at the Regional Hospital of Loreto in Iquitos. We performed a screening test (recombinant HTLV I+II ELISA) and confirmed the results with INNO-LIA. Among 293 PWH analyzed, 14 (4.8%) were HTLV-positive: 1/293 was HTLV-1-positive (0.3%; 95% CI 0.06–0.9), 11/293 were HTLV-2-positive (3.8%; 95% CI 2.1–6.8), and 2/293 were non-typeable (0.7%; 95% CI 0.1–2.7). Compared with HIV-monoinfected individuals, superinfected patients were older (55 vs. 39 years; p = 0.001). Low education was more frequent in the univariate analysis (35.7% vs. 15.4%; p = 0.05) but was not retained in the multivariable model. In conclusion, HIV–HTLV-2 co-existence is relatively common (~4%) in the Peruvian Amazon, particularly among older individuals, highlighting the need for targeted screening and prevention strategies. Integrating HTLV testing into routine HIV clinic workflows, along with brief and focused counseling for superinfected patients, may help optimize follow-up and care. Full article

(This article belongs to the Special Issue HIV Testing, Prevention and Care Interventions, 2nd Edition)

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17 pages, 787 KB

Open AccessArticle

Prevalence of Antimicrobial and Colistin Resistance in Enterobacterales in Healthy Pigs in Ghana Before and After Farmer Education

by Elvis Fiam Amegayibor, Rita Ohene Larbi, Matilda Ayim-Akonor, Ebenezer D. O. Ansa, Pruthu Thekkur, Helena Owusu, Robert Fraser Terry, Anthony D. Harries, Benjamin Kissi Sasu, George Kwesi Hedidor and Richael Odarkor Mills

Trop. Med. Infect. Dis. 2025, 10(9), 266; https://doi.org/10.3390/tropicalmed10090266 - 17 Sep 2025

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Abstract

High levels of antimicrobial resistance (AMR) were found in healthy pigs in the Greater Accra region of Ghana in 2022; this led to awareness creation and education of pig farmers about how to improve antimicrobial practices and biosecurity. To assess changes in AMR [...] Read more.

High levels of antimicrobial resistance (AMR) were found in healthy pigs in the Greater Accra region of Ghana in 2022; this led to awareness creation and education of pig farmers about how to improve antimicrobial practices and biosecurity. To assess changes in AMR after the intervention, we compared AMR, multi-drug resistance (MDR), and determined colistin resistance levels in healthy pigs in the region before (2022) and after (2024) the education of farmers. Rectal swabs (n = 140) from pigs in 14 farms were cultured for isolation of Enterobacterales (Escherichia coli and Enterobacter spp.) and subjected to antimicrobial susceptibility testing. A selective culture method was employed to isolate colistin-resistant Enterobacterales, which were further screened for the mcr-1 gene. AMR and MDR findings were compared with those from 140 pigs from the same farms in 2022. Enterobacterales were found in 137 (2022) and 138 (2024) rectal swabs, with Escherichia coli predominating. There was a marked increase in AMR prevalence for eight of the nine tested antibiotics in 2024. Notable increases in resistance were for tetracycline (58–82%), ampicillin (33–49%), and ciprofloxacin (3–33%). MDR prevalence was highest in Escherichia coli, increasing from 20% to 44%. Phenotypic colistin resistance was found in 44% of Escherichia coli isolates in 2024 (in 2022, using different methodology, phenotypic colistin resistance was 8%)—in 2024, the mcr-1 gene was found in 51% of these isolates. There were no relevant associations between farm and pig characteristics and prevalence of MDR and phenotypic colistin resistance. Although education is an important aspect of AMR control, the findings highlight that education alone cannot curb the rise of AMR. Further interventions including continuous surveillance, stronger regulatory policy on antimicrobial use, and behavioral interventions will be needed to mitigate the situation. Full article

(This article belongs to the Special Issue Field Impact of the SORT IT Initiative on Combating Antimicrobial Resistance Through a One Health Approach in Ghana)

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15 pages, 957 KB

Open AccessArticle

Campylobacter Colonisation of Poultry Slaughtered at Nigerian Slaughterhouses: Prevalence, Antimicrobial Resistance, and Risk of Zoonotic Transmission

by Emmanuel O. Njoga, Philip P. Mshelbwala, Akwoba J. Ogugua, Excel C. Enemuo-Edo, Onyinye S. Onwumere-Idolor, Temitope M. Ogunniran, Sunday N. Bernard, Joel C. Ugwunwarua, Ebube C. Anidobe, Chinwe E. Okoli, Enid Godwin, Simon I. Enem and James W. Oguttu

Trop. Med. Infect. Dis. 2025, 10(9), 265; https://doi.org/10.3390/tropicalmed10090265 - 17 Sep 2025

Viewed by 620

Abstract

Zoonotic Campylobacter species (ZCS), particularly C. jejuni and C. coli, cause major foodborne gastroenteritis and poultry is the principal reservoirs. However, there is limited data on Campylobacter transmission risk practices and antimicrobial resistance (AMR) in Nigeria. Therefore, this study determined the prevalence, [...] Read more.

Zoonotic Campylobacter species (ZCS), particularly C. jejuni and C. coli, cause major foodborne gastroenteritis and poultry is the principal reservoirs. However, there is limited data on Campylobacter transmission risk practices and antimicrobial resistance (AMR) in Nigeria. Therefore, this study determined the prevalence, AMR, and risk practices aiding Campylobacter transmission in two major slaughterhouses processing poultry carcasses in Enugu State, Nigeria. Four hundred poultry faecal samples were analysed for zoonotic Campylobacter organisms using standard protocols. Antimicrobial resistance was profiled via Kirby–Bauer disk diffusion technique, against eight antimicrobial agents. Risk practices were assessed through slaughterhouse observations and interviews with 56 workers. The overall prevalence of Campylobacter infections was 14.5% (58/400), while the species-specific prevalence were 13% (52/400) and 1.5% (6/400) for C. coli and C. jejuni, respectively. Campylobacter colonisation was significantly higher (p < 0.05) in broilers, and during the wet season. The AMR profile of the isolates against the eight antibiotics tested was: Amoxicillin/clauvlanic acid (100%), vancomycin (100%), tetracycline (96.6%), ciprofloxacin (55.2%), chloramphenicol (44.8%), ceftazidime (10.3%), azithromycin (3.4%) and streptomycin (3.4%). All the 58 Campylobacter isolates were multidrug-resistant. The multiple antibiotic resistance indices ranged from 0.4 to 0.9, with a mean of 0.7. Major risk practice associated with ZCS transmission include non-use of personal protective equipment (100%), slaughtering on unsanitary surfaces (100%), using visibly unclean water for meat processing (100%), improper manual evisceration (75%), eating or drinking during processing (64.4%), slaughtering sick animals (37.5%), inadequate cleaning of surfaces and equipment after use (21.4%) and consuming raw meat during carcass processing (19.6%). The findings reflect critical gaps in food safety, occupational health, prudent antimicrobial use in poultry farming and zoonotic disease control, emphasizing the need for antibiotic regulation, training on hygienic meat processing, public education, infrastructural development of slaughterhouse facilities, and inter-sectorial collaboration to curb Campylobacter contamination and spread of antimicrobial resistance. Full article

(This article belongs to the Special Issue One-Health Perspectives and Solutions in Antimicrobial Resistance and Infectious Disease)

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19 pages, 3536 KB

Open AccessArticle

Wastewater-Based Surveillance of SARS-CoV-2 and Modeling of COVID-19 Infection Trends

by Wenli Wang, Ruoyu Li, Shilin Chen, Liangping Chen, Yu Jiang, Jianjun Xiang, Jing Wu, Jing Li, Zhiwei Chen and Chuancheng Wu

Trop. Med. Infect. Dis. 2025, 10(9), 264; https://doi.org/10.3390/tropicalmed10090264 - 16 Sep 2025

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Abstract

Background: This study was performed to evaluate the early warning value of wastewater-based epidemiology (WBE) in monitoring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its correlation with population-level coronavirus disease 2019 (COVID-19) infection trends. Methods: Wastewater samples from Fuzhou’s Sewage Treatment Plant [...] Read more.

Background: This study was performed to evaluate the early warning value of wastewater-based epidemiology (WBE) in monitoring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its correlation with population-level coronavirus disease 2019 (COVID-19) infection trends. Methods: Wastewater samples from Fuzhou’s Sewage Treatment Plant A were concentrated via membrane filtration and quantified using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Viral load data were integrated with sentinel hospital positivity rates and respiratory outpatient visits from 11 city hospitals. Stratified cross-correlation lag analysis was performed by gender, age, and hospital type. Results: Using the lowest single-day genome concentration as a proxy for daily SARS-CoV-2 levels was advantageous. Wastewater viral concentrations correlated positively with clinical cases, with peaks preceding reports by 0 to 17 days. Stratified analysis further indicated that women, older adults, and individuals from general hospitals were more sensitive to changes in wastewater viral loads, showing stronger correlations between infection trends and wastewater signals. Conclusions: Wastewater surveillance of SARS-CoV-2 can effectively predict COVID-19 infection trends and offers a scientific basis for stratified and targeted interventions. The findings underscore the value of WBE as an early warning tool in public health surveillance. Full article

(This article belongs to the Section Infectious Diseases)

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13 pages, 582 KB

Open AccessArticle

Asymptomatic Pneumococcal Carriage, Antimicrobial Resistance, and Associated Risk Factors Among Paediatric Healthcare Workers in Benin

by Chakir Ishola Bello, Cyriaque Comlan Degbey, Yves Eric Denon, Adolphe Adjanonhoun and Lamine Baba-Moussa

Trop. Med. Infect. Dis. 2025, 10(9), 263; https://doi.org/10.3390/tropicalmed10090263 - 15 Sep 2025

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Abstract

Healthcare professionals (HCPs) working in paediatric settings are routinely exposed to respiratory pathogens, increasing their risk of asymptomatic colonisation by meningitis-associated bacteria. This study is the first to assess oropharyngeal and nasopharyngeal carriage of major bacterial meningitis pathogens among paediatric HCPs in Benin, [...] Read more.

Healthcare professionals (HCPs) working in paediatric settings are routinely exposed to respiratory pathogens, increasing their risk of asymptomatic colonisation by meningitis-associated bacteria. This study is the first to assess oropharyngeal and nasopharyngeal carriage of major bacterial meningitis pathogens among paediatric HCPs in Benin, and to identify associated risk factors. A cross-sectional analytical study was conducted in nine hospitals between 1 September 2023 and 30 September 2024. Data collection involved a structured questionnaire and paired oropharyngeal and nasopharyngeal swabs. Culture-based identification and antimicrobial susceptibility testing were performed according to CA-SFM guidelines. By culture method, Streptococcus pneumoniae was the most frequently isolated pathogen, mainly from oropharyngeal samples (47.5%). Most of these strains exhibited multidrug resistance. In nasopharyngeal samples analysed by real-time PCR, detection rates for S. pneumoniae were markedly higher (24.4%) compared to culture (5.0%), highlighting the limited sensitivity of conventional methods in detecting asymptomatic carriage. Pneumococcal colonisation was significantly associated with recent respiratory tract infections, and residence in high-risk areas (p < 0.05). These findings underscore the need for enhanced molecular surveillance, along with strengthened infection control measures and targeted vaccination strategies, to mitigate the risk of horizontal transmission in paediatric wards. Full article

(This article belongs to the Special Issue One-Health Perspectives and Solutions in Antimicrobial Resistance and Infectious Disease)

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7 pages, 792 KB

Open AccessBrief Report

Praziquantel Pretreatment Reduces Schistosoma japonicum Infection in Mice by Targeting Immature Worm Stages

by Xiang Gui, Rongxue Lv, Haoran Zhong, Hao Li, Ke Lu, Zhiqiang Fu, Yamei Jin and Jinming Liu

Trop. Med. Infect. Dis. 2025, 10(9), 262; https://doi.org/10.3390/tropicalmed10090262 - 12 Sep 2025

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Abstract

Schistosomiasis remains a significant public health concern, with Schistosoma japonicum infection endemic in certain regions of Asia. Praziquantel (PZQ), primarily known as an effective therapeutic agent, has recently shown potential as a prophylactic measure against delayed S. japonicum infections. This study investigated the [...] Read more.

Schistosomiasis remains a significant public health concern, with Schistosoma japonicum infection endemic in certain regions of Asia. Praziquantel (PZQ), primarily known as an effective therapeutic agent, has recently shown potential as a prophylactic measure against delayed S. japonicum infections. This study investigated the preventive efficacy of PZQ pretreatment at varying cercarial infection intensities and determined the parasite developmental stages targeted by the pretreatment in a mouse model. Results demonstrated that PZQ pretreatment significantly reduced both worm burdens and liver egg counts at low (10 and 20 cercariae) and high (100 cercariae) infection intensities, with reductions in worm burdens ranging from approximately 48% to 60% and liver egg counts by 47% to 73% compared to control groups (p < 0.05). Further analysis revealed that the mortality of parasites in PZQ-pretreated mice predominantly occurred during the juvenile schistosomula stages, particularly in worms younger than 15 days post-infection. These findings provide critical evidence supporting the application of PZQ pretreatment as a practical prophylactic measure to prevent S. japonicum infections, particularly in populations and animals frequently exposed to contaminated water in endemic areas. Full article

(This article belongs to the Special Issue Research Advances and New Perspectives on Helminthic Diseases)

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10 pages, 1565 KB

Open AccessCase Report

Recurrent Malaria with Plasmodium vivax: A Case Report and Brief Review of the Literature

by Ákos Vince Andrejkovits, Adrian Vlad Pop, Magdolna Fejér, Elena Cristina Gîrbovan, Răzvan Lucian Coșeriu, Camelia Vintilă and Anca Meda Văsieșiu

Trop. Med. Infect. Dis. 2025, 10(9), 261; https://doi.org/10.3390/tropicalmed10090261 - 12 Sep 2025

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Abstract

Background: Recurrent malaria refers to repeated episodes of the disease in the same individual. Plasmodium vivax is known for its ability to relapse due to dormant liver-stage hypnozoites and poses a particular risk to travelers returning from endemic areas. Prompt diagnosis and treatment [...] Read more.

Background: Recurrent malaria refers to repeated episodes of the disease in the same individual. Plasmodium vivax is known for its ability to relapse due to dormant liver-stage hypnozoites and poses a particular risk to travelers returning from endemic areas. Prompt diagnosis and treatment are crucial to prevent recurrences. Case Presentation: We present the case of a 41-year-old man from Romania who developed Plasmodium vivax malaria after traveling through Southeast Asia without chemoprophylaxis. He presented with fever, chills, myalgia, headache, vomiting, and abdominal pain. Clinical findings included mild jaundice and slight neurological signs. Laboratory tests showed severe thrombocytopenia, elevated bilirubin, inflammatory markers, and borderline creatinine levels. Malaria was confirmed by a rapid diagnostic test and blood smear microscopy. The patient was treated with doxycycline and atovaquone–proguanil. He improved and was discharged, but experienced two relapses, both confirmed as Plasmodium vivax by RT-PCR. Despite receiving primaquine as radical cure after the first Plasmodium vivax malaria relapse, a second relapse occurred. Each episode was managed with blood-stage antimalarial therapy, leading to full clinical and biological recovery. Conclusions: Malaria rarely occurs in non-endemic areas; it should be considered in patients with compatible travel history and symptoms. Given the high relapse potential of Plasmodium vivax, accurate species identification is critical to guide appropriate long-term management. Full article

(This article belongs to the Topic Vector-Borne Disease Spatial Epidemiology, Disease Ecology, and Zoonoses)

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11 pages, 929 KB

Open AccessArticle

Evaluation of an Online Survey for Pertussis Case Investigations in Regional Queensland: Impacts on Workload and Disease Trends

by Ho Yeung Lam, Arifuzzaman Khan, Matthew O’Bryan, Michelle Jones and Josette Chor

Trop. Med. Infect. Dis. 2025, 10(9), 260; https://doi.org/10.3390/tropicalmed10090260 - 12 Sep 2025

Viewed by 260

Abstract

In 2024, a significant pertussis surge in Queensland, Australia, strained public health resources. To improve investigation efficiency, the Wide Bay Public Health Unit introduced an online survey for pertussis cases on 1 August 2024, which collected data and provided automated health advice. This [...] Read more.

In 2024, a significant pertussis surge in Queensland, Australia, strained public health resources. To improve investigation efficiency, the Wide Bay Public Health Unit introduced an online survey for pertussis cases on 1 August 2024, which collected data and provided automated health advice. This retrospective evaluation assessed survey acceptance and staff workload. A controlled interrupted time series (ITS) analysis compared pertussis incidence in the intervention region against a control group of four other de-identified regional hospital and health services in Queensland where the survey was not implemented. Of the 298 eligible cases, 140 responded (47.0%); a total of 67.9% of these required no further staff follow-up, a subgroup for whom time savings were statistically significant (p < 0.01). The ITS analysis for the total population revealed a significant 4.9% weekly reduction in the notification trend compared to the control group (Rate Ratio: 0.95, p = 0.001), with a non-significant immediate level change. The online survey is a practical and effective tool for pertussis investigation in a regional setting. It is associated with significant workload efficiencies and a favourable, statistically significant impact on community disease transmission trends. Full article

(This article belongs to the Special Issue Respiratory Infectious Disease Epidemiology and Control)

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15 pages, 506 KB

Open AccessArticle

Operational Research Improves Compliance with Treatment Guidelines for Empirical Management of Urinary Tract Infection: A Before-and-After Study from a Primary Health Facility in Ghana

by Elizabeth Boateng, Helena Owusu, Pruthu Thekkur, George Kwesi Hedidor, Oksana Corquaye, Mercy N. A. Opare-Addo, Florence Amah Nkansah, Priscilla Vandyck-Sey, Daniel Ankrah and Charles Nii Kwadee Ofei-Palm

Trop. Med. Infect. Dis. 2025, 10(9), 259; https://doi.org/10.3390/tropicalmed10090259 - 11 Sep 2025

Viewed by 480

Abstract

Compliance with standard treatment guidelines (STGs) for the empirical management of uncomplicated urinary tract infections (UTIs) ensures the rational use of antibiotics and mitigates antimicrobial resistance. Operational research (OR) at Korle Bu Polyclinic in Ghana (2022) showed suboptimal STG compliance (prescription of recommended [...] Read more.

Compliance with standard treatment guidelines (STGs) for the empirical management of uncomplicated urinary tract infections (UTIs) ensures the rational use of antibiotics and mitigates antimicrobial resistance. Operational research (OR) at Korle Bu Polyclinic in Ghana (2022) showed suboptimal STG compliance (prescription of recommended antibiotics in the correct dose, route, frequency, and duration). Some of the recommendations from the OR, including training of medical residents, implementation of an antimicrobial stewardship team, and an audit–feedback system, were implemented. This before-and-after study compared the changes in empirical prescribing practices for patients diagnosed with uncomplicated UTIs before (October 2019–October 2021) and after (January 2023–December 2024) the OR. Of the 3717 and 3457 UTI patients in the before and after cohorts, 83% and 86% received empirical antibiotics, respectively. Among those who received empirical antibiotics, STG compliance increased from 60% to 66% (p-value < 0.001). However, STG compliance remained significantly lower among males (18%) compared to females (85%) in the after cohort, as 80% of males were prescribed antibiotics for a shorter period than the recommended 10–14 days. Moving forward, the training and audit–feedback system should emphasize longer antibiotic durations for males with UTI. Given its positive impact, the OR’s approach warrants replication for other disease conditions. Full article

(This article belongs to the Special Issue Field Impact of the SORT IT Initiative on Combating Antimicrobial Resistance Through a One Health Approach in Ghana)

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10 pages, 797 KB

Open AccessArticle

Prevalence and Screening Rates of Hepatitis B and Hepatitis C Infections in Adult Patients with Solitary Organ Tumors

by Seyhmus Abakay, Hüseyin Döngelli, Nilay Danış, Halil İbrahim Ellez, Göksel Bengi, Tuğba Yavuzşen and Hüseyin Salih Semiz

Trop. Med. Infect. Dis. 2025, 10(9), 258; https://doi.org/10.3390/tropicalmed10090258 - 10 Sep 2025

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Abstract

Background and Aims: Hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) remain significant global public health issues despite advances in their diagnosis and treatment. Our country is in a medium endemic region for HBV. Reactivation can occur during [...] Read more.

Background and Aims: Hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) remain significant global public health issues despite advances in their diagnosis and treatment. Our country is in a medium endemic region for HBV. Reactivation can occur during or after immunosuppressive therapy. Therefore, screening patients before treatment is crucial to prevent reactivation. However, pretreatment screening is often insufficiently emphasized in studies. This study aimed to assess the incidence of HBV and pretreatment screening rates in patients with solid organ tumors at our center. Methods: We included patients aged over 18 years who were treated for solid organ tumors at our center between January 2016 and January 2022. Data on age, sex, histopathological diagnosis, and serological parameters were retrospectively collected. Appropriate HBV screening was defined as the assessment of HBsAg, anti-HBs, and anti-HBc IgG levels prior to the initiation of immunosuppressive therapy. Results: In our study, HBsAg testing was requested for 13.3% of the patients, and anti-HCV testing was requested for 13.3%. Among the patients screened for HBV and HCV, the prevalence rates of HBV and HCV infection were 3.3% and 1%, respectively. Conclusions: Our findings reveal inadequate screening rates for HBV and HCV among patients receiving immunosuppressive therapy. Increasing awareness about screening and implementing regular educational programs are crucial to protect patients from reactivation. Full article

(This article belongs to the Special Issue Viral Hepatitis and Other Microbial Threats in Tropical Medicine)

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7 pages, 774 KB

Open AccessCase Report

Nasal Myiasis Mimicking Allergic Rhinitis in Immunocompetent Adults: Case Series of 14 Adults

by Sameh Mezri, Mohamed Anas Ammar, Latifa Mtibaa, Sleheddine Mnasria, Chiraz Halwani and Khemaies Akkari

Trop. Med. Infect. Dis. 2025, 10(9), 257; https://doi.org/10.3390/tropicalmed10090257 - 9 Sep 2025

Viewed by 325

Abstract

Background: Human nasal myiasis is a rare zoonotic infection caused by Oestrus ovis with a non-specific clinical presentation that can mimic more common conditions such as allergic rhinitis. Objective: To report a series of nasal myiasis cases in immunocompetent individuals, emphasizing the clinical [...] Read more.

Background: Human nasal myiasis is a rare zoonotic infection caused by Oestrus ovis with a non-specific clinical presentation that can mimic more common conditions such as allergic rhinitis. Objective: To report a series of nasal myiasis cases in immunocompetent individuals, emphasizing the clinical presentation and complementary investigations (endoscopic findings, parasitological identification, skin prick tests, and imaging studies) that facilitate differential diagnosis from allergic rhinitis and enable early treatment. Methods: We conducted a retrospective study including cases of nasal myasis diagnosed and managed at the ENT department of the Military Hospital of Tunis over an 18-year period (2007–2025). Demographic, clinical, diagnostic, and therapeutic data were analyzed. Results: The mean age was 43 years, with a female predominance. Most patients presented with acute rhinological symptoms initially suggestive of allergic rhinitis. Nasal endoscopy revealed larvae in 79% of cases with parasitological confirmation of Oestrus ovis. Facial CT scans performed in five cases (36%) were unremarkable. Management consisted of multiple daily nasal saline irrigations and albendazole, in association with oral corticosteroids and antihistamines, resulting in symptom resolution within an average of 4 days. Conclusions: Nasal myiasis should be considered in atypical or treatment-resistant rhinitis. Nasal endoscopy is essential for diagnosis. Full article

(This article belongs to the Special Issue Innovative Approaches to Combat Infectious Diseases in Low and Middle Income Countries (LMICs): Epidemiology, Diagnosis, and Interventions)

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10 pages, 252 KB

Open AccessBrief Report

Backyard Livestock Guinea Pigs Are Reservoirs for Leptospira Shedding in Rural Households from Ecuador

by Mauricio Xavier Salas-Rueda, Fabricio Dugllay-Montaleza, Darwin Paredes-Núñez, Katherine Natalia Chávez Toledo, Angel Sebastián Rodríguez-Pazmiño, Elsy Carvajal, Maria Belen Paredes-Espinosa, Patricia Peralta-Ortiz, Jairo Guama-Tipas, Juan Pablo Garzon, Alexandra Narvaez, Solon Alberto Orlando and Miguel Angel Garcia-Bereguiain

Trop. Med. Infect. Dis. 2025, 10(9), 256; https://doi.org/10.3390/tropicalmed10090256 - 8 Sep 2025

Viewed by 344

Abstract

Guinea pigs (Cavia porcellus) are bred as livestock in South American countries from the Andean region, including Ecuador. Despite their importance for the local rural economy, no public health management guidelines have ever been implemented for guinea pig farming. Moreover, several [...] Read more.

Guinea pigs (Cavia porcellus) are bred as livestock in South American countries from the Andean region, including Ecuador. Despite their importance for the local rural economy, no public health management guidelines have ever been implemented for guinea pig farming. Moreover, several reports have shown the carriage of diverse zoonotic pathogens in livestock guinea pigs, including respiratory and enteric pathogens, or Toxoplasma gondii. Leptospirosis, a zoonotic disease caused by bacteria from Leptospira genus, is endemic in Ecuador and has multiple animal reservoirs, with rodents considered to be the main vector for transmission to humans. However, the role of livestock guinea pigs in the epidemiology of leptospirosis is poorly understood. In this study, the prevalence of antibodies against Leptospira in guinea pigs from Ecuador was analyzed with the Microaglutiantion Test (MAT). Moreover, the shedding of Leptospira by backyard livestock guinea pigs was also addressed, analyzing fecal and urine samples by qPCR for lipL32, secY and rrs genes. From the 118 guinea pigs analyzed by MAT, 61.9% were positive for 19 different pathogenic serovars, with Icterohaemorrhagiae, Pomona, Castellonis and Bataviae being the most prevalent ones. From the 231 urine samples and 225 fecal samples collected, 27.7% and 78.7% were positive for Leptospira by qPCR, respectively. Our results highlight the role of livestock guinea pigs as a reservoir for leptospirosis. Moreover, this study underscores the zoonotic threat associated with the shedding of Leptospira within households in rural communities where guinea pigs are bred as livestock. Animal and public health guidelines from a One Health perspective must be implemented to prevent leptospirosis transmission from guinea pigs in Ecuador and other countries in the Andean Region where the breeding of backyard livestock guinea pigs is common. Full article

(This article belongs to the Special Issue Leptospirosis and One Health Approach: Current Status and Future Prospects, 2nd Edition)

12 pages, 675 KB

Open AccessArticle

Genetic Diversity of Plasmodium falciparum in Korhogo Health District, Northern Côte d’Ivoire

by Edjronké M. A. Benié, Carla Beuret, Annina Schnoz, Sara L. Cantoreggi, Xavier C. Ding, Kigbafori D. Silué and Christian Nsanzabana

Trop. Med. Infect. Dis. 2025, 10(9), 255; https://doi.org/10.3390/tropicalmed10090255 - 7 Sep 2025

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Abstract

Understanding Plasmodium falciparum population genetic diversity is crucial to assess the impact of malaria control interventions. This study investigated P. falciparum genetic diversity using merozoite surface protein 1 (msp1), msp2 and glutamate-rich protein (glurp) in Korhogo district, Northern Côte [...] Read more.

Understanding Plasmodium falciparum population genetic diversity is crucial to assess the impact of malaria control interventions. This study investigated P. falciparum genetic diversity using merozoite surface protein 1 (msp1), msp2 and glutamate-rich protein (glurp) in Korhogo district, Northern Côte d’Ivoire. DNA was extracted from dried blood spots (DBSs) collected in the health district of Korhogo between 2019 and 2020. The msp1, msp2, and glurp genes were amplified by polymerase chain reaction (PCR), and amplicon sizes were determined by capillary electrophoresis. Out of 179 samples randomly selected and genotyped, 82% were successfully amplified for msp1, 85% for msp2, and 75% for glurp. For msp1, the K1 allelic family had 20 genotypes, MAD20 had 23, and RO33 had only one genotype. For msp2, there were 59 and 33 genotypes for 3D7 and FC27, respectively, and for glurp, 45 genotypes were detected. The parasite population was highly diverse with an expected heterozygosity (H_E) of ≥0.9 for all 3 markers. Our study showed high genetic diversity of msp1, msp2, and glurp in P. falciparum isolates from Korhogo district, Northern Côte d’Ivoire. These data could provide baseline information on P. falciparum genetic diversity for further epidemiological studies, needed to assess interventions implemented in this area. Full article

(This article belongs to the Section Vector-Borne Diseases)

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18 pages, 2450 KB

Open AccessArticle

Morbidity and Mortality Profile of Leishmaniasis in an Andean Region of Ecuador in the Context of Climate Change

by Enma Veronica Páez-Espinosa, Delia Maria Sosa-Guzmán, Luis René Buitrón-Andrade, Nicole Dávila-Jumbo, Martín Israel Cáceres-Ruiz, Vinicio Francisco Robalino-Flores and Eugènia Mato-Matute

Trop. Med. Infect. Dis. 2025, 10(9), 254; https://doi.org/10.3390/tropicalmed10090254 - 3 Sep 2025

Viewed by 426

Abstract

Leishmaniasis is a parasitic disease transmitted by female sandflies of the genus Lutzomyia. Ecuador is divided into three distinct natural regions: the Andes, the Coast, and Amazonia, each characterized by significant variations in altitude and climate. While most reported cases of leishmaniasis are [...] Read more.

Leishmaniasis is a parasitic disease transmitted by female sandflies of the genus Lutzomyia. Ecuador is divided into three distinct natural regions: the Andes, the Coast, and Amazonia, each characterized by significant variations in altitude and climate. While most reported cases of leishmaniasis are associated with humid, low-altitude rural areas, our study uncovered an unexpected trend: confirmed cases occurring in traditionally cold Andean regions. To investigate this issue, we conducted a cross-sectional ecological study using official morbidity and mortality records from the Ecuadorian Health Care Registration Platform, focusing on the cantons of Alausí and Chunchi in Chimborazo Province from 2013 to 2022. Chimborazo Province, in the Andes, is characterized by higher altitudes (2740 m above sea level) and a cold climate (averaging 13 °C throughout the year). Among a population of 44,089 residents in Alausí, we reported a total of 40 confirmed cases, with 97.5% classified as cutaneous and 2.5% as mucocutaneous, predominantly affecting children and males. No mortality cases were recorded during the study period. To further explore environmental influences, we examined the Alausí region, where climate change has led to rising average temperatures, deforestation, and changes in humidity levels. Leishmaniasis cases in Alausí showed seasonal peaks, particularly in 2018 and 2019, correlating with warmer and more humid conditions. Environmental factors such as temperature and humidity were strongly associated with the prevalence of the disease, suggesting that climate change may be increasing transmission risks. These findings point to the value of incorporating environmental monitoring into public health strategies for vector-borne diseases that affect vulnerable populations in the Andes. Full article

(This article belongs to the Topic Vector-Borne Disease Spatial Epidemiology, Disease Ecology, and Zoonoses)

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14 pages, 816 KB

Open AccessCommunication

Seropositivity for Pathogenic Leptospira in Dogs, Cats, and Horses at a Teaching Veterinary Hospital in Southern Chile

by Lucía Azócar-Aedo, Gloria Meniconi, Carolina Pino-Olguín and María Gallardo

Trop. Med. Infect. Dis. 2025, 10(9), 253; https://doi.org/10.3390/tropicalmed10090253 - 3 Sep 2025

Viewed by 456

Abstract

At a veterinary hospital in southern Chile, we conducted an epidemiological study involving domestic dogs, cats, and horses to determine the seropositivity for pathogenic Leptospira spp., identify the infecting serogroups, measure antibody titers, and characterize seropositive animals by sex and age. None of [...] Read more.

At a veterinary hospital in southern Chile, we conducted an epidemiological study involving domestic dogs, cats, and horses to determine the seropositivity for pathogenic Leptospira spp., identify the infecting serogroups, measure antibody titers, and characterize seropositive animals by sex and age. None of the sampled animals showed clinical signs of leptospirosis. The microscopic agglutination test, using a panel of eight serogroups, was used for diagnosis. The seropositivity was 36.5% (95% confidence interval [CI] = 24.5–48.4) in dogs, 12.9% (95% CI = 2.6–23.1) in cats, and 45.2% (95% CI = 30.1–60.2) in horses. Serological reactions were detected for the Tarassovi and Canicola serogroups in dogs, Sejroe, Canicola, Icterohaemorrhagiae, and Grippotyphosa in horses, and Tarassovi in cats. The most frequent antibody titers were 1:200 and 1:400 in dogs, 1:400 in cats, and 1:800 in horses. The distribution of seropositivity varied by sex and age across different animal species. The seropositivity for pathogenic Leptospira in dogs, cats, and horses attending a veterinary hospital underscores the role of domestic animals as sentinels for zoonotic diseases. This finding has implications for epidemiological surveillance systems in increasing awareness of seropositivity and establishing specific prevention measures to mitigate the risk of leptospirosis transmission. Full article

(This article belongs to the Special Issue Leptospirosis and One Health)

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11 pages, 1245 KB

Open AccessArticle

Genotype Analysis on Orientia tsutsugamushi Causing Scrub Typhus in Malaysia: A Re-Emerging Disease

by Shirley Yi Fen Hii, Maswani Nabilah Mohd Zaidi, Wan Norazanin Kassim, Rohaidah Hashim and Siti Roszilawati Ramli

Trop. Med. Infect. Dis. 2025, 10(9), 252; https://doi.org/10.3390/tropicalmed10090252 - 2 Sep 2025

Viewed by 410

Abstract

Introduction: Scrub typhus is caused by Gram-negative bacteria, Orientia tsutsugamushi. Humans are the dead-end host of scrub typhus. Currently, there is no vaccine available. The disease can be fatal without appropriate treatment. Here, we present the circulating OT genotypes in Malaysia and [...] Read more.

Introduction: Scrub typhus is caused by Gram-negative bacteria, Orientia tsutsugamushi. Humans are the dead-end host of scrub typhus. Currently, there is no vaccine available. The disease can be fatal without appropriate treatment. Here, we present the circulating OT genotypes in Malaysia and a tsa56-based single PCR to detect and determine OT genotypes, which is an approach to replace the time-consuming traditional nested PCR. Methods: The patients’ blood or tissue samples (n = 1200), received from all hospitals in Malaysia from December 2022 to November 2024, were screened for rickettsial infections. Both htrA qPCR and nested PCR were performed to detect the presence of OT DNA. Simultaneously, a selection of DNA was evaluated for the new single PCR protocol and confirmed with Sanger sequencing. Results: We report that Pahang state of Peninsular Malaysia presents the highest number of acute scrub typhus infections in Malaysia within the 24 months period. There are four genotypes circulating in the Malaysian population. OT genotype Gilliam (n = 31, 29.2%) and Karp (n = 31, 29.2%) are the predominant OT genotypes in Malaysia, followed by TA763 (n = 22, 20.8%) and Kato (n = 22, 20.8%). The single-run PCR presents longer sequence size and similar results with the nested PCR. Conclusions: Acute scrub typhus infection is not rare in Malaysia and should be considered for undifferentiated febrile illness. The single-run PCR protocol is time-saving and a promising approach for OT detection and genotype analysis in a single run to complement a clinical diagnostic setting and surveillance. Full article

(This article belongs to the Section Vector-Borne Diseases)

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17 pages, 1604 KB

Open AccessArticle

Vector-Borne Disease Control and Management in Irrigation Areas: A Neglected Critical Phenomenon in Malawi

by Levi Kalitsilo, Rose Oronje and Nyanyiwe Masingi Mbeye

Trop. Med. Infect. Dis. 2025, 10(9), 251; https://doi.org/10.3390/tropicalmed10090251 - 2 Sep 2025

Viewed by 535

Abstract

Vector-borne diseases (VBDs) account for more than 17% of all infectious diseases, causing over 700,000 deaths annually, particularly among the poorest populations in tropical and subtropical areas. Climate change, particularly global warming, and certain human activities, including irrigation farming, exacerbate the situation by [...] Read more.

Vector-borne diseases (VBDs) account for more than 17% of all infectious diseases, causing over 700,000 deaths annually, particularly among the poorest populations in tropical and subtropical areas. Climate change, particularly global warming, and certain human activities, including irrigation farming, exacerbate the situation by creating conducive environments that facilitate the breeding of vectors such as mosquitoes and snails. This qualitative study aimed to understand the VBD control and management policy landscape in irrigation areas by gathering perceptions from key stakeholders in the irrigation farming sector in Malawi. Respondents indicated that there are no specific VBD control and management policies targeting irrigation areas in Malawi and that stakeholders essentially work in silos. Notwithstanding this, the Malawi government is committed to expanding irrigation areas to address food security. We, therefore, call for the integration of VBD control and management in irrigation farming, utilising the One Health approach—a promising strategy that could bring significant benefits. Further, we recommend the provision of VBD control and management resources in irrigation investments and the involvement of VBD researchers in the formulation of irrigation policies. Full article

(This article belongs to the Special Issue One Health Approach to Mosquito-Borne Diseases: Epidemiology, Prevention and Treatment Strategies)

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15 pages, 519 KB

Open AccessArticle

Interleukin-8 Predicts Fatal Kala-Azar: A Case–Control Study

by Simone Soares Lima, Débora Cavalcante Braz, Vladimir Costa Silva, Teresinha de Jesus Cardoso Farias Pereira, Líndia Kalliana da Costa Araújo Alves Carvalho, Dorcas Lamounier Costa and Carlos Henrique Nery Costa

Trop. Med. Infect. Dis. 2025, 10(9), 250; https://doi.org/10.3390/tropicalmed10090250 - 1 Sep 2025

Viewed by 397

Abstract

Kala-azar is associated with case-fatality rates as high as 10% in certain regions. Early identification of mortality biomarkers can significantly reduce this risk. This study, strengthened by a relatively high number of kala-azar-related deaths, aimed to identify serum cytokines as predictive biomarkers of [...] Read more.

Kala-azar is associated with case-fatality rates as high as 10% in certain regions. Early identification of mortality biomarkers can significantly reduce this risk. This study, strengthened by a relatively high number of kala-azar-related deaths, aimed to identify serum cytokines as predictive biomarkers of fatal kala-azar. We compared 48 deceased patients with kala-azar to 42 survivors. The concentrations of IL-1β, IL-6, IL-8, IL-10, IL-12, and tumor necrosis factor-α (TNF-α) were measured by flow cytometry. Cytokine levels were compared between groups using the Wilcoxon rank-sum test. Receiver operating characteristic (ROC) analysis, coupled with Youden’s index, defined the optimal diagnostic threshold. Upon admission, IL-8 concentrations were substantially higher in deceased kala-azar patients (median 76.5 pg/mL [IQR 35.2–242.4 pg/mL]) than in survivors (median 26.4 pg/mL [IQR 15.1–47.7 pg/mL]; p < 0.0001). ROC analysis identified 49.3 pg/mL as the optimal cutoff. When rounded to the clinically convenient value of 50 pg/mL, IL-8 predicted a fatal outcome with an area under the curve of 0.75, sensitivity of 70.8%, and specificity of 76.2%. In contrast, IL-1β, IL-6, IL-10, IL-12, and TNF-α showed no significant prognostic utility. Our findings suggest that IL-8 levels equal to or greater than 50 pg/mL are a reliable predictor of fatal kala-azar. Full article

(This article belongs to the Section Neglected and Emerging Tropical Diseases)

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9 pages, 1067 KB

Open AccessCommunication

Compatibility of Serratia ureylitica Su_YN1, Malaria Transmission-Blocking Bacterium, with the Anopheles aquasalis Vector

by Marília Andreza da Silva Ferreira, Elen Sabrina dos Reis Martins, Ricardo de Melo Katak, Keillen Monick Martins Campos, Elerson Matos Rocha, Rosemary Aparecida Roque, Pritesh Jaychand Lalwani, Luciete Almeida Silva, Edson Júnior do Carmo, Paulo Paes de Andrade, Sibao Wang, Luciano Andrade Moreira, Marcelo Jacobs-Lorena and Claudia María Ríos-Velásquez

Trop. Med. Infect. Dis. 2025, 10(9), 249; https://doi.org/10.3390/tropicalmed10090249 - 31 Aug 2025

Viewed by 496

Abstract

Malaria continues to affect millions of people around the world. Current control strategies have not been sufficient, and additional tools are required for malaria elimination. A promising approach is the use of bacteria from the mosquito microbiota, such as the Su_YN1 Serratia ureilytica [...] Read more.

Malaria continues to affect millions of people around the world. Current control strategies have not been sufficient, and additional tools are required for malaria elimination. A promising approach is the use of bacteria from the mosquito microbiota, such as the Su_YN1 Serratia ureilytica bacterium, which is shown to strongly impair the development of P. falciparum and P. berghei in Anopheles mosquitoes. To evaluate the potential of using S. ureilytica Su_YN1 to block the Plasmodium parasite in South American vectors, we investigated its effects on mosquito fitness and survival. We found that this bacterium does not affect the longevity, blood feeding, fecundity and fertility of Anopheles aquasalis, an important South American vector. Overall, our results provide baseline support for the potential implementation of Su_YN1 for the control of malaria transmission in South America. Full article

(This article belongs to the Special Issue The Global Burden of Malaria and Control Strategies)

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16 pages, 383 KB

Open AccessArticle

Alcohol Consumption of Male Tuberculosis Index Cases and Tuberculosis Transmission Among Social Contacts in Puducherry, India: A Cross-Sectional Analytical Study

by Charutha Retnakumar, Palanivel Chinnakali, Balaji Bharadwaj, Karikalan Nagarajan and Sonali Sarkar

Trop. Med. Infect. Dis. 2025, 10(9), 248; https://doi.org/10.3390/tropicalmed10090248 - 30 Aug 2025

Viewed by 531

Abstract

We aimed to compare the proportion of tuberculosis infection among social contacts of male tuberculosis Index case with and without alcohol use in the Puducherry district. A cross-sectional study using ego-centric approach was conducted between November 2023 and May 2024. A total of [...] Read more.

We aimed to compare the proportion of tuberculosis infection among social contacts of male tuberculosis Index case with and without alcohol use in the Puducherry district. A cross-sectional study using ego-centric approach was conducted between November 2023 and May 2024. A total of 713 social contacts of 106 male pulmonary tuberculosis index cases were enrolled, stratified by alcohol-use (AUDIT ≥ 8): 358 contacts from 45 alcohol-using cases and 355 from 61 non-alcohol-use cases. Social contacts were defined based on the frequency and duration of shared indoor exposure with index cases within the past three months. Tuberculosis infection was screened with Cy-Tb skin test (≥5 mm induration) at the third month of index case treatment. Univariate and multivariable analysis were conducted to identify factors associated with tuberculosis transmission. Among the 358 social contacts of alcohol-use index cases, 33.8% (n = 121; 95% CI, 29.1–38.8%) tested positive for tuberculosis infection, significantly higher than 21.7% (n = 77; 95% CI, 17.7–26.3%) among 355 contacts of non-alcohol-use cases. Regression analysis revealed that contacts of alcohol-using index cases (aOR = 1.6, p < 0.05), were significantly associated with tuberculosis infection. Alcohol-use among tuberculosis patients significantly increases the risk of tuberculosis infection in their social networks. Full article

(This article belongs to the Special Issue Tuberculosis Control in Africa and Asia)

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15 pages, 2423 KB

Open AccessArticle

Impaired Lung Function and Quality of Life Outcomes in Patients with Tuberculosis: A Cross-Sectional Study

by Varshini Jagadeesh, Prashanth Chikkahonnaiah, Muskan Dubey, Shashidhar H. Byrappa, Hari Balaji Sridhar, Raghavendra G. Amachawadi and Ravindra P. Veeranna

Trop. Med. Infect. Dis. 2025, 10(9), 247; https://doi.org/10.3390/tropicalmed10090247 - 29 Aug 2025

Viewed by 438

Abstract

Tuberculosis (TB) continues to be the world’s deadliest infectious disease, with an estimated 10.8 million new cases reported in 2023, of which India alone accounted for 28% of the global burden. This study aims to evaluate the impact of tuberculosis on pulmonary function [...] Read more.

Tuberculosis (TB) continues to be the world’s deadliest infectious disease, with an estimated 10.8 million new cases reported in 2023, of which India alone accounted for 28% of the global burden. This study aims to evaluate the impact of tuberculosis on pulmonary function and exercise tolerance, and to examine how these impairments affect health-related quality of life (HRQoL). In a cross-sectional design, 96 bacteriologically confirmed TB patients and 96 age- and sex-matched community controls underwent spirometry, six-minute-walk test (6 MWT), and HRQoL evaluation. DR-TB was detected in 27 patients (28.1%): Isoniazid monoresistance 59.3%, rifampicin monoresistance 11.1%, and XDR-TB 29.6%. Dyspnoea (70.8%) and cough (37.5%) were the most commonly reported symptoms among TB patients. Mean values of FEV₁, FVC, and FEV₁/FVC were significantly lower in TB patients compared to controls (62.8%, 65.97%, and 70.08% vs. 82.55%, 80.09%, and 78.08%, respectively; p < 0.001). Recurrent or DR-TB was associated with reduced spirometric indices and 6 MWT distances (241 m vs. 358 m in drug-sensitive TB). St. George’s respiratory questionnaire (SGRQ) scores indicated significantly poorer health-related quality of life (HRQoL) in patients compared to controls across all domains—symptoms (23.7 vs. 10.7), activity (33.3 vs. 14.2), and impact (20.6 vs. 9.4; p < 0.05). SGRQ scores were inversely correlated with lung function parameters (r = −0.42 to −0.56). These findings underscore the persistent health burden TB poses post-therapy, highlighting the need for routine post-TB functional screening and robust DR-TB control to achieve End-TB goals. Full article

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17 pages, 702 KB

Open AccessArticle

Diagnostic Accuracy of Antigen ELISA and Western Blot IgG for Neurocysticercosis in People Living with HIV/AIDS in Tanzania

by Yakobo Lema, Ulrich Fabien Prodjinotho, Charles Makasi, Marrywinnie A. Nanyaro, Frank Asenga, Andrew Kilale, Sayoki Mfinanga, Charlotte Rüther, Andrea Sylvia Winkler, Eligius F. Lyamuya, Bernard J. Ngowi, Mkunde Chachage and Clarissa Prazeres da Costa

Trop. Med. Infect. Dis. 2025, 10(9), 246; https://doi.org/10.3390/tropicalmed10090246 - 29 Aug 2025

Viewed by 457

Abstract

Background: Neurocysticercosis (NCC) and HIV co-infection frequently occur in sub-Saharan Africa, yet the accuracy of available serological tests for NCC in immunosuppressed patients is uncertain. Methodology: We performed a cross-sectional diagnostic study on 101 people living with HIV from two endemic districts in [...] Read more.

Background: Neurocysticercosis (NCC) and HIV co-infection frequently occur in sub-Saharan Africa, yet the accuracy of available serological tests for NCC in immunosuppressed patients is uncertain. Methodology: We performed a cross-sectional diagnostic study on 101 people living with HIV from two endemic districts in Tanzania. Participants provided serum for cysticercosis antigen ELISA and Western Blot IgG; any positive result prompted neuroimaging investigation with cerebral computed tomography. NCC was diagnosed according to the 2017 revised Del Brutto criteria based on cCT according to Del Brutto criteria modified to exclude serology. Sensitivity, specificity, and area under the receiver–operating–characteristic curve (AUC) were calculated and adjusted for CD4 count and HIV stage. Two algorithms were compared: parallel testing (“either-test-positive”) and sequential screening (Ag ELISA screen, western blot IgG confirm). Results: NCC prevalence was 23%. Western Blot IgG outperformed Ag ELISA (sensitivity 57% vs. 30%; specificity 87% vs. 86%; AUC 0.73 vs. 0.57). Western blot IgG sensitivity declined to 54% when CD4 < 500 cells µL⁻¹, while Ag ELISA remained low. Western blot IgG positivity independently predicted NCC (adjusted odds ratio 4.1, 95% CI 1.4–11.9); Ag ELISA did not. When we counted a positive if either test was positive (parallel rule), sensitivity rose to 78% and NPV to 87%. When we ran Ag ELISA only if IgG was negative (sequential rule), we saved 70% of IgG strips, kept specificity at 95%, and PPV at 69%, but sensitivity fell to 39%. Conclusions: Western blot IgG is the most reliable single serological test for NCC in PLHIV. Parallel testing increased sensitivity and NPV and may suit better primary-level facilities without routine imaging. Sequential testing achieved high specificity, PPV, and conserved test kits, making it ideal for centers with limited reagents or scanner access. Tiered use of these assays can streamline NCC diagnosis in T. solium endemic, resource-limited settings. Full article

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13 pages, 638 KB

Open AccessReview

Structural Drivers of Cutaneous Leishmaniasis: Examining How the Converging Effects of Displacement, Environmental Disruption, and Political Instability Reshape Epidemiology Beyond Endemic Regions

by Janice Kim, Tarek Zieneldien, Sophia Ma and Bernard A. Cohen

Trop. Med. Infect. Dis. 2025, 10(9), 245; https://doi.org/10.3390/tropicalmed10090245 - 28 Aug 2025

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Abstract

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease caused by protozoa of the Leishmania genus. Once confined to endemic regions such as the Middle East, Americas, North Africa, and Central Asia, CL is increasingly emerging in non-endemic areas due to a multitude of [...] Read more.

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease caused by protozoa of the Leishmania genus. Once confined to endemic regions such as the Middle East, Americas, North Africa, and Central Asia, CL is increasingly emerging in non-endemic areas due to a multitude of drivers, including population displacement, environmental disruption, and political instability. These overlapping drivers contribute to expanding sand fly habitats, degrading living conditions, and weakening health systems, increasing transmission. Rising global temperatures further facilitate vector expansion into new regions, where clinical unfamiliarity often leads to misdiagnosis, delayed treatment, increased morbidity, and greater financial burden. Despite its rising incidence and global spread, CL remains a neglected tropical disease since it is seldom fatal, with scant interest by public health authorities and financial donors, limiting activities that further research and prevent spread of the disease. This review synthesizes current evidence on how geopolitical instability, forced migration, and climate-driven ecological changes collectively reshape CL epidemiology and complicate diagnosis, treatment, and surveillance. As CL extends beyond traditional geographic boundaries, it requires integrated strategies that address its multifaceted drivers through strengthened cross-border surveillance, provider education, and international coordination—focusing on prevention, diagnosis, and equitable access to diagnostics and therapeutics, especially among displaced and underserved populations. Full article

(This article belongs to the Special Issue Challenges and Prevention Strategies for Travel-Related Infectious Diseases)

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14 pages, 1646 KB

Open AccessArticle

Feasibility of Oral Rabies Vaccination of Dogs in Mexico

by Verónica Gutiérrez Cedillo, Luis Antonio Montoya Mondragón, Jose Ramón Fernández Colín, Katharina Bobe, Ad Vos, Luis Armando Lecuona Olivares and Ruy López Ridaura

Trop. Med. Infect. Dis. 2025, 10(9), 244; https://doi.org/10.3390/tropicalmed10090244 - 28 Aug 2025

Viewed by 609

Abstract

Mexico has not only successfully eliminated dog-mediated human rabies in recent years, but also the last rabies case in a dog infected with the canine variant of the rabies virus was reported in 2016. Mass dog vaccination campaigns were the cornerstone of these [...] Read more.

Mexico has not only successfully eliminated dog-mediated human rabies in recent years, but also the last rabies case in a dog infected with the canine variant of the rabies virus was reported in 2016. Mass dog vaccination campaigns were the cornerstone of these achievements. Unfortunately, the rabies virus still circulates in wildlife and, thus, spill-over infections in humans, livestock, and pets, including dogs, still occurs. Especially dogs that cohabit at interfaces shared with wildlife, like shepherd dogs, are at risk. These dogs are often free-roaming and difficult to restrain for vaccination purposes. Oral rabies vaccination (ORV) as an alternative vaccination strategy was tested in several rural villages in Querétaro State, Mexico. Bait acceptance and immunogenicity studies were conducted to test a licensed vaccine bait in terms of attractiveness and if the oral rabies vaccine strain, SPBN GASGAS, was able to induce an adequate immune response in local dogs, respectively. Although the egg(-flavored) bait was less well accepted (68.4%) by the dogs than the two other bait types included in the study, a bait made from boiled intestine segments (71.2%) and a bait with fish meal as an attractant (72.3%), dogs offered the egg bait were more often considered successfully vaccinated. 83.3% of the dogs offered an egg bait seroconverted during the immunogenicity study. Hence, ORV can be a suitable alternative by increasing the overall vaccination coverage of dogs that cannot be easily restrained and handled for vaccination. Full article

(This article belongs to the Special Issue Tackling Emerging Zoonotic Diseases with a One Health Approach)

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Trop. Med. Infect. Dis., Volume 10, Issue 9 (September 2025) – 37 articles

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