Trop. Med. Infect. Dis., Volume 9, Issue 3 (March 2024) – 16 articles

Human Visceral Leishmaniasis is an endemic public health problem in the Amazon. This article analyzed the spatial distribution of this disease and its relationship with socioeconomic, environmental and public health policy variables in four mesoregions of the state of Pará, from 2011 to 2022. This ecological study used secondary data obtained from official Brazilian agencies. Spatial analysis was performed using the Flow, Kernel and Global Moran bivariate techniques expressed in thematic maps. In the mesoregions studied, 2685 cases of the disease were confirmed, with the highest number of cases in Southeast Pará state. The epidemiological profile followed the national pattern of occurrence of the disease, with a higher number of cases in children below school age. Spatial dependence was observed between the prevalence of the disease and socio-economic indicators. The most intense movement of patients was towards the Belém Metropolitan mesoregion. The disease showed an inhomogeneous pattern of distribution of cases, with a direct relationship between areas with cases and deforestation associated with different anthropic activities. There is a socio-environmental production of the disease that goes beyond the border limits of the mesoregions, and its establishment is related to the unsustainable development model implemented in the region. Full article

Diarrheagenic Escherichia coli (DEC) are the leading cause of infectious diarrhea and pose a significant global, regional, and national burden of disease. This study aimed to investigate the prevalence of six DEC pathotypes in children with diarrhea and determine their antibiotic resistance patterns. Samples from 107 diarrheagenic children were collected and processed for Escherichia coli (E. coli). Single-plex PCR was used to detect target virulence genes as well as characterize and categorize DEC pathotypes. Antibiotic resistance patterns were determined by the Kirby–Bauer disk diffusion method. E. coli was detected in 79 diarrheal stool samples, accounting for 73.8% of the samples collected. Additionally, 49.4% (39 out of 79) of the isolates harbored various typical virulence factors. Results revealed six pathotypes of virulence: enterotoxigenic E. coli (ETEC) (53.8%), enteropathogenic E. coli (EPEC) (12.8%), enteroaggregative E. coli (EAEC) (10.3%), Heteropathotypes (7.8%), Shiga toxin-producing E. coli (STEC), and enterohemorrhagic E. coli (EHEC) (7.7% each). The isolates exhibited high antibiotic resistance against trimethoprim/sulfamethoxazole (82.1%), amoxicillin (79.5%), ampicillin (74.4%), gentamicin (69.2%), and streptomycin (64.1%). An overall occurrence of 84.6% of multiple-drug resistance was observed in the isolates, with resistance ranging from three to four antibiotic classes. Our findings revealed a high level of pathogenic E. coli that were highly resistant to multiple categories of antibiotics among children in the Awi zone. These findings highlight the potential role of pathogenic E. coli in childhood diarrhea in tropical low-resource settings and underscore the need for continued research on the characteristics of pathogenic and antibiotic-resistant strains. Full article

Introduction: Raw milk may contain pathogenic microorganisms harmful to humans, e.g., multidrug-resistant Escherichia coli non-O157:H7, which can cause severe colitis, hemolytic uremia, and meningitis in children. No studies are available on the prevalence of Shiga toxin-producing E. coli (STEC O157:H7) in sick or healthy dairy animals in the Khyber Pakhtunkhwa Province of Pakistan. Aim: This study aimed to isolate, characterize, and detect antibiotic resistance in STEC non-O157:H7 from unpasteurized milk of dairy bovines in this province. Materials and Methods: We collected raw milk samples (n = 800) from dairy farms, street vendors, and milk shops from different parts of the Khyber Pakhtunkhwa Province. E. coli was isolated from these samples followed by latex agglutination tests for serotyping. The detection of STEC was conducted phenotypically and confirmed by the detection of virulence genes genotypically. An antibiogram of STEC isolates was performed against 12 antibiotics using the disc diffusion method. Results: A total of 321 (40.12%) samples were found to be positive for E. coli in this study. These samples were processed for the presence of four virulence genes (Stx1, Stx2, ehxA, eae). Forty samples (5.0%) were STEC-positive. Of these, 38%, 25%, 19%, and 18% were positive for Stx1, Stx2, ehxA, and eae, respectively. Genotypically, we found that 1.37% of STEC isolates produced extended-spectrum beta-lactamase (ESBL) and contained the bla_{CTX M} gene. Resistance to various antibiotics ranged from 18% to 77%. Conclusion: This study highlights the risk of virulent and multidrug-resistant STEC non-O157:H7 in raw milk and the need for proper quality surveillance and assurance plans to mitigate the potential public health threat. Full article

The fear of missing sepsis episodes in neonates frequently leads to indiscriminate use of antibiotics, and prescription program optimization is suggested for reducing this inappropriate usage. While different authors have studied how to reduce antibiotic overprescription in the case of early onset sepsis episodes, with different approaches being available, less is known about late-onset sepsis episodes. Biomarkers (such as C-reactive protein, procalcitonin, interleukin-6 and 8, and presepsin) can play a crucial role in the prompt diagnosis of late-onset sepsis, but their role in antimicrobial stewardship should be further studied, given that different factors can influence their levels and newborns can be subjected to prolonged therapy if their levels are expected to return to zero. To date, procalcitonin has the best evidence of performance in this sense, as extrapolated from research on early onset cases, but more studies and protocols for biomarker-guided antibiotic stewardship are needed. Blood cultures (BCs) are considered the gold standard for the diagnosis of sepsis: positive BC rates in neonatal sepsis workups have been reported as low, implying that the majority of treated neonates may receive unneeded drugs. New identification methods can increase the accuracy of BCs and guide antibiotic de-escalation. To date, after 36–48 h, if BCs are negative and the baby is clinically stable, antibiotics should be stopped. In this narrative review, we provide a summary of current knowledge on the optimum approach to reduce antibiotic pressure in late-onset sepsis in neonates. Full article

Background: Vaccination constitutes the best strategy against COVID-19. In Tunisia, seven vaccines standing for the three main platforms, namely RNA, viral vector, and inactivated vaccines, have been used to vaccinate the population at a large scale. This study aimed to assess, in our setting, the kinetics of vaccine-induced anti-RBD IgG and IgA antibody responses. Methods: Using in-house developed and validated ELISA assays, we measured anti-RBD IgG and IgA serum antibodies in 186 vaccinated workers at the Institut Pasteur de Tunis over 12 months. Results: We showed that RNA vaccines were the most immunogenic vaccines, as compared to alum-adjuvanted inactivated and viral-vector vaccines, either in SARS-CoV-2-naïve or in SARS-CoV-2-experienced individuals. In addition to the IgG antibodies, the vaccination elicited RBD-specific IgAs. Vaccinated individuals with prior SARS-CoV-2 infection exhibited more robust IgG and IgA antibody responses, as compared to SARS-CoV-2-naïve individuals. Conclusions: After following up for 12 months post-immunization, we concluded that the hierarchy between the platforms for anti-RBD antibody-titer dynamics was RNA vaccines, followed by viral-vector and alum-adjuvanted inactivated vaccines. Full article

The burden of dengue has emerged as a serious public health issue due to its impact on morbidity, mortality, and economic burden. Existing surveillance systems are inadequate to provide the necessary data for the prompt and efficient control of dengue. Passive surveillance of dengue cases may lead to underreporting and delayed mitigation responses. Improved dengue control program requires sensitive and proactive methods for early detection of dengue. We collected and reviewed existing research articles worldwide on detecting dengue virus in Aedes species larvae. Searches were conducted in PUBMED and Google Scholar, including all the studies published in English and Bahasa Indonesia. Twenty-nine studies were included in this review in terms of assay used, positivity rate, and dengue serotype detected. The presence of dengue virus in immature mosquitoes was mostly detected using reverse transcription PCR (RT-PCR) in pooled larvae. In one study, dengue virus was detected in larvae from laboratory-infected mosquitoes using enzyme-linked immunosorbent assay (ELISA). The positivity rate of dengue virus detection ranged from 0 to 50% in field-caught larvae. Although various methods can detect the dengue virus, further research encourages the use of low-cost and less laborious methods for active surveillance of dengue in larvae. Full article

Background: There are wide variations in antibiotic use in neonatal intensive care units (NICUs). Limited data are available on antimicrobial stewardship (AS) programs and long-term maintenance of AS interventions in preterm very-low-birth-weight (VLBW) infants. Methods: We extended a single-centre observational study carried out in an Italian NICU. Three periods were compared: I. “baseline” (2011–2012), II. “intervention” (2016–2017), and III. “maintenance” (2020–2021). Intensive training of medical and nursing staff on AS occurred between periods I and II. AS protocols and algorithms were maintained and implemented between periods II and III. Results: There were 111, 119, and 100 VLBW infants in periods I, II, and III, respectively. In the “intervention period”, there was a reduction in antibiotic use, reported as days of antibiotic therapy per 1000 patient days (215 vs. 302, p < 0.01). In the “maintenance period”, the number of culture-proven sepsis increased. Nevertheless, antibiotic exposure of uninfected VLBW infants was lower, while no sepsis-related deaths occurred. Our restriction was mostly directed at shortening antibiotic regimens with a policy of 48 h rule-out sepsis (median days of early empiric antibiotics: 6 vs. 3 vs. 2 in periods I, II, and III, respectively, p < 0.001). Moreover, antibiotics administered for so-called culture-negative sepsis were reduced (22% vs. 11% vs. 6%, p = 0.002), especially in infants with a birth weight between 1000 and 1499 g. Conclusions: AS is feasible in preterm VLBW infants, and antibiotic use can be safely reduced. AS interventions, namely, the shortening of antibiotic courses in uninfected infants, can be sustained over time with periodic clinical audits and daily discussion of antimicrobial therapies among staff members. Full article

Kiribati is a Pacific Island nation with a widely dispersed population and one of the highest rates of leprosy worldwide. Single-dose rifampicin post-exposure prophylaxis (SDR-PEP) of leprosy contacts has reduced new case detection rates in controlled trials. In 2018, an SDR-PEP programme was introduced in Kiribati that included screening and chemoprophylaxis of household contacts of leprosy cases retrospectively (2010–2017) and prospectively (2018–2022). We conducted a retrospective audit to determine the comprehensiveness, timeliness and feasibility of the SDR-PEP programme. Overall, 13,641 household contacts were identified (9791 in the retrospective and 3850 in the prospective cohort). In the retrospective cohort, 1044 (11%) contacts were absent, 403 (4%) were ineligible for SDR, and 42 new cases were detected (0.4%) Overall, SDR coverage was 84.7%. In the prospective cohort, 164 (4%) contacts were absent, 251 (7%) were ineligible for SDR, and 23 new cases were diagnosed (0.6%). Overall, SDR coverage was 88.1%. Across both cohorts, there were 23 SDR refusals. The median time to SDR administration was 220 days (IQR 162–468) and 120 days (IQR 36–283) for the retrospective and prospective cohorts, respectively. SDR was readily accepted in both cohorts. The new case detection rate (0.5%) is consistent with that in other studies. Overall SDR coverage in both the retrospective and prospective phases met programmatic expectations. Full article

Background: Vaccine hesitancy (VH) has increased over the past decade with large geographical variations between countries, posing a threat to global public health. This phenomenon is growing in the general population as well as among healthcare workers (HCWs), who are the most reliable source of vaccine-related information for patients. Special attention must therefore be paid to medical students, who are the future HCWs. Methods: We conducted a cross-sectional study (November 2022–January 2023) on all the Albanian and Italian students attending medical science courses at the Catholic University “Our Lady of Good Counsel” (Tirane, Albania) to investigate VH and the factors contributing to it (using the Vaccination Attitude Examination Scale-VAX), including COVID-19 vaccination. Vaccine knowledge was assessed using the Zingg and Siegrist Scale. Students were asked to voluntarily answer an anonymous questionnaire. Results: 689 questionnaires were collected (58.8% Albanians, 72.3% female; 70.4% aged 20–25 years; 70.4% attending the Medicine and Surgery course). Generally, students showed low VH, especially Italians (p < 0.001); however, some hesitancy was observed regarding the potential long-term effects of vaccines, especially among Albanians (p < 0.05). The results also showed a significant difference in vaccine knowledge scores between different course years (χ²  =  90.058; df  =  40; p = < 0.001) and different degree courses (χ²  =  89.932; df = 40; p  = < 0.001). With regard to COVID-19 vaccination, being of Albanian origin significantly increases the risk of not being vaccinated (OR = 7.215; 95%CI 3.816–13.640, p < 0.001), highlighting possible differences in vaccine coverage and policy between the two countries. Conclusion: Vaccine hesitancy should be addressed at early stages during medical sciences courses, in order to protect future healthcare workers, to preserve essential health services, and reduce the risk of further pandemics. Full article

Medicine development is a lengthy endeavour. Increasing regulatory stringency and trial complexity might lead to reduced efficiency, dwindled output, and elevated costs. However, alternative models are possible. We compared the operational differences between pharmaceutical industry sponsored trials, product development partnership trials, and investigator-initiated trials to identify key drivers of inefficiency in clinical research. We conducted an exploratory mixed-methods study with stakeholders, including clinical trial sponsors, contract research organisations, and investigators. The qualitative component included 40 semi-structured interviews, document reviews of 12 studies and observations through work shadowing in research institutions in Burkina Faso, Mali, and Switzerland. The findings were triangulated with an online survey polling clinical research professionals. The operational differences were grouped under five categories: (i) trial start-up differences including governance and management structure; (ii) study complexity; (iii) site structural and organisational differences; (iv) study conduct, quality approaches, and standard operating procedures; and (v) site capacity strengthening and collaboration. Early involvement of sites in the planning and tailored quality approaches were considered critical for clinical operations performance. Differences between the types of trials reviewed pertained to planning, operational complexities, quality approaches, and support to the sites. Integration of quality-by-design components has the potential to alleviate unnecessary process burden. Full article

Leishmaniasis is one of the neglected tropical diseases. Studies show that the poor knowledge about epidemiological aspects of leishmaniasis within communities causes the collapse of existing disease control programs. Therefore, the present study focuses on a detailed survey of the existing awareness among the threatened population in the Medawachchiya Public Health Inspector’s (PHI) Area in the Anuradhapura District, Sri Lanka, aiming to assist the health staff to organize community-based vector control programs effectively in the future. Assessment of the awareness of residents of two hundred and seventy households (n = 270) from 10 Grama Niladhari Divisions (GNDs) was carried out by using a structured questionnaire. Among 143 females and 134 males, only 75.1% had knowledge about the disease, 5.8% (n = 16) of the participants knew only about the vector, and 28.9% (n = 80) knew about control methods. The study showed a considerable lack of awareness about the disease among the studied population. The study found that age and education levels had significant impacts on knowledge, attitudes, and practices. However, factors like gender, marital status, occupation, income, and expenses did not show significant correlations. The present study suggests huge scope for greater achievements in community-related vector control methods by implementing a continuous educational program. Full article

The aim of this study was to identify factors associated with non-adherence to tuberculosis (TB) preventive treatment among contacts with latent TB infection for new cases of pulmonary TB cases reported in Catalonia in 2019–2021. All contacts aged 18 years or older with a latent TB infection who received a TB preventive treatment were included in the study. The Chi square test and the odds ratios (OR) were used to assess the association between non-adherence to TB preventive treatment and the study variables; a p < 0.05 was considered statistically significant. Multiple logistic regression analysis was used to detect the independent factors associated with TB preventive treatment non-adherence; a p < 0.05 was considered statistically significant. The percentage of non-adherence to TB preventive treatment found in this study was 23.7%. A multivariable logistic regression analysis determined that the following factors were significantly associated with TB preventive treatment non-adherence among adult contacts: “exposure at school or workplace” (aOR = 3.34), “exposure to an index case without laboratory confirmation of TB” (aOR = 2.07), “immigrant contact” (aOR = 1.81), “male gender” (aOR = 1.75) and “exposure duration < 6 h per week or sporadic” (aOR = 1.60. By contrast, the factor “short-term TB preventive treatment regimen” (aOR = 0.38) was significantly associated with a lower treatment non-adherence. Adherence to TB preventive treatment should be improved among adult contacts of TB pulmonary cases with latent TB infection by recommending short-term treatment regimens and by developing health education activities, with a greater focus on contacts with factors associated with treatment non-adherence. Full article

Aedes aegypti and Culex quinquefasciatus mosquitoes are vectors of different arboviruses that cause a large burden of disease in humans worldwide. A key step towards reducing the impact of arboviruses on humans can be achieved through integrated mosquito surveillance and control approaches. We carried out an integrated approach of mosquito surveillance and control actions to reduce populations of these insects along with a viral surveillance in a neighborhood of Recife (Northeastern Brazil) with high mosquito densities and arbovirus transmission. The actions were carried out in 40 different houses in the Nova Descoberta neighborhood. The area was divided into two groups, the control group using tools to monitor the mosquito density (1 OVT; 1 Double BR-ovt; monthly capture of alates) and the experimental group with control actions using surveillance tools in an intensified way (2 OVTs; 2 Double BR-ovts; fortnightly capture of alates; toxic baits). We evaluated the study’s impact on the mosquito density via the Egg Density (ED) and Adult Density (AD) over a period of 12 cycles of 28 days each. The collected adult mosquitoes were processed via RT-qPCR for DENV, CHIKV and ZIKV and, subsequently, the Minimum Infection Rate (MIR) was calculated. After 12 cycles, we observed a 91% and 99% reduction in Aedes ED and AD in the monitored properties, as well as a 76% reduction in the AD of Cx. quinquefasciatus in the same properties. Moreover, we detected circulating arboviruses (DENV and ZIKV) in 19.52% of captured adult mosquitoes. We show that enhancing entomological surveillance tools can aid in the early detection of possible risk areas based on vector mosquito population numbers. Additionally, the detection of important arboviruses such as ZIKV and DENV raises awareness and allows for a better selection of risk areas and silent virus spread. It offers supplementary information for guiding emergency mosquito control measures in the target area. The goal is to minimize human–vector interactions and, subsequently, to lower the risk of transmitting circulating arboviruses. Full article

Cutaneous leishmaniasis (CL) caused by Leishmania aethiopica is transmitted by Phlebotomus longipes in northern Ethiopia. No studies have been conducted to investigate the transmission dynamics of CL, despite its high endemicity in both rural and urban settings. Evidence on the ecology and behavior of the vector from this area are required to develop integrated disease control strategies. Sand flies were collected in the dry and wet seasons in 2021 in CL-endemic rural Gindmeteaye and urban Addis-Alem in northwest Ethiopia. Trapping was performed with sticky and Centers for Disease Control and Prevention (CDC) light traps in three habitats, including inside patients’ houses, peridomestic areasand in caves/rocky areas. Sand flies were morphologically identified to species level. Female Phlebotomus species were categorized according to blood feeding status and tested by spliced-leader (SL-) ribonucleic acid (RNA) polymerase chain reaction (PCR) to screen for Leishmania infection. Of 1161 sand flies, the majority (77%) were P. longipes, six (0.5%) were P. orientalis and the remaining were Sergentomyia. The abundance of the 430 female P. longipes was significantly linked to seasonality (p < 0.001), with the majority in the dry season occurring in the outdoor rocky (37%) and peridomestic (34%) sites, while, in the wet season, most (62%) were captured indoors. This seasonality was more pronounced in rural Gindmeteaye, where housing construction is poor. The number of blood-fed and gravid P. longipes was significantly higher in the wet (31%; 22%), compared to the dry season (13%; 8%), and their proportion was highest indoors. Eighteen (4%) female P. longipes were Leishmania positive, with highest infection prevalence in caves (7% compared to 3% indoors, p = 0.022), and in the dry season (6%, p < 0.001). Phlebotomus orientalis specimens were all captured in May in rural Gindmeteaye, five indoors and one in a peridomestic site. Further research should be conducted to investigate the absolute contribution of humans and indoor transmission to the transmission cycle of CL. Inhabitants of endemic villages should be made aware that evening outdoor activities near caves may increase their exposure to infectious sand flies. Whether P. orientalis can breed and become infected at high altitudes should be further studied. Full article

Background: Despite all of the efforts, leprosy continues to affect hundreds of thousands of people every year, including children, showing the ongoing transmission of the disease within the population. The transmission of leprosy can be interrupted through an integrated approach that includes active case-finding, contact tracing and capacity building of health workers. Methods: A cross-sectional study design was used to assess the knowledge, attitudes and skills of health workers in the screening and diagnosis of leprosy. One hundred and eighty-one and eighty-eight health care workers participated in the pre-and post-assessment surveys, respectively. Data were collected through interviews and an observational checklist. Frequency tables and graphs were used to describe the study variables, and statistical significance between pre- and post-assessment surveys was declared at p-value < 0.5. Result: The percentages of healthcare workers with good knowledge, positive attitudes and skills were 61.2%, 55.6% and 51.7% in the pre-assessment survey and 77.3%, 56.3% and 75.0%, respectively, in the post-assessment survey. There was a significant improvement in the knowledge and skill scores of participants in the post-assessment survey (p < 0.01). During the campaign, 3780 index contacts were screened; 570 (15.1%) were diagnosed with skin diseases, and 17 new leprosy cases were diagnosed (case detection rate of 45 per 10,000 contacts). Conclusion: Training improved the knowledge and skills of healthcare workers, and a large number of skin diseases were detected through mass screening and active case findings. Providing training for frontline healthcare workers contributed to the detection of more cases and facilitated early detection of leprosy cases. Full article