Search Results (1,064)

Rickettsia rickettsii is the most virulent agent of the genus Rickettsia that causes one of the most relevant vector-borne diseases in the Americas (RRSF). RRSF manifests with many non-specific acute clinical symptoms complicating its diagnosis and can lead to death if not treated appropriately. RRSF has been reported in Canada, the United States of America, Mexico, Costa Rica, Panama, Colombia, Brazil, and Argentina. In addition to R. rickettsii, mild and severe spotted fever group rickettsioses (SFGR) have been reported in the Americas; however, the true prevalence of these diseases is unknown. In Panama, RRSF have been reported in four of 14 provinces during two outbreak periods: five cases including two fatalities were identified in 1950–1951, and 23 cases including 17 fatalities between 2004 and 2025. This paper presents the clinical characterization of a fatal case of RRSF in Coclé province and a severe case of SFGR in a mountainous area of the Gnäbe Buglé Indigenous Comarca (GBIC). Laboratory confirmation was performed by molecular analysis of tissues obtained from necropsies in the case of RRSF and by immunofluorescence assay (IFA) in the case of SFGR. Furthermore, this paper identifies existing gaps in the initial clinical suspicion and pertinent to SFGR in Panama, which may be applicable to other countries in the region. In the last 21 years, cases have occurred upon contact with ticks in rural areas (13), urban and suburban locations (7), rural woodlands (2), and forests (1). Provinces with more cases are Panamá (7 of 23, 6 died), Coclé (5 of 23, 5 died), Colón (3 of 23, 1 died), Panamá Oeste (1 of 23, 1 died), and GBIC (7 of 23, 4 died), including a cluster of seven cases in 2019. Therefore, Coclé province is considered one of the endemic areas for RRSF in Panama, while the latest cases from the GBIC since 2019 indicate that mountainous areas are an eco-epidemiological scenario to include in the transmission of these diseases. Although this disease has a low prevalence, patients who present symptoms commonly associated with more common diseases such as dengue, other arboviruses, malaria, and leptospirosis, among others, should be included in the diagnostic suspicion. Without diagnostic suspicion and adequate treatment, the patient can die. Full article

Subterranean ecosystems represent some of the most unique and fragile habitats on Earth, yet they remain poorly understood and highly vulnerable to human-induced disturbances. Despite their ecological significance, these systems are rarely integrated into conservation planning, and surface-level protected areas alone are insufficient to safeguard their biodiversity. In southeastern Brazil, a karst landscape spanning approximately 1200 km², recognized as the region with the highest cave density in South America (approximately 2600 caves), is under increasing pressure from urban expansion, agriculture, and mining, all of which threaten the ecological integrity of subterranean habitats. This study sought to identify caves of high conservation priority by integrating species richness of non-troglobitic invertebrates, occurrence of troglobitic species, presence of endemic troglobitic taxa, and the degree of anthropogenic impacts, using spatial algebra and polygon-based mapping approaches. Agriculture and exotic forestry plantations (54%) and mining operations (15%) were identified as the most prevalent disturbances. A total of 32 troglobitic species were recorded, occurring in 63% of the 105 surveyed caves. Notably, seven caves alone harbor 25% of the region’s known cave invertebrate diversity and encompass 50% of its cave-restricted species. The findings highlight the global significance of this spot of subterranean biodiversity and reinforce the urgent need for targeted conservation measures. Without immediate action to mitigate unsustainable land use and resource exploitation, the persistence of these highly specialized communities is at imminent risk. Full article

Background. Melioidosis is a severe infection caused by Burkholderia pseudomallei and is endemic in regions with a high prevalence of thalassemia. Patients with thalassemia are thought to be at increased risk due to iron overload, splenectomy, and immune dysfunction. However, the pooled prevalence and mortality outcomes of melioidosis in this population remain unclear. Methods. We conducted a systematic review and meta-analysis in accordance with PRISMA 2020 guidelines (PROSPERO: CRD420251108294). PubMed, Embase, and Scopus were searched from inception to July 2025. Observational studies reporting prevalence or mortality of melioidosis in patients with thalassemia were eligible. Pooled odds ratios (ORs) for mortality were calculated using random-effects models, with subgroup and sensitivity analyses based on age, thalassemia subtype, and study quality. Results. Six retrospective studies including 7529 melioidosis patients, of whom 173 had thalassemia, were analyzed. The prevalence of thalassemia among melioidosis cases ranged from 0.5% to 40.7%. Mortality among thalassemia patients varied from 0% to 100%. Pooled analysis demonstrated no significant excess mortality compared with non-thalassemia controls (OR 0.55, 95% CI 0.16–1.89; I² = 44.9%). Sensitivity analysis restricted to moderate- and high-quality studies showed a significantly lower risk of death (OR 0.23, 95% CI 0.15–0.36; I² = 0%). Subgroup analyses by thalassemia subtype and age revealed no clear effect modification, although power was limited. Conclusions. Despite biological plausibility, thalassemia was not associated with increased melioidosis mortality. These findings suggest that closer clinical monitoring, iron chelation, and comorbidity profiles may influence outcomes. Prospective, well-characterized cohort studies are needed to refine risk stratification and guide management in endemic regions. Full article

Background/Objectives: Hepatitis B virus (HBV) remains a persistent challenge for transfusion safety. Although testing for hepatitis B surface antigen (HBsAg) and nucleic acid testing (NAT) reduces transmission risk, antibodies to hepatitis B core antigen (anti-HBc) and antibodies to hepatitis B surface antigen (anti-HBs) provide additional insight into past infection and vaccine-induced immunity. We aimed to determine their seroprevalence among blood donors in southern Croatia and assess associations with age, occupation, and time since vaccination. Methods: This cross-sectional study was conducted between February and November 2024 at two regional transfusion centers in southern Croatia. A total of 1008 voluntary blood donors, all HBsAg- and NAT-negative, were tested for anti-HBc and anti-HBs using chemiluminescent microparticle immunoassay. Demographic and vaccination data were collected through verified medical records. Results: Anti-HBc was detected in 0.5% of donors, exclusively among the unvaccinated. Protective anti-HBs levels were found in 38.1% overall and 70.6% of vaccinated donors, with significant declines by age and more than 15 years post-vaccination (p = 0.024). Healthcare workers showed higher seroprotection than non-healthcare donors (67.0% vs. 35.1%; p < 0.001), although one-third still lacked protective levels. Conclusions: HBV exposure was rare, but waning vaccine-induced immunity was evident, with protective anti-HBs levels in 70.6% of vaccinated donors, declining with age and time since vaccination. These findings highlight the need for periodic monitoring of anti-HBs and targeted booster strategies, especially in older and occupationally exposed groups. HBsAg and NAT provide a high level of transfusion safety, while the role of routine anti-HBc testing in this low-endemic context should be carefully evaluated in view of its potential benefits and drawbacks. Donor-based surveillance is a valuable tool for evaluating long-term vaccine effectiveness and guiding public health policy. Full article

Human T-cell leukemia virus type 1 (HTLV-1), the first oncogenic human retrovirus, causes adult T-cell leukemia/lymphoma (ATLL), an aggressive neoplasm of mature CD4+ T-cells that is incurable in most patients and is associated with a median survival of less than 1 year. HTLV-1 also causes inflammatory disorders, including HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and uveitis. The estimated lifetime risks of ATLL and HAM/TSP in HTLV-1 carriers are 3–5% and 0.25–1.8%, respectively. Although there is uncertainty about other health effects of HTLV-1, a recent meta-analysis showed an association between HTLV-1 and cardiovascular, cerebrovascular, and metabolic diseases and a 57% increased risk of early mortality in HTLV-1 carriers, independent of ATLL or HAM/TSP. Furthermore, emerging studies in endemic areas show that outcomes for common cancers, such as cervical cancer and lymphoma (non-ATLL), are inferior in HTLV-1 carriers compared to publicly reported data. Thus, the impact of HTLV-1 may be greater and more diverse than currently understood. This review provides an outline of the prevalence and impact of HTLV-1 and associated disorders in the US, focused on—but not limited to—ATLL, with an emphasis on the social determinants of health that can affect the success of screening and prevention strategies. We also discuss the mechanisms by which HTLV-1 drives the pathogenesis of ATLL and potential strategies for early diagnosis and intervention. Finally, we conclude by suggesting approaches to designing and implementing community-informed research initiatives in HTLV-1 and ATLL. Full article

Leishmaniasis is a vector-borne parasitic disease caused by Leishmania spp., transmitted to humans by phlebotomine sand flies. The development of Leishmania into infective metacyclic promastigotes occurs within the sand fly gut, where the bacterial microbiota plays a pivotal role in parasite development and transmission dynamics. This study aimed to characterize the gut bacterial composition of phlebotomine sand flies collected from both endemic (Lalla Aaziza) and non-endemic (Marrakech) regions of leishmaniasis in Morocco. We investigated the microbiota of Phlebotomus papatasi, P. sergenti, P. perniciosus, and P. longicuspis, all proven vectors of cutaneous and visceral leishmaniasis in the Old World, including Morocco, as well as Sergentomyia minuta, a potential vector in the Mediterranean basin. Gut bacteria were isolated using conventional microbiological techniques and identified by MALDI-TOF mass spectrometry. Fifteen bacterial strains from three phyla were identified, with Bacillus pumilus being the most frequently detected species. Significant differences in colony-forming unit (CFU) counts and bacterial richness were observed between sand fly species and collection sites. Notably, Bacillus simplex (in P. papatasi), Nocardia ignorata (in P. sergenti), and Serratia spp. (in P. longicuspis) were identified for the first time in these vectors. This study is the first to investigate the gut bacterial composition of sand flies in Morocco, revealing species and locality-dependent differences in microbial communities. The predominance of Bacillus spp., particularly B. pumilus, suggests a potentially influential role in sand fly physiology and vector competence. Furthermore, the novel detection of B. simplex, N. ignorata, and Serratia spp. underscores previously unrecognized microbial associations that warrant further investigation. These findings provide a critical baseline for future studies exploring the microbiota-mediated modulation of sand fly–Leishmania interactions. Full article

The global citrus industry faces unprecedented challenges due to Huanglongbing (HLB), which is associated with the bacterial pathogen Candidatus Liberibacter asiaticus (CLas). This study evaluates the field performance of 11 rootstocks, grafted with ‘Valencia’ orange (Citrus sinensis), under Florida’s HLB-endemic production conditions, while also examining the impact of systemic applications of oxytetracycline (OTC) via trunk injection. Mature trees received annual OTC injections and were assessed over two production seasons. In year 1, OTC-treated trees exhibited significant improvements regardless of the rootstock, including a 36% increase in yield, an 11% increase in juice TSS, and reduced leaf bacterial titers. During year 2, the positive effects of OTC were sustained, or even enhanced. CLas titers were reduced in both leaves and roots; yield increased by 70%; and fruit weight, juice color, and TSS also improved significantly. Moreover, OTC-injected trees exhibited a larger percentage of finer roots compared to non-injected trees. US-1688 and US-1672, both hybrids of C. maxima ‘Hirado’ and C. reticulata ‘Cleopatra’, emerged as the most productive rootstocks. These results demonstrate the importance of rootstock selection for sustainable citrus cultivation while highlighting the benefits of integrating the systemic delivery of OTC to manage HLB and maximize the resilience of citrus. Full article

Endophytic fungi represent key microbial symbionts that colonize internal plant tissues without causing apparent disease, playing vital roles in host growth, stress resistance, and biosynthesis of bioactive compounds. Carpesium lipskyi C. Winkl., a medicinal plant endemic to the Gaoligong Mountains in Yunnan, remains largely unexplored regarding its endophytic fungal composition. In this study, a total of 737 amplicon sequence variants (ASVs) were identified through high-throughput sequencing, spanning 9 phyla, 36 classes, 67 orders, 137 families, 206 genera, and 277 species. The dominant phyla were Ascomycota, Basidiomycota, and Glomeromycota. Alpha diversity in stems and leaves followed a unimodal distribution along the elevational gradient, in contrast to root endophytic communities, which showed no significant correlation with altitude. Peak diversity occurred at 2734 m, indicating a non-linear altitude-diversity relationship. Altitude, along with stable precipitation and temperature (2600–3210 m), significantly influenced fungal diversity. Medicinal fungi such as Cladosporium sp., Meyerozyma guilliermondii, Phialocephala fortinii, and Rhodotorula mucilaginosa were found in either roots or stems. This is the first comprehensive assessment of endophytic fungi in C. lipskyi from this region, providing a foundation for future ecological and pharmacological studies. Full article

Natural resins are complex mixtures of secondary metabolites produced by many plants in response to stress or injury and have long been used for their antimicrobial, anti-inflammatory, and antioxidant properties. Among resin-producing genera, Commiphora Jacq. (Burseraceae) stands out for the traditional and medicinal relevance of its oleogum resins, commonly known as myrrh. In this study, we investigated, for the first time, the non-volatile fraction of the oleogum resin of Commiphora ornifolia (Balf.f.) J.B.Gillett, which is an endemic species of Socotra Island. Ethanol extraction followed by chromatographic and spectroscopic analysis (HPLC-DAD, NMR, HRMS) led to the isolation of (+)-yangambin, a furofuran lignan not previously reported in this species. Quantitative analysis showed yangambin to be present in all eight resin samples analyzed, at concentrations ranging from 3.50 (±0.02) to 9.05% (±0.19) of the ethanol extract. In addition, the analysis of the hydrolyzed polysaccharide fraction revealed the presence of arabinose, rhamnose, galactose, and galacturonic acid. These preliminary findings highlight the phytochemical richness of C. ornifolia oleogum resin and suggest the presence of other potentially bioactive compounds. The presence of yangambin, known for various pharmacological activities, supports further phytochemical and biological studies on this largely unexplored species. Full article

The genus Lavandula represents one of the most valuable aromatic and medicinal plants, holding significant economic importance in the pharmaceutical, food, perfumery, and cosmetics industries. Among them, L. multifida is a traditionally used medicinal plant in the Mediterranean region. This work provides a comprehensive review of L. multifida, focusing on its traditional uses, phytochemistry, and pharmacological properties. Unlike conventional lavenders, its essential oil is dominated by phenolic monoterpenes, principally carvacrol, alongside significant concentrations of β-bisabolene, 1,8-cineole, and camphor. This distinct phytochemical profile is further complemented by a rich range of non-volatile constituents, including flavonoids, phenolic acids, and triterpenoids. Pharmacological investigations have validated its broad-spectrum antimicrobial activity, demonstrating efficacy against multidrug-resistant bacterial strains and fungal pathogens through mechanisms such as membrane disruption, metabolic interference, and quorum sensing inhibition. Furthermore, the species exhibits significant antioxidant and anti-inflammatory properties, mediated primarily through radical scavenging, cyclooxygenase inhibition, and cytokine modulation. Owing to its distinct chemistry, specific traditional uses for respiratory and digestive ailments, limited endemic habitat, and underexplored status, L. multifida presents a promising candidate for future research with high potential for novel drug discovery, particularly in antiparasitic and respiratory therapies. This review concludes by identifying key research priorities for L. multifida, including a detailed analysis of its non-volatile compounds, mechanistic elucidation, toxicological assessments, and standardization of extracts. Addressing these gaps is essential to validate its traditional applications and advance its development into evidence-based phytomedicines, adjuvant therapies, and natural agrochemicals. Full article

Knowledge gaps exist on whether SARS-CoV-2 co-infection alters recombination frequency or induces phylogenetic incongruities in endemic β-coronaviruses (HCoV-OC43, HCoV-HKU1), limiting our understanding of cross-species evolution. Among 7213 COVID-19 and 1590 non-COVID-19 acute respiratory cases (2021–2022) screened via multiplex PCR, β-coronavirus co-infections (SARS-CoV-2 + HCoV-OC43/HKU1) and single HCoV-OC43/HKU1 infections were identified. Whole-genome sequencing (Illumina NovaSeq) was performed. Phylogenies were reconstructed using Bayesian inference (MrBayes). Recombination was assessed via Bootscan analysis (SimPlot). Co-infection prevalence was low (0.51%, mainly HCoV-HKU1: 0.28%, HCoV-OC43: 0.11%). HCoV-OC43 diverged into lineage 1 (genotype K) and a novel recombinant lineage 2 (genotypes F/J/G/I segments), exhibiting accelerated evolution. HCoV-HKU1 remained genetically stable (genotype B). Co-infection status did not influence evolutionary outcomes. While SARS-CoV-2 co-infection may favor transmission of endemic HCoVs, their evolution appears driven by population-level selection, not co-infection. HCoV-OC43 underwent recombination-driven diversification, contrasting sharply with HCoV-HKU1’s stasis, highlighting distinct evolutionary strategies. Integrated genomic and clinical surveillance is critical for tracking coronavirus adaptation. Full article

Biodiversity conservation in South Korea faces increasing challenges from alien plant invasions. These invasions threaten endemic species uniquely adapted to specialized habitats, making it crucial to understand their ecological interactions. This study quantitatively compared the species composition, ecological niches, and species turnover patterns of alien and endemic plants in South Korea using data from the National Ecosystem Survey. Non-metric multidimensional scaling (NMDS) and multi-response permutation procedure (MRPP) analyses revealed significant compositional heterogeneity between groups. Kernel density estimation (KDE) revealed niche overlap in water-related factors (precipitation, water yield), but clear separation in topographic and climatic variables (altitude, slope, temperature). Alien plants exhibited broader niche breadths, confirming their ecological generalist traits, whereas endemic species displayed narrower niches confined to specialized habitats. Zeta diversity analysis indicated slower species turnover in alien species, suggesting niche assimilation and habitat homogenization. Both groups fit a power-law model, emphasizing deterministic environmental filtering. These findings highlight the ecological risks posed by alien species to stability of endemic plant communities and underscore the importance of targeted, science-based management strategies. Full article

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

Introduction: Nasopharyngeal carcinoma (NPC) is a distinct malignancy of the head and neck with high prevalence in endemic regions and a strong association with Epstein–Barr virus (EBV). In locally advanced stages, neoadjuvant chemotherapy (NAC) followed by chemoradiotherapy improves outcomes, but response rates vary. Identifying early predictors of NAC response is essential for guiding personalized treatment strategies. This study aims to assess whether baseline [¹⁸F]FDG PET/CT parameters can predict NAC response in NPC patients. Methods: In this retrospective study, 27 patients with histologically confirmed, locally advanced (stage III) NPC underwent baseline [¹⁸F]FDG PET/CT prior to NAC between 2015 and 2023. Quantitative PET parameters including SUVmax, SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were extracted from the primary tumor. NAC response was assessed using RECIST 1.1 criteria and classified as responders (CR + PR) or non-responders (SD + PD). Group comparisons were performed using Student’s t-test. ROC analysis was used to identify optimal cut-off values. A p-value < 0.05 was considered significant. Results: The cohort included 20 males and 7 females (mean age: 60.8 ± 15.2 years). The predominant histotype was undifferentiated non-keratinizing carcinoma (92.6%). A total of 19 patients (70.4%) responded to NAC. Responders had significantly lower baseline SUVmax (10.9 ± 4.8 vs. 15.8 ± 4.1, p = 0.021), MTV (16.2 ± 12.4 vs. 27.8 ± 19.5 cm³, p = 0.045), and TLG (128.6 ± 98.2 vs. 218.7 ± 152.4, p = 0.038). SUVmean was also lower in responders (6.1 ± 2.1 vs. 9.3 ± 2.8), although not statistically reported. ROC analysis identified SUVmax > 12.5 and MTV > 20.0 cm³ as thresholds associated with poor NAC response. Conclusions: Baseline metabolic parameters from [¹⁸F]FDG PET/CT, particularly SUVmax and MTV, may assist stratification of NAC response in nasopharyngeal carcinoma. These biomarkers may facilitate pre-treatment stratification and guide more personalized therapeutic approaches. However, the limited sample size may affect the generalizability of these findings, and larger prospective studies are needed to confirm the results. Full article

Andes virus (ANDV) is the leading cause of hantavirus cardiopulmonary syndrome (HCPS) in South America, a severe zoonosis with high mortality. Advances in critical care and extracorporeal membrane oxygenation (ECMO) have significantly improved survival rates; however, data on recovery beyond survival remain limited. This multicenter cohort study enrolled laboratory-confirmed HCPS survivors in Chile between 2021 and 2024, with follow-up at 3–6 months post-symptom onset to assess physical and neuropsychological sequelae. Participants were stratified by ECMO requirement and the clinical severity of HCPS, and evaluated using self-reported recovery, standardized symptom questionnaires, and EQ-5D quality-of-life instruments. Among 21 survivors (11 ECMO, 10 non-ECMO), 61.9% reported incomplete recovery. While 60–70% of patients received general medical follow-up, only 30% of non-ECMO patients—compared to all ECMO patients—had contact with a rehabilitation provider. Motor dysfunction and palpitations were more frequent in ECMO survivors; however, Jaccard index analysis revealed clustering of physical and neuropsychological symptoms across both groups. EQ-5D assessments showed comparable quality-of-life impairment, though non-ECMO survivors more often reported pain/discomfort (90.0% vs. 63.6%) and higher rates of analgesic self-medication. These findings highlight the burden of persistent symptoms after HCPS and the need for multidisciplinary post-discharge care in endemic regions. Full article