Tropical Medicine and Infectious Disease最新文献

In hospitals with limited resources, chlorine solutions are commonly used for biocleaning. The effectiveness of these solutions depends on the concentration of active chlorine and how they are prepared and stored. A study conducted in six University Hospitals in Benin from 10 March to 11 July 2025 aimed to evaluate the stability of active chlorine and the bactericidal efficacy of chlorine solutions used for disinfecting hospital environments. A total of 103 samples were analyzed using iodometric titration following the AFNOR (Association Française de Normalisation) standard NF EN ISO 7393-3 (2000) and WHO (World Health Organization) recommendations. Bactericidal activity was tested on multi-resistant hospital strains using the germ carrier method based on the standard NF T72-281. The study revealed that 88.4% of the solutions had inadequate active chlorine concentrations. Overall, the bactericidal activity was low, with only 14.6% effectiveness compared to 85.4% ineffectiveness. Ineffectiveness was particularly pronounced against Gram-negative bacilli, with 79.6% ineffectiveness and 20.4% effectiveness. Similarly, Gram-positive cocci showed a high level of ineffectiveness, reaching 84.5%, corresponding to 15.5% effectiveness. A significant association was observed between compliance with active chlorine concentrations and bactericidal effectiveness, with an OR of 42.5 and a p-value below 0.000001. Factors contributing to inefficiency included storage without light protection, use of transparent containers, storage for more than two days, inadequate active chlorine concentration, and incorrect pH levels. These issues compromise hospital disinfection and contribute to the persistence of multi-resistant bacteria in the hospital environment.

Objective: To determine the prevalence of and risk factors for congenital toxoplasmosis in neonates treated in the public health network of the eastern region of the Brazilian Amazon, northern Tocantins state.

Methods: A retrospective cohort study was conducted with neonates born to mothers with gestational toxoplasmosis who received care between 2017 and 2024. The outcome under analysis was positivity for immunoglobulin M in the electrochemiluminescence assay (CLIA). We estimated the prevalence of transplacental infection and respective 95% confidence intervals (95% CI) and its association with risk factors using the odds ratio (or) with a p-value < 0.05 in infected neonates before and after 16 gestational weeks at maternal infection diagnosis.

Results: A total of 1142 neonates were surveyed, in which 496 were diagnosed with congenital toxoplasmosis (IgM positive), thus obtaining a prevalence of vertical transmission of 45.4%. The main risk factors for vertical transmission were the mother's education level equal to or less than eight years, (OR = 1.5; 95% CI 1.2; 2.0) and having less than six prenatal consultations (OR = 22.8; 95% CI 3.0; 172.6).

Conclusions: A high prevalence of congenital toxoplasmosis was observed, with higher rates of infection in neonates born to mothers with lower levels of education.

In southern Brazil, dengue transmission in the state of Paraná has shown a significant increase in the number of cases since the first recorded occurrence in 1995, with more frequent outbreaks in the west, northwest, and north of the state. We evaluated the impact of a campaign of dengue vaccination administered to a fraction of the population in 30 municipalities in the state by conducting a 15-year interrupted time-series ecological study using data obtained from an official Brazilian data register. We modeled dengue incidence using Poisson regression adjusted by covariates (demographic, climate, and epidemiological factors), allowing for specific temporal variation for each site. A reduction of 18.7% in dengue incidence rate was estimated for a vaccination coverage of 100%. Although there was an increase in the crude dengue incidence rate, considering the three-dose coverage achieved in the municipalities, we estimated an 8.2% relative reduction in the incidence rate. This reduction would increase to 17% with a hypothetical coverage of 90%. The campaign was more effective in small municipalities since they had higher vaccination coverage. These findings underscore the significant impact of the vaccination campaign on reducing dengue incidence trends across the targeted municipalities.

It has been demonstrated that infants and young children exhibit immune tolerance as a consequence of immature immune systems, which are characterized by a natural Th2 bias. RSV infection has been reported to result in acute lower respiratory infection (ALRI), while formalin-inactivated vaccination has been observed to exacerbate Th2 responses, consequently leading to enhanced respiratory disease (ERD). Transcriptomic data from three independent cohorts of RSV-infected infants were analyzed (GSE246622 served as the discovery and train set; GSE105450 and GSE188427 were used as validation sets). Immune infiltration analysis revealed immunological characteristics, which were then used to perform unsupervised clustering using feature-related genes. WGCNA was used to identify co-expressed gene modules, while Mfuzz and TCseq were employed to analyze temporal expression patterns. Machine learning models were developed using a refined panel of candidate genes. Severe symptoms of RSV infection exhibited a strong correlation with age, with younger infants demonstrating more intense inflammatory responses from neutrophils, macrophages, mast cells and dendritic cells. A predictive model was constructed using ten co-expressed genes: The following genes were identified: MCEMP1, FCGR1B, ANXA3, FAM20A, CYSTM1, GYG1, ARG1, SLPI, BMX and SMPDL3A. It was observed that infants of a younger demographic demonstrated a heightened degree of immunosuppression and pronounced innate immune activation in patients of severe symptoms with RSV infection. However, eosinophils exhibited minimal involvement in these processes. These gene models pertaining to the neutrophil, macrophage or mast cell was found to be a relatively effective predictor in patients of severe symptoms.

Introduction: Seroprevalence of antibodies for vaccine-preventable diseases (VPDs), due to vaccination or previous infection, can provide a more accurate estimate of immunity compared to vaccination coverage data alone. This study aimed to examine the seroepidemiology and spatial distribution of VPD seroprevalence in Samoa in 2018 and 2019.

Methods: Dried blood spot (DBS) samples were collected from two nationally representative community-based surveys of participants aged ≥5 years from the Surveillance and Monitoring to Eliminate Lymphatic Filariasis and Scabies from Samoa (SaMELFS) project. DBSs were tested using multiplex bead assays (MBAs) to detect antibodies against measles, rubella, diphtheria, and tetanus. Seroprevalence was estimated at the national and primary sampling unit (PSU) levels, and cluster analysis was completed using SaTScan.

Results: Overall, 8394 valid MBA results were analysed across 35 PSUs. The highest overall seroprevalence was observed for tetanus (91.0%; 95% CI: 90.2-91.7), followed by diphtheria (83.7%; 95% CI: 82.7-84.7), rubella (79.3%; 95% CI: 78.2-80.3), and measles (45.8%; 95% CI: 44.8-46.9) with substantial heterogeneity across PSUs. Clusters of seronegativity to measles (relative risk [RR]: 1.16, p < 0.001) and diphtheria (RR: 1.16, p < 0.001) were also identified.

Conclusions: These findings demonstrate significant variation in seroprevalence and pockets of low population immunity to multiple VPDs, highlighting the key advantage of an integrated rather than siloed approach. The relatively high seroprevalence to rubella suggests potential community transmission, emphasising the need to strengthen congenital rubella surveillance and improve vaccination coverage. Identifying low immunity to VPDs can provide an early warning to potential outbreak risk and support the Ministry of Health to target public health interventions in higher-risk areas.

Background: Tuberculosis (TB) remains a major global health problem, and the WHO central Africa region continues to bear the heaviest disease burden. Gabon is one of the high-TB-burden countries in the world; however, its national TB program performance remains weak despite financial support from international health agencies. Identifying and mapping high-TB- and multi-drug-resistant-TB (MDR-TB)-burden areas for targeted public health interventions was the objective of this study. Methods: A region-wide mixed method study was carried out, comprising ecological design and a desk review, with the use of medical records from TB diagnosis and care units in 12 health facilities located across the capital Libreville, Republic of Gabon, from 1 January through December 2022. Libreville is the region that bears the heaviest TB burden in Gabon. With the collaboration of the Agency for Space Studies and Observations (AGEOS, Gabon), collected data were transferred to and analyzed using QGIS software in order to develop satellite images. Results: In the Libreville health region, there were 4560 cases diagnosed in 2022, representing 77.9% of all cases in the country, with an annual incidence of 509 per 100,000. Spatial mapping of incident cases by county of residence showed that a large majority of the TB cases diagnosed at the CHUL care center in 2022 were from Nzeng-Ayong (range: 36-50 cases) and Owendo (26-35 cases), whereas higher TB incidence at the Nkembo care center was from Nzeng-Ayong (range: 356-455 cases) and Owendo (256-355 cases), followed by Nkembo, Akebe ville, Akebe Baraka, Akebe Plaine/plateau, Angondje, Angondje village, Charbonnages, Bikele, Pk11, Pk12, Pk9, Mindoube I, Mindoube II (66-255 cases), Sotega, and Nkok (46-65 cases). Other counties accounted for less than 45 TB cases. Considering MDR-TB cases, higher incidence was observed in Pk9 county, which accounted for six cases (14.6%), followed by Owendo, accounting for four (9.7%). Discussion: Findings suggest that Nzeng-Ayong and Owendo are high-TB-burden counties in Libreville, whereas Pk9 and Owendo counties are counties categorized as high-MDR-TB-incidence areas. They should be subject to targeted to public health interventions to enhance TB control in Libreville.

Background/Objectives: The USAID STOP Spillover project in Cambodia aimed to reduce the risk of zoonotic virus spillover from bats to humans in bat guano farming communities. Methods: Using participatory tools, such as Outcome Mapping and Trials of Improved Practices, a team of local experts and community members collaboratively designed, tested, and refined biosafety and hygiene practices that are acceptable and sustainable to mitigate the risk of bat-borne disease spillover. We tracked progress and rolled out interventions to promote the adoption of safe behaviors that strengthen the understanding of zoonotic disease and reinforce the adoption of safety practices among bat guano producers and their neighbors. The intervention's effectiveness was evaluated after three-month trials. Results: An improvement in knowledge, attitudes, and risk reduction practices was observed among participants. The primary motivators for adopting these measures were fear of disease, families' well-being, cost savings, and experience of the COVID-19 pandemic. Conclusions: The community-driven approach fostered a sense of ownership, enabling participants to find the best solutions for their circumstance for long-term sustainability of the intervention. The findings recommended continued community engagement, improved access to biosafety and hygiene resources, and reinforced routine zoonotic disease surveillance. This model can be applied to mitigate emerging infectious disease spillover risks in similar contexts.

This scoping review aimed to identify and synthesise spatially relevant environmental, demographic, and socio-economic factors associated with vector-borne diseases (VBDs) in Pacific Island Countries and Territories (PICTs), a region particularly vulnerable due to its ecological and climate diversity. A systematic search of PubMed, Scopus, and Web of Science was conducted in March 2025 with no time restrictions, yielding 3008 records. After applying the inclusion criteria, 21 studies were selected for analysis. Environmental factors such as temperature, precipitation, and land cover were consistently associated with increased burden of malaria, dengue, and lymphatic filariasis, while associations with elevation and flooding were mixed or inconclusive. Demographic factors, including population density and household composition, were found to be associated with disease occurrence, although the direction and the strength of these associations varied. Three studies reported a negative association between population density and disease outcomes, including lymphatic filariasis in American Samoa and dengue in New Caledonia. Spatial socioeconomic factors such as low income, unemployment, and limited education were positively correlated with disease burden, particularly lymphatic filariasis and dengue. These findings underscore the importance of spatial determinants in shaping VBD transmission across PICTs and highlight the utility of spatial risk mapping to inform geographically targeted vector control strategies. Notably, infrastructure, health care access, and intra-island mobility remain underexplored in the literature, representing critical gaps for future research. Strengthening surveillance through spatially informed public health planning is essential to mitigate disease burden in this climate-sensitive and geographically dispersed region.

Leishmaniasis is a severe parasitic disease transmitted by sandflies that affects both humans and animals, with clinical manifestations ranging from cutaneous lesions to life-threatening visceral involvement. Current treatments are limited by toxicity, high cost, and the emergence of drug-resistant strains, underscoring the need for safer and more effective therapeutic strategies. In this study, we investigated the antiparasitic potential of combining Amphotericin B, a drug commonly used for leishmaniasis treatment, with 1,10-phenanthroline-5,6-dione (phendione) coordinated to copper (Cu²⁺-phendione), an experimental coordination compound, against Leishmania amazonensis promastigotes. The combination markedly impaired parasite proliferation, disrupted ultrastructural integrity, and interfered with metabolic activity. Mechanistic analyses revealed the presence of autophagosomes and pronounced mitochondrial alterations in treated parasites, suggesting the induction of cellular stress and the disruption of essential survival pathways. In addition, the treatment reduced the association index with THP-1 cells, indicating a decrease in parasite infectivity. Collectively, these findings demonstrate that the combination of Cu²⁺-phendione and Amphotericin B exerts potent antiparasitic effects through multiple mechanisms. Our results also showed that Cu²⁺-phendione combined with AmB displayed an additive effect, although the isobologram suggested that certain ratios approached synergy. The results support the potential of this combination as a novel chemotherapeutic approach against leishmaniasis and provide a basis for future in vivo studies to evaluate safety, efficacy, and optimal dosing strategies.

To better understand recent adolescent (10-19 years) HIV trends in Central America, we analyzed routine data from countries supported by the United States President's Emergency Plan for AIDS Relief (PEPFAR): Guatemala, El Salvador, Honduras, Panama, and Nicaragua, over the period from October 2020 to September 2024. Key PEPFAR indicators included HIV testing, HIV positivity rates, new treatment initiations, advanced HIV disease (AHD) at diagnosis, viral load coverage (VLC), viral load suppression (VLS), and multi-month dispensing (MMD) uptake for children and adolescents living with HIV (CALHIV) from 10-19 years of age. Since October 2020, the number of HIV tests conducted among adolescents has increased; however, the positivity rate has remained stable at approximately 2%. The number of adolescents initiating treatment increased by 21%. At the same time, VLS has shown steady regional improvement (from 73% to 90%), though VLC is a persistent challenge (80%). Treatment interruption rates have been relatively stable, fluctuating between 2% and 3%. Advanced HIV is high in adolescents new to treatment (34%), especially among females (40%), though cluster of differentiation 4 (CD4) testing at diagnosis has only been collected recently and coverage is not complete. The high prevalence of AHD among adolescents underscores the need to reinforce earlier and more targeted interventions for adolescents, especially in countries with greater HIV prevalence such as Panama and Guatemala.