PLoS Neglected Tropical Diseases最新文献

Background: To inform a prospective cohort study five-year automated surveillance study, this study explores households and stakeholder perceptions of using drones for mosquito breeding site surveillance as part of dengue control strategies in Selangor, Malaysia. A qualitative design identified diverse perspectives across eight high-risk localities. Data were collected through 480 in-depth interviews with household heads, from a newly established cohort of households, and six key informant interviews with public health professionals. Participants were selected using typical case and expert sampling methods to ensure representation across socioeconomic and urban heterogeneity.

Methods: This study developed a conceptual framework integrating community-based vector control, public health technology adoption, and drone-assisted surveillance, structured into five stages: Inputs, Processes, Outputs, Outcomes, and Impacts. It was applied in Selangor, Malaysia, a dengue-endemic state, to assess the feasibility and perception of drone-based interventions. Data were collected through 480 in-depth household interviews and six key informant interviews with public health experts, using semi-structured formats. Thematic analysis was conducted using Braun and Clarke's approach to identify recurring patterns across technical, organizational, and social dimensions of implementation.

Results: Participants supported drone use when positioned as mosquito breeding site monitoring tools rather than personal surveillance. Transparent communication about purpose, data use, and operational boundaries was key to maintaining trust. Targeted use in known mosquito hotspots was preferred over random surveillance. Privacy concerns were minimal, and most households strongly supported using drones for surveillance of mosquito habitats to aid in dengue control. Many simply requested advance notice of flight schedules to stay informed and engaged.

Conclusions: Community motivation stemmed from a sense of collective responsibility, with most participants valuing their involvement as a contribution to neighborhood well-being. Trust, transparency, and consistent communication were identified as essential for long-term engagement and the success of the project. These findings underscore the importance of aligning innovation with local social dynamics and demonstrate the value of participatory approaches in public health surveillance technologies interventions.

Chagas disease, a neglected tropical disease, is endemic in the Amazon region, where oral transmission predominates. Autonomic nervous system (ANS) impairment is a recognized pathophysiological mechanism contributing to disease progression, including Chagas cardiomyopathy. This study aimed to assess ANS function in patients with acute Chagas disease from the Amazon, evaluating responses pre- and post-benznidazole treatment. We included 28 acute-phase patients and 20 healthy controls. Participants underwent comprehensive cardiac evaluations, including 12-lead ECG, echocardiogram, 24-hour Holter monitoring, treadmill stress testing, and 5-minute heart rate variability (HRV) assessment. HRV was analyzed across time, frequency, and nonlinear domains, with statistical comparisons performed between groups and within the patient cohort. The study population predominantly comprised individuals from rural Amazonian municipalities (89.3%), with oral transmission accounting for 85.7% of infections. While resting ECGs were normal in 60.7%, diffuse ventricular repolarization was the most common abnormality (21.4%). Before treatment, 24-hour HRV showed significant reductions in SDANN and SDNN, indicating sympathovagal imbalance. For 5-minute HRV, significant alterations were observed across time (rMSSD, SDNN), frequency (LF, HF, LF/HF ratio), and nonlinear domains, reflecting reduced parasympathetic tone. Intragroup comparisons (pre- vs. post-treatment) further reinforced the sustained sympathovagal imbalance and parasympathetic inhibition. These findings highlight persistent autonomic modulation alterations, characterized by sympathovagal imbalance and reduced parasympathetic activity, in acute Chagas disease patients from the Amazon. Such dysfunction may predispose individuals to long-term structural cardiac changes and arrhythmias, underscoring the critical need for continued monitoring and potential targeted interventions to address autonomic imbalance in this vulnerable population.

Background: The immunopathogenesis of dengue infection and immune correlates of protection are uncertain, no therapeutic anti-viral is available, and the long-term risks of severe breakthrough infection after vaccination remain of concern. Dengue controlled human infection models (DCHIM) have found increasing utility and have the potential to address these unmet needs. We reviewed the clinical, biochemical and immunologic features of modern day DCHIMs.

Methods: A systematic review protocol was developed and registered with PROSPERO [CRD42024558534]. We searched MEDLINE, Cochrane and Embase for controlled human infection studies using attenuated dengue virus strains from January 2000 - December 2025. No restriction was placed on study setting (dengue endemic/non-endemic) or whether the study was conducted in seronegative or seropositive individuals. The primary outcome was the proportion of inoculated participants who developed viraemia ('attack rate').

Results: Our search yielded 1181 results, and identified 11 published studies, recruiting 248 participants aged 18-55 years. All studies were performed in non-dengue endemic areas and were models of primary dengue. Four studies challenged previously vaccinated individuals, and one utilised DCHIM to assess antiviral efficacy. Attenuated dengue virus strains of all four DENV 1-4 serotypes were utilised as challenge agents. Attack rate across all serotypes was 50-100% in seronegative participants and 0-83% in previously vaccinated participants and was strain-dependent. Clinical and biochemical features of dengue fever varied between strains, with peak viral load and probability of fever being highly correlated (r = 0·91, p < 0·01). There were no serious adverse event reported, and 9 (4%) participants met protocol criteria for hospitalisation. Viral and/or immune evidence of disease enhancement was observed in 5/81 (7%) of challenged seropositive participants.

Conclusion: DCHIMs of primary dengue are a valuable and safe tool that has supported vaccine development. Further work is needed to expand DCHIMs to endemic settings and as a model of secondary dengue.

Background: This study systematically analyzed the prevalence of Hantavirus (HVs) in small mammals across Southeast Asia to evaluate the risks of this zoonotic disease.

Methods: We searched the Web of Science, PubMed, Embase, Scopus, and Cochrane Library for studies published up to 6 February 2025, extracted data from 28 eligible studies.

Results: Meta-analysis revealed a pooled prevalence of HVs was 6.07% (986/11,806) in small mammals in Southeast Asia, with the highest prevalence in Indonesia (17.49%) and Singapore (10.53%). The prevalence was higher in samples detected by Enzyme-Linked Immunosorbent Assay (10.68%) and in rodents (8.07%).

Conclusions: The results of our study highlight the urgency of strengthening surveillance in trade networks with Southeast Asia, particularly in high-risk areas such as Indonesia and Singapore, to mitigate the threat of imported zoonotic diseases.

Background: Hookworms remain problematic in Dak Lak province, Vietnam, despite a school preventive chemotherapy (PC) program since 2007. As hookworms depend on favourable ecological conditions, geospatial modelling incorporating environmental and climatic variables can predict high-risk areas for targeted interventions. This study provides geospatial risk predictions for hookworm infection and intensity among school-aged children in Dak Lak.

Methods: Hookworm infection status and intensity from 7,964 school-aged children from 64 schools collected in 2019-2020 during the Community Deworming for STH trial was combined with environmental and climatic data to develop risk prediction models for (i) overall hookworm infection and (ii) moderate-and-heavy intensity (MHI) Necator americanus infection. Environmental and climatic predictors for the multivariable generalised linear models were selected by identifying the model with the lowest Akaike Information Criterion. Semivariograms were examined for residual spatial autocorrelation, and if present, was accounted for using Matérn's covariance. Regression coefficients were used to predict overall hookworm and MHI N. americanus infection risk across Dak Lak province pre- and post-intervention.

Results: Temperature, precipitation, soil and vegetation variables were included in the hookworm model, while temperature and precipitation variables were included in the MHI N. americanus model. Most of Dak Lak had a predicted hookworm risk of 10-15% pre- and post-intervention, with high-risk hotspots in southern and eastern parts. Moderate-and-heavy intensity N. americanus infection risk pre-intervention was higher than 2% throughout the province and considerably reduced to small pockets in southeastern, central and northern areas post-intervention.

Conclusion: School-based PC should be delivered across Dak Lak at least annually, in keeping with World Health Organization recommendations. However, several hotspots have been identified that would benefit from increased frequency of school-based PC or community-wide mass drug administration.

Hepatitis E virus (HEV) remains a leading cause of acute viral hepatitis globally, particularly in South Asia and Africa. However, epidemiological prioritization is hampered by fragmented data and discordant disease burden estimates. Following JBI and PRISMA-Sc guidelines, we conducted a scoping review of global HEV evidence. We used the PCC framework: (P) general and high-risk populations (pregnant women, immunocompromised, and displaced groups); (C) quantitative estimates of burden, risk factors, or virological gaps; and (C) global evidence across all WHO regions to include studies. We searched PubMed, Scopus, and Web of Science, supplemented by country-specific searches in Google Scholar and IHME. From 11,583 citations, 395 articles met the inclusion criteria. The temporal distribution shows a marked increase in research volume, with 65.3% of studies published after 2010; however, 54.9% relied on observational descriptive designs while experimental investigations remained infrequent (4.3%). We identified three estimates of the global burden of HEV: the IHME Global Burden of Disease (GBD) published in 2021 (19.4 million cases) and two widely cited systematic reviews published in 2012 (20.1 million infections) and 2020 (939 million infections). A significant virological "blind spot" was observed, as 47.8% of studies did not report genotype information, though Genotype 3 (21.8%) was the most frequently identified among specified reports. Key risk domains identified were environmental (sanitation/water contamination) and cultural/occupational practices. Pregnant women, immunocompromised patients, and patients with pre-existing liver conditions were high at-risk populations. Key knowledge gaps identified were limited confidence in burden of disease estimates: severe molecular blind spots and evidence deserts, limited public health resources for surveillance, diagnostics, and reporting of cases and deaths in highest risk settings; exclusion of outbreaks from estimates of the burden of disease and unreliable convenience sample derived estimates. Hepatitis E virus is often neglected by international communities, global actors and national governments. However, it is difficult for stakeholders to prioritize a pathogen with highly variable and unreliable global burden of disease estimates. Comprehensive country level data based on more access to routine testing could facilitate global initiatives to devise strategies for equitable vaccination and mitigate the morbidity and mortality associated with this vaccine-preventable disease.

[This corrects the article DOI: 10.1371/journal.pntd.0013899.].

Ascomycetes belonging to the Histoplasma capsulatum species complex can cause severe manifestations in patients with disseminated histoplasmosis. Based on data from hemagglutination assays and histopathological findings related to H. capsulatum, we investigated their potential role in the disseminated intravascular hemagglutination events. Human erythrocyte hemagglutination was produced with H. capsulatum yeasts of 10 isolates/strains, belonging to different phylogenetic species and lineages. Hemagglutination assays were inhibited by pre-incubating their yeasts with β-galactose, ratifying previously published data for a unique H. capsulatum clinical strain. This lectin was partially purified through affinity chromatography using erythrocyte stroma, and its hemagglutinating activity was confirmed. Results underlined the consistent involvement of a β-galactose-binding lectin of H. capsulatum yeasts in hemagglutination assays by using genetically distinct H. capsulatum species, which support its conserved origin. Serendipitous findings in histopathological sections of human and bat tissues supported that H. capsulatum yeasts adhered to erythrocytes, consistent with intravascular hemagglutination. Hence, in hosts with disseminated histoplasmosis and sepsis, we hypothesized that this H. capsulatum lectin may favor an intravascular hemagglutination, which could occur concomitantly with a procoagulant state, aggravating hypoxia and leading to disseminated intravascular coagulation, a lethal complication.

Background: Scrub typhus and murine typhus, caused by Orientia tsutsugamushi and Rickettsia typhi, respectively, are important causes of febrile illness in Laos. Although several studies have assessed rickettsial infection in selected provinces, the nationwide distribution remains unclear. This study aimed to estimate exposure to scrub typhus group (STG) and typhus group (TG) across twelve provinces of Laos and identify potential hotspots.

Methodology: We screened 1,200 serum samples from blood donors (100 per province) for STG and TG IgG antibodies using enzyme-linked immunosorbent assays (ELISA). Samples with optical density ≥ 0.5 were confirmed by immunofluorescence assays (IFA).

Results: Overall seroprevalence was 7.26% (95%CI:5.93-8.87) for STG and 4.09% (95% CI:3.11-5.37) for TG. STG seroprevalence was highest in Huaphan (27%), Oudomxay (19%) and Xiangkhuang (17%), all in northern Laos. TG seroprevalence was 10% in both Oudomxay (north) and Attapue (south). Compared with Vientiane Capital, these provinces had significantly higher seropositivity. No significant association was observed with age group. STG seropositivity was higher in males, whereas TG seropositivity was higher in females.

Conclusion: Rickettsial infections are widespread in Laos, with STG seroprevalence concentrated in the north and TG seroprevalence present in both the north and south, guiding future research priorities and informing targeted public health interventions.