Infectious Diseases of Poverty最新文献

Background: Phlebotomus chinensis is the primary vector of visceral leishmaniasis (VL) in China. However, the lack of a high-quality genome assembly for this species has limited research on its biology, vector-pathogen interactions, and evolutionary adaptations. To address this critical gap, the first chromosome-level genome assembly of Ph. chinensis was constructed.

Methods: Nanopore long-read sequencing served as the primary method, complemented by Illumina short-read sequencing for base-level error correction and Hi-C mapping for chromosomal anchoring and chromosome-level scaffolding. Genome annotation integrated transcriptome data from adult, larvae and pupae, homologous protein predictions from closely related sand fly species, and ab initio gene prediction. Comparative genomic analyses were further performed to explore evolutionary relationships and genomic differences between Ph. chinensis, Ph. papatasi, and Lutzomyia longipalpis.

Results: A total of 127.05 Gb of Nanopore data, 10.57 Gb of Illumina clean data, 52.95 Gb of Hi-C clean data, and 14.95 Gb of RNA-seq data were obtained. The final assembled genome size was 195.21 Mb with a scaffold N50 of 49.30 Mb, and 97.24% of the sequences were successfully anchored to 4 chromosomes. Annotation identified 10,909 protein-coding genes (91.48% of which were functionally annotatable), along with 73 rRNAs, 92 small RNAs, 82 regulatory RNAs, 374 tRNAs, 11,870 simple sequence repeats, 6053 tandem repeats, and 478,622 transposable elements. Phylogenetic analysis revealed that Ph. chinensis is phylogenetically closest to Ph. papatasi, with an estimated divergence time of approximately 27.1 million years ago. Gene family evolution was dominated by contraction, with 229 expanded and 575 contracted gene families identified in the Ph. chinensis branch. Additionally, 209 positively selected genes were detected, which are crucial for immune response regulation and metabolic processes related to its vectorial capacity. Furthermore, 95 P450 genes were identified, classified into four subfamilies: CYP2, CYP3, mitochondrial CYP (mito), and CYP4.

Conclusions: A high-quality chromosome-level genome assembly of Ph. chinensis is reported here for the first time. This assembly serves as a critical genomic resource to advance research into the vector biology, insecticide resistance mechanisms, and evolutionary history, and lays a solid foundation for the development of precision VL control strategies in China.

Background: While the agricultural sector is a known contributor to antimicrobial resistance (AMR), the potential role of food loss and waste (FLW) in AMR dissemination has been largely overlooked. FLW, a byproduct of inefficient food systems, poses economic, environmental, and food security challenges. It may also act as a reservoir and vector for antimicrobial resistance genes and antibiotic-resistant bacteria, contributing to the environmental spread of AMR if improperly managed. This narrative review assessed the presence, fate, and risks of AMR in FLW management.

Methods: Peer-reviewed studies were identified through systematic searches in PubMed and Web of Science using keywords related to food waste, AMR, and treatment methods. Additional studies were retrieved through reference screening. Only English-language articles addressing AMR in the context of FLW were included.

Results: Bioconversion processes such as composting, anaerobic digestion, and conversion to animal feed can reduce antimicrobial resistance genes and antibiotic-resistant bacteria under optimized conditions. However, without adequate treatment, end products like fertilizers or biomaterials may still pose AMR risks. In contrast, FLW disposal in landfills and open dumps exacerbates both greenhouse gas emissions and AMR risks, due to co-contamination with other AMR-promoting pollutants like heavy metals and microplastics. AMR can spread through multiple pathways, including leachate, aerosols, wildlife, and direct human contact.

Conclusions: FLW should be recognized as a potential AMR source, requiring improved management strategies and integration into AMR surveillance. This review highlights the need to both reduce antimicrobial use and minimize FLW generation to limit environmental and public health risks.

Schistosomiasis is a neglected tropical disease, affecting 253 million people worldwide. This study aimed to describe the clinical and epidemiological characteristics of schistosomiasis in sub-Saharan African migrants evaluated through a general screening program for imported infectious diseases at a specialized international health unit in Barcelona, Spain. We performed a retrospective observational study (2014-2023) including confirmed (defined by egg detection in stool or urine) and probable cases (identified by positive serology against Schistosoma). Data on epidemiology, clinical presentation, diagnosis, treatment, and follow-up were collected. Among 3214 screened migrants, 855 (26.6%) were diagnosed with schistosomiasis. Most were male (87%) with a median age of 21.9 years, mainly originating from Mali, Gambia, and Senegal. Only 2.2% reported symptoms, while anemia and eosinophilia were observed in 9.7% and 29.7% of cases, respectively. Parasitological confirmation was achieved in 24.9%, with the remainder diagnosed by serology alone. Abdominal ultrasound was performed in 122 patients, revealing abnormalities in 20.4%. Multivariate analysis showed that confirmed cases tended to be younger (22.4 years vs 25.8 years) and had higher frequencies of women (17.8% vs 11.3%), symptoms (5.6% vs 1.1%), eosinophilia (49.4% vs 22.5%), and ultrasound abnormalities (22.7% vs 17.8%) than probable cases. Praziquantel treatment was administered to 775 patients (90.6%). Follow-up information was available for 218 individuals (28.1%); among those, eggs persisted in 7.4% (9/122), and 84% (74/88) maintained positive serology. Schistosomiasis prevalence in this migrant population was high and mostly asymptomatic, with limited laboratory abnormalities but notable radiological findings, particularly in confirmed cases. Serology was useful diagnostically but had limited value in follow-up. Systematic screening of at-risk populations remains crucial for early detection and treatment.

Background: Countries in the Greater Mekong Subregion (GMS) have committed to eliminating malaria by 2030. The success of a national malaria programme's transition from malaria control to elimination is dependent on the readiness of the health system to implement malaria elimination strategies. Understanding the readiness of health systems and what needs to be adapted is key to identifying barriers in achieving malaria elimination goals. This study aims to assess health system needs for malaria elimination, identify national-level barriers to effective implementation, and provide recommendations for policymakers and programme managers to strengthen strategies through a health system perspective.

Methods: A multi-country qualitative study was conducted in the GMS. Semi-structured interviews were conducted with 39 stakeholders including national malaria policymakers (n = 5), basic health staff from Ministries of Health (n = 12), managers and field supervisors from malaria implementing partners (n = 16) and personnel from technical agencies (n = 6). Reflexive thematic analysis of national level health system requirements was carried out aligned with themes adapted from the World Health Organization (WHO) health system building blocks.

Results: Stakeholders discussed that malaria elimination required inputs from all six WHO health system building blocks at the national level. Major inputs included strong political commitment, targeted interventions for high-risk groups, reliable forecasting and supply chains, skilled workforce, and robust quality assurance. Furthermore, National Malaria Elimination Programmes should expand access to diagnostic kits and medicines and enforce mandatory glucose-6-phosphate dehydrogenase enzyme testing. Stakeholders identified health system barriers such as the lack of targeted interventions in high-risk groups in national policies, incomplete reporting from private sector, lack of experienced workforce for elimination, administrative constraints in supply chain, declining malaria funding from international donors, and poor compliance to regulations for malaria elimination. For malaria elimination in the GMS to succeed, comprehensive health system strengthening across all six building blocks is essential.

Conclusions: National programmes must assess national health system readiness for malaria elimination to avoid inefficiencies, financial strain, and unattended gaps, using a systems thinking approach. This study also highlighted the importance of evaluating the national programmes from the perspective of health system needs and readiness for successful transitioning from control to elimination phase.

This editorial, published on the occasion of the World Neglected Tropical Diseases Day in 2026, highlights the persistent and pressing issue of neglected tropical diseases (NTDs) and their impact on global health equity. It argues that addressing NTDs is not only a moral imperative but also a strategic necessity for achieving global health security and advancing the Sustainable Development Goals (SDGs). The editorial emphasizes the need for integrating NTD control strategies with the SDGs to leverage synergies and maximize impact. For instance, improving water and sanitation (SDG 6) directly contributes to the prevention of schistosomiasis. Additionally, the Pandemic Agreement, co-signed by member countries of World Health Organization in 2025, provides an opportunity to mainstream NTDs into health security planning, ensuring resilience against future outbreaks. The editorial concludes by calling for sustained action and increased investment in research and development, One Health approaches, and policy coherence to embed NTDs in pandemic preparedness and universal health coverage agendas. Achieving a future free from NTDs is possible, but it requires unwavering commitment, collaboration, and equitable resource allocation.

Background: The sterile insect technique (SIT) is an environmentally friendly tool for suppressing Aedes aegypti populations. While promising in controlled settings, its application in large urban environments presents logistical and biological challenges. This trial focused on releasing sterile males, sent from a long-distance production facility to suppress the local mosquito population.

Methods: Sterile males of Ae. aegypti were mass-reared, irradiated, and transported 712.2 km from a central facility to Recife, Brazil. Releases were performed once (SIT 1 ×) or twice per week (SIT 2 ×). Entomological indices-including eggs/trap per day (ETD), hatch rate, induced sterility, and adult female abundance-were monitored through ovitraps and BG-Sentinel traps. Data were analyzed using generalized linear mixed models (GLMMs) and Bayesian time-series modeling (CausalImpact).

Results: Dose-response experiments established that pupae required 35 Gy and adults 65 Gy to achieve > 99% sterility, with no difference between gamma and X-ray sources. Adult sterilization was effective across 24-96 h post-emergence, facilitating operational flexibility. Handling and transport reduced flight ability by up to 35 percentage points, highlighting cumulative stress effects. In field trials, SIT 1 × yielded limited suppression, with ETD values remaining similar to or higher than those of the control. In contrast, SIT 2 × produced consistent suppression, reducing ETD by 39%, hatch rate by 33%, and female abundance by 51%.

Conclusions: In this study, increasing the release frequency was essential to achieve significant model outcomes, representing varying degrees of mild suppression of Ae. aegypti in a complex urban setting. In Addition, male handling, chilling, and transport emphasize the need to reduce the exposure to these parameters by improving the protocols. These results highlight key areas for scaling SIT within integrated vector management strategies in tropical urban settings.

Background: Dengue remains a major public health challenge, particularly in endemic areas like Puerto Rico, where its economic burden is substantial. This study aimed to update the economic burden of dengue in Puerto Rico using recent data from patients, hospitals, and insurance companies, providing a clearer picture of the current situation. We estimated the total number of dengue cases with fever who sought care by adjusting for underreporting through a robust statistical framework linking island-wide passive surveillance data to sentinel acute febrile illness surveillance.

Methods: We obtained cost data from hospitals and conducted interviews with a random sample of people diagnosed with dengue (n = 101) from December 2021-November 2022, collecting detailed information on direct medical costs, non-medical costs, and indirect costs. We analyzed median, epidemic and long-term dengue incidence patterns from 2010-2023. We conducted a cost-of-illness analysis using Bayesian multiplier methods to adjust for underreporting, followed by a bottom-up costing approach during a typical median incidence year and an epidemic year to illustrate the current economic burden of dengue in Puerto Rico.

Results: In the median incidence year (2014), from 597 reported dengue cases we estimated 4500 [95% credible interval (95% CrI): 3700-5400] outpatient and 3900 (95% CrI: 3200-4700) hospitalized cases. During an epidemic year (2010), these figures rose substantially from the reported 10,359 dengue cases to an estimated 77,300 (95% CrI: 64,600-93,200) outpatient and 67,300 (95% CrI: 56,100-81,700) hospitalized cases. The median cost per hospitalized dengue case was 5200 USD for children and USD 6800 for adults, while outpatient costs were 2300 USD for children and 2700 USD for adults. Direct medical costs and indirect costs constituted the largest share of total costs. The total economic burden was 1.1 billion USD (95% CrI: 785 million-1.6 billion) during the epidemic year, compared to 62.7 million USD (95% CrI: 45.9-95.4 million) in the median incidence year.

Conclusions: These findings highlight the considerable financial strain of dengue, particularly during epidemics, and underscore the urgent need for enhanced resource allocation, effective prevention strategies, and policy interventions to mitigate the economic impact of future outbreaks.

Background: Leptospirosis is endemic in the Philippines; however, its diagnosis remains challenging because of the lack of rapid and accurate diagnostic tools for detecting infection. Physicians must therefore resort to diagnosing leptospirosis through their clinical judgement, and this often results in under- or overestimation of cases. This study aimed to assess and compare the diagnostic accuracy of physicians' clinical judgement and commercially available rapid test kits for leptospirosis against reference methods such as the microscopic agglutination test (MAT) and real-time polymerase chain reaction (qPCR) in the Philippines.

Methods: A total of 127 serum samples were collected from patients suspected to have leptospirosis at three hospitals in the Philippines from August to December 2024. Rapid test kit results and final diagnoses were retrieved from the patients' charts. MAT was performed on all the samples as a confirmatory method. Moreover, qPCR was performed on 30 randomly selected samples to increase the sensitivity of the reference standard. Sensitivity, specificity, positive and negative predictive values, and 95% confidence intervals were computed to determine the accuracy of both clinical judgement and rapid tests.

Results: Among the 75 MAT-confirmed leptospirosis cases, approximately 24.0% were misdiagnosed as other febrile illnesses, such as dengue and typhoid fever, on the basis of clinical judgement, whereas 67.3% of the 52 MAT-negative patients were falsely diagnosed with leptospirosis. Overall, clinical judgement demonstrated high sensitivity (76.0%) but low specificity (33.7%), indicating possible overdiagnosis. The rapid test kits used in the laboratory exhibited significantly lower sensitivity (42.7%) but higher specificity (82.7%), suggesting a high probability of false-negative results. When qPCR was used in conjunction with these methods, relatively similar results were obtained.

Conclusions: These findings highlight the diagnostic limitations in detecting leptospirosis in the Philippines, where laboratory testing options remain limited and inaccurate, resulting in physicians often relying on their clinical judgement. Misdiagnosis, whether through clinical judgement or rapid testing, could lead to inappropriate patient management, increased morbidity, and underestimation of leptospirosis incidence.

Background: Hookworm infection remains a major public health concern in the Lao People's Democratic Republic (Lao PDR), where it is endemic nationwide and particularly prevalent in remote communities. However, information regarding species-specific identification is limited. This study aimed to determine the prevalence of hookworm infection and identify the infecting species among humans, dogs, and cats in both northern and southern regions of the Lao PDR.

Methods: A cross-sectional study was conducted between May and July 2023 in Luangprabang Province (northern Lao PDR) and Champasak Province (southern Lao PDR). All residents aged 18 years and older who were present during the survey period and met the inclusion criteria were enrolled. In addition, dogs and cats owned by enrolled participants and/or their household members were included. Hookworm infection was detected by identifying eggs in preserved stool samples using the formalin-ethyl acetate concentration technique (FECT). Species identification was performed using polymerase chain reaction (PCR) targeting the internal transcribed spacer (ITS) region to amplify Necator americanus (485 bp) and Ancylostoma spp. (380 bp), followed by sequencing analysis of stool samples preserved in 70% ethanol. Descriptive statistics summarized hookworm prevalence in humans, dogs, and cats. Chi-square, Wilcoxon rank-sum, and Kruskal-Wallis tests compared rates and means, with significance defined as P < 0.05.

Results: A total of 382 human participants, along with 37 dogs and 9 cats, completed all study procedures and were included in the analysis. Examination of preserved stool samples using FECT detected hookworm infection in 24.1% of humans (southern region: 36.6%; northern region: 11.8%) and in 76.1% of dogs and cats combined, with the highest prevalence observed in the southern region (92.6%). Molecular analysis identified N. americanus as the predominant species in humans (64.6%), followed by A. ceylanicum (20.5%). Among dogs and cats, N. americanus and A. caninum were each detected in 39.1% of samples, while A. ceylanicum accounted for 13.0%.

Conclusions: This study demonstrates a high prevalence of zoonotic hookworm infections in humans, dogs, and cats, highlighting the potential for interspecies transmission that complicates current prevention and control measures. Implementation of integrated control strategies-such as the One Health approach-that simultaneously address human and animal reservoirs is essential for achieving effective and sustainable hookworm control in the Lao PDR.

Background: Anopheles mosquitoes pose notable public health concerns as competent vectors of malaria and other diseases. Although malaria is no longer endemic in the United States, recent locally acquired cases in states including Maryland highlight the need to better understand Anopheles dynamics in the region. This study aimed to identify geographic hotspots of Anopheles presence in Maryland and evaluate how land cover, microclimatic conditions, and socioeconomic vulnerability shape their spatial and temporal distribution.

Methods: Monthly Anopheles occurrence data (1999-2024) from Global Biodiversity Information Facility (GBIF) were aggregated at county and Census Block Group (CBG) scales. Counties were ranked by mean annual presence to identify hotspots. Associations with land cover, microclimatic, and socioeconomic conditions were assessed using Spearman's rank correlation (ρ; P < 0.05). At the CBG scale, significantly correlated variables (|ρ| ≥ 0.25) were used to fit an Extreme Gradient Boosting model to quantify the relative importance of environmental and socioeconomic predictors. Spatial dependence was addressed through blocked cross-validation, and model interpretability was evaluated with SHapley Additive exPlanations (SHAP) values.

Results: Prince George's and Anne Arundel Counties emerged as primary hotspots of presence with highest observer effort during the analysis period. Seasonal analysis revealed an annual cycle, with peak presence from May to September, coinciding with warmer conditions favorable to vector proliferation. SHAP analysis at the CBG-scale identified habitat availability as the most influential predictor (33.1% of total model impact for low impervious surface percentage) with woody wetland emerging as the most preferred habitat; followed by humid conditions (24.6%), and low elevation (18.2%). Notably, cooler and more humid microclimates within the warm season provide optimal habitat, reflecting fine-scale environmental controls on Anopheles distribution. Therefore, CBG-level analysis within Prince George's County revealed a negative correlation between Area Deprivation Index and Anopheles presence (ρ = -0.35), indicating fine-scale ecological drivers-such as woody wetland habitat, low impervious surface, and humid cooler microclimates-more prevalent in affluent suburban residential neighborhoods.

Conclusions: This study demonstrates that fine-scale habitat characteristics and warm-season microclimates structure Anopheles mosquito presence in Maryland. These insights support more spatially targeted vector control and improved public health surveillance strategies.