Infectious Diseases of Poverty最新文献

Background: Zoonotic diseases remain a significant public health challenge in China. This study examines the temporal trends, disease burden, and demographic patterns of major zoonoses from 2010 to 2023.

Methods: This study analyzed data from China's National Notifiable Infectious Disease Reporting System (NNIDRS, 2010-2023) on nine major zoonoses, including echinococcosis, brucellosis, leptospirosis, anthrax, leishmaniasis, encephalitis (Japanese encephalitis), hemorrhagic fever, rabies, and schistosomiasis. Joinpoint regression was applied to assess annual trends in incidence rates, while autoregressive integrated moving average (ARIMA) and exponential smoothing models were used to forecast incidence trends from 2024 to 2035. To assess the performance of the Global Burden of Disease (GBD) 2021 model in China, disease-specific multipliers-defined as the ratio of GBD estimates to national surveillance data-along with their corresponding 95% confidence intervals (CIs) were calculated to quantify discrepancies and evaluate the consistency between modeled estimates and empirical observations.

Results: From 2010 to 2023, the incidence rates of leptospirosis [average annual percent change (AAPC) = - 5.527%, 95% CI: - 11.054, - 0.485], encephalitis (AAPC = - 16.934%, 95% CI: - 23.690, - 11.245), hemorrhagic fever (AAPC = - 5.384%, 95% CI: - 7.754, - 2.924), rabies (AAPC = - 20.428%, 95% CI: - 21.076, - 19.841), and schistosomiasis (AAPC = - 28.378%, 95% CI: - 40.688, - 15.656) showed a declining trend in China. In contrast, brucellosis exhibited a modest but statistically significant increase (AAPC = 0.151%, 95% CI: 0.031, 0.272). For most diseases, incidence rates were consistently higher in males than females. Children aged 0-5 years accounted for a substantial proportion of encephalitis and leishmaniasis cases, while adults aged 14-65 years represented the primary affected group across the majority of diseases. Occupationally, farmers and herders were the most affected populations. Compared to national surveillance data, the GBD 2021 model substantially overestimated the burden of zoonotic diseases in China, particularly for echinococcosis (by 3.611-7.409 times) and leishmaniasis (by 3.054-10.500 times).

Conclusion: The study revealed significant decline in several major zoonoses in China, while brucellosis showed a continued upward trend. These findings highlight the urgent need for a One Health-based prevention and control system to interrupt cross-species transmission and reduce long-term public health risks.

Background: Seasonal patterns of mycobacterial infections affecting humans and animals remain a complex and understudied aspect of infectious disease dynamics. These intra-annual patterns are increasingly relevant in the context of global climate change, which may influence the timing and geographic spread of these diseases. A better understanding of such patterns could improve surveillance, prevention, and control strategies.

Methods: We conducted a mixed-methods bibliometric review combining bibliographic searches and scoping analysis to synthesize decades of research on the seasonality of mycobacterial infections in humans and animals. We systematically searched three major scientific databases-Scopus, PubMed-MEDLINE, and Web of Science-for articles published between 1971 and April 2023. From an initial dataset of 1830 unique articles, we identified and analysed 122 studies that met predefined inclusion criteria. We extracted information on pathogen type, statistical methods, geographic location, and host species. In addition, we conducted a co-citation network analysis to identify key methodological influences and research clusters.

Results: The retained studies encompassed tuberculosis, Buruli ulcer, bovine tuberculosis, and other mycobacterial diseases such as leprosy and Johne's disease. Most articles focused on tuberculosis in humans, followed by Buruli ulcer caused by Mycobacterium ulcerans. There was a marked increase in studies on seasonal trends in tuberculosis and Buruli ulcer over time, with notable variation in geographic and methodological coverage. Research was heavily concentrated in the northern hemisphere, especially in China, while southern regions remained underrepresented. Advanced statistical tools, including generalized linear models and time-series analyses, were instrumental in detecting seasonality, particularly for tuberculosis and Buruli ulcer.

Conclusion: Seasonality appears to be a common yet understudied feature of many mycobacterial infections. Greater interdisciplinary collaboration and the use of appropriate analytical tools are essential to better understand these patterns, especially in underrepresented regions. Addressing methodological and geographic gaps will be crucial to improve responses to these diseases in a changing global environment.

Background: Dirofilaria immitis and D. repens are mosquito-borne nematodes with dogs as primary hosts, but other mammalian species including humans can be also infected. In the last century, circulation of both pathogens was predominantly restricted to Southern Europe. However, different studies indicated a potential establishment in Central, Eastern and Western parts of Europe as an increasing threat to animal and human health. Therefore, we conducted a systematic literature review of Dirofilaria data in Europe to give a comprehensive overview of potential mosquito vectors and vertebrate hosts, including the collection of different metadata (e.g. sampling year and site), allowing to analyse the spread pattern of the parasites in Europe.

Methods: On 24 January 2022, we conducted a systematic literature review of all available publications in the PubMed database reporting D. immitis and D. repens screening in mosquitoes and mammalian vertebrates in Europe. We only included acute infection of Dirofilaria spp., i.e. excluding studies only screening antibodies, and in addition noted the travel history and the accuracy of the sampling locations. These data were used to analyse the range of potential vectors and hosts and for a comparison of the spatial distribution between the twentieth and twenty-first century.

Results: Both nematodes appear to have a high overlap of Aedes, Anopheles and Culex as potential vector species, which are abundant in Europe. Most published D. immitis infections were reported in dogs, while D. repens predominantly were reported in humans. Dirofilaria immitis infections were detected in a wider range of wild and zoo animals. Compared to the last century, many more countries especially in Central Europe were affected by Dirofilaria spp. circulation, illustrating a significant spread over the last 20 years.

Conclusions: Our findings suggest that D. immitis and D. repens are a growing health concern for animals and humans in Europe. Continuous globalisation and climate warming will probably lead to a further spread and increased circulation in the future. All data are made available open access, which will enable further analysis.

Background: The World Health Organization recommends seasonal malaria chemoprevention (SMC) using sulfadoxine-pyrimethamine and amodiaquine (SPAQ) to prevent malaria among children aged 3-59 months in regions with marked seasonality of malaria transmission. Socioeconomic disparities in household malaria prevention within the SMC context remain uncharacterized. This study aimed to construct a household wealth index and examine its association with SMC implementation, children malaria infection, and malaria prevention practices in South Sudan.

Methods: We utilized data from repeated cross-sectional household surveys conducted in Aweil County in 2022, involving 2767 households. The survey included asset-based questions tailored to the local context. We constructed a 12-item wealth score scale based on asset ownership using Mokken scale analysis and calculated weighted scores using multiple correspondence analysis to obtain wealth index quintiles. Survey-weighted logistic regressions were performed to assess the association of household wealth index quintiles with SMC implementation, children malaria infection, and malaria prevention practices.

Results: The constructed 12-item wealth scale demonstrated strong internal consistency (Cronbach's alpha = 0.72). However, households in the lower wealth quintiles (1st quintile) had lower odds of ownership of mosquito nets compared with those in the 3rd quintile [odds ratio (OR) = 0.12, 95% confidence interval (CI): 0.05-0.26, P < 0.001)]. Households in the highest wealth quintile (5th quintile) had higher odds of access to alternative malaria prevention tools (e.g., repellents) compared with the 3rd quintile (OR = 2.75, 95% CI: 1.30-5.83, P = 0.010). However, household wealth was not significantly associated with SMC implementation (household visits by SMC boma distributors, child receipt of Day 1 SPAQ, and caregiver SMC knowledge) or malaria infection outcomes within SMC context.

Conclusions: The new wealth index tailored to South Sudan is a useful tool for assessing socioeconomic health determinants. While household access to SMC showed a low degree of wealth-associated disparities, reflecting the equitable coverage of the door-to-door SMC delivery model, significant inequities remain in household access to other malaria prevention practices, such as mosquito nets. These findings imply the need for strategies to enhance equity in distributing essential malaria prevention resources.

Background: The rapid increase in the number of monkeypox cases poses a considerable threat to the international community, necessitating sensitive, fast, and available diagnostic methods. Therefore, the objective of this study was to develop a rapid, sensitive and simple method with high clinical applicability.

Methods: We developed a simple, rapid point-of-care assay to detect monkeypox virus (MPXV) using multienzyme isothermal rapid amplification (MIRA) coupled with the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas13a system. The detection system was optimized by synthesizing plasmids, and the detection sensitivity was explored by the continuous dilution of the plasmid. We validated the accuracy of this assay on 202 clinical MPXV samples and 104 interference samples through the kappa test. The visual interpretation of the results was realized by combining the assay with lateral flow strips. In addition, we developed a PCR-based method to identify MPXV Clades I and II, and the accuracy was tested through a kappa test on 202 clinical monkeypox samples and 104 interference samples.

Results: Our assay achieved an analytical sensitivity of 14.4 copies/ml and high selectivity, as it differentiated MPXV from three other Orthopoxvirus species. The clinical testing results for 202 monkeypox samples and 104 interference samples demonstrated 100% sensitivity and specificity. Compared with quantitative PCR (qPCR), three samples tested as positive using our assay, which showed that the performance of this assay was superior to that of the qPCR assay. Combined with lateral flow strips, its availability and simplicity provide an alternative point-of-care diagnostic method for MPXV testing in remote settings and resource-poor areas. The results of 32 clinical samples showed that lateral flow strips had a high detection sensitivity and could identify samples with Ct value of 39 as positive. The clade identification assay detected as few as 200 copies/ml within 40 min and no cross-reaction was observed between Clades I and II. The clinical samples tested were all Clade II, which was consistent with the circulating clade in the Chinese mainland.

Conclusions: The MIRA-CRISPR-Cas13a-MPXV system offers a rapid, sensitive and specific approach for monkeypox diagnosis, with significance for monitoring monkeypox epidemics. The clade identification assay based on PCR could accurately distinguish Clade I from Clade II within 40 min and can be implemented for high-throughput operation.

Background: Malaria continues to pose a significant health challenge, particularly in low-resource settings (LRS), where access to reliable and timely diagnostics is often limited. In this context, point-of-care (POC) in vitro diagnostics (IVDs) play a key role in supporting early detection and treatment. The aim of this scoping review was to better understand the landscape of malaria IVD technologies, with the aim of identifying both their strengths and limitations to guide and accelerate the development of POC diagnostics suitable for endemic regions and LRS. To support this analysis, the ASSURED (Affordability, Sensitivity, Specificity, User-friendliness, Rapidity, Equipment-free, Deliverability) criteria were applied to rank each technology in terms of its potential for POC applications in LRS.

Methods: A literature search was conducted in PubMed and Web of Science for original research articles on malaria POC diagnostic devices published in English over the last 20 years (2003-2023). Records were screened based on eligibility criteria. For each paper, we identified biomarkers, biological specimens used, analytical methods, and readout technologies. Each record was ranked from low to high for its compatibility with the seven ASSURED criteria and for the Technology Readiness Level.

Results: The final dataset included 118 records. Of the methods considered, immunoassays were the most frequently reported (41.5%), followed by loop-mediated isothermal amplification (LAMP, 22.8%), polymerase chain reaction (PCR, 6.7%) and optical microscopy (4.2%). The limit of detection was highest for LAMP and PCR. Biomarkers employed for diagnosis included the Plasmodium parasite, parasite protein antigens and hemozoin. Blood was the most commonly employed biological specimen (76.2%), followed by urine and saliva (5.1%). Despite a focus on malaria IVDs for POC applications, only 8% of the records mentioned ASSURED criteria, with most studies manifesting low compatibility with the criteria.

Conclusions: Although meeting the ASSURED criteria remains challenging, microscopy is still the gold standard because of its diagnostic accuracy. Recent developments in low-cost, high-magnification lenses and innovative manufacturing techniques have enabled the production of microscopy devices in LRS. Combined with advancements in image processing and shape recognition through machine learning, there is strong potential for intellectual and economic investments to enhance microscopy for POC malaria diagnostics.

Background: Toxoplasma gondii, an intracellular parasitic protozoan, which infects almost all warm-blooded animals, including humans, causes toxoplasmosis. However, we lack effective drugs and vaccines to control toxoplasmosis, representing a clinical challenge. Therefore, safe and effective vaccines are urgently needed. In this study, a self-replicating mRNA vaccine comprising four T. gondii antigens: ROP18, TGME49_237490, TGME49_268230, and MIC13, named 4x-mRNA-LNP (lipid nanoparticle), was developed, and its protective efficacy was evaluated in mice.

Methods: The expression of this vaccine in eukaryotic Human embryonic kidney 293 T (HEK-293 T) cells and mouse myoblast (C2C12) cells were analyzed, followed by enzyme-linked immunosorbent assay (ELISA) evaluation of the elicited humoral immune response. Subsequently, the vaccine-triggered immune responses in mice were detected, including antibody titers, T lymphocyte subsets, and cytokine levels. Finally, its immunoprotective effects were evaluated after challenging mice with T. gondii PRU oocysts or tachyzoites of different strains and analyzing the pathological changes, parasite loads, and mouse survival time. Western blotting and ELISA confirmed the successful eukaryotic expression and immunogenicity of 4x-mRNA, respectively. Statistical analyses, including the log-rank (Mantel-Cox) test, Student's t-test, and one-way ANOVA, were performed using GraphPad Prism software.

Results: Mice vaccinated with 4x-mRNA-LNP generated higher levels of IgG1 and IgG2a antibodies (P < 0.05) and cytokines (IL-2, IL-4, IL-10, IL-12, IFN-γ) (P < 0.05) compared with the control group. The high specific IgG titer was maintained for at least 10 weeks after the last vaccination. The proportion of CD3⁺CD4⁺ T cells and CD3⁺CD8⁺ T cells also increased significantly (P < 0.05), along with increased spleen cell proliferation in 4x-mRNA-LNP-vaccinated mice. Notably, limited pathological changes and < 10 fg of parasites/mg were found in the immunized mice tissues post-pathogen challenge. During observation for 30 days, 4x-mRNA-LNP-immunized mice survived significantly longer under challenge with lethal doses of RH, ME49, or WH6 tachyzoites (survival rates = 60%, 80%, and 60%, respectively). Following PRU oocyst challenge, vaccinated mice had notably decreased cyst burdens (72.5%, P < 0.05) compared with control mice.

Conclusions: The 4x-mRNA-LNP vaccine triggered effective long-term antibody levels in mice, thus representing a promising candidate to further develop anti-toxoplasmosis vaccines.

Background: Despite being key components of global tuberculosis policy, poverty reduction and social protection interventions have been inconsistently implemented. We aimed to characterise how poverty and interrelated personal risk factors increase tuberculosis risk in Peru to inform the design of locally appropriate, person-centred, equity-oriented interventions.

Methods: We undertook a case-control study among people aged 15 years and over in 32 communities in Peru between 2016 and 2019. Cases (n = 2337) were people diagnosed with any form of tuberculosis. Controls (n = 981) were people living in randomly selected households in the same communities. We derived measures of household poverty from three dimensions (physical, human, and financial capital) and investigated the associations between these; personal risk factors more specifically linked to health (e.g. smoking); and tuberculosis. We used logistic regression to calculate adjusted odds ratios (aOR), 95% confidence intervals (95% CI), and population attributable fractions (PAF). A directed acyclic graph was used to inform the analytical approach.

Results: Household poverty was strongly associated with tuberculosis (aOR = 3.1; 95% CI: 2.3-4.2 for people from the 'poorer' versus 'less poor' half of households). There was a non-linear social gradient across deciles of household poverty, with odds of tuberculosis increasing exponentially as poverty deepened (aOR = 12.6; 95% CI: 6.8-23.2 for the 'poorest' decile versus the 'least poor' decile). Overall, tuberculosis burden could be halved by reducing poverty in the 'poorer' half of households to the level of the 'less poor' half (PAF = 47%; 95% CI: 40-54). For key personal risk factors, we estimated PAF for alcohol excess (PAF = 12.3%, 95% CI: 7.2-17.2); underweight (PAF = 10.3%, 95% CI: 8.7-11.8); smoking (PAF = 8.8%, 95% CI: 3.8-13.5); HIV (PAF = 5.7%, 95% CI: 4.6-6.7); and diabetes (PAF = 4.6%, 95% CI: 3.3-6.0). We also identified other important risk factors including previous tuberculosis (PAF = 14.8%, 95% CI: 11.6-17.9); incarceration (PAF = 9.5%, 95% CI: 6.8-12.1); and lower social capital (PAF = 4.1%, 95% CI: 2.6-5.6). Most personal risk factors, particularly education and substance misuse, tuberculosis exposures (e.g. incarceration and homelessness), and undernutrition, exhibited a social gradient across quintiles of household poverty and were more prevalent in people living in poorer households (Cochran-Armitage test for linear trend P < 0.001 for variables showing these social gradients).

Conclusions: Interventions addressing multidimensional household poverty and interrelated personal risk factors could substantially reduce tuberculosis burden. Our results provide an evidence base for designing person-centred, equity-oriented interventions; and support more effective implementation of poverty reduction and social protection within the global tu

Background: The seasonal cycle of the influenza virus causes substantial morbidity and mortality globally. The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the circulation of influenza viruses can influence influenza-associated excess mortality. Given the few studies that have explored this topic, the objective of this study was to evaluate influenza-associated excess mortality in the Chinese mainland from 2012 to 2021 and quantify the changes from 2020 to 2021 compared with 2012-2019.

Methods: Using data from national influenza surveillance report and disease surveillance points, we fitted a generalized additive model on all-cause (AC), pneumonia & influenza (P&I), and respiratory (R) mortality rates. In this model, we included data of influenza activity (A/H1N1, A/H3N2 and B), temperature, absolute humidity, the COVID-19 pandemic, and time trends. The excess mortality was estimated by subtracting the fitted baseline mortality from the predicted mortality, which set influenza activity to zero.

Results: The respiratory mortality model explained more than 90% of the variance, indicating the good performance. We found that the influenza-associated mortality was generally decreasing from 2020 to 2021, for instance, influenza A/H1N1-associated excess respiratory mortality (ERM) decreased from 2.62 per 100,000 persons (95% confidence interval: 0.16-5.21) to 0.31 (0.02-0.60) in the northern region and from 3.79 (0.09-7.05) to 0.24 (0.02-0.46) in the southern region between 2012-2019 and 2020-2021. A similar pattern was observed for A/H3N2-associated ERM. While the influenza B remained similar scale, for instance, the ERM was 2.90 (0.72-4.3) and 2.26 (1.76-2.76) in the southern region between 2012-2019 and 2020-2021, respectively. Distinct pattern was observed for the AC and P&I outcomes.

Conclusions: The COVID-19 pandemic has reduced influenza-associated excess mortality, which may be a result of the reduced activity of the influenza virus caused by nonpharmaceutical interventions. Different patterns of regional differences differed for influenza-associated AC, P&I and R mortality. It should be noticed that the contribution of influenza B was generally similar when comparing 2012-2019 and 2020-2021, which highlighted the attention on the influenza B activity. Additional studies are needed to explore the changes in influenza-associated excess mortality afterwards.

Background: Poverty, disease, and vector ecology intersect to present ongoing health threats, particularly in ecologically sensitive regions. Guizhou Province in China, with its complex karst topography and rich biodiversity, offers a unique environment to study mosquito-borne viral transmission. Despite over 5000 reported cases of Japanese encephalitis in the past two decades and the detection of Zika virus in 2016, the virological landscape of this region remains poorly understood. This study aims to characterize the mosquito-associated virome, assess viral diversity, and identify factors influencing transmission dynamics in Guizhou Province.

Methods: Between 2021 and 2022, we conducted a 2-year mosquito surveillance across eight ecologically distinct regions in Guizhou Province. Adult mosquitoes were collected using a variety of methods, including BG Mosquitaire CO₂ traps, mosquito-killing lamps, manual collection, human bait traps, and oviposition traps. To investigate the virome diversity and dynamics within mosquito populations, we performed metagenomic sequencing and bioinformatics analysis on pooled mosquito samples collected from geographically diverse sampling sites.

Results: We collected more than 40,000 adult mosquitoes, primarily belonging to four genera: Aedes, Anopheles, Armigeres, and Culex. Dominant species included Aedes albopictus, Anopheles sinensis, Armigeres subalbatus, and Culex tritaeniorhynchus. Notably, we report the first provincial record of the Anopheles baileyi complex, expanding the known distribution of mosquito vector in this region. Viral metagenomic sequencing, coupled with bioinformatic analysis, identified 162 viral contigs, including 140 known and 22 previously uncharacterized viruses. We experimentally confirmed the genotypes of three medically important zoonotic viruses: Japanese encephalitis virus (JEV-GI), Getah virus (GETV-GIII) and Banna virus (BAV-A2). Comparative analysis of viral abundance across mosquito species revealed that Aedes albopictus populations in Guizhou harbor a distinct virome composition, diverging from those reported in other geographic regions.

Conclusions: This study presents the comprehensive characterization of the mosquito-associated virome in Guizhou Province, providing critical insights into viral diversity, vector competence, and transmission dynamics within karst ecosystems. The detection of multiple zoonotic viruses highlights the need for strengthened surveillance and targeted public health interventions in this region.