Infectious Diseases of Poverty最新文献

Background: Clonorchiasis and opisthorchiasis, caused by the liver flukes Clonorchis sinensis and Opisthorchis viverrini respectively, represent significant neglected tropical diseases (NTDs) in Asia. The co-existence of these pathogens in overlapping regions complicates effective disease control strategies. This study aimed to clarify the distribution and interaction of these diseases within Southeast Asia.

Methods: We systematically collated occurrence records of human clonorchiasis (n = 1809) and opisthorchiasis (n = 731) across the Southeast Asia countries. Utilizing species distribution models incorporating environmental and climatic data, coupled machine learning algorithms with boosted regression trees, we predicted and distinguished endemic areas for each fluke species. Machine learning techniques, including geospatial analysis, were employed to delineate the boundaries between these flukes.

Results: Our analysis revealed that the endemic range of C. sinensis and O. viverrini in Southeast Asia primarily spans across part of China, Vietnam, Thailand, Laos, and Cambodia. During the period from 2000 to 2018, we identified C. sinensis infections in 84 distinct locations, predominantly in southern China (Guangxi Zhuang Autonomous Region) and northern Vietnam. In a stark contrast, O. viverrini was more widely distributed, with infections documented in 721 locations across Thailand, Laos, Cambodia, and Vietnam. Critical environmental determinants were quantitatively analyzed, revealing annual mean temperatures ranging between 14 and 20 °C in clonorchiasis-endemic areas and 24-30 °C in opisthorchiasis regions (P < 0.05). The machine learning model effectively mapped a distinct demarcation zone, demonstrating a clear separation between the endemic areas of these two liver flukes with AUC from 0.9 to1. The study in Vietnam delineates the coexistence and geographical boundaries of C. sinensis and O. viverrini, revealing distinct endemic zones and a transitional area where both liver fluke species overlap.

Conclusions: Our findings highlight the critical role of specific climatic and environmental factors in influencing the geographical distribution of C. sinensis and O. viverrini. This spatial delineation offers valuable insights for integrated surveillance and control strategies, particularly in regions with sympatric transmission. The results underscore the need for tailored interventions, considering regional epidemiological variations. Future collaborations integrating eco-epidemiology, molecular epidemiology, and parasitology are essential to further elucidate the complex interplay of liver fluke distributions in Asia.

Background: Schistosomiasis is highly endemic in sub-Saharan Africa and frequently imported to Europe. Male urogenital manifestations are often neglected. We aimed to ascertain the prevalence of genitourinary clinical signs and symptoms among long-term African migrants in a non-endemic European country using a serology test.

Methods: We carried out a prospective, community-based cross-sectional study of adult male migrants from sub-Saharan Africa living in Spain. Schistosoma serology tests and microscopic urine examinations were carried out, and clinical data were obtained from an electronic medical record search and a structured questionnaire.

Results: We included 388 adult males, mean age 43.5 years [Standard Deviation (SD) = 12.0, range: 18-76]. The median time since migration to the European Union was 17 [Interquartile range (IQR): 11-21] years. The most frequent country of origin was Senegal (N = 179, 46.1%). Of the 338, 147 (37.6%) tested positive for Schistosoma. Parasite eggs were present in the urine of only 1.3%. Nine genitourinary clinical items were significantly associated with positive Schistosoma serology results: pelvic pain (45.2%; OR = 1.57, 95% CI: 1.0-2.4), pain on ejaculation (14.5%; OR = 1.85, 95% CI: 1.0-3.5), dyspareunia (12.4%; OR = 2.45, 95% CI: 1.2-5.2), erectile dysfunction (9.5%; OR = 3.10, 95% CI: 1.3-7.6), self-reported episodes of infertility (32.1%; OR = 1.69, 95% CI: 1.0-2.8), haematuria (55.2%; OR = 2.37, 95% CI: 1.5-3.6), dysuria (52.1%; OR = 2.01, 95% CI: 1.3-3.1), undiagnosed syndromic STIs (5.4%), and orchitis (20.7%; OR = 1.81, 95% CI: 1.0-3.1). Clinical signs tended to cluster.

Conclusions: Urogenital clinical signs and symptoms are prevalent among male African long-term migrants with a positive Schistosoma serology results. Genital involvement can be frequent even among those with long periods of non-residence in their sub-Saharan African countries of origin. Further research is needed to develop diagnostic tools and validate therapeutic approaches to chronic schistosomiasis.

Background: The 2022-2023 mpox (monkeypox) outbreak has spread rapidly across multiple countries in the non-endemic region, mainly among men who have sex with men (MSM). In this study, we aimed to evaluate mpox's importation risk, border screening effectiveness and the risk of local outbreak in Chinese mainland.

Methods: We estimated the risk of mpox importation in Chinese mainland from April 14 to September 11, 2022 using the number of reported mpox cases during this multi-country outbreak from Global.health and the international air-travel data from Official Aviation Guide. We constructed a probabilistic model to simulate the effectiveness of a border screening scenario during the mpox outbreak and a hypothetical scenario with less stringent quarantine requirement. And we further evaluated the mpox outbreak potential given that undetected mpox infections were introduced into men who have sex with men, considering different transmissibility, population immunity and population activity.

Results: We found that the reduced international air-travel volume and stringent border entry policy decreased about 94% and 69% mpox importations respectively. Under the quarantine policy, 15-19% of imported infections would remain undetected. Once a case of mpox is introduced into active MSM population with almost no population immunity, the risk of triggering local transmission is estimated at 42%, and would rise to > 95% with over six cases.

Conclusions: Our study demonstrates that the reduced international air-travel volume and stringent border entry policy during the COVID-19 pandemic reduced mpox importations prominently. However, the risk could be substantially higher with the recovery of air-travel volume to pre-pandemic level. Mpox could emerge as a public health threat for Chinese mainland given its large MSM community.

Background: Brucellosis is a severe zoonotic disease that is often overlooked, particularly in impoverished countries. Timely identification of focal complications in brucellosis is crucial for improving treatment outcomes. However, there is currently a lack of established indicators or biomarkers for diagnosing these complications. Therefore, this study aimed to investigate potential warning signs of focal complications in human brucellosis, with the goal of providing practical parameters for clinicians to aid in the diagnosis and management of patients.

Methods: A multi-center cross-sectional study was conducted in China from December 2019 to August 2021. The study aimed to investigate the clinical characteristics and complications of patients with brucellosis using a questionnaire survey and medical record system. The presence of warning signs for complications was assessed using univariate and multivariate logistic regression models. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used for variable screening and model evaluation.

Results: A total of 880 participants diagnosed with human brucellosis were enrolled. The median age of the patients was 50 years [interquartile range (IQR): 41.5-58.0], and 54.8% had complications. The most common organ system affected by complications was the osteoarticular system (43.1%), with peripheral arthritis (30.0%), spondylitis (16.6%), paravertebral abscess (5.0%), and sacroiliitis (2.7%) being the most prevalent. Complications in other organ systems included the genitourinary system (4.7%), respiratory system (4.7%), and hematologic system (4.6%). Several factors were found to be associated with focal brucellosis. These factors included a long delay in diagnosis [odds ratio (OR) = 3.963, 95% confidence interval (CI) 1.906-8.238 for > 90 days], the presence of underlying disease (OR = 1.675, 95% CI 1.176-2.384), arthralgia (OR = 3.197, 95% CI 1.986-5.148), eye bulging pain (OR = 3.482, 95% CI 1.349-8.988), C-reactive protein (CRP) > 10 mg/L (OR = 1.910, 95% CI 1.310-2.784) and erythrocyte sedimentation rate (ESR) elevation (OR = 1.663, 95% CI 1.145-2.415). The optimal cutoff value in ROC analysis was > 5.4 mg/L for CRP (sensitivity 73.4% and specificity 51.9%) and > 25 mm/h for ESR (sensitivity 47.9% and specificity 71.1%).

Conclusions: More than 50% of patients with brucellosis experienced complications. Factors such as diagnostic delay, underlying disease, arthralgia, eye pain, and elevated levels of CRP and ESR were identified as significant markers for the development of complications. Therefore, patients presenting with these conditions should be closely monitored for potential complications, regardless of their culture results and standard tube agglutination test titers.

Background: Tuberculosis is one of the most significant infectious diseases for global public health. The reallocation of healthcare resources and the restrictions imposed by the COVID-19 pandemic have hindered access to TB diagnosis and treatment. Increases in unfavorable outcomes of the disease have been observed in Brazil. The objective of this study was to analyze the spatial distribution of unfavorable TB treatment outcomes in Brazil before and during the pandemic.

Methods: An ecological study with spatial analysis was conducted with all 5569 municipalities in Brazil. All reported cases of tuberculosis between January 2010 and December 2021, as well as reported cases of COVID-19 from February 2020 to December 2021, were included. The outcomes studied encompass loss to follow-up, drug-resistant tuberculosis, and death. The Getis Ord GI* technique was employed to assess spatial association, and the Kernel density estimator was used to identify areas with concentrated increases or decreases in outcomes. Bivariate Local Moran's I was used to examine the spatial association between outcomes and COVID-19 incidence. The study was approved by the Research Ethics Committee of Ribeirão Preto Nursing School, University of São Paulo.

Results: There were 134,394 cases of loss to follow-up, 10,270 cases of drug resistance, and 37,863 deaths. Clusters of high and low values were identified for all three outcomes, indicating significant changes in the spatial distribution patterns. Increases in concentrations were observed for lost to follow-up cases in the Southeast, while reductions occurred in the Northeast, South, and Midwest. Drug-resistant tuberculosis experienced an increase in the Southern and Southeastern regions and a decrease in the Northeast and South. TB-related deaths showed notable concentrations in the Midwest, Northeast, South, and Southeast. There was an increase in high occurrence clusters for deaths after 2020 and 2021 in the Northeast.

Conclusions: The pandemic has brought additional challenges, emphasizing the importance of enhancing efforts and disease control strategies, prioritizing early identification, treatment adherence, and follow-up. This commitment is vital for achieving the goal of tuberculosis elimination.

Background: The World Health Organization recommends the use of Schisto point-of-care circulating cathodic antigens (Schisto POC-CCA) for screening of Schistosoma mansoni as it offers better sensitivity than microscopy. However, there are limitation facing the use of this method including timely availability of the test cassettes. The aim of this study was to determine the reliability of dried urine spot (DUS) method for collection of urine and detection of S. mansoni using Schisto POC-CCA cassettes in a resource-limited settings.

Methods: A cross-sectional study was conducted between October and November 2022 among 250 primary school children in Sengerema District, northwestern Tanzania. S. mansoni CCA was detected in filter paper-based DUS, liquid urine using DUS Schisto POC-CCA (index), and direct urine Schisto POC-CCA (comparator) methods respectively. S. mansoni eggs in stool were detected using duplicate Kato-Katz (KK) method. The measures of accuracy were computed and compared between the index and comparator methods. The strength of agreement between inter-raters precisions was tested using Cohen's kappa (k).

Results: This study revealed S. mansoni prevalence rates of 28.8%, 54.0% and 50.8% by duplicate KK, direct urine Schisto POC-CCA and DUS Schisto POC-CCA methods respectively. The mean intensity of infection among infected participants was 86.3 eggs per gram of stool (EPG) ranging from 12.0 EPG to 824.0 EPG. The sensitivity of DUS Schisto POC-CCA and direct urine Schisto POC-CCA was 94.44% (95% CI: 89.15-99.74%) and 97.22% (95% CI: 93.43-100.00%) respectively. The DUS Schisto POC-CCA method had slightly higher specificity (66.85%) than direct urine Schisto POC-CCA method (63.48%). The accuracy of the DUS Schisto POC-CCA was found to be slightly high (74.80%, 95% CI: 68.94-79.06%) compared to that of direct urine Schisto POC-CCA (73.20%, 95% CI: 67.25-78.59%). There was good agreement between two laboratory technologists who performed the DUS Schisto POC-CCA method on similar samples (k = 0.80, 95% CI: 0.59-0.95).

Conclusions: The DUS Schisto POC-CCA method had comparable S. mansoni detection accuracy to direct urine Schisto POC-CCA. This suggests that the method could be a potential alternative to direct urine Schisto POC-CCA for screening S. mansoni in resource-limited situations.

Background: Current soil-transmitted helminth (STH) control guidelines endorse the use of albendazole or mebendazole for school-based targeted preventive chemotherapy (PC), yet their reduced efficacy against Strongyloides stercoralis and Trichuris trichiura presents significant limitations. Emerging evidence indicates that community-wide PC [or mass drug administration (MDA)] using ivermectin, commonly used in other neglected tropical disease (NTD) control programs, may play an important role in controlling these parasites. We conducted a systematic review and meta-analysis to evaluate the effectiveness of ivermectin PC in reducing STH prevalence in endemic populations.

Methods: We searched Pubmed, EMBASE, and Web of Science on February 14, 2023, for studies that investigated the effectiveness of ivermectin PC, either alone or in combination with other anthelmintic drugs, on STH infections, and provided a measure of STH prevalence before and after PC. We calculated pooled prevalence reductions for each STH using random-effects meta-analyses. Our protocol is available on PROSPERO (registration number CRD42023401219).

Results: A total of 21 were eligible for the systematic review, of which 15 were eligible for meta-analysis. All studies delivered ivermectin through MDA. The pooled prevalence reduction of S. stercoralis following MDA with ivermectin alone was 84.49% (95% CI 54.96-94.66) across five studies and 81.37% (95% CI 61.62-90.96) across seven studies with or without albendazole. The prevalence reduction of T. trichiura was 49.93% (95% CI 18.23-69.34) across five studies with ivermectin alone, and 89.40% (95% CI 73.66-95.73) across three studies with the addition of albendazole. There was high heterogeneity for all syntheses (I² > 65%).

Conclusions: This study underscores the key role of ivermectin-based MDA in addressing limitations in current global STH guidelines in terms of limited efficacy against S. stercoralis and T. trichiura. Based on these findings, revising international STH guidelines to include ivermectin is a promising option to progress the control and eventual elimination of STHs and other NTDs.

Many countries have adopted higher-valent pediatric combination vaccines to simplify vaccination schedules and minimize health expenditures and social costs. However, China is conservative in the use of pediatric combination vaccines. By reviewing and synthesizing quantitative and qualitative data, in this commentary we identify gaps and challenges to combination vaccine use and make recommendations for promoting use of higher-valent pediatric combination vaccines in China. Challenges are in four dimensions: (1) legislation and regulation, (2) immunization schedule design, (3) vaccine awareness and price, and (4) research and development capacity. To optimize the use of combination vaccines to reduce vaccine-preventable disease burden, we make recommendations that address key challenges: (1) develop policies and regulations to strengthen enforcement of the Vaccine Administration Law and remove regulatory hurdles that hinder combination vaccine research and development, (2) establish an evidence-informed policy-making mechanism for combination vaccines, (3) resolve immunization schedule conflicts between monovalent and combination vaccines, and (4) implement effective interventions to increase vaccine awareness and reduce price.

Background: Anthrax is a non-contagious zoonotic disease caused by the Gram-positive, spore-forming bacterium Bacillus anthracis. Infection is common in livestock and wild animals such as cattle, goats, sheep, camels, and antelopes. In humans, anthrax may occur after contact with contaminated carcasses or animal products like milk and meat. The best method to prevent anthrax in people is to ensure livestock are vaccinated, which significantly limits the risk of zoonotic spread to humans. However, the rate of vaccination of domesticated animals kept by nomadic pastoralists in West Africa is low. These groups regularly cross over national boundaries with their grazing herds. Nigeria is a country that historically has done comparatively well to contain this public health threat. However, in 2023 several outbreaks of human disease appear linked to the consumption of anthrax-contaminated animal products brought into Nigeria by pastoralists from neighboring countries. Clinical manifestations include skin sores or ulcers, nausea, vomiting, and fever. This article aims to raise awareness of recent outbreaks of anthrax in West Africa and to call for a renewed focus on measures to combat this neglected public health concern to the region.

Main body: The imperative to pinpoint pivotal issues relating to the ongoing emergence of anthrax cases in Nigeria cannot be overstated. By delving into the prevalence of anthrax in both livestock and human populations residing along Nigeria's borders, unraveling the genetic diversity and potential sources of B. anthracis strains, and identifying the primary animal host(s) responsible for transmission, we stand to enhance our understanding of this critical issue. Furthermore, investigating the multifaceted factors contributing to anthrax transmission, assessing community knowledge and practices, mapping common migratory routes of pastoralists, and formulating targeted intervention strategies tailored to the challenges of border communities, are each crucial steps towards effective control and prevention.

Conclusion: Closing these knowledge gaps on anthrax is not only essential for safeguarding both animal and human health but also for fostering sustainable and resilient communities. Addressing research questions on these interdisciplinary concerns will undoubtedly pave the way for informed decision-making, proactive measures, and a more secure future for Nigeria and its border regions.