American Journal of Tropical Medicine and Hygiene最新文献

Rural Rwandan communities face health challenges for humans and animals, and the topography and climate of the Kirehe District of Rwanda put farmers at high risk for mosquito-borne diseases. Individuals from 92 Rwandan farms were surveyed about farm practices, as well as animal and human health histories between December 2017 and February 2018. Human, animal, and environmental factors were investigated to determine whether there is a pattern of risk for abortion incidence and/or history of malarial disease on the farm. Iterative, complementary logistic regression models were used to determine whether there was an association between variables and abortion history in animals. These factors were then used to investigate association with a reported history of malaria. Of the 92 farms in our study, 82 were family farms and 10 were commercial farms. On average, 88% of the farms had cattle, and 30% of farms had experienced a cattle abortion in the past 2 years. There was no observed statistical significance in the risk factors for history of abortion in cattle and the measured variables. Using One Health as a guiding framework, we sought to determine whether human, animal, and environmental factors were statistically associated with observed disease outcomes. From our study of the practices of the farmers with respect to biosafety and self-protection against disease, we have identified potential sources of risk that could be targeted to enhance education and protection on these farms.

Rodent malaria models serve as important preclinical antimalarial and vaccine testing tools. Evaluating treatment outcomes in these models often requires manually counting parasite-infected red blood cells (iRBCs), a time-consuming process, which can be inconsistent between individuals and laboratories. We have developed an easy-to-use machine learning (ML)-based software, Malaria Screener R, to expedite and standardize such studies by automating the counting of Plasmodium iRBCs in rodents. This software can process Giemsa-stained blood smear images captured by any camera-equipped microscope. It features an intuitive graphical user interface that facilitates image processing and visualization of the results. The software has been developed as a desktop application that processes images on standard Windows and MacOS computers. A previous ML model created by the authors designed to count Plasmodium falciparum-infected human RBCs did not perform well counting Plasmodium-infected mouse RBCs. We leveraged that model by loading the pretrained weights and training the algorithm with newly collected data to target Plasmodium yoelii- and Plasmodium berghei-infected mouse RBCs. This new model reliably measured both P. yoelii and P. berghei parasitemia (R2 = 0.9916). Additional rounds of training data to incorporate variances due to length of Giemsa staining and type of microscopes, etc., have produced a generalizable model, meeting WHO competency level 1 for the subcategory of parasite counting using independent microscopes. Reliable, automated analyses of blood-stage parasitemia will facilitate rapid and consistent evaluation of novel vaccines and antimalarials across laboratories in an easily accessible in vivo malaria model.

Melioidosis is an emerging tropical infectious disease with a rising global burden caused by the environmental bacterium Burkholderia pseudomallei. It is endemic in Southeast and South Asia, including Bangladesh. A rare aminoglycoside-susceptible B. pseudomallei isolate (Y2019) has recently been reported from a melioidosis patient in Dhaka, Bangladesh. To understand the geographical origins of Y2019, we subjected it and 10 other isolates from Bangladesh to whole-genome sequencing. In a phylogenetic tree with a global set of B. pseudomallei genomes, most Bangladeshi genomes clustered tightly within the Asian clade. In contrast, Y2019 was closely related to ST881 isolates from Sarawak, Malaysian Borneo, a gentamicin-sensitive sequence type, suggesting infection in Borneo. Y2019 also contained the same gentamicin sensitivity conferring nonsynonymous mutation in the drug efflux pump encoding the amrB gene. In the absence of a full travel history, whole-genome sequencing and bioinformatics tools have revealed the likely origin of this rare isolate.

Visceral leishmaniasis (VL) is endemic in Baringo County, Kenya, and contributes significantly to the burden of disease in the region. Housing structures and other environmental risk factors contribute to transmission dynamics, but these have not been specifically studied in Baringo. The aim of this study was to increase understanding of VL transmission in the region through determining relationships between VL infection, housing, and other environmental factors. Data collection occurred from February 1 to May 31, 2023 at Chemolingot Sub-County Hospital and patients' homesteads via questionnaires of primary VL patients being treated and VL follow-up patients who were still residing in the same house as when the infection occurred. Factors assessed were housing structures, proximity to vector breeding and resting sites, and prevention and control measure practices. A baseline assessment of housing types was conducted through direct ethnographic observation and used in the analysis. Forty-one patients were included in the study. A χ2 analysis and Fisher's test were used to determine association between VL infection and housing materials, where VL patient housing data were compared with the regional baseline assessment. Significant associations with VL infection were found between mud and stick walls (P <0.001); mud walls (P <0.001); mud, stick, and grass combination walls (P = 0.02); and stick and grass walls (P <0.001). Behavior comparison showed that most VL-protective behaviors were practiced by follow-up patients after infection. Results showed an increased need for VL prevention focusing on environmental factors.

A 4-year-old girl, previously treated with prednisolone and cyclosporin A due to autoimmune lymphoproliferative syndrome, presented with acute fever, progressive pancytopenia, intermittent abdominal pain, and acute episode of hematemesis. Esophagogastroduodenoscopy revealed diffuse erythematous gastric mucosa and blunt duodenal villi. Histopathology of the duodenal mucosa was notable for numerous acid-fast bacilli within foamy macrophages in the lamina propria, and nontuberculous Mycobacterium DNA was detected by polymerase chain reaction of duodenal tissue. Azithromycin, rifampicin, and ethambutol were started while waiting for species identification and drug susceptibility testing. Macrolide-resistant Mycobacterium intracellulare was demonstrated from blood culture, indicating disseminated infection. The patient died of overwhelming infection, despite receiving newly adjusted regimen (rifampicin, ethambutol, clofazimine, and amikacin). This case highlights the importance of considering disseminated Mycobacterium avium complex (MAC) in the differential diagnosis of immunocompromised, non-HIV patients presenting with gastrointestinal manifestations. Early identification of macrolide-resistant MAC is crucial for guiding appropriate treatment and potentially improve patient outcomes.

The COVID-19 pandemic has exerted a notable impact on worldwide health across diverse age groups. Although children and adolescents were initially considered less vulnerable, they have also shown susceptibility to the virus, emphasizing the importance of understanding associated risk factors. Epidemiological data reveal an increasing number of COVID-19 cases in this age group. The aim is to conduct a systematic assessment of the association between the level of vitamin D and COVID-19 infection in children and adolescents following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive literature search was performed across various databases up to October 7, 2023. Studies assessing laboratory-confirmed COVID-19 patients, the level of 25-hydroxyvitamin D in serum, and clinical outcomes were encompassed. Quality assessment was performed using the Newcastle-Ottawa Scale. Thirteen studies, conducted across six countries and involving 1,071 pediatric patients, were included. Vitamin D deficiency was prevalent among children and adolescents with COVID-19. Some studies suggested that vitamin D deficiency significantly increased the risk of COVID-19 infection and was linked to disease progression. Furthermore, deficiency in vitamin D demonstrated an association with increased levels of inflammatory markers, reduced lymphocyte counts, and heightened clinical symptoms, including fever and cough. Maintaining adequate vitamin D levels may be a crucial strategy for reducing COVID-19 severity and associated complications in children and adolescents. Nevertheless, there is a requirement for additional high-quality research to establish specific guidelines regarding vitamin D supplementation in this population amid the ongoing COVID-19 pandemic.

Multiplex-based serological surveillance is a valuable but underutilized tool to understand gaps in population-level exposure, susceptibility, and immunity to infectious diseases. Assays for which blood samples can be tested for antibodies against several pathogens simultaneously, such as multiplex bead immunoassays, can more efficiently integrate public health surveillance in low- and middle-income countries. On March 7-8, 2023 a group of experts representing research institutions, multilateral organizations, private industry, and country partners met to discuss experiences, identify challenges and solutions, and create a community of practice for integrated, multi-pathogen serosurveillance using multiplex bead assay technologies. Participants were divided into six working groups: 1) supply chain; 2) laboratory assays; 3) seroepidemiology; 4) data analytics; 5) sustainable implementation; and 6) use case scenarios. These working groups discussed experiences, challenges, solutions, and research needs to facilitate integrated, multi-pathogen serosurveillance for public health. Several solutions were proposed to address challenges that cut across working groups.

Antibiotic use in animals has been identified as a major contributing factor for antibiotic resistance. Given the limited access to veterinary services, the choice of antibiotic and the dosage are determined by the farmers. By analyzing prescription practices and their appropriateness, we can compare performance in antibiotic stewardship across regions to drive change toward national goals and to guide policy interventions. This study used an integrated approach to assess antibiotic use at the grassroots in a rural poultry-keeping community in Wakiso District, Uganda. Medical prescriptions of 347 outpatients were captured between September 2021 and November 2021 via systematic random sampling of patients attending a local health center and were reviewed to decode antibiotic use characteristics and patterns. In the same period, structured questionnaires were issued to 36 poultry farmers in the same area to obtain information on their antibiotic use practices. Of the 347 human outpatient prescriptions reviewed, 250 (72%) recommended at least one antibiotic at a mean of 1.7 antibiotics per prescription. Conversely, all the poultry farms reported antibiotic use. There was significantly more use of macrolides and tetracyclines on poultry farms than at the local health centers and more use of penicillins, nitroimidazoles, and cephalosporins in humans than in poultry. There is unregulated use of critically important antibiotics in poultry and a misuse of antibiotics in the health center due to the lack of adequate diagnostic services. There is a need to improve point-of-care diagnostics of both human and poultry diseases in this community to guide antibiotic use.

Mental health stigma remains a major global problem associated with low self-esteem, social withdrawal, and poor health-seeking behavior in individuals. However, limited published evidence details these challenges in Liberia. Knowledge of public perceptions toward mental illness and key trends in the associations between knowledge of mental, neurological, and substance use disorders (MNSs) and stigma is crucial to designing evidence-based mental health policies and supporting service delivery. This population-representative survey explored and quantified stigma related to MNSs in four health regions in Liberia, using a multistage stratified random sampling of 1,148 residents. Four internationally validated scales were used to assess knowledge, attitudes, and perceptions toward schizophrenia, bipolar disorder, epilepsy, and substance use disorder including the 1) Mental Health Attribution Questionnaire; 2) Five Question Stigma Indicator Questionnaire to assess Community Stigma; 3) Reported Intended Behavioral Scale; and 4) Personal Acceptance Level of Conditions. Data from interviews with 1,140 participants (96% response rate) were analyzed using central tendencies, hypothesis testing with simple logistic regression, and bivariate analysis for association between dependent and independent variables. Low mental health knowledge was found to be a strong predictor of discriminatory behaviors and stigma. Results revealed that exposure to movies or television significantly predicted increased discriminatory tendencies and that a lesser degree of acceptance was shown toward substance use disorder than any of the other conditions. These findings underscore the need for increased awareness and education about mental health to eliminate stigma and promote better care and inclusion for people living with MNSs.

Tuberculous meningitis (TBM) is a common infectious disease of the central nervous system. Detection of cerebrospinal fluid (CSF) adenosine deaminase (ADA) activity for the diagnosis of TBM has a relatively high accuracy. Most previous reports determined ADA levels by following the colorimetric method of Giusti (endpoint assay). Recently, a Diazyme ADA assay kit was developed to determine CSF ADA levels. This study aimed to define the cutoff value of CSF ADA that is diagnostic for TBM with the Diazyme ADA assay kit. Adults with meningitis were included in the study. The diagnostic properties of CSF ADA for TBM as determined by the Diazyme ADA assay kit were assessed by the receiver operating characteristic curve, area under the curve, sensitivity, specificity, and likelihood ratios. There were 97 patients enrolled in the study, comprising 15 cases of TBM and 82 cases of non-TBM meningitis. The median CSF ADA activity level in the TBM group was significantly higher than in the non-TBM group (P = 0.002), with a mean difference of 14.5 U/L (95% CI: 5.3-23.8 U/L). A CSF ADA level of 6.1 U/L was the best cutoff value to differentiate between the TBM and non-TBM groups, with a sensitivity of 53.33%, a specificity of 89.02%, a positive likelihood ratio of 4.86, a negative likelihood ratio of 0.52, and an area under the curve of 0.75. A CSF ADA level of 6.1 U/L determined by the Diazyme ADA assay kit could be used as a diagnostic tool in the early diagnosis of TBM.