Journal of Tropical Medicine最新文献

Mosquitoes, notorious for their deadly impact as disease vectors, also hold economic value owing to their roles in disease transmission. The present study focuses on the importance of understanding mosquito gut microbiota for implementing innovative vector control strategies, thereby mitigating disease transmission. The study was conducted in the Gampaha Medical Office of Health (MOH) area of Sri Lanka with the focus of elucidating the microbial diversity within the midgut of Culex quinquefasciatus, a crucial step to support ongoing paratransgenesis efforts. Sampling was performed by utilizing standard mosquito sampling techniques and their midgut homogenates were plated on Plate Count Agar to isolate bacteria, which were then identified through biochemical tests. Subsequently, the most abundant bacterial families were subjected to DNA extraction, PCR amplification, and gene sequencing for species identification. The study revealed the presence of four bacterial families (Staphylococcaceae, Streptococcaceae, Neisseriaceae, and Moraxellaceae) in adult mosquitoes, while larvae harbored an additional family, Micrococcaceae. Interestingly, the relative distribution of midgut bacteria varied significantly among field-caught larval and adult strains from different study areas (chi-square = 1.673; P < 0.05), indicating similar bacterial flora across mosquito life stages and geographical locations. Of particular interest is the identification of Lysinibacillus sphaericus, a bacterium with potential for paratransgenesis applications. Given the high mosquito density in the study area, leveraging paratransgenesis for Cx. quinquefasciatus control is recommended. Furthermore, insights into gut microbes could inform the integration of gut microflora from modified strains into existing Sterile Insect Technique (SIT) and Incompatible Insect Technique (IIT) approaches in Sri Lanka.

Background: Schistosomiasis is a common public health problem throughout the world and Schistosoma mansoni is the most prevalent species in Africa. Most endemic countries use the Kato-Katz (KK) stool smear examination for diagnosis, mapping, and monitoring of intervention programs. However, its poor sensitivity calls for an urgency to evaluate and use more accurate diagnostic tools, of which detection of circulating cathodic antigen (CCA) in urine seems promising.

Methods: Studies published until May 2022 were searched from PubMed, Google Scholar, and grey literature for systematic review and meta-analysis following the PRISMA guideline. Eligible studies were selected based on preset inclusion and exclusion criteria. Quality of included studies was assessed using the QUADAS-2 tool. Heterogeneity between studies was assessed using Cochrane Q test and I ² test statistics. Data were analyzed using Review Manager 5.4.1 and Meta-DiSc 1.4 software programs.

Results: Thirty-seven studies published in 29 papers and enrolling 21159 study participants were included for analysis. Overall analysis of Point-of-Care Circulating Cathodic Antigen (POC-CCA) test against KK reference standard revealed a pooled sensitivity and specificity of 0.86 (95% CI: 0.85-0.87) and 0.66 (95% CI: 0.65-0.67), respectively. Subgroup analysis among 24 studies comparing single POC-CCA with test single KK revealed a high sensitivity (0.88) but low specificity (0.66). Based on findings of 24 studies, the area under the curve (AUC) for the systematic receiver operating characteristic (SROC) curve was 0.7805, indicating that the POC-CCA test effectively separates those with the disease from those who do not have it. Higher sensitivity estimates of 0.93 and 0.90 were reported when comparisons were made between test results of 2 urine and 1 stool samples, and 3 urine and 3 stool samples, respectively. Single POC-CCA test resulted in a pooled sensitivity estimate of 0.81 (95% CI: 0.78-0.84) as evaluated by the polymerase chain reaction (PCR) reference test.

Conclusions: The POC-CCA test has higher sensitivity than KK and may serve as a routine diagnostic alternative for disease diagnosis, mapping, and monitoring of interventions. However, its accuracy should further be evaluated at different transmission settings and infection intensity.

Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality worldwide. It also contributes significantly to hospital admissions, particularly in low-income countries such as Ethiopia, where it accounts for major public health problems. This could be attributed to the increasing prevalence of antibiotic-resistant pathogens in CAP patients. This study aimed to identify and assess the antibiotic resistance patterns of bacterial isolates from CAP patients at the Adama Hospital Medical College in Adama City, Ethiopia. A cross-sectional study was conducted from November 10, 2022, to November 30, 2023. Demographic, clinical data, and sputum samples were collected from patients with CAP (n = 369). Sputum samples were subjected to standard microbiological procedures, including culture, Gram staining, and a panel of different biochemical tests for the identification of pathogenic bacterial isolates. The Kirby-Bauer disc diffusion method was used for drug susceptibility testing. Descriptive statistics were computed by using SPSS (version 26). Of the 369 patients with CAP, bacterial pathogens were identified in 31.7% (n = 117, 95% CI: 27.0%-36.7%). The most common isolates were Moraxella catarrhalis (n = 15; 12.8%), Staphylococcus aureus (n = 15; 12.8%), Klebsiella pneumoniae (n = 12; 10.3%), Escherichia coli (n = 11; 9.4%), Pseudomonas aeruginosa (n = 11; 9.4%), Enterobacter species (n = 11; 9.4%), and Citrobacter species (n = 11; 9.4%). Among the identified isolates, resistance rates were high in Enterobacteriaceae, followed by Gram-positive bacteria, and non-Enterobacteriaceae. Overall, 68 (58.1%) of the identified bacterial isolates were multidrug resistant (MDR), with K. pneumoniae accounting for the highest proportion of multidrug resistant isolates (91.7%), while P. aeruginosa accounted for the lowest proportion (9.1%) of MDR isolates. This study revealed a high prevalence (31.7%) of bacterial pathogens in CAP patients and higher (58.1%) MDR bacterial pathogens. Therefore, regular surveillance and monitoring systems are warranted for assessing predominant pathogens and antibiotic resistance patterns.

Background: Neglected tropical diseases (NTDs) are a heterogeneous group of medical conditions that commonly occur in underprivileged populations. NTDs are primarily diagnosed in tropical areas. Although South Africa is not situated in a tropical region, the high poverty rate makes the country susceptible to some NTDs. Limited data are available on the burden of NTDs in the Free State province of South Africa. This study aimed to determine the number of NTDs diagnosed on histopathological specimens in the public sector of the Free State province over a six-year period and to evaluate the patient demographics.

Methods: A retrospective, descriptive study was performed. All NTDs diagnosed in histopathological specimens from public sector hospitals in the province submitted to the Department of Anatomical Pathology, National Health Laboratory Service, and University of the Free State between 1 January 2015 and 31 December 2020 were included in the study. The demographic information, biopsy site, and referring hospital were noted for each case identified.

Results: A total of 72 NTDs were diagnosed. The five most common diagnoses were echinococcosis (n = 33; 45.8%), bilharzia (n = 13; 18.1%), leprosy (n = 9; 12.5%), mycetoma (n = 8; 11.1%), and intestinal worms (n = 5; 6.9%). Ten (30.3%) patients diagnosed with echinococcosis came from the Free State's neighbouring country, Lesotho.

Conclusion: Echinococcosis was the most prevalent NTD diagnosed in central South Africa. We recommend that the South African Department of Health add echinococcosis to the principal NTDs of significance in South Africa, alongside soil-transmitted helminths, schistosomiasis, leprosy, and rabies.

This review summarizes the predatory potential of Toxorhynchites mosquitoes as biological control agents for Aedes vectors. A single larva can consume hundreds of mosquito larvae during its development, with preference for larger prey and higher consumption rates at higher prey densities. Studies suggest Toxorhynchites can significantly reduce Aedes populations. Beyond direct predation, they may indirectly influence prey behavior and adult mosquito lifespan. Despite the demonstrably positive effects of Toxorhynchites species as biocontrol agents, there are acknowledged limitations that require further investigation. These limitations include potential variations in effectiveness across diverse habitats and mosquito developmental stages. Additionally, long-term ecological sustainability and potential ramifications warrant further research. Future efforts should prioritize optimizing rearing and release strategies to enhance effectiveness. Exploring the potential for combined control methods with other biocontrol agents or traditional methods is also crucial. Finally, investigating the influence of environmental factors on predation rates can further refine and optimize the application of Toxorhynchites in mosquito control programs.

Methods: We systematically searched the PubMed, Web of Science, African Journals Online, Embase, Cochrane Library, and Google Scholar databases for studies conducted up to March 1, 2023, that estimated the prevalence of HBV in Tanzania based on HBV surface antigen measurements. The DerSimonian-Laird random effects model was used to estimate the overall prevalence of HBV with 95% confidence intervals (CIs). Potential sources of heterogeneity were also investigated.

Results: Thirty-one studies with a total sample size of 37,988 were included in the meta-analysis. The overall average HBV prevalence estimate in Tanzania was 6.91% (95% CI = 5.18-8.86%). Subgroup analysis revealed the highest prevalence in the northern zone (9.32%, 95% CI; 2.24-20.36%), among the blood donors (18.72%, 95% CI: 17.43-20.05%) and among the community volunteers (8.76%, 95% CI: 4.55-14.15%). The lowest prevalence was observed in the lake zone at 4.66% (95% CI: 3.49-5.99) and in pregnant women at 4.72% (95% CI: 3.42-6.21). The overall between-study variability showed significant heterogeneity (I ² = 97.41%, P < 0.001).

Conclusions: Our results showed that Tanzania is a country with moderately high HBV endemicity, with large interregional differences and significantly high numbers of HBV infections within the community. This underscores the need for immediate development of targeted prevention strategies and further epidemiological studies to better understand the pattern of the disease.