Transactions of The Royal Society of Tropical Medicine and Hygiene最新文献

Background: Snakebite is a priority neglected tropical disease, but incidence data are lacking; current estimates rely upon incomplete health facility reports or ad hoc surveys. Spatial analysis methods harness statistical associations between case incidence and spatially varying factors to improve estimates. This systematic review aimed to identify variables associated with snakebite risk in spatial and temporal analyses for inclusion in geospatial studies to improve risk estimation accuracy.

Methods: We searched MEDLINE, Global Health, PubMed and Web of Science in January 2023 for studies published since 1980 assessing snakebite outcomes and spatially varying factors at the setting level. Study quality was assessed using an adapted Joanna Briggs Institute tool. The results are presented by narrative synthesis.

Results: Thirty-five studies were eligible; the majority were from Central and South America (18), then Asia (11). Climate and environment were most frequently assessed, with temperature, humidity and tree cover predominantly positively associated with snakebite risk, drought negatively associated and altitude negative/mixed. Crop and livestock variables mostly showed positive associations; population density and urban residence overwhelmingly displayed negative associations.

Conclusions: This review identifies key variables that should be considered in future snakebite risk research. Limitations include low research availability from the highest risk regions. There is an evident need for greater research into snakebite risk variation, particularly in sub-Saharan Africa.

Background: Certain micronutrient levels have been associated with the risk of developing TB disease. We explored the possible association of selected at-risk micronutrient levels with the development of Mycobacterium tuberculosis (M.tb) infection.

Methods: This cohort study in Bandung, Indonesia, followed Interferon Gamma Release Assay (IGRA) negative TB case contacts with a repeat IGRA test at 3 mo. At baseline, blood was analysed for haemoglobin, 25-hydroxyvitamin D, retinol-binding protein, C-reactive protein, alpha-1-acid glycoprotein, serum transferrin receptor (sTfR), ferritin, zinc and selenium. Total body iron was calculated using ferritin and sTfR status. Associations between case contact micronutrient concentration and IGRA conversion were estimated using Poisson regression.

Results: Of 430 contacts, 115 (27%) underwent IGRA conversion. Ferritin concentration (adjusted for inflammation) was positively associated with risk of IGRA conversion (incidence rate ratio [IRR] for ferritin=1.17; 95% CI 1.01 to 1.35; p=0.03), but other select micronutrients were not. This association held for ferritin in the final multivariable model (IRR=1.27; 95% CI 1.09 to 1.47; p=0.002).

Conclusions: The risk of developing M.tb infection, as defined by IGRA conversion, is associated with increasing ferritin. Interventions in TB case contacts to temporarily reduce iron levels, including considering withholding any iron supplementation, may be worthy of evaluation.

Background: Determining esophageal and colon involvement in patients with Chagas disease occurs through invasive and uncomfortable examinations, which in most cases are not performed. The objective of this study was to assess the involvement of anti-M2-pyruvate kinase (M2-PK) autoantibodies in the development of digestive alterations and/or in the diagnosis of the digestive form of human Chagas disease.

Methods: The total IgG and isotype (IgG1, IgG2, IgG3, IgG4) production was quantified using the antigen of Trypanosoma cruzi and the human M2-PK recombinant protein via the ELISA technique. The tests were conducted with serum samples from patients with indeterminate, cardiac, digestive and cardiodigestive clinical forms of Chagas disease, and the results were correlated with the dilatation degree of the esophagus and colon.

Results: Patients with the digestive form of Chagas disease had higher IgG4 anti-M2-PK autoantibody production compared with patients with the indeterminate and cardiac forms and the healthy control group. Furthermore, a positive correlation was observed between sigmoid and rectum size with IgG4 anti-M2-PK autoantibody production.

Conclusions: These results demonstrate that IgG4 anti-M2-PK autoantibodies correlate with digestive damage in human Chagas disease, and their presence may also be implicated in the development of digestive lesions.

Background: Noma is a severe orofacial disease with high mortality and morbidity. Although severity scales exist, they fail to fully capture the extent of damage caused by the disease.

Methods: This study analysed 404 photos of 260 noma cases from Facing Africa (n=228) and Project Harar (n=32) to create a new severity classification system. Photos were displayed on a large screen for better visualization. Tissue damage was assessed in terms of width, depth and surface area using the American Burn Association's grading system. A mathematical formula was also developed to quantify the extent of noma-induced orofacial damage.

Results: Fifteen orofacial anatomical units vulnerable to noma were identified, leading to the development of a new severity classification system that enhances the assessment of noma. This system evaluates tissue damage qualitatively as minor, moderate or major and quantitatively using a purpose-built mathematical formula.

Conclusions: Current classification systems inadequately capture noma severity due to vague definitions and limited consideration of the affected anatomical units. The new approach addresses these gaps by considering all tissue damage, including dentition, and allows for precise qualitative and quantitative assessment of disease severity. Continued research and validation are essential to refine this method, improving its clinical and research applications and enhancing outcomes for noma patients worldwide.

Background: Multiple mechanisms may contribute to the occurrence of renal impairment (RI) in patients with spontaneous bacterial peritonitis (SBP). One such mechanism is systemic inflammatory response syndrome, which involves the release of pro-inflammatory cytokines (tumour necrosis factor [TNF]-α, interleukin [IL]-6 and vascular cell adhesion molecule [VCAM]-1). The goal of this research was to evaluate the role of IL-6, TNF-α and VCAM-1 as potential predictors of RI and mortality in cirrhotic patients with SBP.

Methods: This study included 90 cirrhotic patients with SBP, divided into two equal groups: group A was patients without RI and group B was patients with RI. Based on mortality outcomes, the patients were further categorized into group 1 (recovery, n=70) and group 2 (death, n=20). TNF-α, IL-6 and VCAM-1 serum levels were measured using enzyme-linked immunosorbent assay.

Results: RI occurred in 50% (45/90) of the study population. Among the 90 patients, 10 (11.1%) had elevated IL-6 levels, 8 (8.9%) had elevated TNF-α levels and 6 (6.7%) had elevated VCAM-1 levels. There were no significant variations in cytokine levels between groups A and B. With an area under the curve of 0.5, the three cytokines showed comparable sensitivity and specificity as predictors of RI.

Conclusions: The use of TNF-α, IL-6 and VCAM-1 as predictive markers for RI and mortality in SBP patients is not recommended, as these biomarkers demonstrated limited diagnostic value.

Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to multiple classes of antibiotics and primarily affects immunocompromised individuals, such as those with poorly controlled diabetes or malignancies. In this case, a 58-y-old female farmer with poorly controlled diabetes (HbA1c of 11.4%), metastatic breast cancer with chemotherapy-induced pancytopenia and disseminated melioidosis showed no improvement despite receiving antibiotics and supportive care. However, the introduction of adjunctive nivolumab, combined with an antibiotic regimen, resulted in significant therapeutic benefit, suggesting a promising new approach for managing severe and refractory melioidosis.

Background: Vietnam harbours a high species richness of venomous snakes with >60 recognised species but snakebite pathology and treatment are still understudied, particularly in northern Vietnam.

Methods: A retrospective study from 2008 to 2020 was conducted, focusing on snakebite cases at the Poison Control Center of Bach Mai Hospital, a major centre in northern Vietnam for treating envenoming incidents.

Results: A total of 5805 snakebite cases were reported over 12 y. The demography of patients was predominantly male snakebite victims (70%), middle-aged (30-59 y) and mostly from rural districts. Cobra (Naja spp.) attacks were the main culprit, accounting for 39% of cases, and most snakebites occurred in the rainy season. The majority of patients were from Hanoi, but the percentage of cases from other provinces increased over the years up to 75% in 2020. The highest number of snakebites were recorded from communes with snake farms.

Conclusions: Male gender, rainy season, rural residency and snake farming were identified as major risk factors for contracting snakebites. Multicentre hospital studies, cross-sectional community surveys and a central snakebite database are needed to better understand and deal with snakebites in Vietnam.

Background: Snakebite envenoming, classified as a neglected tropical disease, poses a significant threat to life in India, where it is estimated to cause 58 000 fatalities as well as 140 000 morbidities annually. To reduce the occurrence of snakebite, we need a comprehensive understanding of human-snake conflict ecology. Snake rescue networks represent a vital resource for gathering such ecological data.

Methods: In this study, we utilised snake rescue data from 520 rescue encounters carried out by a local rescue network in Hooghly, West Bengal, from July 2020 to October 2022, to investigate patterns of human-snake conflict and the influence of climatic factors on these patterns.

Results: The spectacled cobra Naja naja was the most encountered of the five venomous species involved in 365 rescues. Our analysis revealed a significant correlation between rescue location and venomous/non-venomous encounters, with non-venomous encounters being more prevalent inside built-up locations. Rainfall on the previous day significantly increased encounters and influenced the species involved, while daily minimum temperature also influenced encounters with venomous species. We also found that both Bungarus (krait) species present were mostly encountered between 18:00 h and midnight.

Conclusions: This study highlights the multifaceted factors influencing human-snake conflicts in the region, including seasonality, geographic location, rainfall patterns, and temperature dynamics. It underscores the potential of snake rescue data as a valuable resource for deepening our understanding of regional variations in snake-human interactions.

Sub-Saharan Africa (SSA) is affected by the high direct and indirect costs of snakebite envenomation. With >30% of global mortality, different economic barriers still exist, and effective strategies must be employed to avert the burden and promote quality of life. With the WHO target of reducing the number of snakebites by one-half by 2030, different aspects concerning snakebite envenomation economics must be evaluated, and potential strategies must be developed. Strategies such as exploring the different snakebite prevention interventions, and the costs associated with these interventions, must be prioritized through extensive research and targeted surveys. Information obtained from these surveys can be used to draft effective policies to minimize snakebite envenomation incidence, reduce the economic burden associated with envenomation and improve the quality of life of people at risk. In this narrative review, we evaluate the different aspects concerning the health economics of snakebite envenomation and explore the financial capacity of SSA countries to mitigate envenomation. Additionally, we propose multiple steps that could be undertaken to mitigate the financial burden of envenomation in SSA. Furthermore, we propose critical research strategies to minimize direct and indirect costs arising from snakebite envenomation in the region.