Leptospirosis in humans and selected animals in Sub-Saharan Africa, 2014-2022: a systematic review and meta-analysis.

BACKGROUND: Leptospirosis is an emerging neglected tropical zoonotic disease of public health importance causing substantial morbidities and mortalities among humans. The infection is maintained within the population through interactions between humans, animals, and the environment. Understanding the burden of disease in both humans and animals is necessary for effective prevention and control in Sub-Saharan Africa (SSA). Therefore, we aimed to determine the seroprevalence of leptospirosis in humans, selected domestic animals, and rodents in SSA. METHODS: A comprehensive search was done in six databases: Scopus, PubMed, Google Scholar, CINAHL, Web of Science, and African Journals Online databases for articles published between 01 January 2014 and 30 August 2022. Thirty-seven articles distributed across 14 out of 46 countries in SSA were included. The random effects meta-analysis model was used to pool the extracted seroprevalence data. RESULTS: The overall pooled seroprevalence of leptospirosis among humans was 12.7% (95% CI: 7.5,20.8), 15.1% (95% CI: 9.4,23.5), and 4.5% (95% CI: 0.4, 35.6) based on results obtained using ELISA, MAT, and PCR diagnostic methods respectively. The pooled seroprevalence estimates among cattle were 29.2%, 30.1%, and 9.7% based on ELISA, MAT, and PCR respectively. Further, the pooled seroprevalence in goats was 30.0% for studies that used MAT, and among rodents, the pooled seroprevalence estimates were 21.0% for MAT and 9.6% for PCR diagnostic criteria. The seroprevalence of leptospirosis varied extensively between studies, across SSA regions and study setting (rural or urban). CONCLUSION: Leptospirosis is widespread in SSA in both humans and animals based on the current results of the pooled seroprevalence in the limited studies available. The burden is high in animals and humans and underestimated due to limited studies and challenges with limited diagnostic capacity in most healthcare settings in SSA. Hence, we recommend that leptospirosis should be listed as a disease of concern and be included on the list of routine diagnostics among patients presenting with febrile illness in healthcare settings. Further, we recommend the enhancement of surveillance of leptospirosis in all countries in SSA and the development of strategies with a One Health perspective to effectively prevent and control leptospirosis.

A review of place-related contextual factors in syndemics research.

This review investigates the extent to which a place-based approach has been used to conceptualize context, as well as the place-related contextual factors explored in studies that explicitly invoked a syndemic framework. The literature search focused on 29 peer-reviewed empirical syndemic studies. Only 11 studies used a place-based approach to define and measure contextual factors and the spatial context was denoted using administrative boundaries such as census tracts, counties, and countries. A narrow range of place-related contextual factors were explored and most of them were related to social and economic factors that were used to define a place. Methodological gaps like a paucity of multilevel studies and studies using a place-based approach to measure context were identified. Future syndemics research should leverage multidimensional geospatial approaches to decipher the role of place-related contextual factors in syndemic dynamics.

Incidence and distribution of human leptospirosis in the Western Cape Province, South Africa (2010-2019): a retrospective study.

Introduction: leptospirosis is an emerging zoonosis of global importance. In South Africa, the infection is an underreported public health concern, with limited information on its incidence and distribution. This study investigated the incidence of human leptospirosis in Western Cape Province (WCP) between 2010 and 2019, and compared the incidence based on seasonal and demographic factors. Methods: a retrospective study was conducted with data on leptospirosis diagnoses in WCP obtained from the National Health Laboratory Services. With the provincial population sizes as the denominator, incidence of leptospirosis was estimated and expressed as cases per 100,000 population. Negative binomial regression was used to estimate the effect of sex, season, and year on the incidence of leptospirosis. Results: two hundred and fifty-four (254) cases of leptospirosis were reported between 2010 and 2019, with the highest number of cases being in 2015 and the annual incidence ranged between 0.15 and 0.66/100,000 population. Males had a higher incidence compared to females (0.55 vs. 0.25/ 100,000 population; incidence rate ratio (IRR) 2.2, 95% CI: 1.66,3.03). The 18-44 age cohort had the highest average incidence (0.56/100,000 population), while the ≤17 age cohort had the lowest incidence (0.07/100,000 population). The 18-44 (IRR 8.0, 95% CI: 4.65,15.15) and ≥45 (IRR 7.4, 95% CI: 4.17,14.17) age cohorts were more at risk of infection compared to ≤17 age cohort. Conclusion: leptospirosis is an important zoonosis in WCP disproportionately affecting males and the productive age demographic groups. These findings should enhance targeted prevention and provoke further investigation on the importance of environmental and socioeconomic factors on leptospirosis burden.