Epidemiological Study of Schistosomiasis in Salvador: Data from a Reference Laboratory (2012-2023)

Schistosomiasis is a neglected tropical disease affecting approximately 240 million people globally. Brazil has the largest endemic region in the Americas, with over 101,293 cases reported between 2003 and 2012. In Brazil, transmission occurs via Schistosoma mansoni, with snails of the genus Biomphalaria serving as intermediate hosts. This study aims to estimate the prevalence of schistosomiasis among individuals attending the Clinical and Toxicological Analysis Laboratory of the Faculty of Pharmacy (LACTFAR/UFBA) in Salvador, Bahia, between 2012 to 2023. Parasitological data from examinations conducted at LACTFAR/UFBA were retrospectively analyzed, and statistical analyses were performed using SPSS version 29.0.10. A total of 691 individuals were found to have at least one S. mansoni egg in their fecal samples. The highest incidence was observed in 2015, with 110 cases, followed by 98 cases in 2012. The lowest incidence occurred in 2020 and 2021, representing only 1% of total cases, with five and nine cases, respectively. Among the infected individuals, 635 were monoinfected, while 56 presented confections with other helminths, including Strongyloides stercoralis (9 cases), hookworms (23 cases), Ascaris lumbricoides (16 cases), and Trichuris trichiura (17 cases). The mean age of S. mansoni-positive individuals was 40 years (IQR: 28-50 years), with a female-to-male ratio of 1.1:1. The mean age for males was 44 years (IQR: 32.3-52 years), while for females, it was 36 years (IQR: 25-47), showing a significant difference between the genders. Given the considerable economic and health impacts of schistosomiasis, targeted public health interventions are urgently needed to address this neglected population.