Global variation in force-of-infection trends for human Taenia solium taeniasis/cysticercosis.

Infection by Taenia solium poses a major burden across endemic countries. The World Health Organization (WHO) 2021-2030 Neglected Tropical Diseases roadmap has proposed that 30% of endemic countries achieve intensified T. solium control in hyperendemic areas by 2030. Understanding geographical variation in age-prevalence profiles and force-of-infection (FoI) estimates will inform intervention designs across settings. Human taeniasis (HTT) and human cysticercosis (HCC) age-prevalence data from 16 studies in Latin America, Africa, and Asia were extracted through a systematic review. Catalytic models, incorporating diagnostic performance uncertainty, were fitted to the data using Bayesian methods, to estimate rates of antibody (Ab)-seroconversion, infection acquisition and Ab-seroreversion or infection loss. HCC FoI and Ab-seroreversion rates were also estimated across 23 departments in Colombia from 28,100 individuals. Across settings, there was extensive variation in all-ages seroprevalence. Evidence for Ab-seroreversion or infection loss was found in most settings for both HTT and HCC and for HCC Ab-seroreversion in Colombia. The average duration until humans became Ab-seropositive/infected decreased as all-age (sero)prevalence increased. There was no clear relationship between the average duration humans remain Ab-seropositive and all-age seroprevalence. Marked geographical heterogeneity in T. solium transmission rates indicate the need for setting-specific intervention strategies to achieve the WHO goals.

Assessment of sanitary conditions of unregistered pig slaughter slabs and post mortem examination of pigs for Taenia solium metacestodes in Kaduna metropolis, Nigeria.

BACKGROUND: A number of studies document the prevalence of Taenia solium infections in Nigeria, yet these studies do not cover porcine cysticercosis in private home slaughter slabs where there is no routine meat inspection and backyard pig keeping, slaughtering and sale are common practice. METHODS: An environmental and sanitary assessment was conducted within two unregistered home pig slaughter slabs in selected parts of the Kaduna metropolis in Nigeria. Slaughter premises were inspected for availability of basic facilities and questionnaires were used to elicit necessary informative data. Butchers were examined for taeniasis by stool microscopy and copro-antigen enzyme linked immunosorbent assay (copro-Ag ELISA) to ascertain T. solium - taeniasis. Pigs slaughtered at the premises were examined for cysticerci. RESULTS: Home slaughter conditions were substandard, unhygienic and lacked the basic facilities of a proper slaughterhouse. Prevalence of porcine cysticercosis was 9.3%. The butchers participating in the study had very poor knowledge of T. solium infections and 30% tested positive for taeniasis by copro-Ag ELISA at the time of the study. CONCLUSION: Home slaughter of pigs in the areas studied should be considered and integrated as a component of prevention and control programmes - particularly through educational interventions - in order to equip individuals involved with a good understanding of the risks associated with animal husbandry and human practices.