Seroprevalence of Toxoplasma Gondii in Slaughtered Pigs and Risk of Exposure for Abattoir Workers in Kiambu County, Kenya

Abstract

Toxoplasmosis is one of the neglected zoonotic diseases with serious health impact in im-munocompromised individuals. Ingestion of infective stages of Toxoplasma gondii (T. gondii) present either in raw or uncooked meat, contaminated vegetables, fruits and water is the major route for human infections. The main aim of this study was to determine the sero-prevalence of T. gondii in pigs slaughtered at Ndumbu-ini abattoir and predisposing practices that exposes slaughterhouse workers to this infection across four operational areas within the slaughterhouse: stunning area, scalding and dehairing area, evisceration and cutting and dis-patch area. A cross-sectional study was conducted at a medium-scale pig abattoir in Kiambu County, Kenya where 529 blood samples were collected from pigs slaughtered between the 5th Janu-ary and 5th March, 2021. Data on the county of origin, farm size, sex and pig liveweight were collected in pigs that were recruited into the study. Sera samples obtained were subjected to Indirect-Enzyme Linked Immunosorbent Assay to detect the presence of T. gondii Immuno-globin G (IgG). The overall seroprevalence of T. gondii was 34.53% (95% C.I. 30.16 - 39.17%). Pigs’ liveweight was used as a rough proxy for age and a statistically significant association was found between increasing liveweight and T. gondii status in slaughtered pigs (p = 0.044). Farm size also was statistically significant with T. gondii seropositivity (<0.001) and when subjected to logistic regression model, farm size with approximately >100 pigs was a significant protective factor towards T. gondii seropositivity (OR= 0.17). Qualitative data were collected on various predisposing practices that would expose slaugh-terhouse workers to infection across four operational areas within the pig slaughterhouse. Within the slaughterhouse, 100 % of the abattoir workers did not wash their hands and work-ing tools with soap and water at the stunning and scalding and dehairing areas and 95.83% at the evisceration points. Washing of hands and working tools with soap and water was only xi practiced at cutting and dispatch section. Abattoir workers were observed adhering to basic personal protective clothing with 100 % wearing their gumboots and white overcoats in three stations with only a small number, 1.04% who did not wear their white overcoats at the cut-ting and dispatch area. Wearing of gloves was not a common practice with 100 % of workers at stunning, scalding and dehairing and evisceration areas and 95.83% at cutting and dispatch section were observed not wearing gloves. Splashing of blood and raw pork on the faces of the slaughterhouse workers was observed in; 62.50% of workers at the stunning area, 50 % at the scalding and dehairing area, 58.33% at evisceration and 62.50% at cutting and dispatch section. A small number, 8.33% and 4.17 % were observed eating within the slaughterhouse at evisceration and cutting and dispatch sections respectively. About 71.0 % of workers at stunning, 70.83% at scalding and dehairing, 45.83% at evisceration and 66.67% at cutting and dispatch areas were observed not wearing their mask properly despite the ongoing Covid-19 pandemic. This finding calls for training of slaughterhouse workers on the risks for expo-sure to zoonoses during slaughter process and the need for management to mitigate these risks by establishing standard operating procedures at the abattoirs to minimize risk of infec-tions of workers and also to guarantee food safety.