Detection of circulating antigens for Taenia spp. in pigs slaughtered for consumption in Nairobi and surroundings, Kenya

Abstract

Background & methods Taenia solium a zoonotic tapeworm, responsible for neurocysticercosis in humans is a major public health threat, being a leading cause of acquired epilepsy in endemic regions. Eastern and southern African nations have experienced a recent rapid growth in pig production, including small-scale, free-range systems, with an accompanying increased risk of T. solium transmission. Seven hundred blood samples were collected from randomly selected pigs presented for slaughter at one of the largest porcine abattoir supplying unprocessed pork to Nairobi city and its surroundings. The samples were tested using an antigen ELISA to determine the prevalence of infection with Taenia spp. Results The prevalence, adjusted for diagnostic test characteristics, was estimated to be 4.4% (95% CI: 1.9–7.1) with no significant statistical difference by pig sex or age. Infection with Taenia spp. was detected in pigs from all regions of the country supplying pigs to this slaughterhouse. Official post-mortem inspection did not detect cysticercosis in the duration of the study. Therefore, all the carcasses entered the food chains of Nairobi (70%), or neighboring counties (30%). Conclusions Circulating antigens of Taenia spp. were detected in pigs slaughtered in one of the largest porcine slaughterhouses in Kenya, which receives pigs from several regions in the country. This is an indication that pigs entering the value chain are raised under poor husbandry conditions and that pork consumers in Nairobi and its surroundings may be exposed to the important zoonotic parasite. Whilst further research utilizing full carcass dissection is required to confirm T. solium positive cases, interventions to improve food-safety throughout the pork value chains in Kenya should be seriously considered.

Serological and molecular evidence of Brucella species in the rapidly growing pig sector in Kenya

“…A total of 700 blood samples were collected from pigs in a prevalence study on pig cysticercosis as previously described (16). All pigs presented for slaughter from the months of October to December 2014 were eligible for sampling (16). Based on the data available from Kenya at the time of the parent study design, assumed prevalence of 32.8% was used with 95% confidence level and a precision of 5% to obtain an adequate sample size for the estimation of the population prevalence of cysticercosis (16).…”

“…All pigs presented for slaughter from the months of October to December 2014 were eligible for sampling (16). Based on the data available from Kenya at the time of the parent study design, assumed prevalence of 32.8% was used with 95% confidence level and a precision of 5% to obtain an adequate sample size for the estimation of the population prevalence of cysticercosis (16). Pigs were systematically selected; the first pig presented for slaughter was sampled, followed by every fifth to get an average of 15 pigs each day for 47 days.…”

“…The project was reviewed and approved by the ILRI Institutional Animal Care and Use Committee (IACUC Ref No. 2014.34) (16). Oral and written informed consent was sought from pig owners before conducting interviews and sample collection…”

“…However, the pork industry is one of the fastest growing in East Africa and particularly in Kenya, with a very limited understanding of the role of pigs in the transmission dynamics of brucellosis. Previous studies have looked into pork value chains and their potential role in the transmission of other priority zoonoses (16,17). This study, was therefore, done to detect and identify Brucella spp.…”

Possibilities of establishing a smallholder pig identification and traceability system in Kenya

“…Cysticercosis due to T. solium has been reported in a number of studies, at prevalence rates of the following: 14% (n = 107, lingual test, Githigia et al 2005), 9.8% (n = 316, lingual test, Mutua et al 2007), 4% (n = 284, Ag Elisa, Kagira et al 2010), 32% (n = 392, Ag Elisa, Eshitera et al 2012), 37.6% (n = 343, Ag Elisa, Thomas et al 2016a) and 4% (n = 700, Ag Elisa, Akoko et al 2019). Some rural slaughterhouses are a risk to public health (Cook et al 2017); hygiene is poor, ante-mortem inspections are lacking and slaughter of sick pigs is common.…”