Seroprevalence of Porcine Cysticercosis in Ludewa District, Njombe, Tanzania

Abstract

Small-scale subsistence farmers keep over 80% of the pigs in Tanzania as a backyard activity in mixed agro-ecological farming systems under unhygienic conditions that risk persistency of zoonoses including Taenia solium cysticercosis. Pig production and demand for pork has tremendously increased in Tanzanian townships and major cities. Rural areas are the main sources of pigs and pork and that the business is jeopardized by the presence of porcine cysticercosis (PC). Ludewa district is one of the PC unsurveyed sources of pork in townships and cities in Tanzania. The aim of this study was to assess the status of PC in Ludewa district, Tanzania. Auricular venous blood samples were collected from pigs in households for seroprevalence analysis of PC. In this study, 10.07% (95% C.I. 06.86%-14.47%) of the collected 268 serum samples tested positive in the cysticercosis antigen enzyme-linked immune-sorbent (Ag ELISA) assay. PC infection rate was 10.71% (n = 24) in adult pigs and 6.82% (n = 3) in piglets. PC infection between adult pigs and piglets was not statistically significant (OR = 0.6108; 95% C.I. 0.1125-2.1575), p = 0.5877). The highest and lowest number of PC positive cases were detected in Mapogoro (n = 16, 13.91%, 95% C.I. 8.41-21.91) and Ludewa Mjini (n = 6, 6.67%, 95% C.I. 2.74-14.50) villages respectively. The Chi-Square test indicated no significant statistical difference in the status of PC infection between the three villages (p = 0.1881) involved in this study. PC prevalence in the study area indicates the presence of T. solium tapeworm human carriers and environmental contamination by T. solium eggs. This is the first survey to reveal the prevalence of PC in Ludewa district and therefore calls for further studies on the magnitude, economic and public health impacts of taeniasis and cysticercosis in the human population. The result of this study is also important in the determination of effective control measures of cysticercosis.

Seroprevalence of circulating taeniid antigens in pigs and associated risk factors in Kongwa district, Tanzania

“…Although the findings from this study are comparable to studies from elsewhere in the world (Bowles et al., 1992; R. Core Team, 2017), the seroprevalence in this study is higher than that recently reported using the same diagnostic test in Ludewa district (10%) in the southern highlands (Maganira et al., 2018), but lower than that reported in Nyasa district (33%) in the southern highlands (Shonyela et al., 2017) and Babati (25%) in the northern highlands (Kavishe et al., 2017) of Tanzania. These local differences suggest differences in exposure to T. solium eggs by human carriers in different districts in Tanzania.…”

“…Sample size was estimated using the equation n = Z 2 PQ/L 2 (Thrusfield, 2002); where n is the number of pigs included in this study, P is an estimated seroprevalence in Kongwa (10%) based on data from nearby regions (Ngowi et al., 2010), (Maganira et al., 2018), Z is the score of the desired confidence interval (95%), Q = 1 – P and L is the desired precision (5%). Therefore, the minimum samples size of pigs in this study was 138; however, by including several pigs from the same household a clustering effect may be expected.…”

Socio-economic and health costs of porcine/human cysticercosis, neurocysticercosis and epilepsy to small-scale pig producers in Tanzania

“…A well-managed pig can weigh between 90 and 120 kgs within 6 months and become ready to be slaughtered for pork meat. Due to the rapid expansion of human settlements, there is a shortage of ruminant grazing land which accelerated many householders to engage in pig keeping (Maganira et al 2018 ). Unfortunately, Taenia solium ( T. solium ) infections hinder pig keeping and pork consumptions in T. solium endemic countries including Tanzania.…”

“…Its larval form ( Cysticercus cellulosae ) causes both porcine cysticercosis and human cysticercosis, while its adult form causes taeniasis in human beings (Engels et al 2003 ; Flisser et al 2003 ; Kimbi et al 2015 ; Chembensofu et al 2017 ). The infection of T. solium cysticerci into the human central nervous system was reported to cause cerebral cysticercosis, popularly known as neurocysticercosis, a more deadly condition connected to seizures, convulsions, and acquired epilepsy (Maganira et al 2018 ; Mwang’onde et al 2018 ; Mwang’onde 2019 ). Porcine cysticercosis, human cysticercosis and neurocysticercosis are serious threats in pig farming; they affect pigs, pig keepers, pork and non-pork consumers.…”

Soil contamination by Taenia solium egg DNA in rural villages in Kongwa district, Tanzania

“…The prevalence of T. solium infection in Tanzania and elsewhere in Sub-Saharan Africa has been reported to range between 2.0% to 56.7% in pigs and 0.1% to 21.6% in humans [ 7 ], where they impact on the economies and nutritional well-being of rural communities. Reports are based on tongue palpation, conjunctival examination or meat inspection of pigs [ 2 , 8 ] and serological screening of both humans and pigs [ 5 , 9 – 12 ]. Application of coprological examination and computed tomography scanning methods, are restricted to the screening for T. solium infection in humans [ 10 , 11 , 13 ].…”