A Targeted Survey for Scrapie in Jos Plateau State, Nigeria

Scrapie, a disease of sheep and goats with a progressive course and fatal outcome, has not been identified in Nigeria. Anecdotal scrapie reports by livestock workers abound. Livestock diseases like scrapie form huddles in livestock economics of countries. For 8 months we surveyed for scrapie targeting emergency/casualty slaughter sheep and goats in Jos, Nigeria. We clinically examined 510 sheep and 608 goats of local breeds, aged from 12 months to 5 years. In total 31 (5.10%) goats and no sheep were clinically suspicious for scrapie. Caudal brainstem tissues of suspect animals collected postmortem were analyzed for the disease specific form of the prion protein, PrPSc, using Bio-Rad’s TeSeE ELISA rapid test kit. No sample was positive for scrapie. Fluorescent antibody test for rabies and H&E staining on samples were carried out for differential diagnosis. These showed no pathological lesions indicative for neurological disease. While our findings do not exclude the presence of scrapie in Jos, we demonstrate that targeted sampling of small ruminants for neuroinfectious disease is feasible in developing countries, pointing to the possibility of implementing such a monitoring scheme in Nigeria to prevent economic losses in small ruminant livestock as scrapie caveats from endemic countries have shown. 1. Introduction Scrapie is a naturally occurring progressive, fatal, infectious, and neurodegenerative disease of sheep and goats that has been recognized for over 250 years. The occurrence of scrapie preceded the recognition of other prion diseases of mammals and so can be referred to as the archetype of prion disorders [1]. It is caused by an infectious misfolded protein, termed prion. Like other TSEs, this misfolding is thought to be caused by conformational change of the normal host prion protein (PrPC) mediated by the presence of the abnormal, misfolded prion protein (PrPSc). Host PrP variations are known to play a role in the susceptibility of goats and sheep to scrapie [2–4]. It has been proposed as the root from which bovine spongiform encephalopathy (BSE) emanated [5]. Scrapie is now considered a worldwide disease of small ruminants and currently represents a significant part of the detected transmissible spongiform encephalopathies (TSEs). The estimated population of sheep and goats in Nigeria is 27 million, and 40.8 million respectively [6]. Sheep are mainly kept for subsistence and religious inclinations while certain goat species are kept for food and high quality leather production [7]. Livestock diseases pose a challenge to this growing economic