Post-Anthrax Vaccination Associated Morbidity and Mortality in Sheep in Samre and Tanqua Abegelle Wereda, Tigray (Ethiopia): A Case Report

Abstract

This is a case report on anthrax suspected morbidities and mortalities among vaccinated sheep and goats in Samre and Sahrti Woreda, Tigray (Ethiopia) following three-day of anthrax vaccination. Animal data, health event data (number of sick and dead animals), vaccination data (vaccine handling, vaccine administration, etc.) and epidemiological data were gathered and the case was diagnosed by Woreda and Regional Veterinary Laboratory experts based on clinico-epidemiological approach. Accordingly, the investigation revealed an overall morbidity, mortality and case fatality of 3.26% (4.06% in Samre and 2.56% in Tanqua Abergele), 1.88% (2.81% in Samre and 1.06% in Tanqua Abergele) and 57.66% (69.23% in Samre and41.30% in Tanqua Abergele) and 57.66%) in anthrax-vaccinated sheep population, respectively.  A direct market value (financial loss) of the dead sheep and goats estimated at ETB 848,500.00 (630,000 in Samre and 218,500 in Tanqua Abergele) was also reported. However, there was no such sickness and or death in unvaccinated sheep and goats. The clinic-pathological reactions (the development of widespread edematous conditions an, systemic shock reactions), along with the epidemiological findings suggested that sheep and goats could have been suffered from saponin-derived anthrax post-vaccination complications (Immuno-pathological systemic reaction). Such unwanted immunological responses in goats are also reported in the literature. The immediate cessation of the vaccination was also wise decision to reduce further sickness and deaths. The frontline animal health experts need to get appropriate technical support from the vaccine manufacturer and regional and/or national disease diagnostic and investigation laboratories on how to handle such cases.  Moreover, the vaccine manufacturer need to take also necessary measurement actions.