Clinical Indicators of Moribundity in Swine Experimentally Inoculated with African Swine Fever Virus.

Abstract

African swine fever virus (ASFV), the causative agent of African Swine Fever (ASF), is an infectious disease of swine that is associated with high rates of morbidity and mortality in naive populations. ASFV is challenging to work with in vitro and the in vivo immune response remains an active area of study. Vaccine development, pathogenesis, and diagnostic assay development studies often require use of live swine housed in high-containment laboratories. Studies of this type are intended to obtain key data yet must minimize the pain and distress experienced by the animals. To implement humane endpoints, pigs are ideally euthanatized by barbiturate overdose prior to death from ASFV infection, as the final stages of ASF can be clinically severe. However, due to the complex nature of ASFV pathogenesis, predicting when an infected animal will become moribund and require euthanasia is difficult. The current study was intended to aid in predicting the onset of moribundity in swine. Toward this end, we performed statistical analyses of historical health record data from 103 swine experimentally infected with ASFV. Regression analysis suggested that rectal temperature has potential utility as a marker for predicting moribundity, whereas viral strain and duration of survival after inoculation were significant risk factors for death due to disease rather than euthanasia.