Laboratory validation of confirmatory tests for rabies diagnosis: Approaches to reduce animal use and facilitate sample collection

Abstract

Rabies is an encephalitis caused by rabies virus, whose transmission occurs upon contact with infected animals' saliva. The diagnosis is usually performed post-mortem through a direct fluorescent antibody test (DFAT). If the DFAT results are negative, they must be confirmed with an isolation test, usually the mouse inoculation test (MIT), which implies the suffering and death of the animals, high costs and most importantly, up to 28 days to confirm a negative result. Another issue related to rabies diagnosis is the sample collection and storage, which is critical for the rabies virus' RNA genome.Thus, this study aimed to evaluate (i) reverse transcriptase polymerase chain reaction (RT-PCR) and Rabies Tissue Culture Infection Tests (RTCIT) in comparison to DFAT and MIT and (ii) FTA ® cards as an alternative sample collection and preservation method.Eighty animal samples were evaluated through DFAT, RTCIT and RT-PCR; MIT was performed only in DFAT-negative samples. FTA ® cards were evaluated with a subset of 64