Diagnosis of Rabies via RT-PCR on Skin Samples of Wild and Domestic Animals

In developing countries, brain tissues from rabies suspect animals are not always available for diagnosis for a variety of reasons, such as lack of transport to submit a carcass or the difficulty of removing an animal’s head or brain under field conditions. To enable diagnosis in such cases, there is a need for a reliable method, using an alternative non-neural tissue, which can be removed and submitted to the diagnostic laboratory without special training or equipment. In human medicine, skin is used successfully for the detection of rabies virus antigen using RT-PCR technology. Little work has been done in animals using RT-PCR on skin or extracted hair follicles. The current study was conducted in Grenada on skin from 36 wild and domestic animals, in which rabies virus infection had been confirmed in brain tissue via the direct fluorescent antibody (DFA) test, and in 31 negative control animals. RT-PCR on skin yielded a sensitivity of 97.2% (35/36) and a specificity of 100% (31/31). It is concluded that the examination of skin samples via RT-PCR provides a valuable diagnostic alternative in those cases where brain tissue is not readily available.