Evaluation of LN34 real-time PCR assay for detection of rabies virus in human and animal specimens.

OBJECTIVES: Rabies, a neglected zoonotic encephalitis caused by lyssaviruses, claims around 59,000 lives annually. PCR-based methods are pivotal for laboratory confirmation of rabies in humans and animals. The LN34 pan-lyssavirus real time PCR assay has demonstrated good diagnostic performance in detecting rabies viral RNA in extensive evaluations with animal brain tissues. However, its application has not been adequately evaluated on human samples. METHODS: This study assessed the utility of the LN34 assay on human brain tissues, and antemortem samples such as cerebrospinal fluid, saliva and nuchal skin. Furthermore, this assay was also evaluated using postmortem dog saliva samples, in addition to animal brain samples. RESULTS: Compared to the gold-standard fluorescent antibody test (FAT), the LN34 assay showed 100 % sensitivity and specificity for both human and animal brain samples. For human antemortem samples, there was perfect agreement between the LN34 assay and routine real-time RT-PCR for detection of rabies virus (RABV). Similarly, there was complete agreement between the two assays when testing dog saliva samples. The sensitivity and specificity of saliva LN34 assay in laboratory-confirmed rabid dogs was 50 and 100 % respectively. CONCLUSIONS: The LN34 assay is a suitable alternative for diagnosis and surveillance of rabies in humans and animals in an area endemic for rabies lyssavirus.