Rabies occurs in more than 150 countries and territories, resulting in at least 55,000 human deaths per year worldwide according to World Health Organization estimates. Rabies is a vaccine-preventable viral disease caused by numerous lyssaviruses that are found in a variety of animal species throughout the world. Rabies virus infects the central nervous system, causing disease in the brain with almost 100% mortality once clinical symptoms manifest. Rapid and accurate laboratory diagnosis of rabies in humans and other animals is essential for timely administration of post-exposure prophylaxis.

Due to significant sequence variation among rabies and related lyssaviruses, no single molecular diagnostic test detects all species that may cause fatal human rabies. Using modified nucleotide detection technologies, CDC scientists have developed a real-time RT-PCR assay that can detect all current known lyssaviruses (up to 15 species) responsible for rabies. This one-step test has improved sensitivity and specificity compared to current rabies diagnostic assays; it is also simpler to run and ready for field use. The real-time RT-PCR assay allows for rapid and efficient detection of rabies in both humans and animals, with an ability to distinguish between all known lyssavirus species that cause rabies.