WWAV is an emerging virus; previously, it was widely distributed among woodrats (Neotoma spp.

However, during June 1999 – May 2000, three female patients, aged 14, 30, and 52, developed similar fatal illnesses.

The illnesses were associated with nonspecific febrile symptoms including fever, headache, and myalgias and acute respiratory distress syndrome.

The nucleotide sequence of the patients were essentially identical and was 87% similar to the WWA virus prototype strain (obtained from a white-throated woodrat (Neotoma albigula) from New Mexico in the early 1990s).

However, the virus has been found in woodrats in New Mexico and, more recently, in Utah, Oklahoma, and Texas.