On 20 December, the International Health Regulations National Focal Point (IHR NFP) of Argentina notified the WHO of a human case of WEE infection. The patient is an adult from the province of Santa Fe. This is the first human case of WEE reported after more than two decades, since the last cases reported in humans in Argentina occurred in 1982/1983 (associated with an outbreak in equines) and 1996 (an isolated case based on clinical and serological findings but with no equine cases detected).
WEE is a rare mosquito-borne disease caused by a virus belonging to the genus Alphavirus of the Togaviridae family. In humans, WEE virus can cause diseases ranging from subclinical or moderate symptoms to severe forms of aseptic meningitis and encephalitis.
