Mayaro virus is an alphavirus of the Semliki Forest virus complex. The virus is mosquito-borne, and it is endemic in South America (where several small outbreaks have occurred). Cases of this disease in returning travelers in Europe have also been reported.

Patients present with fever, a nonspecific rash, arthralgias, and eye pain. The rash is typically seen around day 5 of the illness. Other symptoms that may be present include headache, retro-orbital pain, nausea, vomiting, diarrhea, and photophobia. Symptoms typically resolve over about 5 days, but arthralgias can persist for weeks to months and up to 1 year after acute illness.

The symptoms of Mayaro virus are similar to those seen following infection with other alphaviruses including chikungunya virus, and it may be impossible to distinguish these infections based solely on the clinical history and physical examination.