BASICS
- Getah virus is a mosquito-borne arbovirus classified in the Semliki Forest complex genus Alphavirus, family Togaviridae. The virus or one related to it (Sagiyama, Ross River, or Bebaru, which are also included in the Getah virus subgroup) can be found over a wide geographic range, extending from Eurasia to Australia
- Although serologic studies suggest widespread exposure to the virus among vertebrates (mammals, birds, and reptiles) including humans, naturally occurring disease due to Getah virus has only been reported infrequently in horses and very uncommonly in swine
- Racetrack outbreaks have been reported in Japan (1978, 1979, 1983, 2014, 2015, 2016) and on a breeding farm in India (1990)
- In areas of the world considered endemic for Getah virus, it is thought to be maintained in a mosquito-swine-mosquito cycle. Pigs and perhaps other vertebrates are regarded as amplifying hosts of the virus
Whereas experimental infection with Getah virus can be established in various horse breeds, the majority of reported outbreaks have been in Thoroughbreds at racetracks, frequently in 2-year-old horses in training, with spread of infection recorded over a 4–6 week period.
- Most cases of primary Getah virus infection are asymptomatic
- The virus can cause extensive outbreaks of mild illness that is self-limiting, nonfatal, and apparently without sequelae
- Clinical signs appear 2–6 days after exposure. They can include some or all of the following—fever (3–4 days’ duration), anorexia, depression, limb and preputial edema, skin rash, serous nasal discharge, submandibular lymphadenopathy, stiff gait, and mild icterus. Limb edema and rash supervene several days after onset of fever
- Complete clinical recovery occurs within 7–14 days
- Getah virus can frequently cause a peracute fatal illness in neonatal piglets
- Getah virus infection is primarily transmitted by certain species of Culex and Aedes mosquitos in regions of the world where the virus is endemic
- Since the virus can be shed into the respiratory tract of some acutely infected horses, there is the potential for horse-to-horse transmission via the respiratory route, either by direct animal contact or indirectly, through virus-contaminated fomites
DIAGNOSIS
TREATMENT
MEDICATIONS
FOLLOW-UP
MISCELLANEOUS