Reviewed by Emmett T. Cunningham, MD, PhD, MPH
Hillsborough, CA—Diagnosis of mosquito-borne forms of uveitis are occurring more often in developed countries, in addition to developing-world countries where their diagnosis is often expected—largely because of extensive global air travel and easy interconnectivity among the world's countries.
Mosquitos are the culprits in the spread of some of these diseases, specifically, West Nile virus, Dengue fever, and Chikungunya.
Though the three diseases can appear similar, there are some characteristics that can help physicians distinguish among them, said Emmett Cunningham, MD, PhD, MPHâ¨.
"Considering the three diseases, West Nile virus tends to be less severe than Dengue fever, which is less severe than Chikungunya," said Dr. Cunningham, director, Uveitis Service, California Pacific Medical Center, Hillsborough, CA.
West Nile virus
This is a flavivirus of about 12 kilodaltons in size that was first identified in 1937 in Uganda. The virus's natural reservoirs are birds, which, in turn, transmit the virus to mosquitos that then pass it to mammals.
The infection entered the United States in 1999, and the incidence has grown since that time, making the disease a global disorder. The incidence is less than one case per 100,000 people, according to Dr. Cunningham.
West Nile virus appears cyclically and seasonally, with outbreaks tending to occur more often in summer and fall.