Dr. Anthony Fauci’s recent diagnosis with a case of West Nile virus has brought renewed attention to the little-known illness that is the leading cause of mosquito-borne disease in the continental United States.
Fauci, 83, the former director of the National Institute of Allergy and Infectious Diseases, became a household name as one of the government’s leading experts during the COVID-19 pandemic. He was most likely bitten by an infected mosquito in his back yard, according to news reports. He experienced fever, chills, and severe fatigue, was hospitalized briefly, and is now believed to be recovering at his home.
Unlike the other mosquito-borne virus making news this summer — eastern equine encephalitis, which is a rare but a very serious illness with an approximately 30 percent fatality rate — West Nile virus is more common, and most people (8 out of 10) do not develop any symptoms when they are infected. One in 150 infected people with West Nile virus develop a serious, sometimes fatal illness.
According to the U.S. Centers for Disease Control and Prevention, West Nile virus is most commonly spread through the bite of an infected mosquito. People become infected after being bitten by mosquitoes that have fed on the blood of infected birds. Symptoms include fever, headache, body aches, vomiting, diarrhea, or rash.
Yale School of Public Health Associate Professor Nathan Grubaugh, an infectious disease epidemiologist, said the number of cases of West Nile virus nationally has stayed relatively stable over the past decade with about 1,000 to 3,000 cases per year. So far this year, the CDC has reported 216 cases in 33 states, but August and September are usually the months where the virus is most prevalent so it remains to be seen if this year will be different from those past.
The Connecticut Agricultural Experiment Station, which is responsible for testing and tracking mosquitos in the state, is reporting high levels of mosquitos infected with West Nile virus this year, Grubaugh said.