Nine mosquito traps were set in the vicinity of Gerlach, Nevada for the purposes of checking for West Nile Virus the week before Burning Man, and results are now in from a state lab showing a positive test for West Nile. This means that mosquitos very close to the annual influx of 66,000 or so people at Burning Man were carrying the disease, for which there have been 181 confirmed human cases in California this year though none so far locally.
Despite our damper-than-usual San Francisco summer, no West Nile has been detected yet this year, though some non-human cases (possibly dead birds) have appeared in San Mateo County.
As the Reno Gazette-Journal reports, "The traps [near Gerlach] were checked Aug. 22 and were sent to the state lab on Aug. 25 and they got the state results on Tuesday." Nevada officials gave a press conference about the results on Wednesday.
This means that anyone who was at Burning Man and may have been bitten needs to be on the lookout for symptoms. As Mic notes, those include fever, headache, vomiting or a rash, however 70 to 80 percent of those infected are asymptomatic. Only about 1% of people develop serious symptoms, like meningitis or encephalitis, and those most at risk are people with cancer, diabetes, hypertension, or kidney disease.