Alachua County health officials say they've detected three human cases of West Nile virus.
 
Health department director Paul Myers told the Gainesville Sun Tuesday that red flags were raised when the three people tried to donate blood and there were "indicators" that they could be infected with the virus.
 
Myers says all three have reported certain symptoms associated with West Nile virus. They are currently awaiting results of blood testing, which should be in sometime next week.
 
He told the newspaper that antibodies indicate there is an infection, but it's not known whether it's a recent infection or a past one.
 
The virus was detected in sentinel chickens in Alachua County on Sept. 20. The county remains under a mosquito-borne illness advisory that began Sept. 27.