West Nile virus is transmitted to animals and people by an infected mosquito and most people who are bitten will not develop any symptoms. About 15 percent to 20 percent of those bitten do develop a moderate, flulike illness called West Nile fever, with symptoms including fever, body aches and rash. Rarely, West Nile virus can lead to complications including encephalitis (brain inflammation), coma or paralysis. So far this year, the virus has sickened 56 people across the state. By the end of July 2006, though, just 20 human cases of West Nile Virus had been reported in California. Officials continue to reiterate the need to prevent mosquito breeding and to protect against bites as high numbers of insects have tested positive for the virus this year. "We have a lot of West Nile activity this year," Aaron Devencenzi of the San Joaquin County Mosquito and Vector Control District told the Record. "Dump and drain any standing water. Even the smallest amount of water can breed mosquitoes." The Stockton Record contributed to this story.