The North Shore Mosquito Abatement District has detected the first West Nile virus infected mosquito pools in Northbrook this year.
Officials recently announced that two pools inspected by the district's scientists on June 18 tested positive for West Nile. So far, the West Nile virus has also been detected among mosquitoes in Kenilworth, Glencoe, Lincolnwood and Skokie.
Although there are no reported human infections so far this season, people are encouraged to take precautions, said Dave Zazra, spokesman for the North Shore Mosquito Abatement District.
District officials recommend residents protect themselves from mosquito bites by covering exposed skin with loose-fitting, light-colored clothing and by wearing a repellent.
Standing water on property should also be avoided, Zazra said, as it creates a breeding ground for mosquitoes.
"Even though these are recommendations, residents really need to do these things," Zazra said.
At this point in the summer, the likelihood of people getting infected is low, he said.
"But it could ramp up very quickly if temperatures stay hot," he said, adding people typically get infected with West Nile at the end of July.
The symptoms of West Nile virus include fever, headache and body aches. Most people who become infected do not show symptoms of the illness, he said, but some may become ill up to three weeks after being bit.
Less than 1 percent of infected people develop potentially fatal neurological illnesses, such as encephalitis and meningitis, according to the U.S. Centers for Disease Control and Prevention.
Last year, the North Shore Mosquito Abatement District, which monitors about 13 communities on the North Shore, including Northbrook and Glenview, detected four West Nile disease cases, Zazra said.
One person was infected in Skokie, Zazra said. Two were infected and one died because of the virus in Niles.
In total, the state has recorded 117 human cases of West Nile disease and 11 deaths, during the 2013 season.
In 2012, when Illinois saw the second-highest number of West Nile virus cases in the state's history, there were 290 human cases of West Nile disease and 12 deaths, according to the state public health department.