West Nile virus appears to have made another victim in Iowa this time in the person of an elderly woman from western Iowa, the Iowa Department of Public Health announced last week. This brings the number of Iowans diagnosed with the illness this summer to eight.

The news comes as a reminder that September is still a high-risk period for exposure to the virus (which is transmitted through mosquito bites), especially if the weather continues to be warm, IDPH Medical Director, Dr. Patricia Quinlisk said.

“The number of Iowans infected with West Nile virus tends to increase in September and sometimes into October if the weather stays nice.”

Dr. Quinlisk also added that the risk continues “until the state’s first hard frost.” Therefore, people should take precautions in order to avoid mosquito bites and, consequently, the West Nile virus.

Officials advise residents to reduce their risk of mosquito bites by limiting time outdoors between dusk and dawn when mosquitoes are most active, wear insect repellent containing DEET, eliminate all sources of standing water, which are a breeding ground for mosquitoes. A single source of standing water can produce millions of mosquitoes, which can pose health risks to a large area. People are encouraged to report dead birds to health agencies for testing.

The mosquito-transmitted disease is a potentially serious illness for people and can cause inflammation of the brain or spinal cord. Symptoms can include fever, headache and body aches; skin rash or fatigue; and weakness. Severe infections are marked by rapid onset of high fever, head and body aches, tremors, convulsions, and in rare cases paralysis and death. People older than 50 and those with a weakened immune system have the highest risk for serious illness.

According to preliminary reports released last week, there were 368 severe cases of West Nile, with 18 deaths this year, which qualify this West Nile season as the mildest in seven years, with less than a third the number of serious cases as last year’s total. Mississippi and California account for nearly half of the cases. Most cases of west Nile infections are reported in August and September. Therefore, health officials believe the worst of the season is probably over, but people still need to be cautions about exposing themselves to mosquito bites.

In 2007, there were more than 1,200 cases of severe West Nile illness and 124 deaths. The peaks occurred in 2002 and 2003, when severe illnesses numbered nearly 3,000 and deaths surpassed 260.

The West Nile virus appeared in the United States as a problem in 1999 and in California in 2003. Twenty-nine people died and 779 others were infected in California during the year of 2004. In the next two years, the infections declined, but last year rose them up again.