Stanislaus County has been experiencing a relatively mild season of West Nile virus so far, but officials warn the worse may be yet to come.

To date, public health officials are reporting a total of five cases of human West Nile virus in Stanislaus County, which is a marked decrease from the 12 human cases at this time last year. However, officials have recently noted a much higher prevalence rate of infected mosquitoes and birds over the last two weeks and are urging residents of Stanislaus County to continue to use mosquito repellants when outdoors.

Last year, the county saw 26 human infections of the virus and no fatalities.

So far this year, the state has recorded 101 West Nile virus cases.

In addition to the human case, Stanislaus County has detected West Nile virus in 154 mosquito samples, 13 dead birds, eight sentinel chickens and two horses as of Sept. 6.

West Nile virus is transmitted to humans and animals through a mosquito bite. Mosquitoes become infected when they feed on infected birds.

In the United States, most people are infected from June through September, and the number of these infections usually peaks in mid-August, according to the Centers for Disease Control. Seasonal outbreaks often occur in local areas that can vary from year to year. For example, Stanislaus County had at least one human case reported in October 2011.

Approximately 1 in 5 people who are infected with West Nile virus will develop symptoms such as fever, headache, body aches, joint pains, vomiting, diarrhea, or rash. Less than 1 percent will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues). About 10 percent of people who develop neurologic infection due to West Nile virus will die, according to the CDC.  People over 50 years of age and those with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease, and organ transplants, are at greater risk for serious illness.

There are no medications to treat, or vaccines to prevent, West Nile virus infection. People with milder illnesses typically recover on their own, although symptoms may last for several weeks or months. In the neuroinvasive forms, patients can suffer severe and sometimes long-term symptoms.

Stanislaus County citizens are encouraged to continue their efforts with regards to West Nile virus prevention. People can use these simple steps to help people protect themselves and others from mosquito bites and West Nile virus:

• Eliminate sources of standing water where mosquitoes lay their eggs.

• Avoid spending time outside when mosquitoes are most active, at dawn and dusk, and especially for the first two hours after sunset.

• When outdoors, wear long pants, long-sleeved shirts and other protective clothing.

• Exclude mosquitoes from your home with tight fitting screens on doors and windows.

• Apply insect repellent containing the active ingredient DEET when outdoors, according to label instructions.

• In addition to DEET-based products, the Centers for Disease Control also recommends insect repellants containing oil of lemon eucalyptus and Picaridin.

Both East Side and Turlock Mosquito Abatement districts have been busy treating mosquito habitats using ground and aerial spray equipment. The districts use aircraft in rural locations and ground equipment for more precision spraying in urbanized areas. The districts continue to be concerned with neglected swimming pools. The districts also provide mosquito fish, free of charge, to put in ornamental ponds and other backyard locations.

Reporting and testing of dead birds is an important step in preventing West Nile Virus. A confirmed case of the virus in dead birds or mosquito samples helps to identify areas that need treatment to reduce mosquito activity. To report a dead bird, call the California State hotline at 1-877-WNV-BIRD or report it online at www.westnile.ca.gov. Birds of particular interest are crows, ravens, magpies, jays and raptors (hawk or eagle).

To report mosquito-breeding problem areas, Stanislaus County residents should contact one of the two mosquito abatement districts that serve the county. For Stanislaus County addresses north of the Tuolumne River, residents should call the Eastside Mosquito Abatement District at 522-4098 (www.eastsidemosquito.com) and all others should contact the Turlock Mosquito Abatement District at 634-1234 (turlockmosquito.org).