The Stanislaus County Health Services Agency announced Friday that the county’s first confirmed human case of West Nile Virus has been diagnosed in a 52-year-old woman.
The health services agency stated the woman has been hospitalized from the disease. Stanislaus County Health Services Agency Public Health Officer Dr. John Walker said the woman has been diagnosed with the more serious neuroinvasive form of the virus, but at this time agency didn’t know if the woman has any preexisting medical conditions that may have contributed to her illness.
This year West Nile Virus was first detected in Stanislaus County when a dead bird found in Modesto tested positive for the virus. It marked the presence of the virus in the region earlier than previous years, according to health officials. In 2014, the first dead bird to test positive for West Nile virus in Stanislaus County wasn’t announced until June. That same year marked a period that saw the second highest number of human cases of the disease in the state since it first appeared in California in 2003. In 2014, California recorded 801 cases of the potentially fatal disease.
As of Friday, California has recorded 18 confirmed cases of the virus, and one fatality. The fatality was that of a senior citizen in Nevada County, according to the California Department of Public Health. A total of 37 counties have reported confirmed West Nile Virus activity.
The Turlock Mosquito Abatement District reported they have seen an increased level of adult mosquito activity in and near Turlock. The district reported having zero human cases, two dead birds and five mosquito samples testing positive for the virus, though that is only through July 28. The district has been spraying to control the mosquito population during the morning hours, as weather permits.
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.
“Unfortunately because of the drought the season may go on longer,” Dr. Walker said. “The period of risk is likely to go beyond the end of summer.”
Officials believe the drought is also providing conditions favorable for the spread of the virus.
“As birds and mosquitoes sought water, they came into closer contact and amplified the virus, particularly in urban areas. The lack of water could have caused some sources of water to stagnate, making the water sources more attractive for mosquitoes to lay eggs,” said CDPH Director and State Health Officer Dr. Karen Smith.
Dr. Walker also cautioned that those people trying to conserve water by collecting it can also be providing prime breeding areas for mosquitoes.
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.
“State health officials have been warning that people with diabetes have a higher risk of developing the neuroinvasive form of the disease,” Dr. Walker said.
The California Department of Public Health recommends that individuals prevent exposure to mosquito bites and West Nile virus by practicing the “Three Ds:”
1. DEET – Apply insect repellent containing DEET, picaradin, oil of lemon eucalyptus or IR3535 according to label instructions. Repellents keep the mosquitoes from biting you. DEET can be used safely on infants and children 2 months of age and older.
2. DAWN AND DUSK – Mosquitoes bite in the early morning and evening so it is important to wear proper clothing and repellent if outside during these times. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.
3. DRAIN – Mosquitoes lay their eggs on standing water. Eliminate all sources of standing water on your property, including flower pots, old car tires, rain gutters and pet bowls. If you know of a swimming pool that is not being properly maintained, please contact your local mosquito and vector control agency.
Both the Eastside and Turlock Mosquito Abatement districts can treat 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).