West Nile Virus cases in Imperial County


The St. Louis encephalitis virus is also detected in local mosquitoes.

IMPERIAL COUNTY – The Imperial County Public Health Department has received confirmation of three cases of West Nile virus in local residents, according to a new release from the department. Two cases were identified as a neuroinvasive illness, the most severe form of West Nile virus (WNV). The onset of symptoms for the three cases occurred from mid-July through late August and the cases are unrelated to each other, the release stated. The median age of the individuals is 68 years. All three have been released from care and are reportedly now recuperating. 

“These reports of West Nile virus serve as a reminder of the importance of taking precautions against mosquito bites,” said Dr. Stephen Munday, Health Officer for Imperial County. “Mosquitoes infected with viruses such as WNV and St. Louis encephalitis are currently active in Imperial County. We urge everyone to take simple steps to eliminate mosquito breeding sources around their homes in order to protect themselves, their loved ones, and communities.”

St. Louis encephalitis virus (SLEV), another mosquito-borne disease with similar symptoms as WNV, was recently detected in mosquitoes collected in Imperial County, the new release said. To date, no human cases of SLEV have been reported. SLEV has been found historically in many regions of California, such as the Central Valley and southern California. However, since the introduction of West Nile virus into California in 2003, SLEV has been rarely detected.

Most individuals who are infected with West Nile virus do not experience any illness. Others will have only mild symptoms, such as fever, headache and body aches. However, WNV can be severe in the elderly and individuals with lowered immune systems. Severe symptoms of WNV include fever, nausea, vomiting and seizures.

To date, there have been no WNV-related deaths in Imperial County. West Nile virus is transmitted to humans and animals through a mosquito bite. Mosquitoes become infected when they feed on infected birds. Human-to-human transmission of WNV generally does not occur absent a blood transfusion or tissue donation from an infectious donor.

Individuals can reduce their risk of mosquito-borne diseases by taking the following precautions:

·         Limit time outdoors during dawn and early evening.

·         When outdoors, wear loose fitting, light colored, long-sleeve shirts and pants when mosquitoes are most active (during dusk and dawn).

·         Apply insect repellent that contains DEET, Picaridin or oil of lemon eucalyptus according to label instructions to prevent mosquito bites.

·          Make sure that doors and windows have tight-fitting screens. Repair or replace screens that have tears or holes.

·         Eliminate all sources of standing water on your property that can support mosquito breeding by:

–       Draining or eliminating, old tires, buckets, plastic covers, toys, or any other container where mosquitoes can breed.

–       Emptying and changing the water in bird baths, fountains, wading pools, rain barrels, and potted plant trays at least once a week to destroy potential mosquito habitats.

–       Draining or filling temporary pools of water with dirt.

–       Keeping swimming pool water treated and circulating.

·         Contact Imperial County Vector Control if there is a significant mosquito problem where you live or work.

For general information about WNV and SLEV or to report a problem with mosquitoes in Imperial County please contact Environmental Health at (442) 265-1888.

For information about WNV, visit the Web site: http://www.westnile.ca.gov/ or http://www.icphd.com/environmental-health/bee—mosquitoes/west-nile-virus-information/