San Joaquin County Reports First Human Case Of West Nile Virus

Ruzanna Harutyunyan's picture

San Joaquin County Public Health Services announced that a 59 year old male living in the southern area of San Joaquin County has tested positive for West Nile Virus (WNV). He was identified when donating blood but has no symptoms of the virus. This is the first reported infection in a San Joaquin County resident in 2009.

West Nile Virus (WNV) is transmitted to humans and animals through the bite of a mosquito. “With the increase in the mosquito population, the season for West Nile Virus in the county and around the state has arrived again. It is very important that people take all precautions to protect themselves from mosquito bites,” said Dr. Karen Furst, Health Officer of San Joaquin County.

About one in five people infected with WNV will develop West Nile Fever with symptoms of headache, fever and fatigue. In some people the fatigue may last several weeks to months. The risk of severe disease is highest in people over 50 years old and those with other health problems effecting their immune systems. People with diabetes are also at increased risk of severe disease from WNV. How to protect yourself from infection with WNV:

· When outdoors, apply insect repellent containing the active ingredient DEET or Picaridin, or products containing oil of lemon eucalyptus, according to label instructions.

· 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.

· Look around your property and remove all standing water to prevent mosquito breeding


· Report neglected swimming pools to the San Joaquin County Mosquito and Vector Control District.

Use of Insect Repellents:

· Never use insect repellents over cuts, wounds or irritated skin.

· Apply repellents only to exposed skin and/or clothing (as directed on the product label.) Do not use repellents under clothing.

· Do not apply to eyes or mouth, and apply sparingly around ears. When using sprays, do not spray directly on face—spray on hands first and then apply to face.

· Do not allow children to handle repellent products. When using on children, apply to your own hands first and then put it on the child. You may not want to apply to children’s hands.

· Use just enough repellent to cover exposed skin and/or clothing. Heavy application and saturation are generally unnecessary for effectiveness. If biting insects do not respond to a thin film of repellent, then apply a bit more.

· After returning indoors, wash treated skin with soap and water or bathe. This is particularly important when repellents are used repeatedly in a day. Also, wash treated clothing before wearing it again. (This precaution may vary with different repellents—check the product label.)

· If you or your child gets a rash or other bad reaction from an insect repellent, stop using the repellent, wash the repellent off with mild soap and water, and call your doctor or the poison control center for further guidance. If you go to a doctor because of the repellent, take the repellent with you to show the doctor.