31 July 2003

Contact: Jeff Zayach, Environmental Health Division Manager, 303-441-1182 or
Julie Handy, RN; Communicable Disease Control Nurse, 303-413-7531

Boulder County Records its First 
Human Cases of West Nile Virus Infection

The first human cases of West Nile virus (WNV) have been confirmed in Boulder County. The first case, a 48-year-old Louisville woman, was seen at an urgent care center on July 9th, and then by her primary care physician. She presented with symptoms of fever, headache, stiff neck, body discomfort, muscle weakness, and joint and bone pain, and is now recovering at home. 

A second Boulder County case was confirmed this week. A 46-year-old woman from Longmont experienced flu-like symptoms similar to the first case, including fever, body aches, and eye pain. She also suffered from a "hive-like" rash. She is receiving care for her symptoms from her family doctor, and is now recovering at home.

To date, Colorado has reported a total of 18 confirmed human cases of WNV, with multiple cases still pending confirmation. All are recovering. There have been no fatalities in Colorado so far this year. This number of cases is comparable to the incidence of human cases of the virus in other states across the nation.

West Nile virus is a disease that can be transmitted to humans by mosquitoes. It can cause encephalitis (inflammation of the brain) and/or meningitis (inflammation of the brain's lining); however, most infections are mild. Symptoms include fever, headache, body aches, and can occasionally include skin rashes and swollen lymph nodes. 

Severe illness from WNV occurs in only less than 1 percent of those bitten by an infected mosquito. Generally, symptoms appear 3-14 days after being bitten by a mosquito. 
"The amount of activity that we're seeing across the state and the country is what we have been expecting since last season" said Boulder County Public Health (BCPH) Communicable Disease Nurse Julie Handy. "We have anticipated this activity, and have worked hard to get messages out to the public about how to protect themselves this summer." 

It is anticipated that there will be more cases of WNV in Boulder County this season, but the number of cases depends on the level of precautions individuals take to protect themselves.
Public health authorities recommend the following precautions to reduce your risk for contracting the virus:

• Avoid outdoor activities, such as gardening, at dusk and dawn when mosquitoes are most active.

• If outside during the periods when mosquitoes are most active, cover up by wearing long-sleeved shirts, pants, shoes, and socks.

• Install or repair window and door screens so mosquitoes cannot get indoors.

• Use mosquito repellents containing DEET. Products with 10 percent or less DEET are recommended for children.

• Eliminate standing water in tires or similar water-holding containers, as these may serve as mosquito breeding sites. Change the water in birdbaths at least weekly.
  

In addition to these precautions, Boulder County has one of the most comprehensive mosquito control and monitoring programs in the state of Colorado. Mosquito management in Boulder County reduces the risk of exposure to WNV and includes surveillance, larva control, and adult mosquito control. 

More than 50 mosquito traps are used to monitor mosquito populations, and more than 1,000 potential mosquito-breeding sites are continually monitored and treated during the mosquito season.

Beginning the first week of August, BCPH will discontinue testing of dead birds in areas where existence of WNV-positive mosquito populations have been confirmed, and instead will focus testing efforts in mountain communities. 

"Public response to bird submission has been outstanding," said Jeff Zayach, BCPH Environmental Health Division manager. "Now that we know where the affected areas are, we no longer need the public to submit dead bird samples, except in mountain communities." 

"We need to focus our attention on areas that have had little testing to date. By testing these areas, we will be able to implement precautionary measures for residents if WNV appears." 

Although it is highly unlikely that WNV can be contracted from picking up an infected dead bird, Zayach stressed exercising caution when disposing of dead birds, or any other dead wildlife. Persons who find dead birds should, using gloves, pick them up with a shovel, place them in a plastic bag, and dispose of them in a trash dumpster.

For more information about WNV, please visit Boulder County Public Health's website at www.bouldercountymosquito.net  or the Colorado Department of Public Health and Environment's website at www.FighttheBiteColorado.com. BCPH's recorded message for general information is available at 303-441-1460. To ask specific questions, call the Colorado Health Education Line for the Public at 1-877-462-2911 (available in Spanish and English).
If you think you may have symptoms of WNV, consult your primary care physician.