News provided by Pinal County

In all of 2009, Pinal County had no reported cases of West Nile virus in humans and little of the disease found in its carrier, mosquitoes. In just the last 2 months, Pinal County has had six cases of West Nile virus in humans, all of them with meningitis, one of the most severe complications of the disease.

According to state health officials, Arizona is leading the nation in the number of human West Nile cases as of this date.

Substantial West Nile virus activity has been reported in portions of Maricopa and Pinal counties as evidenced by mosquito surveillance and documented human cases in the past two months. The area of most intense activity has been in the suburban east valley area of Phoenix including Gilbert, Chandler, Mesa, Queen Creek, and San Tan Valley. Surveillance activities are now indicating a further spread into Pinal County with positive mosquitoes identified in Maricopa, Florence, Coolidge, Casa Grande, Arizona City and Stanfield. Additionally, human cases have been reported in Casa Grande, Coolidge, San Tan Valley, Apache Junction and on tribal land over the last two weeks.

There have been approximately 50 human cases of West Nile identified statewide this year, compared to 20 for all of 2009. All cases to this point have occurred in Maricopa and Pinal counties. Three West Nile-associated deaths have also been identified in Arizona in 2010. There have been no Pinal County deaths from West Nile so far.

Pinal County has recorded six cases so far, but many more cases are likely occurring since most people who are exposed experience no symptoms or very mild symptoms and do not seek medical care. Physicians generally test for West Nile only if severe symptoms develop.

“West Nile virus has been around for several years and the past couple of years we have seen a decrease in concern among the public. The fact is West Nile virus is a significant threat to public health and should not be taken lightly. While the illness from West Nile virus is often times minor, we continue to see severe illness that can result in permanent neurological damage and or death. I urge all Pinal County residents to take the simple steps needed to protect themselves, family and friends from West Nile virus. West Nile risks need to be taken seriously,” said Tom Schryer, Director of Pinal County Public Health.

Pinal County Environmental Health monitors more than 140 mosquito traps around the county to identify areas where mosquitoes are carrying West Nile virus. Fogging is then conducted in areas identified with mosquitoes carrying the disease to decrease the potential for transmission to humans. Pinal County Environmental Health has also responded to approximately 300 complaints regarding mosquitoes, standing water or neglected swimming pools since the start of mosquito season. Once identified, pools are treated to ensure that mosquitoes are not able to breed in the water.

What Are the Symptoms of West Nile?
No Symptoms in Most People. Approximately 80 percent of people (about 4 out of 5) who are infected with West Nile will not show any symptoms at all.
Milder Symptoms in Some People. Up to 20 percent of the people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.
Serious Symptoms in a Few People. About one in 150 people infected with West Nile will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent.

What Can I Do to Prevent West Nile?
The easiest and best way to avoid West Nile is to prevent mosquito bites.
When you are outdoors, use insect repellent containing an EPA-registered active ingredient. Follow the directions on the package.
Many mosquitoes are most active at dusk and dawn. Be sure to use insect repellent and wear long sleeves and pants at these times or consider staying indoors during these hours.
Make sure you have good screens on your windows and doors to keep mosquitoes out.
Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels. Change the water in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out. Keep children’s wading pools empty and on their sides when they aren’t being used.
Other Resources for Information on West Nile:

The Centers for Disease Control and Prevention

Arizona Department of Health Services