2009 Cases of West Nile Virus Making Appearances

With people still reeling from the swine flu epidemic, it feels too soon to start thinking about West Nile virus but alas, the time is upon us. The first West Nile virus cases of 2009 have already been reported in isolated parts of the county and it is unknown at this point how many cases might occur.

West Nile Virus (WNV) began appearing in the U.S. in 1999 with an outbreak in New York City. It has since spread to all 48 contiguous states. In 2002, the number of people affected with WNV suddenly increased to 4,156. In 2003 the number of people doubled to 9,862 diagnosed and 264 people died. Since then the outbreaks have lessened considerably to less than 1,500 occurrences and less than 34 deaths by mid-November of 2008.

WNV is caused by a virus that is spread by mosquitoes and ticks that have fed on infected birds. Humans or animals bitten by mosquitoes carrying WNV become infected as the virus is passed on to them. It can take 3-14 days for symptoms to appear.

Mild symptoms usually are fever, headache, body aches, body rash and swollen lymph glands. More severe symptoms that should be evaluated right away by a doctor or emergency room are: high fever, headache, neck stiffness, disorientation, convulsions, muscle weakness, vision loss, numbness or paralysis. These can be early symptoms of WNV induced encephalitis or meningitis.

There is no way to predict who will come down with WNV flu or other complications but luckily only 20% who get WNV will develop mild symptoms and 80% won't even knowing they have had it. Just 1 in 150 cases will come down with a more severe infection of encephalitis or meningitis which can cause nerve damage and partial paralysis. Less than 1 in 1000 people who contract WNV die from it. Those over the age of 50 are at the greatest risk and those who are immunocompromised.

One of the concerns for 2009 is that with the downturn in the economy there are many homes foreclosures leaving swimming pools filled with water uncared for. These unattended bodies of water are prime breeding ground for mosquitoes.

In San Gabriel, California workers were pulled away from "bee duty" to instead do "pool duty" testing for larvae in unattended swimming pools. Since the homes are in foreclosure, delays screening these pools are frequent as permission to enter the backyards must be obtained from either realtors or banks involved.

An infected mosquito has already been collected in Carson, California first of the season to be found in this zip code and eight other mosquitoes have been found elsewhere in California. In York County, Pennsylvania the first West Nile virus mosquito was recently found. This is the one of the earliest findings of WNV discovered in Pennsylvania in many years.

Hernando County, Florida is arming itself against WNV outbreak by using "sentinel chickens" dispersed in five separate locations through out the county. Each week blood will be drawn from the chickens and tested for WNV and encephalitis in order to stay on top of outbreaks. Chickens were chosen because they are sensitive to the virus but are not likely to die of an infection.

Precautions against WNV include making sure there is no standing water left outside your home to breed mosquitoes. Empty the water in wading pools, buckets and in pet's water dishes. Drain and replace water to bird baths weekly. Avoid being outside during dawn or dusk when mosquitoes are most active and if outside during these times, wear long sleeves and long pants.

Use DEET insecticide or other EPA registered insecticide. EPA approved Lemon Eucalyptus Insect repellent has been tested to be an effective non-DEET mosquito repellent option. Follow directions on labels closely, use the lowest dose of DEET needed for protection and reapply as directed.

Hopefully with early attention to prevention, this season's WNV outbreak will be even lower than in 2008 as increased awareness is felt to have contributed to the significant drop of cases last year.

Source:

Baeder, Ben. (May 15, 2009) Bee removal service canceled; West Nile has vector control agency buzzing. Retrieved May 18, 2009, from http://www.sgvtribune.com/ci_12380868

Martin, Kyle. (May 13, 2009) 'Sentinel'Chickens guard against mosquito-borne disease. Retrieved May 18, 20009 from http://www2.hernandotoday.com/content/2009/may/13/sentinel-chickens-guard-against-mosquito-borne-dis/

Woolston, Chris. West Nile Virus. Retrieved May 18, 2009 from VHI healthcare. Web site: http://www2.vhi.ie/topic/westnile

Woolston, Chris. West Nile Virus. Retrieved May 18, 2009 from VHI healthcare. Web site: http://www2.vhi.ie/topic/westnile

West Nile Virus: What You Need To Know. CDC Fact Sheet. Retrieved May 18, 2009. Web site: http://www.cdc.gov/ncidod/dvbid/westnile/wnv_factsheet.htm

West Nile Virus Statistics. Retrieved May 18, 2009 from West Nile Virus. Web site: http://www.west-nile-virus-prevention.com/statistics.html

Wire Services. (April 28, 2009) Mosquito in Carson tests positive for West Nile virus. Retrieved May 18, 2009. http://www.wavenewspapers.com/news/local/west-edition/43825207.html