Thursday, August 23, 2012

U.S. West Nile Virus

The U.S. is experiencing record numbers of West Nile Virus (WNV) this year.
So far, 38 states have reported human cases, but the epicenter is Texas, which has reported half of the WNV infections. The CDC said so far it has received reports of 1,118 cases, including 629 people with the neuroinvasive form of the disease. Nationally, 41 deaths have been reported.
West Nile virus has no vaccine and no cure and can cause permanent neurological sequelae or death in about 1 in 150 people infected. About 80% of those infected do not experience any symptoms but 20% will have moderate symptoms that mimic the flu and can last from days to weeks even in healthy people.

Forty-seven states have detected West Nile Virus in either humans, birds or mosquitoes.  You can navigate the maps to view the status of your area.  It is imperative that people follow the guidelines for preventing WNV.  In areas where standing water cannot be removed such as rainbarrels and ornamental ponds, use mosquito dunks to control larvae (this is not an endorsement of a specific product but rather an example).


  1. I remember when I worked as a public health nurse in a County health department, close to the epicenter of the first WNV cases in the Western Hemisphere. IIRC a scientist in Queens, NYC, first identified the presence of the virus and the fine work done by the NYC and the NYS Health Departments and their case surveillance.

    Staff from these health departments went house to house in Queens to ask for volunteers to be tested for the presence of WNV antibodies in their blood serum. The results of these blood tests added immeasurably to the knowledge base of the WNV epidemic.

    Dr. Mark Crislip at the SBM website just blogged about genetically modified sterile male mosquitoes as a tool to decrease reported cases of dengue fever and other mosquito-borne diseases. Would you believe...that some people are concerned about the release of GM sterile male mosquitoes "in the environment"?

  2. Well, I always figure that the people who so fear GM anything probably have no fear of broccoli or bananas. Not to mention they might own a fancy breed of dog.

  3. I don't get the GM fear either. Concern with certain things, yes but a sterile male mosquito? With as dry as the country is/has been, it will be interesting to see if other ecological factors have changed to cause an increase in WNV.

  4. Actually, every state and every county is concerned about WNV and how to control mosquito populations, using various types of "Integrative Pest Management". In my County, surrounded by natural salt water wetlands and estuaries we implemented "Integrative Pest Management", years ago:

    I know that in my County, we used *sentinel chickens* in chicken coops situated throughout the county in our parks, when WNV encephalitis was diagnosed and caused the deaths of some elderly residents. The lab techs from our County lab would draw blood weekly from the sentinel chickens (they got infected, but didn't die from WNV), for testing for the presence of WNV antibodies. Our public health sanitarians would respond to telephone calls to pick up birds (especially crows), which were dropping like flies (pun intended), for testing at our County and State laboratories.

    Perhaps it is the public perception and lack of science in our education systems that cause people to reject GM food and GM sterile male mosquitoes. They would rather face up to the real risk of WNV and other mosquito-borne diseases. Pathetic.