USA combating its worst West Nile Virus outbreak ever
By Jan Boshoff | Published August 16, 2012
While American farmers are struggling to deal with widespread losses due to the sustained period of drought this summer, a second menace is thriving in the unusually dry climate. The USA is now facing its worst year of the annual West Nile Virus outbreak since the virus was first identified in the USA in 1999.
To date, there have been 26 deaths and 693 confirmed cases of the virus in 32 states, according to the U.S. Centers for Disease Control and Prevention.
The West Nile Virus is transmitted to people by infected mosquitoence no symptoms, while roughly 1 in 5 people will develop symptoms such as fever, headachs. The virus can infect people of all ages, however most people who become infected will experiee, body aches, joint pains, vomiting, diarrhea, muscle tremors, dizziness, or skin rashes. Fewer than 1 percent will develop more serious illnesses, such as West Nile encephalitis or meningitis.
Children generally have very mild illnesses associated with the West Nile Virus, but adults, especially those over 50 or those suffering from conditions that suppress the immune system, diabetes, or hypertension face the highest risk of developing a serious illness due to WNV infection.
There are no specific drugs used for treating WNV infection; medical care is mostly supportive while the person’s own immune system fights the disease. Most people who get the milder form of disease called “West Nile Fever” recover fully within a couple of weeks. However, those who develop the severe neurological disease associated with WNV often face weeks of rehabilitation and may never return to their normal level of activity.
Health officials say this summer’s dry weather has made people less concerned about mosquitoes, normally associated with wetter weather, and become less conscientious in applying the usual anti mosquito measures. Unfortunately, the type of mosquito that carries the virus does well in dry weather with occasional rain, and so the current drought has proved to be a very favourable breeding environment.
Mayor Mike Rawlings declared a state of emergency in Dallas and announced the city’s first aerial spraying of insecticide since 1966. More than 200 cases of the virus have been reported in Dallas County and 10 people have died in the state this season. Mayor Rawlings said that Dallas County accounts for 25 percent of all reported West Nile virus cases in the United States. Public health officials decided that increased measures, such as aerial spraying, are necessary because of increased findings of West Nile Virus in mosquitoes captured in traps.
The West Nile Virus is primarily an avian disease often resulting in the death of infected birds. In the Western Hemisphere, the American Crow and the American Robin are the most common carriers. The disease is spread by mosquitoes and can also infect some mammals including humans, horses and pets. Human cases of the WNV were first documented in Uganda in 1937, but it is now widespread in Africa, India, southern Europe, Australia and south west Asia. It was first detected in the USA in 1999, in New York, but infections have now been reported all over the United States, Canada, Mexico, the Caribbean and Central America.
In the USA, most infections occur between June and September with a peak in August, according to the CDC. “It is not clear why we are seeing more activity than in recent years,” CDC medical epidemiologist Marc Fischer announced on Friday. “Regardless of the reasons for the increase, people should be aware of the West Nile Virus activity in their area and take action to protect themselves and their family.”
The single most effective anti-mosquito measure is eliminating the standing water where larvae grow into adults. The proper disposal of used tires, cleaning out rain gutters, bird baths, empty flower pots and unused swimming pools greatly reduces the mosquito population in an area.
Individuals are advised to take proper precautions against mosquito bites. These include wearing light coloured, long sleeve clothing, using insect repellent containing DEET and staying indoors between dusk and dawn when mosquitoes are most active.