Every summer, outbreaks of West Nile virus disease occur in the U.S. This year, some parts of the country are experiencing earlier and greater activity, and the Centers for Disease Control and Prevention is urging people to take preventive steps to protect against West Nile virus infections.

Infected mosquitoes transmit the West Nile virus to people. The main season for infections in the U.S. is generally between June and September, with a peak in mid-August. Local areas frequently experience seasonal outbreaks that vary from one year to the next and which depend on factors like the weather, the numbers of mosquitoes spreading the virus and human behavior.

Until this month, 42 U.S. states have already reported West Nile virus infections in people, birds, or mosquitoes and the CDC has received reports, of which 80% stem from Texas, Mississippi, and Oklahoma, involving a total of 241 cases of West Nile virus disease, including four deaths. This is a record high number of cases until the end of July since 2004.

Marc Fischer, M.D., M.P.H., medical epidemiologist with CDC's Arboviral Diseases Branch said: "It is not clear why we are seeing more activity than in recent years. 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 best way to protect against West Nile virus disease is to avoid mosquito bites. The following steps can help you avoid the itchy and dangerous bites we all get in the summer:
  • Install or repair mosquito screens on windows and doors und use air conditioning, if available.
  • Wear long sleeves and pants during dawn and dusk.
  • Use insect repellents when you go outdoors.
  • Do not keep any standing water outside your home, like buckets of water, flowerpots, and paddling pools.
The symptoms of the West Nile virus include: These symptoms affect around 1 in 5 infected people. Only less than 1% of those infected will develop a serious neurologic disease like encephalitis or meningitis, i.e. an inflammation of the brain or surrounding tissues and 10% of those who develop a West Nile virus-related neurologic infection will die. The risk is greater for those above the age of 50 years and people with certain medical conditions, including cancer, diabetes, hypertension, kidney disease, and those who had organ transplants.

To date, there are no treatments or vaccines to prevent West Nile virus infection. Those who suffer a milder degree of the illness generally recover unaided, even though symptoms may sustain for several weeks, whilst people with more severe cases often require hospitalization for supportive treatments, including intravenous fluids, pain medication, and nursing care.

Anyone with symptoms who is concerned should seek medical advice.

Written By Petra Rattue