I imagine you have heard in the media about the high rate of West Nile virus infections this year. Lyle Peterson, M.D, the director of the CDC’s division of Vector-Borne Diseases states “this year’s outbreak is the most serious to date since West Nile virus was discovered in the U.S.” This is not just a summer virus danger: the potential for exposure continues through the fall season.
West Nile virus is spread by mosquitoes to humans from the ever annoying bite. The mosquito acquires the virus from feeding on infected birds and then transmits the virus to us humans and other mammals. The bite site itself is just like an ordinary mosquito bite – it is not more itchy or redder. But 3-14 days after the bite occurs symptoms can start. The good news is the majority of people have no symptoms after exposure. Up to 20% of the time mild symptoms of infection can occur. These symptoms are usually fever, headache, body aches, nausea, vomiting, and sometimes a rash or swollen lymph nodes. The illness can last a few days to weeks. Unfortunately one out of 150 cases of infection can lead to severe illness. These symptoms are high fever, headache, neck stiffness, muscle weakness, seizures, disorientation and even coma.
Diagnosis of West Nile virus infection is done by testing blood or spinal fluid. There is no treatment medication specific against the virus. Supportive care is provided to the patient. One may think the most susceptible people to get West Nile infection are infants and children, but instead the most likely to have severe symptoms are the elderly. People with immunodeficiency and individuals with history of organ transplant are also more likely to have symptoms. Pregnant women are to avoid infection due to rare transmission of the virus to the fetus.
How do you avoid getting West Nile virus infection?
- Avoid being outside at dawn and dusk hours. The Culex mosquito is the usual type to carry the virus and they are most active at these times.
- Use a mosquito repellent. Mosquito repellents containing DEET (diethyltoluamide) are the most effective. The American Academy of Pediatrics recommends NO mosquito spray repellent for infant under 2 months of age, and approves mosquito sprays containing less than 30% DEET for infants and children.
- Remove mosquito breeding sites. Empty any areas of standing water: in potting saucers, and children’s wading pools; change outdoor pet water dishes often and birdbath water areas weekly.
We may be seeing a positive note to this bad West Nile season. As of September 12 the CDC believes the epidemic has reached its peak. But don’t let your guard down. Now that the weather is cooler you may be tempted to pack up the bug spray – but those pesky mosquitoes are still playing!
Dr. Lisa Gold is a pediatrician practicing in Crown Point, Indiana, at the Franciscan Physician Network – Crown Point Pediatric Health Center.