Recently a mosquito infected with West Nile Virus was discovered in Medford, and several people in Massachusetts have been diagnosed with the disease. For nearly two decades, West Nile Virus has been endemic to New England and cases typically develop during the late summer and early fall.
Edward Butler, MD, an infectious diseases specialist with Tufts Medical Center Community Care at Lawrence Memorial Hospital of Medford, has seen cases of West Nile Virus over the years. He offered the following four things to know about West Nile Virus.
- Not everyone who contracts West Nile Virus gets sick.
In fact, the Centers for Disease Control and Prevention estimates that eight out of 10 people who contract West Nile Virus will remain symptom-free. The remaining 20% develop a fever along with other symptoms that may include a headache, body aches, joint pains, vomiting, diarrhea or rash. In a much smaller population, West Nile Virus can cause illness ranging from a mild fever to more serious disease such as encephalitis, meningitis or even death.
- Why do some people get sick while others don’t?
According to Dr. Butler, there are two factors that may determine who gets sick and who doesn’t. “People with weaker immune systems, such as the very young, the very old or those with certain chronic conditions that affect their immune systems may be more susceptible. Also, those who receive a larger dose of the virus, perhaps from being bit more than once, may be at greater risk.”
- You cannot catch West Nile Virus from a dead bird.
As Dr. Butler explains, West Nile Virus requires a complex ecology that consists of intermediate hosts of the disease – typically birds. Birds cannot transmit the disease directly to a human. A mosquito bites the bird and then gets infected. When the mosquito bites a human, the virus gets transmitted to the human.
- The best defense to keep from getting West Nile Virus is mosquito control. Try these mosquito control tips:
- Use insect repellent registered by the Environmental Protection Agency (EPA).
- Wear pants and long sleeves.
- Avoid areas heavily populated by mosquitos at dusk and dawn.
- Use screens on windows and doors. Repair holes in screens to keep mosquitoes outside.
- Use air conditioning when available.
- Sleep under a mosquito bed net if air-conditioned or screened rooms are not available or if sleeping outdoors.
- Once a week, empty, scrub, turn over, cover, or throw out items that hold water, such as tires, buckets, planters, toys, pools, birdbaths, flowerpots, or trash containers. Check inside and outside your home. Mosquitoes lay eggs near water.
For more information on West Nile Virus, visit https://www.cdc.gov/westnile/.
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