Ask EpicentRx™

Oct 27, 2023

“Assume nothing. Question everything. Verify all.”

“Always Zika the truth.”

Q: “Now that it’s gotten warmer, how scared should I be of West Nile and Zika viruses when I visit the US?” MMC from Sweden

A: OK, this is a 2fer.

West Nile virus, originally seen in Africa, is now seen all over the world, and on every continent, including Europe, except Antartica. Several US states including Georgia, Maryland, and Texas have issued West Nile alerts. The virus spreads to humans following a bite from the Culex mosquito, which mainly feeds on birds such as rows, ravens, jays, pigeons, and domestic geese that are infected with it. Symptoms of a mild, flu-like disease are present in 25% of those infected; the remaining 75% show few to no symptoms. Less than 1% will develop serious neurological disease such as encephalitis or meningitis (inflammation of the brain or surrounding tissues), or paralysis. Advanced age, concurrent diseases like diabetes, and immunocompromised status are the most significant risk factors for serious neurological disease. There are no vaccines for West Nile virus, and treatment consists of supportive care.

So, MMC from Sweden, serious disease is rare enough that we recommend not to let fear of the virus spoil your travel plans. That said, it is always a good idea to take precautions. These include the use of insect repellant such as DEET, picaridin, or oil of lemon eucalyptus, protection of skin with loose fitting, long sleeved clothing and long pants, limitation of time spent outdoors at dawn, dusk, and early evening when mosquitoes are most active, and avoidance of standing water where mosquitoes breed.

As for the Zika virus, which the Aedes species mosquito transmits, the last reported U.S. case was in 2019. Most individuals infected with Zika are asymptomatic; those that are symptomatic may develop rash, fever, conjunctivitis, muscle and joint pain, malaise and headache that last for 2-7 days. The real danger from the virus is to pregnant women because of Zika’s association with birth defects such as microcephaly (small head and brain size). However, the United States is currently a Zika-free destination.

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