San Diego County confirmed Thursday the first case of West Nile Virus in a human this year, in a 71-year-old man who became infected while traveling.
The man is hospitalized after he recently traveled to rural Colorado, where it is believed he was bitten by a mosquito carrying the virus, county public health officials said.
The largely avian disease can be transferred to humans, where it can materialize in a headache, fever, fatigue, nausea, rash or swelling -- and even serious illness or death.
Although the hospitalized man is not thought to have contracted the virus in the county, it is present in the local area, health officials said.
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On Sept. 13, a dead crow found in the Clairemont area tested positive for the virus and prompted county public health officials to warn county residents to take precautions against mosquitoes.
In 2015, 44 San Diego County residents tested positive for West Nile virus and six died, according to the county.
To avoid virus-carrying mosquitoes, county guidelines recommend finding and disposing of standing water to eliminate breeding grounds.
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Additionally, preventing mosquito bites is crucial in avoiding the virus. Tips include using DEET insect repellent, wearing long sleeves and pants, and securing windows and screens in homes.
If residents see a stagnant pool or other mosquito breeding grounds -- or find dead birds like hawks, jays, crows and owls -- they are encouraged to contact the county Vector Control Program at 858-694-2888 or vector@sdcounty.ca.gov.