A person is in serious condition at a Manhattan hospital with West Nile virus, the first human case of the 2017 season, city health officials say.
The patient is less than 50 years old and has underlying medical conditions, according to the health department.
Human cases of West Nile happen each year in New York City, and most of them are identified between late July and October.
While the mosquito population this year remains at an average level, the number of mosquito pools testing positive for West Nile virus has reached a record high at this point in the season -- 337, according to the health department. That could mean a greater risk of infection and may result in a larger number of human cases relative to other years.
The majority of the positive West Nile samples were detected on Staten Island, but mosquitoes with West Nile have been found in every borough.
The health department has completed seven rounds of pesticide spraying and two aerial larvicide treatments to reduce the risk of West Nile, and more treatments are planned.
The West Nile virus was first detected in New York City 18 years ago, and since 1999, the number of human cases has ranged from three to 47 annually. Of the 317 West Nile cases overall, 38 (15 percent) have died due to their infection.
West Nile virus infection can cause a mile or moderate flu-like illness, or sometimes no symptoms at all. In some people, it can cause a serious and potentially fatal infection of the brain and spinal cord.
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