While the end of the mosquito season is close at hand and may even arrive this morning if temperatures dip low enough, the danger posed by the West Nile virus persists until the bitter end.

That warning was issued by the South Heartland District Health Department in a news release Tuesday, which announced the fourth human case of the mosquito-borne malady in its four-county jurisdiction this year.

The latest patient required hospitalization.

The South Heartland district encompasses Adams, Webster, Clay and Nuckolls counties in south central Nebraska.

“West Nile virus is considered to be endemic, established in Nebraska, so the best defense against it is prevention,” Bever said. “West Nile virus is spread through the bite of an infected mosquito. The best way to fight back is to use an insect repellant with DEET any time you are outside.”

As of Tuesday, the Nebraska Department of Health and Human Services had logged 86 cases of West Nile illness in 2021. Fifty-two of those cases were neuro-invasive, meaning they affected the patients’ brains. Forty-six of the patients required hospitalization, and five had died.

Symptoms of infection with the virus can include fever, headache, body aches, nausea, vomiting, and sometimes a rash of the chest, stomach and back.

The symptoms typically persist for a few days, but occasionally lead to serious and even life-threatening illness.

“Approximately one in every 150 people will develop severe illness,” said Jessica Warner, South Heartland’s disease surveillance coordinator. “These symptoms may last several weeks and the neurological effects can be permanent and even fatal.”

Symptoms of severe illness may include high fever, severe headache, neck stiffness, disorientation, paralysis and coma.

From June through September, South Heartland worked with NDHHS for weekly trapping and testing mosquitoes in Adams County. The mosquitoes then were sent to the state laboratory for testing.

From mid-August through September, three of the batches of mosquitoes sent off for testing came back with a positive result.

“Mosquito trapping and testing has ended for this year, but West Nile season is not over as long as the mosquitoes are still out,” Bever said.

According to the Central Massachusetts Mosquito Control Project, mosquitoes function best at 80 degrees, become lethargic at 60 degrees and cannot function when the temperature falls below 50 degrees.

In Nebraska, that means the mosquito season effectively ends by early to mid-October. The season officially ends with the first freeze.

The National Weather Service had Hastings under a frost advisory for 3-10 a.m. today, with temperatures expected to reach the lower to mid-30s.

As long as mosquitoes are flying, landing and biting, however, the risk to human health continues and precautions are in order.

Warner recommends staying indoors or taking extra protective steps from dusk to dawn; wearing long sleeves, pants and socks when outside during the peak hours and locations for mosquito activity, thereby reducing the amount of exposed skin; using repellants containing DEET; and draining standing water around your home to disrupt the mosquito breeding cycle.

For more information call the health department office in Hastings, 402-462-6211 or 877-238-7595 or visit www.southheartlandhealth.org.