LOCAL

Tests detect St. Louis Encephalitis and West Nile in mosquitoes in Reno County

Health officials advise caution against bites, larvae elimination efforts should continue

John Green
jgreen@hutchnews.com
St. Louis encephalitis virus disease cases reported by state of residence, 2008–2017. [Centers for Disease Control}

Mosquitoes collected from traps in Reno County recently tested positive for both West Nile Virus and St. Louis Encephalitis, the Reno County Health Department advised this week.

While temperatures have significantly cooled, health officials warn mosquitoes that can carry both viruses, though less active, are still present, so the chance of infection remains.

Which means, said Darcy Basye, Environmental Health coordinator at the local department, that efforts to reduce mosquito numbers and to prevent mosquito bites should also continue.

“There’s still some danger,” Basye said. “It’s not cold enough to completely reduce them out. People need to be aware and to protect themselves. Be aware of standing water and come to the health department to get some free dunks to stop mosquitoes at the breeding source.”

Though rare, both West Nile virus and St. Louis Encephalitis can cause inflammation of the brain, causing serious illness or even death, particularly in elderly populations or people with immune system deficiencies.

While mosquito trapping throughout the summer indicated the presence of the species of mosquitoes capable of carrying and transmitting both viruses – as well as the species that can carry the Zika virus – the recent test was the first one this year to show either of the first two viruses actually present in the insects captured.

It was also the first time, said Elliot Koester, epidemiologist for Reno County, that the state tested for St. Louis Encephalitis in mosquitoes trapped in the county.

So, it might have been present in the past, but officials didn’t know it, he said.

“Once you learn about anything new within a community or within an environment it raises concerns, which is why we’re raising awareness,” Koester said. “However, it is similar to West Nile in the sense it does not hurt most people if bit by a mosquito. Most people flush it out of their system. But older adults and those immuno-compromised are at higher risk.”

The only cases of St. Louis Encephalitis recorded in Kansas since 2003 – which is as far back as data on the federal Centers for Disease Control website goes – were single confirmed human cases in Ellis and Sedgwick counties, both in 2004.

In contrast, the CDC website showed human infections of West Nile virus have occurred in Reno County 11 of the past 15 years, with the highest incidence being eight cases in 2013.

Like West Nile, St. Louis Encephalitis, is not contagious from person to person and the symptoms of infection are similar, including include fever, headache, stiff neck, disorientation, and altered level of consciousness.

There is no specific treatment for the virus and antibiotics are not effective against it, the CDC reports. Severe illnesses are treated by supportive therapy which includes hospitalization, respiratory support, IV fluids, and prevention of other infections.

Total trapped mosquito numbers in Reno County also shot up significantly earlier this month, Health Department Director Nick Baldetti reported to the County Commission last week, particularly in the southwest part of the county, after several heavy rains and some flooding in parts of Pratt and Reno counties.

Officials could not say how many trapped mosquitoes were infected with either virus, only that the viruses were present.

That’s because all of the trapped insects are ground together to produce the DNA which scientists then test for the viruses, Bayse explained.

State health officials last weekend also advised of confirmed positive West Nile infections in horses in five counties in the state, including Seward, Marion and Wichita counties in The News coverage area.

The virus, which is preventable in horses with annual vaccinations, can be fatal to the animal. Other symptoms in horses range from depression, loss of appetite and fever to severe neurologic signs such as incoordination, weakness, inability to rise, and hypersensitivity to touch or sound.

Teams will continue to monitor the mosquito traps in Reno County through the end of Fall, with the last trapping scheduled for Oct. 24, Bayse said.

It’s unclear whether the state will continue mosquito trapping and testing in Reno County next year. The effort was funded through a federal grant this year after three West Nile fatalities in the region a year ago.