Three mosquito samples from the Animas Valley have tested positive for West Nile virus over the last two weeks.

The samples are the first collected by the Animas Mosquito Control District to test positive for West Nile since 2016, said Melody Schaaf, officer manager and lab technician for the district.

The district samples for disease by trapping mosquitoes each night and sending them in for testing regularly, she said. Each sample can have five to 65 mosquitoes, she said.

Most people infected with mosquito-borne viruses don’t get sick. However, those who do contract the viruses start experiencing symptoms two to 14 days after getting a mosquito bite, according to a news release from San Juan Basin Public Health.

Symptoms of West Nile virus include fever, nausea, headache and muscle aches. In rare instances, the virus can also cause encephalitis and meningitis and can be fatal. Anyone with West Nile virus symptoms should see a health care provider.

People older than 60 are most at risk for serious illness or disease from the virus.

Residents can protect themselves by using insect repellent containing DEET, draining standing water around homes and wearing long-sleeve shirts and pants.

Residents should be especially cautious at dusk and dawn when mosquitoes are most active.

Common sources of standing water include pools and rain barrels, Schaaf said.

Residents can also ask the Mosquito Control District to treat their property for the insects if necessary, she said. For example, the district can treat marshes for the insects, she said.

For a list of EPA-approved insect repellents, visit epa.gov/insect-repellents.

For more prevention information visit cdc.gov/westnile/prevention.

mshinn@durangoherald.com