VIDALIA — With West Nile Virus confirmed in one human in the area, many who work or play in the fields may be asking how the virus can be found before it infects more human — or horse — victims.

The virus, a disease that finds its genesis in birds and is spread through mosquito bites, can lead to encephalitis — a potentially fatal swelling of the brain — in humans and horses.

Mississippi Department of Health state medical entomologist Jerome Goddard said the department tries to confirm mosquitoes in an area are carrying the virus before anything is infected.

The department does this by testing a mosquito pool, a representative sample of about 50 adult insects from the mosquito population of an area.

“We don’t just test one mosquito,” he said.

The sample mosquitoes are ground and their remains are tested for the virus, Goddard said.

A mosquito pool should not be confused with standing water, he said.

“West Nile Virus cannot be contracted by walking through a puddle or water,” he said.

The virus can only be contracted through mosquito bites, he said.

Mosquitoes are active year round, and it is possible for a person to catch West Nile during the winter months, Goddard said.

The chances of contracting the disease are much more likely during the warmer months, when West Nile activity peaks in the mid-to-late summer, he said.

Protections those who will be exposed to mosquito activity can take include using insect repellents and limiting skin exposure, Goddard said.

“Source reduction is also important,” he said. “We try to get people to get rid of mosquitoes where they are growing them.”

Draining stagnant water and making sure everyday places where water might stand, such as birdbaths, is a good start to limiting the mosquito population, Goddard said.

Mosquito larvae grow in still waters.

Using a larvacide on bodies of water where mosquitoes grow and using an adulticide — usually a spray — are also good ideas, Goddard said.

The cities of Natchez and Vidalia have trucks rigged to spray for mosquitoes, Concordia Parish has a mosquito abatement program and the Adams County Road Department provides a larvacide to citizens who want it.