West Nile virus monitoring programs started detecting this year’s first batch of disease-carrying mosquitoes and infected birds earlier this month in Illinois, California, Tennessee and other states. Forecasting how many people may catch the disease presents a challenge for officials, according to the Centers for Disease Control, because many local factors influence the disease along with larger scale weather patterns.

A frigid winter and chilly spring may have worked to knock the insect population down in many areas of the U.S. However, the rainy spring that helped break the drought in many areas also increased the number watery breeding sites for disease-spreading mosquitoes. High temperatures also increase the rate of mosquito reproduction, according to the CDC.

Social and economic factors also play a part in West Nile outbreaks, according to the CDC. Higher risk of West Nile exists in places where people spend more time outdoors,  have less access to enclosed, air-conditioned areas or lack public health initiatives to destroy mosquito breeding areas.

Pet Poisons Lurk in Gardens

People can reduce the threat of West Nile in their area. To eliminate mosquito breeding grounds, the CDC recommends emptying standing water from flowerpots, gutters, buckets, pool covers, pet water dishes, discarded tires, and birdbaths.

Unused swimming pools can become mosquito playgrounds. People can fight nature with nature by tossing the bacteria, Bacillus thuringiensis, into old pools and other stagnant bodies of water. Many garden centers sell the bacteria in the form of donut-shaped inoculating floats.

NEWS: Get Ready for Invading Asian Tiger Mosquitoes

Despite the best efforts to eradicate mosquito nurseries, the insects will still be out for for blood this summer.

The CDC offers tips for avoiding mosquito-borne diseases, including West Nile:

  • Wear insect repellant

  • Wear long-sleeved shirts and long pants from dusk to dawn

  • Install intact screen windows and doors

  • Use air conditioning

Only one in five people infected with West Nile develop a fever. However, one percent of those infected suffer severe, even fatal neurological illness, according to the CDC. People over 60 years of age are particularly susceptible to the disease.

NEWS: Mosquito Parasite Fights Infectious Disease

No vaccine or treatment exists to treat the virus in humans. People can usually fight off the disease without hospital care. In extreme cases, doctors can provide pain medication, intravenous fluids and other help to the infected.

IMAGE: Mosquito larvae (Julien Pellet, Wikimedia Commons)