The area in Michigan at high risk for the dangerous mosquito-borne virus Eastern equine encephalitis is continuing to grow, state health officials say, and now includes 12 counties as ongoing warm weather has allowed mosquitoes to continue biting.

The following counties have confirmed human or animal cases of EEE: Barry, Berrien, Calhoun, Cass, Genesee, Jackson, Kalamazoo, Lapeer, Montcalm, Newyago, St. Joseph, and Van Buren, according to the Michigan Department of Health and Human Services.

The only way to protect yourself from the virus is to avoid being bitten by mosquitoes, which carry EEE after they bite infected birds and then pass it along to humans and other animals.

People living in those high-risk counties should take precautions to avoid mosquito bites until the first hard frost, the MDHHS advises.

EEE has hit especially hard in western Michigan, where there have been eight confirmed human cases. The three people who died of the virus lived in Kalamazoo, Cass and Van Buren counties. The virus also has been identified in 25 animals, including two Mexican gray wolf pups that died in early September at the Binder Park Zoo in Battle Creek.

The virus causes mild or no symptoms in some people, but is fatal in 1 in 3 people who are sickened by it, and can cause long-term disabilities in those who survive it, according to the U.S. Centers for Disease Control and Prevention. There is no treatment for EEE, except to offer support to help a severely ill patient with breathing, hydration and nutrition.

More:Second Mexican gray wolf pup dies from Eastern equine encephalitis at Binder Park Zoo

More:Mom tells encephalitis survival story as virus spikes in western Michigan

Because mosquitoes are most active between dusk and dawn, people in parts of the state that are at high-risk for EEE should consider canceling, postponing or rescheduling outdoor events that occur at or after dusk, especially those that involve children, the MDHHS advises.

This would include events such as late-evening sports practices or games or outdoor music practices and concerts "out of an abundance of caution to protect the public health and applies until the first hard frost of the year," according to an MDHHS news release.

Several New England states also have seen increased EEE activity this year. Three deaths have been reported in Massachusetts and one person died in Connecticut as well as one person in Rhode Island.

The CDC offers these tips for protecting yourself from mosquito bites:

Use bug spray: Apply insect repellents that contain the active ingredient DEET, or other U.S. Environmental Protection Agency-registered product to exposed skin or clothing, and always follow the manufacturer’s directions for use.

Other effective ingredients include:

Picaridin (known as KBR 3023 and icaridin outside the US)

IR3535

Oil of lemon eucalyptus (OLE)

Para-menthane-diol (PMD)

2-undecanone

Wear long sleeves, long pants, and shoes with socks: Even though it's still warm out, long clothing can help prevent bites, especially if you apply insect repellent on top of the clothing.

Inspect your home. Be sure there are no holes in the window and door screens so mosquitoes stay outside. Repair any screens that are damaged or have holes.

Empty standing water, where mosquitoes breed. They can lay eggs in as little water as what collects in a bottle cap. Check your home's gutters and downspouts, in children's toys, bird baths, and flowerpots.

Stay indoors at dusk and after dark, when mosquitoes are most active and likely to feed.

Use nets and/or fans to keep bugs at bay if you plan to eat outdoors/spend time outside when mosquitoes are active.

Babies younger than 2 months old should not use insect repellent. Instead:

Dress your child in clothing that covers arms and legs.

Cover strollers and baby carriers with mosquito netting.

Do not use products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) on children under 3 years old.

EEE symptoms, what to look for

Symptoms off EEE typically appear from four to 10 days after the bite of an infected mosquito, according to the CDC. The infection can be either systemic or encephalitic, which involves the swelling of the brain. Some people who contract EEE do not have symptoms at all.

In those who develop a systemic infection, symptoms can appear suddenly and last up to two weeks. They include:

Chills

Fever

Malaise

Joint and muscle pain

In people who develop the encephalitic infection, the following symptoms typically follow after a few days of systemic illness:

Fever

Headache

Irritability and restlessness

Drowsiness, disorientation

Anorexia

Vomiting

Diarrhea

Cyanosis, which is bluish discoloration of the skin resulting from poor circulation or inadequate oxygenation of the blood

Convulsions

Coma

Anyone with any of those symptoms should seek care from a physician.

Contact Kristen Jordan Shamus: 313-222-5997 or kshamus@freepress.com. Follow her on Twitter @kristenshamus.