Four cases of Powassan virus infection, a serious tick-borne illness, are detected in Connecticut this year, health officials have confirmed.

Powassan virus causes a rare, but serious infection that spreads through bites of black-legged or deer ticks. The virus gets transmitted in as little as 15 minutes following a tick bite. There are no vaccines or drugs to treat the condition.

"The identification of four Connecticut residents with Powassan virus-associated illness emphasizes the importance of taking actions to protect yourself from tick bites from now through the late fall. Using insect repellent, avoiding areas where ticks are likely, and checking carefully for ticks after being outside can reduce the chance of you or your children being infected with this virus," Manisha Juthani, commissioner of the Department of Public Health Connecticut, said in a news release.

Two women and two men were hospitalized with a central nervous system disease in July. The lab results confirmed the presence of Powassan virus antibodies in all of them. They have been discharged and are recovering, officials said.

Symptoms of infection from the Powassan virus usually develop within one week to one month after an infected tick bite. The infection begins with fever, headache, vomiting and weakness.

As the infection gets severe, it can lead to encephalitis (infection of the brain) or meningitis (infection of membranes around the brain and spinal cord). Signs such as confusion, loss of coordination, difficulty speaking and seizures indicate a severe infection. Around 10% of severe cases are fatal and half of those who survive suffer from long-term health problems such as frequent headaches, loss of muscle mass and strength and memory loss.

People with severe infections should be hospitalized as they might need support for breathing and reducing brain swelling.

Although the virus is transmitted mainly through tick bites, in rare cases, it can transmit from person to person through blood transfusion. Health officials recommend people to not donate blood and bone marrow for 120 days following an infection.

The best way to prevent the disease is by limiting exposure to ticks. Simple precautions like keeping pets tick-free and the use of insect repellants and protective cloths while stepping outdoors can help reduce the chances of tick bites.