People in 8 states should be aware of the signs of yet another tick-borne disease as cases rise, CDC says

• People in eight states should know signs of another tick-borne disease as cases rise, the CDC said.
• Babesiosis is caused by tiny parasites that infect red blood cells and are spread by certain ticks.

People in eight states should know the signs of the tick-borne disease babesiosis as cases rise, the Centers for Disease Control and Prevention has said.

Babesiosis cases are on the rise in the North East (Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont), and the disease is newly endemic in three of those states (Maine, New Hampshire, and Vermont), according to a CDC report based on data collected between 2011 to 2019 from 10 states.

"Members of the public and health care providers in states with endemic babesiosis and bordering states should be aware of the clinical signs of babesiosis and risk factors for Babesia infection," the CDC said in the report published on Friday.

The latest report comes amid a 25% rise in the number of US tick borne disease cases overall, including Lyme disease, the CDC said. According to the CDC, the number of babesiosis cases reported increased from 40,795 in 2011 to 50,856 in 2019.

Babesiosis is usually spread by blacklegged ticks

According to the report, most babesiosis cases in the US are caused by tiny parasites spread by blacklegged ticks, called Ixodes scapularis, in northeastern and midwestern states. People can also catch it from contaminated blood transfusions, and organ transplants from infected donors. Babies can catch it from mothers with babesiosis.

The disease, which was first identified in 1969 on Nantucket Island, Massachusetts, can cause a mild illness with no symptoms to a serious disease with multi-organ failure.

Dr. Peter Krause, a senior research scientist at the Yale School of Public Health, who wasn't involved in the CDC study, told NBC that the CDC report highlights "an unfortunate milestone in the emergence of babesiosis in the US."

"More cases means more illness, and actually, some people die," he said. According to Kruse, the disease has an overall fatality rate of around 1% to 2%.

People that contract the disease from blood transfusions are more likely to die than those who get it from a tick bite, the CDC report said.

The severity of an infection also depends on a person's immunity. For example, the condition is more likely to be life-threatening for those who are immunocompromised, including the elderly.

People without flu-like symptoms don't need treatment

People without symptoms usually don't need treatment, but people with a more severe illness can be treated with antimicrobial medications. Symptoms are often non-specific and include: fever, muscle or joint pain, nausea, and headache, according to the CDC.

According to a review on babesiosis published last year, after the parasite infects a person, it can take one to six weeks for any symptoms to show, and around 20% of adults and half of kids that get the disease don't get symptoms.

There could be babesiosis in states where cases aren't reported

The CDC said that 37 states reported a total of 16,456 cases between 2011 and 2019, including 16,174 (98.2%) from the 10 states included in the analysis.

The CDC said that the number of cases could be higher. That's because not all states, like Pennsylvania, record them and people without symptoms often don't get tested. The data also doesn't reliably reflect where a person caught the disease, for example if they've traveled to a state, because cases are reported according to where a person lives.

"Persons spending time outdoors in states with endemic babesiosis should practice tick bite prevention, including wearing long pants, avoiding underbrush and long grass, and using tick repellents," the CDC said.