A new infection causes by ticks that is extremely similar to Lyme disease has been found in 18 people in southern New England and upstate New York.

The unnamed disease has been confirmed in humans for the first time by researchers from Yale University who published their findings in the New England Journal of Medicine.

The report suggests that this new sickness could be infecting more than 4,300 Americans a year with flu-like symptoms and relapsing fevers. Luckily, one dosage of antibiotics seems capable of eliminating the disease.

The researchers used blood tests to find evidence of infection by a bacterium that is present in deer ticks and is similar to the one that produces Lyme disease.

In 21 percent of the 14 patients, positive outcomes were identified for the new infection with unexplained summertime febrile illness.

Out of 273 patients diagnosed with Lyme disease or suspected Lyme disease, three percent had positive results of the new infection, while just one percent of 583 healthy adults living in Lyme disease areas tested positive.

The scientists from Yale have discovered the bacterium called Borrelia miyamotoi in deer ticks found in Connecticut. Borrelia miyamotoi was first found in 1995 in Japan, but it was not until 2011 that investigators noticed that the bacterium was making people sick in Central Russia. The current study concentrated on the first human infections occurring in the U.S.

All participants were from the Northeast, however the researchers think there may be other cases in parts of the country where Lyme disease is common, because the bacterium has been found in approximately two percent of all ticks that carry Lyme disease.

Durland Fish, professor of epidemiology at the School of Public Health and the study’s senior author says:

“This is the first time we have found an infectious organism carried by ticks before we have recognized the disease in humans. We usually discover new diseases during an epidemic and then try to figure out what is causing it.”

The signs of this new illness include: The infection also comes with a rare but distinct rash apparent in about 10 percent of cases. Commonly present with the infection is a fever that occurs then disappears, and reappears several days later.

Written by Kelly Fitzgerald