Newly Discovered Tick-Borne Disease Threatens Immune-Supressed Patients in Sweden

Now that the weather is heating up, insects are starting to come out in full force, and you may want to consider wearing some insect repellent. Scientists have discovered a new, tick-borne disease bacterium that has been implicated in six cases in Sweden.

The bacterium in question is called Neoehrlichia mikurensis. It's primarily a risk for people who are already sick and who are receiving immunosuppressive drugs. First discovered and described in 2010, the bacterium can be spread by rodents and ticks mainly in Asia and Europe, including Sweden. So far, there have been about 19 cases worldwide.

Now, scientists have examined 11 of these cases a bit more closely in order to find out who is most susceptible to the disease.

"Those who run the greatest risk are generally over the age of 50 years, suffer either from a haematological disease or rheumatic disease, and are currently undergoing immunosuppressive treatment with, for example, chemotherapy or cortisone," said Christine Wenneras, one of the researchers, in a news release.

Currently, scientists aren't sure exactly how common the tick-borne disease is in humans, partly because it's difficult to detect. The bacterium can't be grown in culture, which means that it's not picked up in routine diagnostic procedures.

"Furthermore, the symptoms are deceptive: several patients, for example, have been affected by blood clots in the leg or the blood vessel in the head and this has not been coupled to an infectious cause," said Wenneras in a news release. "Other typical symptom such as fever, muscle pain and joint pain can be caused also by the patient's underlying disease. We know very little about how the infection affects otherwise healthy people who are not taking immunosuppressive drugs."

Fortunately, there's good news. Once the infection has been diagnosed, the patients recover completely after treatment with antibiotics.

The findings reveal a little bit more about this tick-borne disease. That said, future research needs to be conducted in order to figure out the exact symptoms and understand how it can affect a healthy individual.

The findings are published in the journal Clinical Infectious Diseases.