Ticks around San Francisco, California have been discovered to be carrying a newly discovered bacterium with unknown health effects.

The Stanford University study said that the bacteria, Borrelia miyamotoi, have been found on ticks that were also carrying the bacteria that cause Lyme disease.  The study is due to be published in the March issue of Emerging Infectious Disease.

The researchers said the amount of ticks with both bacteria were very small, as little as two percent of the entire amount found during the study.  However, the bacteria was found on ticks in all of the 12 recreational areas around San Francisco that was part of the study.

The first human case of infection from B. miyamotoi was discovered in 2013 and other than the patient developing symptoms similar to Lyme disease, little was learned about the bacteria.

One researcher says that patients who are treated for Lyme disease and do not recover could likely be infected with the new bacteria.

The Centers for Disease Control says that Lyme cases are rising because doctors are more familiar with signs of the infection.