Lyme Topics Co-infections


Other Tick-Borne Infections

Ticks can be infected with bacteria, viruses, or parasites, and more than a dozen tick-borne diseases have been documented to cause serious illness in humans. The most common tick-borne diseases in the United States include: Lyme disease, babesiosis, anaplasmosis, ehrlichiosis, Rocky Mountain spotted fever, Southern tick-associated rash illness, tick-borne relapsing fever, tularemia, Colorado tick fever, Powassan encephalitis, and Q-fever (CDC, 2010).

Co-infections with more than one tick-borne infection are common. NatCapLyme conducted an online survey in July 2010 and found that 46 percent of the 1433 respondents had been diagnosed with two or more tick-borne infections. Lyme disease and babesiosis were the most common infections.

Patients who are co-infected with Lyme disease and other tick-borne infections experience more symptoms and more persistent illness than those with only Bb infection. This suggests that “babesial infection may impair human host defense mechanisms, as it does in cattle and mice” (Krause et al., 1996).

Because symptoms for other tick-borne infections can be similar to those of Lyme disease, these infections may go undiagnosed, contributing to ongoing illness despite treatment.

Patients with Lyme disease also become more vulnerable to other infections. Mycoplasma, Epstein Barr virus, yeast, H. pylori and Chlamydia pneumoniae are quite common infections in patients with Lyme disease. The exact role that other tick-borne diseases and opportunistic illnesses play in the disease course is poorly understood, and known treatment options are not always effective.


NatCapLyme. 2010. The Human Dimensions of Lyme and Other Tick-Borne Infections: The Patient Perspective. Report to the Institute of Medicine. September 2010.

CDC, NIOSH. 2010. Tick-borne diseases (NIOSH Safety and Health Topics).


Krause PJ, Telford SR, Spielman A, et al. 1996. Concurrent Lyme disease and babesiosis. Evidence for increased severity and duration of illness. JAMA 275(2):1657-60.

Patel, Raj. Lyme Disease and Co-Infections