Lyme disease may be the most well known illness spread by ticks. But it's far from the only one. The most common vector for Lyme is the deer tick, and it spreads five other known pathogens. One of those pathogens is what’s called the Babesia parasite. It infects red blood cells, like malaria, causing the sometimes-fatal disease babesiosis.

Now we learn that these tick-borne diseases may have more in common than their host. Because Lyme disease may actually facilitate the spread of babesiosis. That's according to a study in the journal PLOS ONE. [Jessica M. Dunn et al, Borrelia burgdorferi Promotes the Establishment of Babesia microti in the Northeastern United States] 

Researchers allowed ticks to feed on mice infected with babesiosis, or with both babesiosis and Lyme. And ticks that fed on mice with just babesiosis were less likely to pick up the parasites than were ticks who munched on mice carrying both infections. Study author Maria Diuk-Wasser of Columbia University says the one-two punch of both diseases could be too much for the mice to handle. "The immune system may be, we could say, occupied with one pathogen, and decreases the response to the other one." Based on field studies, she and her co-authors believe the same phenomenon may be happening in nature, too.

For now, at least, babesiosis isn't as widespread as Lyme. And if these results are correct, cutting down on Lyme's prevalence might also slow the spread of babesiosis, "So we would get a synergistic effect of a control method that could attack both diseases at the same time." If, that is, we can find a truly effective way to limit Lyme.

—Christopher Intagliata

[The above text is a transcript of this podcast.]