In this study, Dr Ostfeld found "significant deviations of levels of co-infection in questing nymphs, most notably 83% more co-infection with Babesia microti and Borrelia burgdorferi than predicted by chance alone

From  Dr. Richard Horowitz

Dr Rick Ostfeld at the Cary Institute for Ecosystems Studies just published a study on the co-infection rate of nymphal ticks with Babesia in Dutchess County. I was the first doctor to discover Babesia 15 years ago in our area after a young woman in a wheelchair with drenching night sweats and resistant Lyme symptoms got out of her wheelchair for the first time after being treated with Mepron and Zithromax (a classical Babesia treatment). In this study, Dr Ostfeld found "significant deviations of levels of co-infection in questing nymphs, most notably 83% more co-infection with Babesia microti and Borrelia burgdorferi than predicted by chance alone. Co-infections involving A. phagocytophilum were less common, and fewer co-infections of A. phagocytophilum and B. microti than predicted by chance were observed in both questing nymphs and larvae fed on small mammals". Babesia has increased in our area since it was first discovered years ago, and we find co-infections with Babesia often accounting for resistant symptoms in our chronic Lyme patients. This study highlights the high risk of infection of these two organisms simultaneously with a tick bite. Health care providers should ask patients with resistant Lyme symptoms whether they suffer from day sweats, night sweats (occasionally drenching), chills, air hunger (shortness of breath) and an unexplained cough, as these are classic symptoms for Babesiosis.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0099348