Acute respiratory failure in patients treated for babesiosis.

Babesiosis is a tick-borne protozoal disease with infrequent clinical complications. We report three cases of noncardiogenic pulmonary edema in patients from Nantucket Island, MA, with a history of Lyme disease and review the clinical presentation of babesiosis and its treatment. Respiratory complications in our patients, as well as in the four previously reported cases in the literature, occurred a few days after initiation of medical therapy. We hypothesize that the pathophysiology of the pulmonary edema is multifactorial, due to decreased deformability of the infected erythrocytes, increased cytoadherence of red blood cells in capillaries and venules, and a possible role of excessive production of certain cytokines, such as tumor necrosis factor and interleukin-1.