Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.

Bacillary angiomatosis and bacillary peliosis are vascular proliferative manifestations of infection with species of the genus bartonella that occur predominantly in patients infected with the human immunodeficiency virus. Two species, B. henselae and B. quintana, have been associated with bacillary angiomatosis, but culture and speciation are difficult, and there has been little systematic evaluation of the species-specific disease characteristics. We studied 49 patients seen over eight years who were infected with bartonella species identified by molecular techniques and who had clinical lesions consistent with bacillary angiomatosis-peliosis. In this case-control study, a standardized questionnaire about exposures was administered to patients with bacillary angiomatosis-peliosis and to 96 matched controls. The infecting bartonella species were determined by molecular techniques. Of the 49 patients with bacillary angiomatosis-peliosis, 26 (53 percent) were infected with B. henselae and 23 (47 percent) with B. quintana. Subcutaneous and lytic bone lesions were strongly associated with B. quintana, whereas peliosis hepatis was associated exclusively with B. henselae. Patients with B. henselae infection were identified throughout the study period and were epidemiologically linked to cat and flea exposure (P< or =0.004), whereas those with B. quintana were clustered and were characterized by low income (P=0.003), homelessness (P = 0.004), and exposure to lice (P= 0.03). Prior treatment with macrolide antibiotics appeared to be protective against infection with either species. B. henselae and B. quintana, the organisms that cause bacillary angiomatosis-peliosis, are associated with different epidemiologic risk factors and with predilections for involvement of different organs.