The epidemiology of bacillary angiomatosis and bacillary peliosis.

Objective: To determine environmental risk factors for bacillary angiomatosis-bacillary peliosis (BAP), and to confirm infection with Rochalimaea species.

Design: Case-control study.

Setting: Community and university hospitals and clinics.

Patients: Case patients (N = 48) had biopsy-confirmed BAP. Controls (N = 94) were matched to patients by institution and by human immunodeficiency virus (HIV) serological status.

Main Outcome Measures: Clinical information was obtained from medical records. Subjects were queried about environmental exposures. Univariate odds ratios (ORs) with 95% confidence intervals (CIs) were determined. Bivariate analyses were performed on variables associated with disease by univariate analysis. DNA from 22 available case-patient tissues and from 22 control tissues was amplified with the polymerase chain reaction (PCR) using primers designed to detect Rochalimaea species.

Results: We identified five HIV-negative, immunocompetent case patients; one HIV-negative, immunodeficient case patient; and 42 HIV-positive case patients. There were no significant differences between case patients and controls by race, sex, age, or risk factors for HIV infection. Owning a cat (OR, 2.8; CI, 1.4 to 5.8) and history of a recent cat lick (OR, 1.95; CI, 1.0 to 3.8), cat scratch (OR, 3.7; CI, 1.7 to 8.0), or cat bite (OR, 3.9; CI, 1.8 to 8.9) were associated with disease in the univariate analysis. In bivariate analyses, only the variables representing traumatic contact with a cat (bite or scratch) remained associated with disease. No other environmental exposure was associated with disease. The PCR amplified a DNA fragment of the size expected for Rochalimaea species in all 22 case-patient tissue specimens.

Conclusions: These data suggest that BAP is a new zoonosis associated with both traumatic exposure to cats and infection with Rochalimaea species or a closely related organism.