Nocardiosis in persons with human immunodeficiency virus infection, transplant recipients, and large, geographically defined populations

To quantify the risk of nocardiosis in various populations, I systematically reviewed articles published between 1966 and 2004. The incidence of nocardiosis in 3 large, geographically defined populations ranged from 0.35 to 0.4 cases per 10⁵ persons·year. In contrast, the incidence of nocardiosis among people with human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) in 1 study was 53 nocardiosis cases per 10⁵ persons·year, approximately 140 times greater than that in the geographically defined populations. The frequency of nocardiosis cases in 4 populations of HIV-infected people averaged 608 cases per 10 ⁵ persons. The incidence of nocardiosis in bone marrow-transplant recipients at 1 hospital was 128 cases per 10⁵ persons·year, an incidence approximately 340 times greater than that in the geographically defined populations and in the same range as in HIV-infected people. The frequency of nocardiosis in 21 series of cases in recipients of a variety of transplanted organs averaged 1122 cases per 10⁵ persons. These estimated incidence rates are imprecise because they were not collected through prospective surveillance systems, but the estimates for the 3 groups were internally consistent and provide useful information for clinicians.