Nocardial infection as a complication of HIV in South Africa

Abstract

Objectives: To assess the occurrence, clinical and microbiological features of nocardial infections complicating HIV in Soweto, South Africa.

Methods: A prospective study was carried out over a 2-year period. Patients were identified after isolation of Nocardia spp. from a clinical specimen. Clinical details were recorded. The nocardial isolates were identified to species level and susceptibility tests performed.

Results: Ten patients were identified as having nocardial disease complicating HIV. Clinical presentations were pulmonary (five patients), pulmonary and cerebral (one patient), cerebral (one patient) and skin and soft tissue infection of the lower limb (three patients). Three infections were fatal. The isolates were Nocardia asteroides (seven patients), N. farcinica (two patients) and Nocardia spp. (one). Isolates of N. farcinica demonstrated opacification of Middlebrook agar. All isolates were sensitive to amikacin and minocycline. Most nocardial isolates were susceptible to cefotaxime, imipenem and coamoxiclav. In vitro resistance to cotrimoxazole was present in five.

Conclusions: Nocardial infection occurs as a complication of HIV infection in the Republic of South Africa. Pulmonary cases may be difficult to distinguish from tuberculosis. Nocardia asteroides is the most common species isolated. Nocardia farcinica has resistance to multiple antibacterial agents and demonstrates opacification of Middlebrook agar, a useful screening test for this species. Agents with good in vitro antinocardial activity were amikacin, minocycline, cefotaxime, imipenem and coamoxiclav. There was a high level of resistance in vitro to cotrimoxazole.