Half of HIV-positive patients with skin infections caused by drug-resistant staph had a recurrence of the infection within one year, according to a research letter in the October 1 issue of the Journal of Acquired Immune Deficiency Syndromes.

Methicillin-resistant Staphylococcus aureus (MRSA), a bacterial infection that cannot be treated using standard antibiotics, is a growing concern in the United States among people living with HIV. A 2005 study in Boston found that HIV-positive patients were acquiring MRSA at a higher rate than HIV-negative patients, particularly HIV-positive men who have sex with men and HIV-positive patients with lower CD4 counts.

To determine the rate of recurring MRSA skin infections, Christopher Graber, MD, MPH, of the University of California at San Francisco, and his colleagues studied the medical records of 264 HIV-positive patients who were diagnosed and treated for MRSA at San Francisco General Hospital between January 2002 and December 2006. Because they were looking only for patients initially diagnosed for skin or soft tissue MRSA infection, they ultimately narrowed down their analysis to 62 patients.

Dr. Graber’s team found that half of the patients had a recurrent skin infection within one year after their first infection. Twenty-seven percent of the patients had a recurrent infection at the same location as the first diagnosis. The specific antibiotics to which their MRSA recurrent infections were resistant often differed, indicating that many were reinfected with another strain of the bacterium and didn’t experience a relapse of the first infection.

The authors acknowledge that the small size of the group analyzed, as well as the fact that they could only review medical records rather than follow people over time, makes it difficult to determine the factors associated with the high recurrence rate. Nevertheless, their study suggests that recurrence of MRSA infections in people with HIV is likely to be high in other cities, and they urge patients and doctors to discuss strategies for preventing infection.