A five-day course of a nasal antibiotic ointment every month showed a trend toward protection from Staphylococcus aureus (staph) infections, according to a study published online August 11 in the Journal of Acquired Immune Deficiency Syndromes.

Staph infections have emerged as a serious problem for people living with HIV. They are much more likely than their HIV-negative counterparts to develop staph infections, especially methycilin-resistance Staphylococcus aureus (MRSA).

Staphylococcus is spread via human-to-human contact and is prevalent in institutional environments, such as hospitals, nursing homes, drug treatment centers, prisons and schools. In approximately 20 percent of HIV-negative people—and a much higher percentage of people living with HIV—the bacterium can take up residence, or become colonized, inside the nose. Not only can colonized staph be transmitted to another person, it can also cause problems for the person with the bacterium, including skin infections and life-threatening diseases.

Some studies, involving HIV-negative people, have suggested that regular application of a nasal ointment including the antibacterial medication mupirocin might reduce staph colonization inside the nose, and therefore potentially reduce the risk of staph infections.

To test this theory, Rachel Gordon, MD, MPH, from the department of medicine at Columbia University in New York City, and her colleagues, randomized 100 HIV-positive men to receive monthly five-day courses of nasal mupirocin ointment or a placebo for eight months. All of the men resided in a drug treatment facility in the Bronx. Ultimately only 39 men completed the study and had results from nasal colonization tests.

Gordon’s team found that those on the antibiotic were 81 percent less likely to have nasal staph colonization. Drug or alcohol relapse and use of other types of antibiotics increased the odds of having staph in the nose.

There was a strong trend toward protection from staph infections in those who received the nasal antibiotic: only 6.5 percent of those receiving the ointment came down with a staph infection compared with 19 percent of those who received a placebo. Unfortunately, too few men completed the study to conclusively determine whether monthly application of mupirocin reduced the risk of staph infections.

“Although this study suggests that mupirocin may reduce the risk of staphylococcal infection, additional studies are needed in select populations,” the authors conclude. “By suppressing colonization, monthly mupirocin use may have a role in skilled nursing facilities, HIV-infected individuals, drug users, and other populations with high rates of [Staph] infections.”