US study that staph prevalent in MSMs inconclusive

A research study published recently in the United States contends that a drug-resistant strain of bacteria called MRSA (Methicillin-Resistant Staphylococcus Aureus) is common in gay men and may be sexually transmitted.

“We were surprised at the strength of association between MSM [men who have sex with men] and the presence of multi-drug resistance,” explains Dr Christopher Graber, one of the study’s authors, and staff physician at Veterans Affairs Greater Los Angeles Healthcare System.

“We would have expected prior antibiotic use to be the strongest predictor of multi-drug resistance, not MSM status,” he says. “This study identifies a [group] at particular risk for infection by a multiple drug-resistant bacteria.”

The study “raises some interesting questions but [isn’t] the sort that shows conclusively that this problem is especially big for men who have sex with men,” argues Dr David Patrick, director of epidemiology services at the BC Centre for Disease Control.

“A lot of the evidence was ecological,” he notes. “They looked at where people lived who had MRSA infections in San Francisco, and then mapped them onto neighbourhoods where there was a high concentration of gay men.

“Being gay might be an element [of a person’s MRSA infection],” he suggests “but it may be some other property of that neighbourhood that wasn’t measured by the study.

“What got me about this paper,” he continues, “was that it emphasized the possibility of sexual transmission when the real truth of staph aureus infection is [that] it’s just skin-to-skin contact.

“Obviously that can happen in an intimate association,” Patrick admits. “It’s much more likely to become a problem where you have crowding and poor hygiene,” he notes.

Graber concedes that sexual transmission of the bacteria was not proven by this study.

“We say ‘might’ based on the fact that a number of the infections encountered were in the pelvic [and] genitoperineal (buttocks) region and that other studies describe direct skin-to-skin transmission of community MRSA infection. Thus, behaviors that increase contact in [that] region, such as sex, may lead to transmission,” Graber elaborates.

“We’re all covered in staph aureus most of our lives,” Patrick observes. “Different strains are on us, and since time immemorial, whether it’s drug resistant or not, [they] can cause boils and things like that now and again.

“That’s much less likely to happen in people who are wealthy enough [to] shower every day or two,” Patrick points out, adding “simple soap and water reduce the concentration of bacteria on your skin so that [infection] doesn’t happen too often. Also [it is] much less likely to happen in people who don’t have a lot of skin-to-skin contact with a lot of other people.”

Staphylococcus bacteria, commonly known as “staph,” are carried by a large portion of the population, usually in their noses or on their skin. However, few people ever become infected or exhibit any negative symptoms from them, but they can still transmit the bacteria.

Problems arise when the bacteria enter the body through a cut or wound. An infection that can start as small red bumps may soon turn into a painful abscess, or in some extreme cases, pneumonia.

“We continue to see staph infections as we always have,” Patrick says. “We know that the particular strain of C-MRSA that was described in the States has been in BC for three or four years.”

“Most of the time if somebody carries it, it’s not a problem, but we have seen some infections in the community at large. I’m sure there have been cases [in the gay community too], but have [doctors] seen a big concentration of cases like in prisons, [with] injection drug users and other poor people from the Downtown Eastside? No, that’s not been described yet,” says Patrick.

Vancouver Coastal Health’s senior media relations officer Viviana Zanocco says MRSA infections are declining in the city. She cites a statistic from her organization’s 2006-2007 Infection Control Annual Report that shows community-associated MRSA cases reduced from 30 percent to 19 percent in one year. However, she cannot provide any specific numbers for gay patients infected with MRSA.

“We don’t isolate patients who are gay when defining numbers. We look at where they acquired infections, period. Our goal is to limit the spread and identify sites where we need to do a better job of infection control.”

Vancouver physician Dr Richard Taylor, whose practice includes a large proportion of gay patients, says that he’s seeing more MRSA but doesn’t think it’s related to gay sexual activity or being homosexual.

“With time, probably most of us will be colonized with MRSA,” Taylor suggests. “This is not something that is going to go away, [but] I can’t think that this is specifically in any way [related] to being a gay man. I certainly haven’t heard of anything definite from physicians who are working with the gay community in BC,” Patrick adds.

“Most of our problems with staph aureus infections are happening among poorer people; people who are having trouble getting regular hygiene, and injection drug users who might be piercing their skin.”

Patrick does admit though that MRSA infection among gay men is possible. “If you have people who are getting a lot of skin-to-skin contact through some social environment like a bathhouse, they may be at higher risk, yes, but we haven’t seen the folks in the emergency rooms tell us that that’s a big factor right now in Vancouver.”

Patrick also believes that MRSA is not a significant concern for people who are HIV-positive.

“If you talk to the docs who are doing HIV care, [MRSA infection]’s not the reason people are going in these days. It’s not a major driver of hospitalization.”

Graber, however, thinks that, “HIV-positive patients are at higher risk of acquiring infections,” but is unsure why. “We were unable to fully assess the role HIV [plays] because the clinic we studied was entirely composed of HIV-positive patients.”

“A lot is made [in this study] that the cases happened among men who had sex with men,” Patrick observes. “What you have to say is ‘What are all the things in somebody’s life?'” It’s skin contact that spreads it, and that can happen to anyone.