A new law went into effect last week requiring that all Maine hospitals screen high-risk patients for a drug-resistant bacteria called MRSA. It's a type of staph infection that was associated with an estimated 19,000 deaths in the United States in 2005. But Maine epidemiologists are questioning the effectiveness of screening.

Last week, the Maine Nurses Association hailed the enactment of the law they had supported to require hospitals to screen patients for MRSA. MRSA is short for Methicillin-resistant Staphylococcus aureus. It's a bacteria that is highly-resistant to some antibiotics.

The Nurses Association reported that 68 out of every 1,000 hospital patients in Maine contract MRSA. They also said Maine has the fourth highest MRSA rate in the country. But those data are based on a national study done in 2006. It was completed in a single day and only a quarter of U.S. hospitals participated.

Because participation varied widely from state to state, Maine epidemiologists say the MRSA rates between states can't be compared.

"People don't come labeled saying they have MRSA," says Maine Public Health Director Dora Mills. "There are a number of people who are carriers. If they're carriers and in the healthcare setting, that can be a real problem. There's so much of it out there, in the community setting particularly, and we aren't necessarily going to do anything about it just because we get a report on it."

But the state is doing something: requiring hospitals to screen patients for MRSA. That means when a patient comes to a hospital, they're asked a few questions to see if they're likely to be carriers. If they are, a nasal culture is administered. Those who are more likely to carry MRSA are people who have been in a hospital or nursing home within the past six months, dialysis patients and people who've been in prison. The law does not dictate further action, but usually hospitals isolate or treat a person with MRSA.

The state Center for Disease Control and Prevention reports that approximately one percent of the American population carries MRSA in their nose or on their skin and may not know it. It's unclear how often MRSA causes serious illness by entering the bloodstream.
In Maine, from 2004 to 2005, an annual average of 111 cases of MRSA were reported, with an incidence rate of 8.6 cases per 100,000 people.

Even though screening is now required, some epidemiologist don't believe it's effective. "It's strongly recommended that this not be done by every professional infection-control organization," says Robert Pinsky, an epidemiologist at Eastern Maine Medical Center in Bangor.

"We learned in the 1980s that trying to identify people with HIV, for example, in the hopes that that would help reduce the risk of accidentally transmitting HIV in hospitals, was not the right way to approach this," Pinsky says. "There was a great deal of support for doing that at the time. The best way we learned then to prevent transmission, not only of HIV but of other organisms, was to treat everyone the same way and to take all the precautions that are necessary to potentially transmit any of those organisms in an institution, and it's really analagous with MRSA."

Pinsky says more frequent handwashing and isolating patients as often as possible is the best way to combat MRSA. And he says screening for MRSA will cost the hospital a quarter of a million dollars and full time staff to analyze the data. That's just for the next six months, at which point hospitals can decide on their own whether to continue screening.

The former Maine epidemiologist testified against the law before it was passed, but Dr. John Jernigan of the federal Centers for Disease Control says the data on how effective screening is in preventing MRSA infection are mixed.

"It is an area of controversy amongst scientists who look at this issue," Jernigan says. "There are some studies that suggest that programs that have employed active screening have been very effective at reducing MRSA infection rates. On the other hand there are those that have used the strategy and not been so effective. Also there are studies that suggest that MRSA infection rates can be reduced effectively without the use of active screening. It may have to be tailored to local situations and circumstances."

A quasi-governmental agency called the Maine Quality Forum wrote the recent MRSA screening legislation with input from the Maine Nurses and Maine Hospital Associations. Dora Mills says the Maine Quality Forum will keep track of how effective the screening process is in helping hospitals identify their individual high-risk populations.