Intensive Care Doctor-Community

In the May issue of Pediatrics, Dr. Mary Lucia Gregory and colleagues report that from August 2000 through August 2007, all 7997 infants admitted to the NICU were screened for MRSA with weekly nasal/rectal swabs. The 102 infants who were colonized or infected were isolated.

In 2000, the incidence of MRSA was 1.79 cases per 1000 patient-days, according to the report. By 2005, the incidence had fallen to 0.15 cases per 1000 patients-days, but by 2007 the incidence was 1.26 cases per 1000 patient-days.

MRSA was introduced into the NICU "from different sources over time," the investigators believe. "There was a shift from isolates predominantly likely to be hospital-associated in 2000-2004 to those likely to be community-associated in 2006-2007," they write.

The authors point out that surveillance-related costs not billed to insurance companies exceeded $1.5 million.

Dr. Gregory, now at Beth Israel Deaconess Medical Center in Boston, told Reuters Health, "The finding that was particularly important is that our MRSA was not clonal and was not completely eradicated. This is because new strains are introduced into the NICU over time by caregivers and parents. Only hand hygiene can reduce the introduction of new strains, but surveillance and isolation programs like ours may prevent spread of MRSA from one infant to another and thus reduce burden of colonization and infection."

Dr. Gregory continued, "I think that NICUs who report MRSA outbreaks, institute screening programs, then when they have no colonization for a time declare MRSA to be 'eradicated' and stop screening are probably missing the introduction of new strains into their units over time as well."

She added, "While we were unable to compare rates of MRSA colonization and infection pre- and post- surveillance (since we don't know infants' colonization status pre-screening and we have never stopped the program since its inception), we do speculate that with the overall rise in MRSA in the community, the rise that we have seen in our NICU over the past 2 years may be an attenuation of what we would see without the isolation program to reduce spread."

Summing up, Dr. Gregory said: "I don't think that clinical practice necessarily should change in response to our findings. I know many NICUs do not routinely screen for MRSA colonization, and I do think that screening is a good and worthwhile practice. However, if they are also not seeing any MRSA infections, they may be safe to continue ignoring what colonization is present."

Pediatrics. 2009;123:e790-e796.