TORONTO, June 18, 2009 -- A snapshot of the health care workers who came down with the H1N1 flu in the first few weeks of the outbreak suggests that proper infection-control practices weren't uniformly followed, the U.S. Centers for Disease Control and Prevention said today.
Despite that, only a handful of health care workers contracted the disease while at work and most of those who did were not seriously ill, according to Dr. Michael Bell, associate director for infection control in the CDC's National Center for Preparedness, Detection, and Control of Infectious Diseases.
They may have dodged a bullet, though, as the pandemic strain has been less dangerous so far than many experts feared, Bell told a telephone news conference.
"I think we've been lucky that this first wave has not been as lethal as some people feared," Bell said.
He said flaws in infection control practices in the early weeks of the outbreak may be a "helpful learning experience."
Bell was referring to a report in the June 19 issue of Morbidity and Mortality Weekly Report, which gave data on 48 cases of H1N1 infection among health care workers up to May 13.
The report is a "snapshot of what we know up to that time," he said, although continuing surveillance now suggests that 81 health care workers have been infected in the course of the outbreak.
But the jump does not reflect a "sudden or alarming change in pattern," Bell said. "We're not seeing anything that would indicate that health care personnel are overly represented among recognized cases in this country."
On the other hand, the lessons from the first 48 cases suggest that rigorous application of the CDC guidelines for infection control is vital to control transmission in health care settings.
A key is rapid recognition that a patient may be infected, he said.
"Probably the single most important thing is that infection patients be identified at the front door" so that health care workers can take the appropriate precautions, he said. "Identifying them up front is essential."
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The report in MMWR found that many of those infected in health care settings reported incomplete or improper use of personal protective equipment, such as masks, gowns, gloves and respirators.
The findings "highlight the need to maintain adherence to comprehensive infection control strategies to prevent transmission of novel H1N1 in health care settings," the agency said.
As of May 13, there were confirmed or probable infections with the pandemic H1N1 virus in health care workers in 11 states. Two workers -- one of whom had an underlying medical condition -- required inpatient care, but not intensive care.
None of the 48 died.
Of the 48 reports, 26 had information regarding risk factors that might have led to infection, the CDC said; 13 were deemed to have taken place in a health care setting, including 12 cases where the infection was passed from patient to worker and one case of transmission between health care personnel.
Community transmission was deemed most likely for 11 others; the remaining two had no reported exposures in either health care or community settings.
Among the 26 for whom there was information, a dozen reported caring for patients with an H1N1 infection or a respiratory illness and six reported contacts or family members with either H1N1 or respiratory illness. Four reported recent travel to Mexico.
Of the 12 health care personnel who were infected by patients, 11 reported information on their use of personal protective equipment when caring for the presumed source patient.
Three reported always using either a surgical mask or an N95 respirator.
Five reported always using gloves.
None reported always using eye protection.
None reported always using gloves, gown and either surgical mask or N95 respirator.
One physician reported always using an N95 respirator when with an infected patient, but also reported never having had a fit test for the respirator. There was no information on whether the doctor wore a gown or eye protection.
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A nurse anesthetist reported always using gloves and a surgical mask with the presumed source patient, but only sometimes using a gown, N95 respirator and eye protection.
And one registered nurse who was caring for an H1N1 patient reported always using a surgical mask and gloves with the patient but never using a gown, N95 respirator, or eye protection.
The CDC infection-control recommendations for the care of H1N1 patients included the use of fit-tested N95 respirators, eye protection, and contact precautions, in addition to routine infection-control practices used for seasonal flu.
Among the 11 health care workers for whom data is available, "none adhered to these recommended practices completely," the agency said.
On the positive side, the agency said, among confirmed and probable cases reported to CDC as of May 13 in adults ages 18 through 64, about 4 percent have occurred in health care workers.
About 9 percent of working adults in the U.S. are employed in health-care settings, the agency said.
The comparison should be interpreted with caution, the CDC said, because the case reports are geographically uneven and substantial under-reporting is probable.
Whatever the actual risk, the CDC noted, it is mostly found in outpatient settings.
As of May 31, only 6 percent of 10,053 H1N1 patients needed inpatient care, the agency said. And six of the 12 health care workers whose infections were associated with employment said they had been caring for outpatients in the week before the onset of symptoms.