Higher flu vaccination rates for healthcare personnel can dramatically reduce the threat of flu outbreak among nursing home residents, according to a study published in the October issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America.
The study, which focused on nursing homes in New Mexico, found that when a facility vaccinated between half to three-quarters of its healthcare personnel involved in direct patient care, the chances of a flu outbreak in that facility went down by 87 percent.
In association with the New Mexico Department of Health, researchers surveyed influenza rates at the state's 75 long-term care facilities during the 2006-2007 and 2007-2008 flu seasons. They then looked for correlations between vaccination rates at each facility and whether there was an influenza outbreak.
While increased vaccination of direct care healthcare workers was associated with fewer flu outbreaks, the study found that vaccination rates among residents did not discourage outbreaks. In fact, higher resident vaccination was correlated with a higher probability of an outbreak. That result was unexpected and hard to explain, researchers said.
“While the explanation is likely multi-factorial, we suspect a large factor is that facilities with high resident vaccination rates may over-rely on the direct protection bestowed by vaccinating the residents and under-value the indirect protection bestowed by vaccinating employees,” researchers wrote.