Fellows-in-Training Newsletter

Spring 2006

Influenza in the Nursing Home: Prevention and Preparedness By Marc Rothman, MD Yale University School of Medicine

The call came in to our nursing home yesterday: an aide who was sent to the emergency room tested positive for influenza A. She had been coughing all day, and when co-workers insisted on checking her temperature, it was 102 degrees. As we took inventory of the exposed patients, counted the number of Tamiflu tabs in the formulary, and began our surveillance, it struck me as ironic that I was preparing this article at the same time that I was preparing for the real thing. And this is not the first episode for our nursing home practice this season, either. A confirmed case in a life-care facility occurred two weeks ago, but was successfully contained using many of the methods discussed here.

This article will briefly review the role of influenza vaccines in preventing influenza-like illnesses and their complications among nursing home residents, and will outline effective control measures for influenza outbreaks in long-term care settings.

Prevention: Preventing influenza, influenza-like illness, and complications from influenza (hospitalization and death) is a high priority for nursing home medical directors and administrators across the country. This is because people aged 65 years and older account for more than 90% of influenza-related deaths in the United States. In this regard, the Centers for Medicare and Medicaid Services (CMS) has recently unveiled an initiative that aims to increase the influenza vaccination rate to over 90% by the year 2010. In the last year for which data are available, 2001, the vaccination rate was only 66%. But how effective is the vaccine in the elderly? And what data are available from the nursing home population to support its use in that setting?

Numerous studies have shown that influenza vaccination works to protect the elderly from serious illness and hospitalizations as a result of influenza-like illness . But the degree to which it works varies from year to year, is affected by how well the vaccine is matched to circulating strains, and can be difficult to measure.

A recent systematic review by Jefferson, et al. in the Lancet presents data from 64 studies that evaluated the efficacy of influenza vaccines in people aged 65 years and older. Among these, there were 29 studies of vaccine effectiveness in persons living in long-term care facilities. When vaccine matching was good, the overall effectiveness against influenza-like illness was 23-33%; against complicating pneumonia, it was 46-65%; against hospital admission for influenza or pneumonia, it was 45-68%; and against influenza-related death, it was 80%. These are impressive numbers when one considers that the effectiveness in preventing influenza illness itself was only 30-40%. The ranges above reflect periods of high vs. low viral circulation, with higher effectiveness observed when viral circulation was low. As you might expect, there was no benefit observed when vaccine matching was poor. The authors conclude that there seems to be a gradient of effectiveness, in which vaccines have little effect on the actual incidence of influenza-like illnesses, but have greater effect on their complications.

Immunizing health care workers who work in the nursing home setting can have a major impact on the risk of influenza-like illness and its complications. In randomized controlled trials , of provision of vaccine to long-term care workers during the 1994 and 1995 flu seasons in Glasgow, U.K., vaccination of health care workers was associated with overall reductions in total patient mortality from approximately 20% to 12% (combined results for both seasons). In the US, only 36% of all healthcare workers were vaccinated during the 2004-05 flu season. CMS is also encouraging nursing homes to provide influenza vaccine to their healthcare workers, though this is not required under proposed regulations.

Preparedness: Several important measures should be taken when influenza is confirmed in nursing home residents or their health care workers. A more expansive list of control measures can be found at www.cdc.gov/flu, but here are a few common sense measures you can implement rapidly, in case you are confronted with a positive case while on call. By definition, an 'outbreak' is defined as one case of laboratory confirmed influenza (by any testing method) in a long-term care facility. When faced with an outbreak, initiate the following control measures immediately:

1. Inform local and state health departments within 24 hours, and ask about clinical specimens/viral isolates.
2. Contact the nursing supervisor and make an assessment of available antiviral supply, in case it is needed.
3. Implement daily surveillance for incident respiratory illness among all residents and all healthcare workers until 1 week after the last influenza case is confirmed.
4. Implement droplet precautions for all residents with suspected influenza.
5. Confine the first symptomatic resident and roommate to their room, including during mealtimes.
6. If other patients become symptomatic, cancel all common activities and serve all meals in individual rooms.
7. Limit visitation, especially by children.
8. Monitor personnel absenteeism and exclude symptomatic personnel from patient care duties until 5 days after onset of symptoms.
9. Limit new admissions.
10. Administer the current season's influenza vaccine to unvaccinated residents and heath care workers.
11. Administer influenza antiviral prophylaxis and treatments to residents and health care workers according to current recommendations (which can be found on-line).

In summary, influenza vaccination is a safe, effective means of preventing pneumonia, hospitalization, and death from influenza-like illness among the nursing home population. Its use in the long-term care setting is supported by the current evidence base, and is now required by the Centers for Medicaid and Medicare Services. Geriatric physicians, medical directors, and nursing home administrators should promote and/or offer vaccination to all nursing home health care workers, as this too has been shown to reduce influenza-related mortality among the patients in their care. Finally, keep in mind the common-sense outbreak control measures discussed above, as nursing homes will look to physicians for leadership when outbreaks occur on your watch.

¹ http://www.cdc.gov/flu/
¹ http://new.cms.hhs.gov/AdultImmunizations/
¹ Pierce, JR and Berk, SL. Influenza in the elderly. Clinical Geriatrics 2006; 14(2): 9-14.
¹ Jefferson T, Rivetti D, Rivetti A, et al. Efficacy and effectiveness of influenza vaccines in elderly people: A systematic review. Lancet 2005; 366: 1165-1174.
¹ Potter J, Stott DJ, Roberts MA, et al. Influenza vaccination of health care workers in long-term-care hospitals reduces the mortality of elderly patients. Journal of Infectious Diseases 1997; 175(1):1-6.
¹ Carman, WF, Elder AG, Wallace LA, et al. Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomized controlled trial. Lancet 2000; 355: 93-97.