Immunization roulette: influenza occurrence in five nursing homes.

Area of Science:

• Gerontology
• Infectious Diseases
• Public Health

Background:

• Influenza outbreaks pose significant risks to vulnerable populations, particularly in congregate settings like nursing homes.
• The effectiveness of influenza vaccination in preventing severe outcomes and deaths in elderly individuals requires ongoing evaluation.

Purpose of the Study:

• To assess the protective effect of A/Bangkok 1/79 (H3N2) influenza vaccination among nursing home residents.
• To investigate the correlation between influenza immunization rates and mortality during an outbreak.
• To highlight potential underreporting of influenza-like illness (I-ILI) as a cause of death in elderly populations.

Main Methods:

• Observational study during an influenza outbreak in 1983 involving nursing home residents.
• Comparison of mortality rates between nursing homes with varying influenza immunization coverage.
• Review of death certificates for cause of death, including influenza-like illness (I-ILI).

Main Results:

• A/Bangkok 1/79 (H3N2) vaccine appeared protective in immunized nursing home residents.
• All thirteen deaths occurred in facilities with low or no influenza immunization.
• Influenza-like illness (I-ILI) was underreported on death certificates for a significant proportion of decedents.

Conclusions:

• Influenza vaccination is a cost-effective measure for protecting nursing home residents.
• Underreporting of I-ILI can skew the perceived impact of influenza in institutionalized elderly populations.
• Vaccination strategies are crucial for mitigating influenza-related morbidity and mortality in long-term care facilities.