Older people healthier during flu epidemics
Elderly people and ‘city dwellers’ are generally less prone to the ‘sniffles’.
Researchers, who studied the 1918 Spanish flu outbreak – which was one of the most devastating epidemics in recorded history, concluded the data they collected was surprising.
The 1918 flu killed 50 million to 100 million people worldwide. In urban communities, less than one in 100 inhabitants died from the strain of flu that year, but in isolated communities, up to 90% died of it.
In cities, young adults were hit hardest, while those older than 65 were largely spared.
The Norwegian School of Public Health researchers who studied the case concluded that urban areas bolstered inhabitants’ defences against the deadly flu strain by boosting their immunity in the years before the flu hit.
The study showed city people had previously experienced greater exposure to flu strains closely related to the Spanish flu than country people had, and were therefore better prepared to ward off the deadly strain.
Similarly, older people in cities, who had probably been exposed to an H1 flu strain that had circulated before 1890, allegedly had a higher mortality than most because they had previously experienced another flu epidemic prior to the Spanish flu.
Lead author of the study, Svenn-Erik Mamelund, wrote: “People who were older than 28 to 30 years in 1918 may have had some protection against severe infection and death from the Spanish flu because of previous exposure to similar viruses.”
The Norwegian’s observations were not limited to the 1918 epidemic. A similar effect came during the 2009 swine flu outbreak where those who were older than 65 years of age usually had the highest mortality associated with seasonal influenza – but because of pre-existing immunity. As a result, few elderly people became ill and died in 2009.
