Study uncovers new groups at risk of influenza complications — new moms and obese people

HAMILTON, Ontario — New mothers and obese people, two groups not typically regarded as risk groups, were found to have a higher risk of death and other severe outcomes from influenza, according to a global study sponsored by the World Health Organization that was released Tuesday.

“Policy makers and public health organizations need to recognize the poor quality of evidence that has previously supported decisions on who receives vaccines during an epidemic,” stated Dominik Mertz, lead author of the study and an assistant professor of medicine of McMaster’s Michael G. DeGroote School of Medicine. “If we can define the risk groups we can optimally allocat[e] vaccines, and that is particularly important when and if there is vaccine shortage, say during a new pandemic.”

“These data reinforce the need to carefully define those conditions that lead to complications following infection with influenza,” added Mark Loeb, senior author on the paper. He also is a microbiologist and professor of medicine of the Michael G. DeGroote School of Medicine.

But, in contrast to current assumption, such ethnic minorities as American aboriginal people and pregnant women were not found to have more complicated influenza and would not need priority vaccination.

The report is published online in the BMJ, the journal of the British Medical Association.

The researchers reviewed 239 observational studies between 1918 and 2011, looking at risk factors for complications of influenza including developing pneumonia or needing ventilator support, admission to hospital or its intensive care unit, or dying.