A new study of the A(H1N1) influenza pandemic strain aims to inform politicians to help them make science-based decisions on optimizing the use of limited resources to manage this and future pandemics.
"Public health officials have the ability to track confirmed cases and hospitalizations in real-time with modern data collection approaches and the aid of modeling as well as the ability to quickly identify new strains and track their evolution,” said co-author Gerardo Chowell-Puente, PhD, from the Arizona State University School of Human Evolution and Social Change in a statement about the study.
The study, "Reported severe respiratory disease and deaths concurrent with atypical A(H1N1) influenza circulation of swine origin in Mexico, 2009," reveals an age shift in the proportion of cases toward a younger population when compared with historical patterns of seasonal influenza in Mexico.
"The data show that the vast majority of cases of severe pneumonia and deaths occurred among those ages between 5 and 59, which is atypical when compared with the age pattern supported by seasonal flu," said Chowell-Puente. "If resources or vaccine supplies are limited, focusing prevention efforts on these age classes must be considered."
During influenza seasons from 2006 through 2008 only 17% of deaths and 32% of severe pneumonia occurred in people 5 to 59 years of age. So far, these percentages jump to 87% of deaths and 71% of the cases of severe pneumonia occurring in persons 5-59 years of age when discussing the current A(H1N1) influenza pandemic.
"These findings suggest relative protection for those persons exposed to H1N1 influenza viruses during childhood prior to the 1957 pandemic," said Chowell-Puente.
"Because achieving high vaccination rates before the fall is not feasible with current technologies, effective distribution of a limited vaccine and antiviral stockpiles will be crucial to mitigate a potential second pandemic wave,” said Chowell-Puente. “The seasonal influenza vaccination strategy focuses on the very young and the very old—the most vulnerable populations. This is not necessarily the case for pandemics as we showed in our study."
The findings are published June 29 online in the New England Journal of Medicine.