A major collaboration between US research centers has highlighted three factors that could ultimately determine whether an outbreak of influenza becomes a serious epidemic that threatens national health. The research suggests that the numbers in current response plans could be out by a factor of two or more depending on the characteristics of the particular pandemic influenza.
Researchers from Argonne, Los Alamos, and Sandia National Laboratories, and the National Renewable Energy Laboratory, have used sensitivity analysis to uncover the most important disease characteristics pertaining to the spread of infection with an influenza virus. These are: the fraction of the transmission that occurs prior to symptoms, the reproductive number, and the length of each disease stage. Their use of data from past pandemics as well as information on potential viral evolution demonstrates that current response planning may underestimate the pandemic consequences significantly.
"It has become critical to assess the potential range of consequences of a pandemic influenza outbreak given the uncertainty about its disease characteristics while investigating risks and mitigation strategies of vaccines, antiviral drugs, and social distancing measures," explains Jeanne Fair of Los Alamos National Laboratory and her colleagues. The team has used a simulation model and rigorous experimental design with sensitivity analysis to show the extremes of consequences of a potential pandemic outbreak in the USA. The simulation incorporates uncertainty in the evolution and characteristics of the pathogen and differences in the epidemic response, and uncertainties in the sociological response to a pandemic.