Measuring the uncertainties of pandemic influenza

July 02, 2012

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.

Although we are yet to face an H5N1 avian influenza epidemic, the team suggests that they have nevertheless been able to develop a worst-case scenario for all possibilities considering mortality rates and infectiousness based on current knowledge and historical patterns dating back to the 1917-1918 global pandemic. They suggest that a future worst-case influenza pandemic might be up to four times as lethal as the pandemic that occurred towards the end of the Great War. Moreover, their simulation suggests that the use of antiviral drugs may not be as effective as healthcare authorities would hope. On a positive note, they have found that social distancing could be the most effective way to contain the spread of infection, usefully reducing symptoms by an average of 16% although it will cost 50% more than antiviral use through lost working days and commerce.

"Do we prepare for the worst-case scenario when preparing for a pandemic?" asks Fair. "While the worst-case scenario is indeed the worst, it may not be as likely. As far as mortality rates, the 1918 was the worst but really still was only around 2% which is could be considered low." While, the next pandemic could be worse than that of 1917-1918, the worst case scenario may not be as likely, the team concludes. Their study supports earlier findings that no single, pure strategy is best and that a mix of pharmaceutical and non-pharmaceutical interventions will be needed to contain the disease and reduce the total number of deaths. It would be prudent to incorporate these findings in planning for the next pandemic, the team asserts.
-end-
"Measuring the uncertainties of pandemic influenza" in Int. J. Risk Assessment and Management, 2012, 16, 1-27

Inderscience Publishers

Related Influenza Articles from Brightsurf:

Predicting influenza epidemics
Researchers at Linköping University, Sweden, have developed a unique method to predict influenza epidemics by combining several sources of data.

Common cold combats influenza
As the flu season approaches, a strained public health system may have a surprising ally -- the common cold virus.

Scent-sensing cells have a better way to fight influenza
Smell receptors that line the nose get hit by Influenza B just like other cells, but they are able to clear the infection without dying.

New antivirals for influenza and Zika
Leuven researchers have deployed synthetic amyloids to trigger protein misfolding as a strategy to combat the influenza A and Zika virus.

Assessment of deaths from COVID-19, seasonal influenza
Publicly available data were used to analyze the number of deaths from seasonal influenza deaths compared with deaths from COVID-19.

Obesity promotes virulence of influenza
Obesity promotes the virulence of the influenza virus, according to a study conducted in mice published in mBio, an open-access journal of the American Society for Microbiology.

Influenza: combating bacterial superinfection with the help of the microbiota
Frenc researchers and from Brazilian (Belo Horizonte), Scottish (Glasgow) and Danish (Copenhagen) laboratories have shown for the first time in mice that perturbation of the gut microbiota caused by the influenza virus favours secondary bacterial superinfection.

Chemists unveil the structure of an influenza B protein
MIT chemists have discovered the structure of an influenza B protein called BM2, a finding that could help researchers design drugs that block the protein and help prevent the virus from spreading.

How proteins help influenza A bind and slice its way to cells
Researchers have provided new insight on how two proteins help influenza A virus particles fight their way to human cells.

Eating elderberries can help minimize influenza symptoms
Conducted by Professor Fariba Deghani, Dr. Golnoosh Torabian and Dr.

Read More: Influenza News and Influenza Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.