Featured Research

from universities, journals, and other organizations

Influenza infection increases likelihood of bacterial pneumonia 100-fold

Date:
June 26, 2013
Source:
University of Michigan
Summary:
It's been known for more than two centuries that pneumonia cases increase during flu epidemics.

It's been known for more than two centuries that pneumonia cases increase during flu epidemics.

But population-level epidemiological studies looking at seasonal patterns of influenza and pneumococcal pneumonia incidence have revealed either a modest association or have failed to identify any signature of interaction between the two.

These seemingly inconsistent observations at the personal and population scales have puzzled public health officials. Now a team of University of Michigan researchers and their colleagues have used a novel approach that they say resolves the dichotomy and shows that influenza infection increases susceptibility to pneumococcus, the most common bacterial cause of pneumonia, by about 100-fold.

An accurate characterization of the influenza-pneumococcal interaction can lead to more effective clinical care and public health measures, including influenza pandemic preparedness, according to the authors.

"The results concerning the nature of the interaction between influenza and pneumococcal pneumonia were unequivocal in our study," said U-M population ecologist and epidemiologist Pejman Rohani, senior author of a paper scheduled for online publication in Science Translational Medicine on June 26. "Simply put, our analyses identified a short-lived but significant -- about 100-fold -- increase in the risk of pneumococcal pneumonia following influenza infection."

Rohani and his colleagues created a computer model of pneumococcal pneumonia transmission that analyzed various hypotheses about the potential effects of a prior influenza infection. By challenging the model with hard data from epidemiological reports -- weekly records of influenza and pneumococcal pneumonia hospitalizations in Illinois between 1989 and 2009 -- they were able to rank the likelihood of each hypothesis.

The clear winner was the susceptibility impact hypothesis, which proposed that individuals infected with influenza are more susceptible to pneumococcal pneumonia. The increased susceptibility to pneumonia lasts for up to a week after infection by influenza.

The researchers also looked at the fraction of pneumonia cases that could be attributed to interaction with influenza. They found that during the peak of flu season, interaction with the influenza virus accounted for up to 40 percent of pneumococcal cases. But on an annualized basis, the fraction was between 2 percent and 10 percent of cases, a relatively subtle signature that could help explain why previous epidemiological analyses failed to detect the connection, Rohani and his colleagues concluded.

"We infer modest population-level impacts arising from strong processes at the level of the individual, thereby resolving the dichotomy in seemingly inconsistent observations across scales," they wrote.

Rohani said the results suggest that the best way to reduce the incidence of bacterial pneumonia is to encourage the public to receive both pneumococcal and influenza vaccinations.

Pneumonia is an infection of the lungs that is usually caused by bacteria or viruses. Globally, pneumonia causes more deaths than any other infectious disease. In 2009, 1.1 million people in the United States were hospitalized with pneumonia, and more than 50,000 people died from the disease, according to the Centers for Disease Control and Prevention. In 1918, at least 24 percent of those killed during the Spanish influenza pandemic showed signs of a bacterial pneumonia infection.

In the United States, the most common bacterial cause of pneumonia is pneumococcus (Streptococcus pneumonia), and the most common viral causes are influenza, parainfluenza, and respiratory syncytial viruses, according to CDC.

Rohani is a professor of ecology and evolutionary biology, a professor of complex systems and a professor of epidemiology at the School of Public Health. The first author of the Science Translational Medicine paper is Sourya Shrestha, a postdoctoral fellow in Rohani's laboratory.

The other authors are Betsy Foxman of the U-M School of Public Health, Daniel M. Weinberger of the Yale University School of Public Health and the National Institutes of Health, Claudia Steiner of the U.S. Agency for Healthcare Research and Quality, and Cecile Viboud of the National Institutes of Health.

Funding was provided by the Vaccine Modeling Initiative of the Bill and Melinda Gates Foundation, the Department of Homeland Security, the Fogarty International Center and the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of Michigan. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Shrestha, B. Foxman, D. M. Weinberger, C. Steiner, C. Viboud, P. Rohani. Identifying the Interaction Between Influenza and Pneumococcal Pneumonia Using Incidence Data. Science Translational Medicine, 2013; 5 (191): 191ra84 DOI: 10.1126/scitranslmed.3005982

Cite This Page:

University of Michigan. "Influenza infection increases likelihood of bacterial pneumonia 100-fold." ScienceDaily. ScienceDaily, 26 June 2013. <www.sciencedaily.com/releases/2013/06/130626142701.htm>.
University of Michigan. (2013, June 26). Influenza infection increases likelihood of bacterial pneumonia 100-fold. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2013/06/130626142701.htm
University of Michigan. "Influenza infection increases likelihood of bacterial pneumonia 100-fold." ScienceDaily. www.sciencedaily.com/releases/2013/06/130626142701.htm (accessed August 27, 2014).

Share This




More Health & Medicine News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WHO Calls for Ban on E-Cigarette Sales to Minors

WHO Calls for Ban on E-Cigarette Sales to Minors

AFP (Aug. 26, 2014) The World Health Organization called Tuesday on governments should ban the sale of e-cigarettes to minors, warning that they pose a "serious threat" to foetuses and young people. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Newsy (Aug. 26, 2014) A study published in the journal "Neurology" interviewed more than 19,000 people and found 15 percent suffer from being "sleep drunk." Video provided by Newsy
Powered by NewsLook.com
Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Newsy (Aug. 26, 2014) A new study found fewer deaths from prescription drug overdoses in states that have legalized medical marijuana. But experts disagree on the results. Video provided by Newsy
Powered by NewsLook.com
Official: British Ebola Sufferer Receiving Experimental Drug

Official: British Ebola Sufferer Receiving Experimental Drug

AFP (Aug. 26, 2014) A British nurse infected with Ebola while working in Sierra Leone is being given the same experimental drug used on two US missionaries who have recovered for the disease, doctors in London say. Duration: 00:44 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins