H1N1 study shows closing schools, other measures effective

May 24, 2011, Arizona State University

Schools were closed, restaurants shuttered and large public gatherings cancelled.

The H1N1 was new, and most of the cases occurred among young people. Health professionals and scientists weren't sure at the onset what the world would encounter with the virus.

Social distancing measures were enacted in Mexico where the pandemic affected different geographical areas of the country during three distinct waves. During the spring of 2009 when the virus affected the Mexico City area, officials choose to take measures to limit the virus' spread including cancelling large gatherings like soccer games.

New evidence suggests that these measures were effective, according to a new study led by ASU assistant professor Gerardo Chowell-Puente, an investigator for the Fogarty International Center at the National Institutes of Health and an assistant professor in the Arizona State University School of and Social Change in the College of Liberal Arts and Sciences.

The study provides the first comprehensive epidemiological description of the age, geographical and severity pattern of the 2009 pandemic in Mexico. Results of the study will be published in PloS Medicine.

"The interesting finding is that and other social distancing measures during the first wave were associated with a reduction in the by approximately 29 to 37 percent," Chowell said. "That is a significant change for a rapidly disseminating pandemic virus." Approximately 1,500 deaths were directly attributed to H1N1 flu in Mexico during 2009, he added.

In addition, declined from about 70 percent to 10 percent during the period when schools closed and other social distancing measures enacted. Results of the study were calculated by applying mathematical modeling to data compiled by the Mexican Institute for Social Security, a private health system representing 40 percent of the population.

"We found a significant effect from the social distancing interventions that could help mitigate the impact of future pandemics by relieving the burden on hospitals," Chowell said. "The peak of the pandemic could be pushed farther away so that health officials can prepare with pharmaceuticals and anti-virals. A vaccine could potentially be developed during that time."

More young people were affected by the H1N1 virus since older people had some immunity after a similar strain circulated years ago.

"There were a significant number of young people with severe respiratory disease particularly during the early pandemic phase," Chowell said.

Researchers also examined how the virus spread spatially, identifying three H1N1 waves with the first cases primarily around the Mexico City metropolis in spring of 2009 and the second summer wave in southeastern Mexico. The third wave was more widespread throughout the country and coincided with the start of school during the fall.

Findings from the study have implications for improving preparedness plans in future pandemics, said Chowell, who noted that in a previous in the 19th century, the majority of deaths occurred two years after the initial wave.

"We must remain vigilant and continue to monitor the circulation and health burden of this flu virus in the coming years," he added.

More information: Chowell G, Echevarría-Zuno S, Viboud C, Simonsen L, Tamerius J, et al. (2011) Characterizing the Epidemiology of the 2009 Influenza A/H1N1 Pandemic in Mexico. PLoS Med 8(5): e1000436. doi:10.1371/journal.pmed.1000436

Related Stories

Recommended for you

Fresh approach to tuberculosis vaccine offers better protection

January 17, 2018
A unique platform that resulted in a promising HIV vaccine has also led to a new, highly effective vaccine against tuberculosis that is moving toward testing in humans.

Study reveals how MRSA infection compromises lymphatic function

January 17, 2018
Infections of the skin or other soft tissues with the hard-to-treat MRSA (methicillin-resistant Staphylococcus aureus) bacteria appear to permanently compromise the lymphatic system, which is crucial to immune system function. ...

Newly-discovered TB blood signal provides early warning for at-risk patients

January 17, 2018
Tuberculosis can be detected in people with HIV infection via a unique blood signal before symptoms appear, according to a new study by researchers from the Crick, Imperial College London and the University of Cape Town.

New study validates clotting risk factors in chronic kidney disease

January 17, 2018
In late 2017, researchers from Boston University School of Medicine (BUSM) discovered and published (Science Translational Medicine, (9) 417, Nov 2017) a potential treatment target to prevent chronic kidney disease (CKD) ...

New study offers insights on genetic indicators of COPD risk

January 16, 2018
Researchers have discovered that genetic variations in the anatomy of the lungs could serve as indicators to help identify people who have low, but stable, lung function early in life, and those who are particularly at risk ...

Previous influenza virus exposures enhance susceptibility in another influenza pandemic

January 16, 2018
While past exposure to influenza A viruses often builds immunity to similar, and sometimes different, strains of the virus, Canadian researchers are calling for more attention to exceptions to that rule.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.