Shiloh
Editor, Senior Moderator
Source: http://www.cidrap.umn.edu/news-perspective/2015/04/flu-scan-apr-21-2015
Flu Scan for Apr 21, 2015
Flu and school closure; Global flu activity ebbs
Filed Under:
H1N1 2009 Pandemic Influenza; Influenza, General; Pandemic Influenza
[h=3]Study: School closures in Michigan didn't curb pandemic flu[/h] School closures in Michigan during the fall wave of the 2009 H1N1 flu pandemic had little impact on disease spread, according to a retrospective study by a team based at the University of Michigan. The group published its findings yesterday in Clinical Infectious Diseases.
Temporary school closure was a nonpharmaceutical option for curbing the spread of the disease, and during the first wave of infection in the spring, federal health officials revised their recommendation, urging localities to make their own decisions and consider closures only when absenteeism interfered with a school's educational mission.
The analysis is the first of its kind to link community influenza-like illness (ILI) surveillance with reports of school closures in real time for an entire state. Using the surveillance data, the researchers determined the peak week of flu activity for each school district, comparing them by three different levels of school closure, ranging from none closed due to flu to 51% to 100% closed.
They found that 559 Michigan schools closed at least once during the fall pandemic wave, and closure was a reactive decision in 83% of them. School districts in the middle range (1% to 50% closure) had lower levels of ILI than the no-closure or higher-closure districts, likely because of population or peak wave timing differences, the team wrote.
The highest level of flu activity was seen in the schools in the highest closure tier, with a significant association between lower housing density and higher ILI activity, which the authors said correlated with findings that less populated parts of the state were heavily affected and had high rates of closures.
Researchers also said school closures may have been implemented too late to be effective, and that more studies are needed to gauge the impact of school closure as an intervention to slow the spread of flu.
Apr 20 Clin Infect Dis abstract
[h=3]WHO: Flu continues to decline across the globe[/h] Influenza activity across the globe decreased further in recent weeks but remained slightly above the seasonal threshold in the Northern Hemisphere, and influenza B mounted its typical late-season surge, according to an update today from the World Health Organization (WHO).
Almost all regions of North America, Europe, western Asia, northern Africa, the Middle East, temperate and tropical Asia, and tropical countries in the Americas reported decreased flu activity.
Exceptions were in Turkey, where flu detections increased and flu B and 2009 H1N1 viruses co-circulated; South Korea; and India and Bhutan, where levels remained high and H1N1 predominated. Flu activity remained at inter-seasonal levels in the Southern Hemisphere.
Globally, 51% of recently circulating flu viruses typed were influenza A and 49% influenza B. Influenza A viruses were divided almost equally between H3N2 and 2009 H1N1. Almost all "B" strains belonged to the Yamagata lineage, which is the strain in the trivalent (three-strain) vaccine.
Apr 21 WHO update
Flu Scan for Apr 21, 2015
Flu and school closure; Global flu activity ebbs
Filed Under:
H1N1 2009 Pandemic Influenza; Influenza, General; Pandemic Influenza
[h=3]Study: School closures in Michigan didn't curb pandemic flu[/h] School closures in Michigan during the fall wave of the 2009 H1N1 flu pandemic had little impact on disease spread, according to a retrospective study by a team based at the University of Michigan. The group published its findings yesterday in Clinical Infectious Diseases.
Temporary school closure was a nonpharmaceutical option for curbing the spread of the disease, and during the first wave of infection in the spring, federal health officials revised their recommendation, urging localities to make their own decisions and consider closures only when absenteeism interfered with a school's educational mission.
The analysis is the first of its kind to link community influenza-like illness (ILI) surveillance with reports of school closures in real time for an entire state. Using the surveillance data, the researchers determined the peak week of flu activity for each school district, comparing them by three different levels of school closure, ranging from none closed due to flu to 51% to 100% closed.
They found that 559 Michigan schools closed at least once during the fall pandemic wave, and closure was a reactive decision in 83% of them. School districts in the middle range (1% to 50% closure) had lower levels of ILI than the no-closure or higher-closure districts, likely because of population or peak wave timing differences, the team wrote.
The highest level of flu activity was seen in the schools in the highest closure tier, with a significant association between lower housing density and higher ILI activity, which the authors said correlated with findings that less populated parts of the state were heavily affected and had high rates of closures.
Researchers also said school closures may have been implemented too late to be effective, and that more studies are needed to gauge the impact of school closure as an intervention to slow the spread of flu.
Apr 20 Clin Infect Dis abstract
[h=3]WHO: Flu continues to decline across the globe[/h] Influenza activity across the globe decreased further in recent weeks but remained slightly above the seasonal threshold in the Northern Hemisphere, and influenza B mounted its typical late-season surge, according to an update today from the World Health Organization (WHO).
Almost all regions of North America, Europe, western Asia, northern Africa, the Middle East, temperate and tropical Asia, and tropical countries in the Americas reported decreased flu activity.
Exceptions were in Turkey, where flu detections increased and flu B and 2009 H1N1 viruses co-circulated; South Korea; and India and Bhutan, where levels remained high and H1N1 predominated. Flu activity remained at inter-seasonal levels in the Southern Hemisphere.
Globally, 51% of recently circulating flu viruses typed were influenza A and 49% influenza B. Influenza A viruses were divided almost equally between H3N2 and 2009 H1N1. Almost all "B" strains belonged to the Yamagata lineage, which is the strain in the trivalent (three-strain) vaccine.
Apr 21 WHO update