Shiloh
Editor, Senior Moderator
Source: http://www.cidrap.umn.edu/news-perspective/2015/12/flu-scan-dec-18-2015
Flu Scan for Dec 18, 2015
Low US flu; H1N1v detected; Avian flu factors in US
Filed Under:
Influenza, General; Avian Influenza (Bird Flu)
[h=3]US flu activity low, with H1N1 back on the scene and 1 novel case[/h] Though overall flu activity in the United States is still low, the US Centers for Disease Control and Prevention (CDC) today reported some new developments, including the 2009 H1N1 virus nudging ahead as the predominant strain for the week and the recent detection of a variant H1N1 (H1N1v) case in Minnesota.
Though it's too early to tell how the flu season will play out, periods when the 2009 H1N1 virus dominates can have a greater impact on younger adults and older children, whereas the H3N2 strain is toughest on older people. Results from public health labs last week showed, that among influenza A viruses, 56.7% were 2009 H1N1, 36.7% were H3N2, and 6.7% were unsubtyped.
The numbers were small, however, with only 17 2009 H1N1 and 11 H3N2 isolates confirmed during the week. And H3N2 continues to vastly dominate for the season, constituting 72.4% of 467 influenza A samples, versus 22.3% for H3N2.
Minnesota's H1N1v case-patient lived and worked near swine but didn't have direct contact with them, the CDC said. The patient wasn't hospitalized and has recovered, and so far no human-to-human transmission has been detected.
At the national level, flu markers remained low, with the percentage of clinic visits for flulike illness rising slightly, from 1.8% to 1.9%, but still below the national baseline of 2.1%. No pediatric flu deaths were reported, keeping the total at three so far this season, and the overall percentage of deaths from flu and pneumonia were below the seasonal baselines.
South Carolina was the only state to report high flu activity, another measure of clinic visits for the disease. Guam was the only area to report widespread geographic spread of flu, with just Puerto Rico, Maryland, and New Hampshire reporting regional spread.
One of 25 2009 H1N1 samples tested for antiviral resistance, none showed resistance to oseltamivir.
Dec 18 CDC FluView report
[h=3]Analysis: Local spread key in this year's Midwest avian flu outbreaks[/h] The many avian flu outbreaks earlier this year in Minnesota and Iowa poultry appeared to have been caused by local spread rather than multiple introductions from wild birds, according to a geospatial analysis in published this week in Emerging Infectious Diseases.
Analysts from the University of New South Wales in Australia noted that H5 highly pathogenic avian influenza (HPAI) viruses emerged in Midwestern states in late February after being confirmed farther west, which would not correlate with typical waterfowl migration patterns. They also noted that, unlike with earlier outbreaks in Canada, high numbers of HPAI were not detected in wild birds in Minnesota and Iowa, the two hardest-hit states. Of 3,300 samples from wild birds in the region, only 1 tested positive for H5 HPAI.
The experts attribute the February introduction of the virus to Minnesota as caused by migrating waterfowl during an earlier-than-usual spring, but then subsequent outbreaks were likely caused by local virus spread.
"Of particular note, outbreaks in poultry were densely concentrated within Minnesota and Iowa in a spatial pattern inconsistent with the much more geographically dispersed spread of infection in wild birds," they wrote.
"The magnitude and clustered distribution of poultry outbreaks are suggestive of local spread, rather than multiple introductions from passing migratory waterfowl," the authors added. "Genetic analyses have similarly shown evidence for concurrent multiple introductions as well as common source exposures, and surveys of affected farms have shown that local spread could be facilitated by the sharing of equipment by multiple farms or through animals entering barns."
In related news, the US Centers for Disease Control and Prevention on Dec 16 updated its clinician guidance for evaluating and treating people exposed to H5 HPAI, as well as guidance for those who respond to HPAI outbreaks.
Dec 16 Emerg Infect Dis abstract
Dec 16 CDC H5 HPAI guidance for clinicians
Dec 16 CDC H5 HPAI guidance for outbreak responders
Flu Scan for Dec 18, 2015
Low US flu; H1N1v detected; Avian flu factors in US
Filed Under:
Influenza, General; Avian Influenza (Bird Flu)
[h=3]US flu activity low, with H1N1 back on the scene and 1 novel case[/h] Though overall flu activity in the United States is still low, the US Centers for Disease Control and Prevention (CDC) today reported some new developments, including the 2009 H1N1 virus nudging ahead as the predominant strain for the week and the recent detection of a variant H1N1 (H1N1v) case in Minnesota.
Though it's too early to tell how the flu season will play out, periods when the 2009 H1N1 virus dominates can have a greater impact on younger adults and older children, whereas the H3N2 strain is toughest on older people. Results from public health labs last week showed, that among influenza A viruses, 56.7% were 2009 H1N1, 36.7% were H3N2, and 6.7% were unsubtyped.
The numbers were small, however, with only 17 2009 H1N1 and 11 H3N2 isolates confirmed during the week. And H3N2 continues to vastly dominate for the season, constituting 72.4% of 467 influenza A samples, versus 22.3% for H3N2.
Minnesota's H1N1v case-patient lived and worked near swine but didn't have direct contact with them, the CDC said. The patient wasn't hospitalized and has recovered, and so far no human-to-human transmission has been detected.
At the national level, flu markers remained low, with the percentage of clinic visits for flulike illness rising slightly, from 1.8% to 1.9%, but still below the national baseline of 2.1%. No pediatric flu deaths were reported, keeping the total at three so far this season, and the overall percentage of deaths from flu and pneumonia were below the seasonal baselines.
South Carolina was the only state to report high flu activity, another measure of clinic visits for the disease. Guam was the only area to report widespread geographic spread of flu, with just Puerto Rico, Maryland, and New Hampshire reporting regional spread.
One of 25 2009 H1N1 samples tested for antiviral resistance, none showed resistance to oseltamivir.
Dec 18 CDC FluView report
[h=3]Analysis: Local spread key in this year's Midwest avian flu outbreaks[/h] The many avian flu outbreaks earlier this year in Minnesota and Iowa poultry appeared to have been caused by local spread rather than multiple introductions from wild birds, according to a geospatial analysis in published this week in Emerging Infectious Diseases.
Analysts from the University of New South Wales in Australia noted that H5 highly pathogenic avian influenza (HPAI) viruses emerged in Midwestern states in late February after being confirmed farther west, which would not correlate with typical waterfowl migration patterns. They also noted that, unlike with earlier outbreaks in Canada, high numbers of HPAI were not detected in wild birds in Minnesota and Iowa, the two hardest-hit states. Of 3,300 samples from wild birds in the region, only 1 tested positive for H5 HPAI.
The experts attribute the February introduction of the virus to Minnesota as caused by migrating waterfowl during an earlier-than-usual spring, but then subsequent outbreaks were likely caused by local virus spread.
"Of particular note, outbreaks in poultry were densely concentrated within Minnesota and Iowa in a spatial pattern inconsistent with the much more geographically dispersed spread of infection in wild birds," they wrote.
"The magnitude and clustered distribution of poultry outbreaks are suggestive of local spread, rather than multiple introductions from passing migratory waterfowl," the authors added. "Genetic analyses have similarly shown evidence for concurrent multiple introductions as well as common source exposures, and surveys of affected farms have shown that local spread could be facilitated by the sharing of equipment by multiple farms or through animals entering barns."
In related news, the US Centers for Disease Control and Prevention on Dec 16 updated its clinician guidance for evaluating and treating people exposed to H5 HPAI, as well as guidance for those who respond to HPAI outbreaks.
Dec 16 Emerg Infect Dis abstract
Dec 16 CDC H5 HPAI guidance for clinicians
Dec 16 CDC H5 HPAI guidance for outbreak responders