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| Credit FluView |
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Although it is still fairly early in the season, today's FluView (week 46) shows two southern states (Mississippi & Louisiana) reporting significant levels of influenza. The CDC also reports 5 influenza related pediatric deaths in their latest reporting period.
Additionally, Iowa reports the first H1N1v (swine variant) infection of 2017.H3N2 continues to make up the bulk (80%) of the influenza A cases identified, with influenza B dominated by the Yamagata lineage. Despite the surge in flu cases in the south, the number of deaths attributed to pneumonia and influenza (P&I) remains below the epidemic threshold.
Reminding us that seasonal influenza can exact a heavy toll on both young and old alike, the CDC reports.
Influenza-Associated Pediatric Mortality:
Five influenza-associated pediatric deaths were reported to CDC during week 46.
Two deaths were associated with an influenza A (H3) virus and occurred during weeks 45 and 46 (the weeks ending November 11 and November 18, 2017, respectively). One death was associated with an influenza A (H1N1)pdm09 virus and occurred during week 44 (the week ending November 4, 2017). One death was associated with an influenza A virus for which no subtyping was performed and occurred during week 44.
A total of five influenza-associated pediatric deaths have been reported for the 2017-2018 season.
One death that occurred during the 2016-2017 season was associated with an influenza A (H3) virus and occurred during week 15 (the week ending April 15, 2017). This death brings the total number of reported influenza-associated pediatric deaths occurring during that season to 110.
Lastly, we have a report the 66th swine variant case of 2017. The CDC describes Swine Variant viruses in their Key Facts FAQ.
What is a variant influenza virus?
When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a “variant influenza virus.” For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an “H3N2 variant” virus or “H3N2v” virus.Swine variant infections are generally mild or moderate in severity, and are indistinguishable from regular flu without a lab test. Most are linked to direct or indirect contact with swine, often at agricultural exhibits and county fairs.
Novel Influenza A Virus:
One human infection with a novel influenza A virus was reported from Iowa during week 46. This person was infected with an influenza A(H1N1) variant (H1N1v) virus and reported direct contact to swine during the week preceding illness onset. This patient was an adult < 50 years of age, was not hospitalized, and has fully recovered from their illness. No human-to-human transmission has been identified. This is the first H1N1v virus infection detected in the United States in 2017. This brings the total number of reported H1N1v infections in the United States since 2005 to 21.
A total of 66 variant virus infections have been reported to CDC during 2017. Sixty-one of these were influenza A(H3N2) variant (H3N2v) viruses (Delaware [1], Maryland [39], Michigan [2], Nebraska [1], North Dakota [1], Ohio [15], Pennsylvania [1], and Texas [1]), one was influenza A(H1N1) variant (H1N1v) (Iowa [1]), and four were influenza A(H1N2) variant (H1N2v) viruses (Colorado [1] and Ohio [3]). Six of these 66 infections have resulted in hospitalization; all have recovered.
Early identification and investigation of human infections with novel influenza A viruses are critical so that the risk of infection can be more fully understood and appropriate public health measures can be taken. Additional information on influenza in swine, variant influenza infection in humans, and strategies to interact safely with swine can be found at http://www.cdc.gov/flu/swineflu/index.htm. .
For more on swine variant viruses, you may wish to revisit:
Zoonosis & PH: Survey Of Animal Exhibitor's KAP During Swine Variant Outbreak
EID Journal: Transmission Of Swine H3N2 To Humans At Agricultural Exhibits - Michigan & Ohio 2016
J. Virol: Novel Reassortant Human-like H3N2 & H3N1 Influenza A Viruses In Pigs
MMWR: Investigation Into H3N2v Outbreak In Ohio & Michigan - Summer 2016
