Influenza Update: 2015-2016, Week Ending 2-27-16

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Influenza 2015-2016
On Feb 1, 2016, the CDC published a notice that the Influenza (Flu) season had begun and that severe cases of flu had been reported. This time frame represents a more typical flu season than the past three years which have had an early onset and peak. This season (2015-16) showed a slow rise of cases through December and a much higher case rate beginning in Jan., with elevated numbers of cases still occurring. This trend is expected for at least a few more weeks. The report goes on to say that Health Care Providers should treat those patients with signs and symptoms consistent with flu who are considered in high risk groups, have severe, complicated or worsening illness, and anyone hospitalized, even if rapid influenza test results are negative. This treatment includes the rapid start of appropriate antiviral medications, ideally within 48 hours of the onset of flu symptoms, but may be appropriate for up to 4-5 days after onset for the those patients who have been hospitalized or at the Provider’s discretion. Anyone who has not been vaccinated with this year’s flu vaccine (2015-16), should still be vaccinated until the flu season has ended according to Public Health Officials.

The strains that are currently being seen are well matched by this year’s flu vaccine, totally unlike the previous year. The season started with H3N2 initially being predominant (the same as last year), but H1N1 pdm09 has taken over that role. Both of these are Influenza A viruses. There is also a circulating Influenza B strain that is also well matched to the current flu vaccine.

Even with the good vaccine match, there are still a significant number of flu cases resulting in serious respiratory illnesses in the young to middle-aged, due to a resurgence of Influenza A (H1N1) pdm09. This is the same virus that caused the pandemic during the 2009-10 season and has been the predominant strain in several recent flu seasons. There has been one case of a variant (H3N2v) has been found; it reportedly didn’t involve direct contact with swine but the individual did visit a farm that had swine. There is always careful monitoring of variant flues, because variant viruses can lead to widespread, unprotected flu cases and even pandemics. Pigs are known to be an animal in which reassortment or changes in flu virus take place. They can get flu viruses from humans, birds, and themselves.

For the most recently reported week ending Feb 27, 2016 the CDC reports:
• The flu cases and influenza-like illness (ILI) remain elevated and above the national baseline but decreased slightly from last week in the US. ILI remains above the national baseline and 33 States reported widespread flu cases.
• Approximately 73% of the flu tests reported were Influenza A, with those that were subtyped appx 90% were H1N1 pdm09 and about 9% were H3 viruses. The rest of the tests showed about 27% Influenza B virus.

For Influenza-like illness (ILI):
High ILI Activity: Puerto Rico, Arizona, Arkansas, Illinois, Maryland, New Mexico, North Carolina, Tennessee, and Utah

Moderate ILI Activity: New York City, Alabama, California, Florida, Hawaii, Kentucky, Mississippi, New Jersey, Oklahoma, and South Carolina

Low Activity: Colorado, Georgia, Indiana, Kansas, Louisiana, Michigan, Minnesota, Missouri, New York, Oregon, Pennsylvania, Texas, and Virginia

Minimal Activity: 20 States (those remaining)

Not Enough Data to Report: Washington DC

For Flu:
Widespread Activity: Puerto Rico and 33 States

Regional Activity: Guam, Alabama, Arkansas, Colorado, Florida, Georgia, Hawaii, Illinois, Indiana, Louisiana, Maine, Missouri, Oklahoma, South Carolina, and Tennessee

Local Activity: Washington DC and Mississippi

Sporadic Activity: US Virgin Islands, Oregon and West Virginia

Other Data:
Hospitalizations from Flu are significantly lower than they were last year. The highest rates are for those 65 years and older; next are children less than 5 years; and then adults 50-64 years.

Death rates for pneumonia and influenza in adults is lower than the epidemic threshold set by the Mortality Surveillance System but above the epidemic rate in the 122 Cities Mortality Reporting System.

There were 4 pediatric deaths attributed to flu; 2 from H1N1 pdm09 and 1 from an Influenza A that was untyped; there was 1 death from Influenza B. There have been a total of 18 influenza attributed deaths for this flu season.

First Responder Specific Information:
• First Responders should be vaccinated for Flu each season to prevent getting flu themselves, taking it home to family members or transmitting it to patients in their care. Family members and patients may be at increased risk of complications from flu.
• Proper hand hygiene including frequent handwashing and the use of hand sanitizers in general and particularly when providing patient care or after touching surfaces.
• Masks should be used in the presence of patients with cough and/or fever.
• Care should be taken to avoid touching mucous membranes (eyes, mouth, nose) since the flu virus is frequently found on surfaces such as door knobs, cot and equipment handles, phones, as well as clothing, bed clothes, etc.
• Report S/S of flu to your physician or other appropriate provider for early assessment and care.
• Cough and sneeze into your sleeve, not onto your hands.
• Stay away from others if you are sick.

Note: the Flu is much more worrisome for the very young and the very old. Signs of ILI in this group requires careful assessment to rule out complications and these groups are much more likely to be transported to assure adequate care. However, with Influenza A (H1N1) pdm09 circulating widely, even young and middle aged adults can have complications including pneumonia. These complications may occur often after the flu has subsided and include chest pain, difficulty breathing, elevated heart rates, or other signs of shock. Anyone with these S/S, even if just reporting the flu, should be evaluated in hospital EDs.