Influenza Update Week Ending 4-28-2018Jenny Abercrombie
Influenza (FLU) Update for Week #17 Week Ending 4-28-18
Continued good news about Flu but two indicators still haven’t shown any sign of abating. Specifically, the rate of hospitalizations from flu continues to increase and there are still a number of pediatric deaths for the week. But, for the fourth time in-a-row since this Flu season became active, influenza activity (ILI) was below the national baseline and the number of flu cases once again decreased.
A quick glance at the graphs for Percentages of Visits for ILI and Pneumonia and Influenza Mortality Surveillance, gives a pictorial presentation of the severity of this flu season.
FirstWatch RIN (Reginal Influenza Network) Alerts occurred rarely, which correlated with CDC reports of continued decreased activity.
For the most recently reported week ending April 28, 2018, the CDC reported:
–ILI visits to clinics and other non-hospital facilities decreased again and was below the baseline of 2.2% at 1.5% (was 1.7% last week). For the third week in a row, only Region 1 (Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont) was listed as “ELEVATED. All other Regions were listed as “NORMAL”.
–Flu cases (documented by positive flu tests) decreased again but remained elevated with widespread flu reported in 3 states. “NO ACTIVITY” was reported by Alabama, Mississippi and the U.S. Virgin Islands. Clinical lab testing for influenza was positive for flu in 7.4% of the total tests (compared with 8.9% last week). Influenza B remained the dominant flu type with 66.4% of the positive flu tests reported. The remainder of the positive flu tests were Influenza A at 33.6%.
The CDC provides an interactive U.S. map that will link to each state’s public health authorities, ILI and flu information and processes, as well as other diseases and public health topics. Find it at this site: https://www.cdc.gov/flu/weekly/usmap.htm
—For Influenza-Like Illness (ILI)
Low ILI Activity (2 states): Alaska and Arizona
Minimal Activity (New York City, Washington D.C., Puerto Rico & 48 states): Alabama, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin and Wyoming
—For Flu (positive flu tests)
Widespread Activity (3 states): Connecticut, Massachusetts and New York
Regional Activity (Guam, Puerto Rico & 7 states): Arizona, Kentucky, Maine, New Hampshire, New Jersey, Ohio, and Vermont
Local Activity (24 states): Alaska, California, Colorado, Delaware, Florida, Georgia, Hawaii, Iowa, Kansas, Maryland, Michigan, Minnesota, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, Pennsylvania, South Carolina, Utah, Virginia, Washington, West Virginia and Wisconsin
Sporadic Activity (Washington D.C., & 14 states): Arkansas, Idaho, Illinois, Indiana, Louisiana, Missouri, Nevada, North Carolina, Oregon, Rhode Island, South Dakota, Tennessee, Texas and Wyoming
No Activity (U.S. Virgin Islands & 2 states): Alabama and Mississippi
Hospitalizations from Flu since Oct. 1, 2017 have had a cumulative rate of 105.3 per 100,000. The cumulative and each age group again reported higher rates than those of the previous week and higher than at the same point in the “Severe” 2014-15 Flu Season. Specifically, those 65 years and older with 454.3 per 100,000 (446.4/100,000 last week); ages 50-64 at 114.4 per 100,000 (112.8/100,000); and ages 0-4 at 73.5 per 100,000 (72.7/100,000). The percentage of pregnant women from the females of childbearing age group (15-44) who were hospitalized were at/near 30% (31.0%), a slight increase, after being around 25% for the peak weeks of the flu season.
Death rates for pneumonia & influenza in adults decreased slightly from last week to 6.2% (6.9% last week) which, for the fifth week in a row, fell below the epidemic threshold of 7.1% for Week #15, ending 4/14/18.
There were 3 more pediatric deaths from Flu reported in Week #17, for a total of 163 for this flu season; it surpassed the total number of deaths for the severe flu season of 2014-15.
—Flu in Canada and Europe for Week #15:
According to the Public Health Agency of Canada (PHAC), in general, influenza activity decreased although some areas, although less than last week, are still reporting localized activity,. Positive tests for flu remained greater for Influenza A than B. The majority of the diagnosed flu cases, hospitalizations, and deaths remained in those 65 years and older.
For more info see: https://www.canada.ca/en/public-health/services/diseases/flu-influenza.html
The European Center for Disease Prevention & Control (ECDC) reported that flu activity was at levels seen between flu seasons except in one country. Lab tests from PCPs were positive for flu 11% of the time with more Influenza A than B currently co-circulating; the majority of the cases were Influenza A. Influenza B caused the majority of the severe cases during this flu season, and mostly for those older than 15 years old. Deaths from all causes returned to pre-season normal levels.
For more info see: http://www.flunewseurope.org/
See this link for more details, including charts, graphs and maps. https://www.cdc.gov/flu/weekly/