​​MDH FluWatch​
​​​​​​​​ 
Welcome to the influenza surveillance reporting website, brought to you by the Division of Infectious Disease Surveillance in the Center for Surveillance, Infection Prevention, and Outbreak Response at the Maryland Department of Health (MDH).

May 16, 2020, marked the last day of the official 2019-2020 influenza surveillance season.  While MDH will continue to monitor local, national, and international flu activity throughout the summer, this will be the last weekly report until we start the 2020-2021 season this fall. 
CURRENT WEEK INFLUENZA ACTIVITY SUMMARY
During the week ending May 16, 2020 (MMWR Week 20), influenza-like illness (ILI) activity was LOW and there was SPORADIC geographic activity. 

(Reports are updated by close of business on Fridays unless otherwise noted.)
 
​INFLUENZA SURVEILLANCE INDICATORS
ILI ACTIVITY:
One indicator we look at is the proportion of visits to sentinel providers for ILI. We compare these proportions to baseline numbers, and then categorize ILI activity levels as minimal, low, moderate, high, or very high. 

 
GEOGRAPHIC ACTIVITY:
A second indicator we look at is the geographic spread of influenza activity.  By looking at where sentinel providers are reporting ILI, where influenza and ILI outbreaks are occurring, and from where specimens are being submitted for testing, we can tell whether influenza is not active, sporadic, local, regional, or widespread.  This is not an indicator of disease severity, only of where the disease is located in Maryland.

 
Note: Only laboratory confirmed influenza tests performed at the MDH Laboratories Administration are used in influenza geographic activity level calculations.​



PREDOMINANT INFLUENZA STRAIN:
A third indicator we look at is the predominant strain of influenza circulating in Maryland.  This is important because different strains have different implications for the community.  For example, a "novel" or "variant" strain will not have a vaccine available.  There are also some strains of influenza that have developed resistance to antiviral medication.  And there are some strains that will not match the strains in the seasonal flu vaccine.  Knowing what is circulating​ is important in planning and responding to influenza outbreaks.  Refer to the weekly report for a full breakdown of the PCR test results reported.​


 
 
​Week Ending
​ILI Activity Level​
​ Activity Level Predominant Strain
​May 16, 2020 Low​ Sporadic​ No specimens tested positive​
​May 9, 2020 Moderate​ Local​ No specimens tested positive​​
​May 2, 2020 ​High ​Local ​Influenza A(H1N1)
​April 25, 2020 ​High ​Local No specimens tested positive
​April 18, 2020 ​High ​Regional ​B/Victoria
​April 11, 2020 High​ ​Widespread ​None
​April 4, 2020 High​ ​Widespread ​Influenza A(H1N1)
​March 28, 2020 High​ Widespread​ ​Influenza A(H1N1)
​March 21, 2020 ​High ​Widespread ​Influenza A(H1N1)
​March 14, 2020 ​High ​Widespread ​Influenza A(H1N1)
​March 7, 2020 ​High ​Widespread ​​Influenza A(H1N1)
​February 29, 2020 High Widespread ​Influenza A(H1N1)
​February 22, 2020 ​High ​Widespread ​Influenza A(H1N1)
​February 15, 2020 High​ ​Widespread ​​Influenza A(H1N1)
​February 8, 2020 High​ ​Widespread ​Influenza A(H1N1)
​February 1, 2020 High​ Widespread​ Influenza A(H1N1)​
​January 25, 2020 ​High ​Widespread ​Influenza A(H1N1)
​January 18, 2020 ​High ​Widespread B/Victoria​
​January 11, 2020 ​High ​Widespread ​B/Victoria
​January 4, 2020 ​High ​Widespread ​B/Victoria
​December 28, 2019 ​High​ Widespread​ B/Victoria​
​December 21, 2019 ​High ​Widespread  ​B/Victoria
​December 14, 2019 ​High ​Widespread ​B/Victoria
​December 7, 2019 ​Moderate ​Widespread ​B/Victoria
​November 30, 2019 ​Moderate ​Local ​B/Victoria
​November 23, 2019 ​Low ​Local None​
​November 16, 2019 Low​ ​Local ​None
​November 9, 2019 ​Minimal Widespread​ Influenza A(H3N2)​​
​November 2, 2019 ​Minimal ​Widespread ​None
​October 26, 2019 ​Minimal ​Sporadic Influenza A(H3N2)​
​​October 19, 2019 Minimal​ ​Widespread Influenza A(H3N2)​
​October 12, 2019 ​Minimal ​Sporadic B/Victoria 
​October 5, 2019 Minimal
​Sporadic No specimens tested positive

 

 
PREVIOUS WEEK REPORTS
​​Week Ending
​File
​May 9, 2020 PDF
​May 2, 2020 PDF
​April 25, 2020 PDF
​April 18, 2020 PDF
​April 11, 2020 PDF
​April 4, 2020 PDF
​March 28, 2020 PDF
​March 21, 2020 PDF
​March 14, 2020 PDF
​March 7, 2020 PDF
​February 29, 2020 PDF
February 22, 2020 PDF
​February 15, 2020 PDF
​February 8, 2020 PDF
​February 1, 2020 PDF
​January 25, 2020 PDF
​January 18, 2020 PDF
​January 11, 2020 PDF
​January 4, 2020 P​DF
​December 28, 2019 PDF
​December 21, 2019 PDF
​December 14, 2019 PDF
​December 7, 2019 P​DF
​November 30, 2019 P​DF
​November 23, 2019 PDF
​November 16, 2019 PDF
​November 9, 2019 PDF
​November 2, 2019 PDF
​October 26, 2019 PDF
​October 19, 2019 PDF
​October 12, 2019 PDF
​October 5, 2019 P​DF
 ​​​
PREVIOUS SEASON SUMMARIES 
​Season
​File
2018-2019 PDF
2017-2018 PDF
2016-2017 PD​F​​
2015-2016
PDF
​2014-2015
PDF
​2013-2014
PDF
​2012-2013
PDF
​2011-2012
PDF
 
 

 
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​Page last updated: May 29, 2020