Investigating gastroenteritis outbreaks in nursing homes and similar settings

• OAR 333-018-0015 permits local health departments to investigate acute gastroenteritis outbreaks in long term care facilities (LTCFs) by legally requiring LTCFs to report such outbreaks.
  
  
• Definitions

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  • Acute gastroenteritis (AGE): acute-onset vomiting, diarrhea, or both without other apparent cause

     

  • Institutional AGE outbreak
    
    
    • general definition: an "unusual" number of residents or employees with AGE clustered by time and place 
      

     

    • working definition: three or more residents or employees who live or work in the same facility (or on the same unit of a large facility) with AGE onset dates ranging from the same date to 96 hours (two incubation periods) after the onset date of the first case(s)

     

  • Lab - confirmed AGE outbreak: 2 + stool or vomitus specimens "(+) for" the same virus or bacteria
    

     

• When an LTCF reports a cluster of residents or employees with AGE, ask for a  Gastroenteritis Case Log (.pdf) of residents and employees with vomiting, diarrhea, or both.  The Gastrointestinal Case Log should start with the first case and include everyone who has (or has had) vomiting, diarrhea, or both up to and including the day AGE was reported to local health.
  
  
• Review the data, confirm the outbreak, and contact ACDP (971-673-1111) to get an outbreak number.
  
  

• After the initial report, getting data for every single, last resident or employee with AGE is not necessary. Instead just use case logs for residents and employees with AGE who:

   

  • provide specimens of stool or vomitus;
    

     

  • see a doctor, go to the emergency room, or are hospitalized for AGE;
    

     

  • die. 

    
    

• Send the LTCF copies of Controlling person-to-person transmission (.pdf),  Cleaning up vomit and other unpleasant tasks (.pdf), and Guidelines for collecting stool specimens (pdf).
  
  
  • List G: EPA's Registered Antimicrobial Products Effective Against Norovirus (Norwalk-like virus), January 9, 2009 (.pdf)

     

• Specimens
  
  
  • Use secure, leak proof containers with screw tops, not flip-tops, labeled with resident or employee name/names and outbreak number/numnbers.

     

  • Collect specimens of walnut-size whole stool, 3 tbs of diarrheal stool (or vomitus) or 3-4 rectal swabs from six residents (or employees) up to seven days after onset. Collecting >6 does not increase the chance of finding something.

     

  • Use proper containers for shipping stool and the OSPHL virology/immunology request form. (.pdf) Keep fresh stool specimens cold from the time they are produced until the time they reach OSPHL.

     

  • Also send OSPHL scoops of fecal material plopped into Cary-Blair transport media (for bacteriology testing if norovirus tests are negative).
    

     

  • Keep in touch with facility until the outbreak is over, seven days after the last case occurs, when the outbreak is considered over.

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  • Enter and analyze Gastroenteritis Case Logs in the CD Database or in a Gastroenteritis Case Log Excel Database (.xls) (and transfer the files to ACDP when the outbreak is over).
  
  
  

• Paperwork
  
  

  • Complete a Gastroenteritis (non-foodborne) Summary Report (pdf) no later than 30 days after the onset of the last case.
    

     

  • Complete a Control Measures Report seven or more days after the last case occurs.
    

     

  • Use the CD Database or the Gastroenteritis Case Log Excel Database to generate an epidemic curve ("epi curve").

  
  

• Outbreak data
  
  

  • Gastroenteritis outbreaks in nursing homes and similar settings by county, 2002-2007 PDF   Excel

     

  • Completed outbreak investigations by mode of transmission and setting, 2002-2007 (pending)

     

  • Completed outbreak investigations by etiology, 2002-2007 (pending)
    

   

• Useful Links

   

  • Investigative Guidelines (revised May, 2008)

     

  • CDC Norovirus (Calicivirus) fact sheet (September 2007)