172420 Epidemiology of norovirus-like illness outbreaks in a large urban health department

Wednesday, October 29, 2008

Andrea Arendt, RN, MPH , Epidemiology, Surveillance, & Informatics, Cuyahoga County Board of Health, Parma, OH
Jackie Napolitano, RS , Epidemiology, Surveillance, & Informatics, Cuyahoga County Board of Health, Parma, OH
Chris Kippes, MS , Epidemiology, Surveillance, & Informatics, Cuyahoga County Board of Health, Parma, OH

Among the Norovirus outbreaks that were reported to the Centers for Disease Control and Prevention (CDC) from July 1997 - June 2000, 57% were foodborne, 16% were person-to-person, 3% were waterborne, and 23% had undetermined transmission. According to the August 2007 MMWR, data suggests that person-to-person transmission accounts for an even larger portion of Norovirus-like outbreaks. Norovirus-like illness accounted for approximately 67% of outbreaks reported by the Cuyahoga County Board of Health (CCBH) in 2007. Of these, 73% were person-to-person transmission and 69% were associated with longterm care, assisted living, or health care facilities.


CCBH completes the CDC Outbreak Report of Suspected Viral Gastroenteritis form on all reported outbreaks of norovirus-like illness. Outbreaks that involve food operations often incorporate a case-control component in the investigation. Attempts are also made to collect stool specimens from each outbreak Using local surveillance and outbreak data from January 1, 2006 through May 31, 2008, we will characterize epidemiological trends of norovirus-like outbreaks in Cuyahoga County, Ohio (Cleveland, Lakewood, and Shaker Heights excluded) using descriptive statistics.


Results are pending. Outbreak characteristics will include outbreak setting, mode of transmission, number ill, provider visits, hospitalizations, symptom presentation, and seasonal trends.


The implementation of a national surveillance system for all acute gastroenteritis outbreaks regardless of mode of transmission may correct a potential surveillance bias. Norovirus outbreaks represent a large portion of outbreaks investigated by local health departments and accurate characterization of these outbreaks will enable local health departments to plan interventions more efficiently.

Learning Objectives:
1. Describe the epidemiology of norovirus-like illness outbreaks investigated by a large urban health department. 2. Apply information on epidemiology of norovirus-like outbreaks to public health interventions aimed at prevention of Norovirus transmission. 3. Identify potential surveillance bias of norovirus-like outbreaks and importance of reporting such outbreaks regardless of mode of transmission.

Keywords: Communicable Disease, Epidemiology

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have a Masters of Public Health with a concentration in Epidemiology. I was directly involved in collecting and analyzing data to be presented.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.