Health Advisory
POSSIBLE FOODBORNE OUTBREAK
OCEAN CITY, MARYLAND 2004

The Delaware Division of Public Health (DPH) wishes to alert the Delaware medical community about a possible foodborne outbreak investigation now in progress.

Background:

Worcester County Health Department (WCHD), along with the Maryland Department of Health and Mental Hygiene (DHMH), is investigating reports of possibly foodborne gastroenteritis (GE) associated with a local restaurant in Ocean City, Maryland. WCHD has received reports of at least 30 patrons who became ill with gastrointestinal (GI) symptoms including nausea, vomiting, and diarrhea after eating at this local restaurant on June 22-24, 2004. In addition, beginning on Wednesday, June 23, 2004, 15 restaurant employees have reported illness consistent with GE.

The etiologic agent of these illnesses is undetermined at this time. Norovirus is suspected on the basis of symptomatology and an incubation period of approximately 24-48 hours. WCHD is collecting viral and enteric stool specimens from ill employees and patrons. No hospitalizations or deaths have been reported; however, at least five patrons have sought medical care from a primary physician or at a hospital emergency department.

WCHD inspected the restaurant on Friday, June 25, 2004. The restaurant voluntarily ceased operations on the evening of Friday, June 25, through the afternoon of Monday, June 28. No additional illness among employees or patrons has been reported since its reopening.

Health Care Providers who receive reports of GE cases with vomiting and or/diarrhea among persons with recent travel to Ocean City during June 22-25 should contact Delaware Division of Public Health at 1-888-295-5156.

Clinical Description:

An illness caused by Norovirus is often characterized by acute - onset of vomiting, watery, non-bloody diarrhea with abdominal cramps and nausea. Low-grade fever also occasionally occurs and vomiting is more common in children. Symptoms usually last 24-60 hours.

Incubation Period:

The incubation period is usually between 24 to 48 hours (median in outbreaks 33-66 hours), but cases can occur within 12 hours of exposure.

Period of Communicability:

During acute stage of disease and up to 48 hours after Norovirus diarrhea stops.

Laboratory Criteria for Diagnosis:

Detection of the presence of noroviruses using reverse transcriptase polymerase chain reaction (RT-PCR). RT-PCR can be used to test stool and emesis samples, as well as on environmental swabs in special studies; or direct and immune electron microscopy of fecal specimens; or detection of fourfold increase of specific antibodies in acute and convalescent phase blood samples.

Reporting of Suspect Cases:

To aid in the investigation, the Delaware Division of Public Health (DPH) requests that health care providers be suspicious of patients presenting with clinically compatible illness and report suspicious cases and laboratory confirmed Norovirus infections to DPH, Bureau of Epidemiology at 1-888-295-5156 immediately. This number is available during normal business hours and during non-business hours for emergencies.

For Further Information:

DPH, Bureau of Epidemiology: 1-888-295-5156. This number is available during normal business hours and during non-business hours for emergencies.