Cause: Bacteria in the genus Vibrio, including V. parahaemolyticus, V. vulnificus, non-toxin-producing V. cholerae and other less common species. Infections caused by toxin-producing V. cholerae are notifiable as Cholera.
Illness and treatment: Symptoms include abdominal pain, watery diarrhea, vomiting, headache and fever. Skin infections can occur. V. vulnificus, a species occurring mainly in the Gulf of Mexico, can cause life-threatening septicemia in persons with weakened immune systems. Most persons recover without treatment but antibiotics may be needed for severe cases.
Sources: V. parahaemolyticus occur naturally in Pacific coastal waters, especially during warmer months. Transmission of vibriosis usually occurs through ingesting contaminated raw or undercooked shellfish or through skin injuries exposed to seawater.
Additional risks: Persons with liver disease, alcoholics, and others with weakened immune systems should be warned not to eat raw or undercooked seafood.
Prevention: Keep shellfish cold throughout the transport from harvest to preparation. To lessen risk of illness, consume raw or undercooked shellfish from only approved harvest areas and only during cooler months of the year.
Recent Washington trends: Two large outbreaks occurred in years when environmental conditions favored growth of Vibrio (1997 and 2006). Annual case counts are variable, ranging from 9 to 80 cases reported, with a mixture of locally acquired and travel associated exposures. Non-laboratory confirmed cases and cases from out of state associated with consumption of Washington shellfish are not included in these counts.
Purpose of Reporting and Surveillance
- To identify sources of transmission (e.g., commercially distributed food product or shellfish collection area) and to prevent further transmission from such sources
- When disease is due to privately collected shellfish, to inform those individuals how to reduce their risk of exposure.
Legal Reporting Requirements
- Health care providers and Health care facilities: notifiable to local health jurisdiction within 24 hours
- Laboratories: Vibrio (non-cholera) species notifiable to local health jurisdiction within 24 hours; isolate or if no isolate specimen associated with positive result, within 2 business days
- Local health jurisdictions: notifiable to Washington State Department of Health (DOH) Communicable Disease Epidemiology (CDE) within 7 days of case investigation completion or summary information required within 21 days
Note: Persons with non-toxigenic strains of V. cholerae are reported as cases of vibriosis. Persons with toxigenic strains of V. cholerae (O1 and O139) are reported as cases of cholera on the cholera case report form (https://www.doh.wa.gov/portals/1/Documents/5100/210-021-ReportForm-Cholera.pdf) and the CDC Cholera and Other Vibrio Illness Surveillance Report form.