CSTE Position Statement(s)
Vibriosis is an under-recognized and under-reported cause of human illness. Vibriosis is caused by infection with pathogenic species of the family Vibrionaceae (species other than toxigenic Vibrio cholerae O1 and O139, which cause cholera). These pathogens typically cause gastrointestinal illness with watery diarrhea that can range in severity from mild to severe. They may also cause bacteremia, wound infections, or other extra-intestinal infections. The most common mode of transmission is consumption of raw or undercooked seafood; raw oysters are the most frequent source. Transmission can also occur through contact with water, especially seawater. Persons with liver diseases, cirrhosis, iron storage disorders, immune suppression, malignancies, and alcoholism are at particularly high risk of serious infection. Surveillance is needed to better define the burden of disease, identify and control outbreaks, as well as define and evaluate prevention strategies.
Vibrio species are included in several of the commercially available multiplex PCR panels, so it is possible that more laboratories will routinely test for Vibrio in stool specimens and more laboratory-diagnosed cases will be reported to public health. The sensitivity and specificity of these new tests is not yet known, in large part because these infections are rare. Further, as with other enteric bacterial pathogens, reflexive culture of specimens with positive Culture-independent diagnostic testing (CIDT) results is not always performed at the clinical laboratory or the state or local public health laboratory. This increase in testing provides public health with an opportunity to learn more about the epidemiology of this family of organisms, but only if CIDT-positive as well as culture-confirmed cases are reported to public health.
Clinical CriteriaAn infection of variable severity characterized by watery diarrhea, primary septicemia, or wound infection. Asymptomatic infections may occur, and the organism may cause extra-intestinal infection.
Laboratory Criteria For DiagnosisSupportive laboratory evidence: Detection of a species of the family Vibrionaceae (other than toxigenic Vibrio cholerae O1 or O139, which are reportable as cholera) from a clinical specimen using a culture-independent diagnostic test. Confirmatory laboratory evidence: Isolation of a species of the family Vibrionaceae (other than toxigenic Vibrio cholerae O1 or O139, which are reportable as cholera) from a clinical specimen.
Epidemiologic LinkageA clinically compatible case that is epidemiologically linked to a case that meets the supportive or confirmatory laboratory criteria for diagnosis.
Criteria to Distinguish a New Case from an Existing Case
A case should not be counted as a new case if laboratory results were reported within 30 days of a previously reported infection in the same individual. When two or more different species of the family Vibrionaceae are identified in one or more specimens from the same individual, each should be reported as a separate case.
The use of CIDTs as stand-alone tests for the direct detection of Vibrio in stool is increasing. Specific performance characteristics such as sensitivity, specificity, and positive predictive value of these assays likely depend on the manufacturer and are currently unknown. It is therefore useful to collect information on the type(s) of testing performed for reported vibriosis cases. When a specimen is positive using a CIDT it is also helpful to collect information on all culture results for the specimen, even if those results are negative. Culture confirmation of CIDT positive specimens is ideal, although it might not be practical in all instances. State and local public health agencies should make efforts to encourage reflexive culturing by clinical laboratories that adopt culture-independent methods, should facilitate submission of isolates/clinical material to state public health laboratories, and should be prepared to perform reflexive culture when not performed at the clinical laboratory as isolates are currently necessary for serogrouping and cholera toxin testing as well as biotype and antimicrobial susceptibility testing.
CDC requests that Vibrio isolates be forwarded to the Enteric Diseases Laboratory Branch (EDLB) per the isolate submission memo and table found at https://www.cdc.gov/ncezid/dfwed/edlb/additional.html. EDLB (specifically the Epidemic Investigations Laboratory) requests that state public health labs immediately forward all suspect V. cholerae isolates.
In addition to reporting through the National Notifiable Diseases Surveillance System (NNDSS), CDC requests that states collect and report the information for cases on the standard form for Cholera and Other Vibrio Illness Surveillance (COVIS), available at: https://www.cdc.gov/nationalsurveillance/cholera_vibrio_surveillance.html . One COVIS case report form should be submitted for each patient, and include all supportive and confirmatory laboratory evidence related to the individual. CDC intends to integrate the COVIS form into the National Electronic Diseases Surveillance System (NEDSS) in the future. Reporting sites should use the COVIS reporting form until the integration is successfully implemented.