Vibriosis 
Annual Summary of Reportable Diseases

• The number of confirmed vibriosis cases remained similar to past years.
• Only 20% of cases positive by multiplex PCR were confirmed by culture, indicating a high number of false-positives on these platforms.

There were 89 Vibrio spp. cases reported in 2023. Of those, 23 were culture-confirmed and 66 tested positive by a culture-independent diagnostic test (CIDT) and were not subsequently culture-confirmed. The 23 culture-confirmed cases of Vibrio spp. infection reported in 2023 represent a 15% increase from the 20 cases reported in 2022 but is similar to the median annual number of cases reported from 2012 to 2022 (median, 22 cases; range, 15 to 40). V. parahaemolyticus accounted for 13 (57%) cases, V. cholerae for 6 (26%), and V. alginolyticus, V. fluvialis, and Grimontia hollisae (in the Vibrionaceae family and prior to 2003 classified in the Vibrio genus) for one case (4%) each. One isolate was not received at the MDH Public Health Laboratory for confirmation and species identification. Serotyping was performed on all V. cholerae specimens, and all were non-O1/non-O139.

Vibrio was isolated from stool in 19 (83%) of the 23 culture-confirmed cases. The specimen source for the remaining four cases was ear effusion (3 cases) and wound (1 case). Four (17%) cases were hospitalized for a median of 2.5 days (range, 1 to 6 days), and no cases died. Travel history was available for 18 cases. Ten (56%) of these cases traveled outside of Minnesota in the week before their symptom onset, including six (33%) who traveled internationally. Four cases traveled to Mexico and two traveled to Costa Rica. Of the 12 cases with Vibrio isolated from stool who were able to be interviewed about exposure to seafood in the week before illness onset, 11 (92%) had raw or undercooked seafood exposure, including 9 (75%) who reported consuming raw oysters.  

In 2023, 84 patients tested positive for Vibrio spp. by CIDT conducted at a clinical laboratory. Of these, 66 (79%) were not culture-confirmed. Six (9%) specimens were not received at the MDH Public Health Laboratory for culture confirmation, and 60 (91%) were received at MDH and tested negative by culture. Ten (13%) CIDT-only cases were hospitalized for a median of 3 days (range, 1 to 50 days) and none died. Fourteen (30%) of the 47 CIDT-only cases who were interviewed traveled outside of Minnesota, and 7 (15%) traveled internationally (3 to the Dominican Republic and 1 each to China, El Salvador, Mexico, and Pakistan). Among the 37 CIDT-only cases interviewed about food exposures, 9 (24%) reported eating raw or undercooked seafood including four (11%) who had raw oysters. CIDT-only cases differed markedly from culture-confirmed cases regarding exposures, suggesting that a high proportion of CIDT-positive tests represented false positives.

One culture-confirmed case was part of an outbreak in Rhode Island associated with consuming raw oysters from the Dutch Island Harbor area. This case ate oysters while traveling to Rhode Island. 

• Find up to date information at>> Vibrio Infection (Vibrio parahaemolyticus)

There were 91 Vibrio spp. cases reported in 2022. Of those, 20 were culture-confirmed and 71 were positive by culture-independent diagnostic tests (CIDT) and not subsequently culture-confirmed. The 20 culture-confirmed cases of Vibrio spp. infection reported in 2022 represent a 17% decrease from the 24 cases reported in 2021, and a 9% decrease from the median annual number of cases reported from 2011 to 2021 (median, 22 cases; range, 9 to 40). V. parahaemolyticus accounted for seven (36%) cases, V. cholerae for six (32%), and V. alginolyticus and V. fluvialis for three (16%) each. One isolate was not received at the MDH Public Health Laboratory for confirmation and species identification. Serotyping was performed on all V. cholerae specimens, and all were non-O1/ non-O139. There were no outbreaks of Vibrio spp. infection identified in 2022.

Vibrio was isolated from stool in 17 (85%) of the 20 culture-confirmed cases. The specimen source for the remaining three cases were wound, blood, and ear effusion. Two (10%) cases were hospitalized for a median of 4.5 days (range, 1 to 8 days), and no cases died. Travel history was available for 19 cases. Fifteen (79%) of these cases traveled outside of Minnesota in the week before their symptom onset, including eight (44%) who traveled internationally. Three cases traveled to Mexico, and one case each to Belize, French Polynesia, Guatemala, and Kenya. One traveled to Kenya and Somalia. Of the 12 cases with Vibrio isolated from stool who were able to be interviewed about exposure to seafood in the week before illness onset, seven (58%) had raw or undercooked seafood exposure, including four (33%) who reported consuming raw oysters.

In 2022, 87 patients were positive for Vibrio spp. by CIDTs conducted at a clinical laboratory. Of these, 71 (82%) were not culture-confirmed and thus were classified as probable cases. Nine (10%) specimens were not received at the MDH Public Health Laboratory for culture confirmation, and 62 (87%) were received at MDH and tested negative by culture. Seventeen (24%) probable cases were hospitalized and one (1%) died. Ten (19%) of the 54 probable cases who were interviewed traveled outside of Minnesota, and 6 (11%) traveled internationally (2 to Nigeria, 1 each to Cambodia, Dominican Republic, Mexico, and Vietnam). Among the 47 probable cases interviewed about food exposures, four (9%) reported eating raw oysters, and no additional cases reported eating another type of raw seafood in the week prior to illness onset. Thus, probable cases differed markedly from culture-confirmed cases regarding exposures, suggesting that a high proportion of CIDT-positive tests represented false positives.

• Find up to date information at>> Vibrio Infection (Vibrio parahaemolyticus)

There were 91 Vibrio spp. (several species) cases reported in 2021. Of those, 24 were culture-confirmed and 67 were positive by culture-independent diagnostic tests (CIDT) and not subsequently culture-confirmed.

The 24 culture-confirmed cases of Vibrio spp. infection reported in 2021 represent a 71% increase from the 14 cases reported in 2020, and a 20% increase from the median annual number of cases reported from 2010 to 2020 (median, 20 cases; range, 9 to 40). V. parahaemolyticus accounted for 12 (50%) cases, V. alginolyticus, V. cholerae, and V. fluvialis for 3 (13%) each, and V. vulnificus for 1 (4%). Two isolates were not received by the MDH Public Health Laboratory for confirmation and species identification. Serotyping was performed on all three V. cholerae specimens, and all were non-O1/non-O139.

Vibrio was isolated from stool in 16 (67%) cases, wounds in 3 (13%) cases, blood in 2 (8%) cases, ear effusion in 2 (8%) cases, and urine in 1 (4%) case. Three (13%) cases were hospitalized for a median of 3 days (range, 1 to 4 days), and one case died. Travel history was available for 21 cases. Fourteen (67%) cases traveled out of Minnesota in the week before their symptom onset, including five (24%) who traveled internationally. Two cases traveled to Mexico, and one case each to the Bahamas, Egypt, and Somalia. Of the 16 cases with Vibrio isolated from stool who were able to be interviewed about exposure to seafood in the week before illness onset, 10 (63%) reported consuming oysters. Of the remaining six cases, three had other raw or undercooked seafood.

In 2021, 74 patients were positive by CIDTs conducted at a clinical laboratory. Of these 67 (91%) were not culture-confirmed and thus were classified as probable cases. Eight (12%) specimens were not received by the public health laboratory for culture confirmation. Fifty-nine (79%) were received at MDH and tested negative by culture. Fifteen (22%) probable cases were hospitalized and two (3%) died.

Ten (19%) of the 53 probable cases who were interviewed traveled outside Minnesota, and five (9%) traveled internationally (one each to Cameroon, France, Mexico, New Zealand, and Somalia). Among the 43 probable cases interviewed about food exposures, three (7%) reported eating raw oysters, and three (7%) reported eating another type of raw seafood in the week prior to illness onset. Thus, probable cases differed markedly from culture-confirmed cases regarding exposures, suggesting a high proportion of CIDT-positive tests represented false positives.

There were no outbreaks of Vibrio spp. infections identified in 2021.

• Find up to date information at>> Vibrio Infection (Vibrio parahaemolyticus)

There were 14 culture-confirmed Vibrio spp. cases reported in 2020 (0.3 cases per 100,000 population). This is a 59% decrease from the 34 cases reported in 2019, and a 30% decrease from the median annual number of cases reported from 2009 to 2019 (median, 20 cases; range, 9 to 40). V. parahaemolyticus accounted for 6 (43%) cases, V. alginolyticus for 5 (36%), V. cholerae for 2 (14%), and V. mimicus for 1 (7%). Serotyping was performed on both V. cholerae specimens, and both were non-O1/ non-O139.

Vibrio was isolated from stool in 8 (57%) cases, ear effusion in 5 (35%) cases, and a wound in 1 (7%) case. One (7%) case was hospitalized for 2 days, and no cases died.

Travel history was available for 6 cases. Two traveled out of Minnesota in the week before their symptom onset, and both traveled internationally. One went to Belize and the other to Vietnam.

Of the 3 cases with Vibrio isolated from stool who were able to be interviewed about exposure to seafood in the week before illness onset, 2 reported consuming raw oysters. The other did not recall consuming any seafood in the week before their symptom onset.

In 2020, 32 patients were positive by culture-independent diagnostic tests (CIDTs) conducted at a clinical laboratory. Twenty-four (75%) of the specimens received at MDH tested negative by culture and therefore were classified as probable cases.

Two (17%) of the 12 probable cases who were interviewed traveled internationally. Among the 12 probable cases interviewed about food exposures, 2 (17%) reported eating raw oysters, and 5 (42%) reported eating another type of cooked seafood in the week prior to illness onset. There were no outbreaks of Vibrio spp. infections identified in 2020.

• Find up to date information at>> Vibrio Infection (Vibrio parahaemolyticus)

There were 34 culture-confirmed Vibrio spp. cases reported in 2019 (0.57 cases per 100,000 population). This is a 15% decrease from the 40 cases reported in 2018, and a 70% increase from the median annual number of cases reported from 2008 to 2018 (median, 20 cases; range, 8 to 40). V. parahaemolyticus accounted for 18 (53%) cases, V. cholerae 11 (33%), V. alginolyticus 1 (3%), V. cincinnatiensis 1 (3%), V. furnissii 1 (3%), V. metschnikovi 1 (3%), and V. vulnificus 1 (3%). Serotyping was performed on an all V. cholerae specimens; 7 (63%) cases were non-O1/non-O139, 3 (27%) cases were O1 Inaba toxigenic, and 1 .9%) was O1 Inaba non-toxigenic.

Vibrio was isolated from stool in 29 (85%) cases, wounds or tissue in 3 (9%) cases, and blood in 2 (6%) cases. Six (18%) cases were hospitalized for a median duration of 2.5 days (range, 2 to 15 days). Two (5%) cases died (a 55 year-old and a 93 year-old). The first case had V. vulnificus isolated from a blood specimen and had chronic liver disease. The other had V. metschnikovi isolated from a blood specimen, and had chronic liver, kidney disease, and cancer.

Travel history was available for 33 cases. Nineteen (58%) cases traveled out of Minnesota in the week before symptom onset, including 10 (30%) who traveled internationally.

Of the 26 cases with Vibrio isolated from the stool who were able to be interviewed about exposure to seafood in the week before illness onset, 18 (69%) reported consuming raw oysters; an additional 3 (11%) reported eating another type of seafood, and 2 of those reported eating raw seafood. The 5 remaining cases with no seafood consumption traveled internationally in the week prior to illness onset to the Dominican Republic, Kenya, Mexico, Pakistan, and Panama.

In 2019, 64 patients were positive by culture-independent diagnostic tests conducted at a clinical laboratory. Thirty-two (56%) of the specimens received at MDH tested negative by culture and therefore were classified as probable cases.

Three (10%) of 31 probable cases traveled internationally. Among the 29 probable cases interviewed about food exposures, 4 (14%) reported eating raw oysters, and 17 (59%) reported eating another type of cooked seafood in the week prior to illness onset.

There was one outbreak of V. parahaemolyticus identified in 2019. The outbreak was associated with consumption of raw oysters at a restaurant. One culture-confirmed case and 3 probable cases who were not tested were part of this outbreak. The oysters consumed were harvested from the Hammersley Inlet in Washington State. This harvest area was closed in response to multiple outbreaks of V. parahaemolyticus across the country, including this one.

• Find up to date information at>> Vibrio Infection (Vibrio parahaemolyticus)

• Archive of Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health
  Archive of past summaries (years prior to 2023 are available as PDFs).