Category Archives: Vibrio vulnificans

Research- FAO and WHO report rise in foodborne diseases related to Vibrio species

New Food Magazine

The FAO/WHO assessment revealed that there have been a series of pandemic outbreaks of V. parahaemolyticus foodborne illnesses due to the consumption of seafood and outbreaks have occurred in regions of the world where it was previously unreported.

Full Report


USA – New Oyster Rules Aim to Reduce Vibrio Cases

Coastal Review

Division of Marine Fisheries Director Steve Murphey implemented the new oyster harvest control measures through Proclamation SS-1-2020  and Proclamation SS-2-2020, both issued Monday.

The Division of Marine Fisheries announced that while the state’s public health record concerning shellfish-related illnesses is one of the best in the country, the number of Vibrio cases nationwide had increased in recent years. Vibrio are naturally occurring bacteria in coastal waters that can cause illness in humans if precautions are not taken during the warmer months of the year.

The new regulations also will bring the state into conformity with guidance from the National Shellfish Sanitation Program, which is the federal, state and industry cooperative program recognized by the U. S. Food and Drug Administration and the Interstate Shellfish Sanitation Conference for the sanitary control of shellfish produced and sold for human consumption.

The changes include the following new requirements to:

  • Shade oysters harvested between May 1 and Oct. 14. This involves providing shade over harvested oysters or covering the oysters with a light-colored tarp or other nontoxic material while they are stored on the vessel, floating container when the oysters are not submerged, or a vehicle (this is already required for the harvest of clams in the summer).
  • Resubmerge oysters exposed to the air for greater than five hours between May 1 and Oct. 14 (this might occur during air-drying or de-fouling with gear such as OysterGro). The oysters must remain submerged for at least 14-days to abate Vibrio levels that may have been elevated.
  • Clarify that when working in intertidal waters the term “start of harvest” begins when the oyster is first exposed by the receding tide.
  • Clarify the tagging procedures when oysters leave the lease for tumbling or culling.
  • Resubmerge oysters moved from one growing area to another for at least 21 days prior to harvest (Certified shellfish dealers with a wet storage permit are exempt). This may prevent the closure of multiple growing areas in the event of an illness outbreak.

Previously implemented regulations pertaining to recording the start of harvest on the harvest tag and delivering the oysters to a licensed dealer within a specified time remain in effect.

For more information, contact Shannon Jenkins, chief of the division’s Shellfish Sanitatio

Research – Researchers find spread of bacteria in seafood likely impacted by trade

Food Safety News

A Centers for Disease Control and Prevention study has found that international trade of shellfish might be involved in the dispersal of Vibrio parahaemolyticus populations into the United States and Spain. The study found that severe weather, such as El Niño conditions in Peru, provide ideal conditions for the proliferation of Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus.

The CDC reports that compared to other major foodborne illnesses, Vibrio parahaemolyticus infections have been steadily increasing. Vibrio parahaemolyticus is the leading cause of seafood-related bacterial infections globally. The CDC estimates that the average annual incidence of all Vibrio infections increased 54 percent during 2006–2017. Vibrio parahaemolyticus is believed to be responsible for about 35,000 human infections each year in the United States and has been the leading cause of foodborne infections in China since the 1990s.

The transition of V. parahaemolyticus disease from a regional to a global pathogen is connected to the emergence of isolates with epidemic potential.

Research – Occurrence and Abundance of Pathogenic Vibrio Species in Raw Oysters at Retail Seafood Markets in Northwestern Mexico

Journal of Food Protection


Seafood has frequently been associated with foodborne illness because pathogens are easily introduced during seafood cultivation, handling, and processing. Vibrio parahaemolyticus and Vibrio cholerae are human pathogens that cause gastroenteritis and cholera, respectively, and Vibrio vulnificus can cause fatal wound infections and septicemia. However, information about the occurrence of these pathogens in oysters from the Pacific coast of Mexico is limited to V. parahaemolyticus. In the present study, we evaluated the presence and abundance of these three Vibrio species in 68 raw oysters (Crassostrea corteziensis) obtained from retail seafood markets in Sinaloa, Mexico. The most probable number (MPN)–PCR assay was used for amplification of the tlh (thermolabile hemolysin), ompW (outer membrane protein), and vvhA (hemolytic cytolysin) genes that are specific to V. parahaemolyticus, V. cholerae, and V. vulnificus, respectively. All oyster samples were positive for at least one Vibrio species. V. parahaemolyticus, V. cholerae, and V. vulnificus prevalences were 77.9, 8.8, and 32.3% overall, respectively, and most species were present in all sample periods with increased prevalence in period 3. The tdh (thermostable direct hemolysin) gene was detected in 30.1%, trh (TDH-related hemolysin) was detected in 3.7%, and tdh/trh was detected in 7.5% of the total tlh-positive samples (53 of 68), whereas the pandemic serotype O3:K6 (orf8 positive) was detected in only 1 sample (1.8%). The total prevalence of tdh and/or trh was 41.5%. In none of the samples positive for V. cholerae were the cholera toxin (ctxA) and cholix (chxA) toxigenic genes or the rfb gene encoding the O1 and O139 antigens amplified, suggesting the presence of non-O1 non-O139 V. cholerae strains. Our results clearly indicated a high prevalence of pathogenic Vibrio species in raw oysters from retail seafood markets in Mexico. Consumption of these raw oysters carries the potential risk of foodborne illness, which can be limited by cooking.

  • V. parahaemolyticus, V. cholerae, and V. vulnificus were prevalent in raw oysters from Mexico.

  • The tdh and trh genes and the pandemic O3:K6 serotype were detected in raw oysters.

  • The ctxA and chxA genes, and O1/O139 serotypes were absent from V. cholerae–positive samples.

  • The consumption of raw oysters represents a health risk for Vibrio infections.

Research -Occurrence, Seasonal Distribution, and Molecular Characterization of Vibrio vulnificus, Vibrio cholerae, and Vibrio parahaemolyticus in Shellfish (Mytilus galloprovincialis and Ruditapes decussatus) Collected in Sardinia (Italy)

Journal of Food Protection


In this study, we investigated the occurrence, seasonal distribution, and molecular characterization of pathogenic vibrios in Mediterranean mussels (Mytilus galloprovincialis) and grooved carpet shells (Ruditapes decussatus) from two harvesting areas of Sardinia (Italy). Samples collected before and after depuration were submitted for qualitative and quantitative determination of Vibrio spp. Vibrio spp. isolates were presumptively identified by means of biochemical methods. Identification and virulence profile of Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus were performed by molecular methods. The prevalence of Vibrio spp. in M. galloprovincialis and R. decussatus was, respectively, 96 and 77%. The averaged enumeration (mean ± standard deviation) of Vibrio spp. in samples of M. galloprovincialis and R. decussatus collected at the harvesting time was 2.04 ± 0.45 and 2.51 ± 0.65 log CFU/g, respectively. The average contamination levels in samples collected after purification were 2.28 ± 0.58 log CFU/g (M. galloprovincialis) and 2.12 ± 0.67 log CFU/g (R. decussatus). Four potentially pathogenic V. parahaemolyticus isolates (tdh+ or trh+) were recovered from grooved carpet shells samples. No isolate was tdh+/trh+. The presence of potentially pathogenic vibrios in Sardinian waters strengthens the need for rational purification practices under controlled conditions to guarantee the protection of consumers.

  • Occurrence and pathogenicity characteristics of Vibrio pathogens were investigated.

  • Prevalence of Vibrio spp. in M. galloprovincialis was 96% and in R. decussatus was 77%.

  • Environmental conditions influence the occurrence of Vibrio spp.

  • Four V. parahaemolyticus isolates carried tdh or trh genes.

  • Rational purification practices are needed to guarantee the protection of consumers.

USA – Vibrio Death Not Caused by NC Shellfish

Coastal review

No North Carolina shellfish products were involved in the death of a state resident who consumed oysters contaminated by Vibrio vulnificus in the Wilmington area.

Jenkins explained that some early media reports about the Vibrio-related death lead to speculation about North Carolina oysters being the source of contamination because the shellfish product was consumed in the Wilmington area, but his agency along with the involved county health departments and the state Department of Health and Human Services learned that the oysters were not from North Carolina waters.

“The main clarification we tried to get out was that it was not North Carolina oysters that were served at the restaurant,” he said. “The implicated shellfish were from several other states in this case.”

USA -N.C. man dies from eating contaminated oysters – Vibrio vulnificus

Star News Online Vibrio

A Cary man is dead after eating oysters in the Wilmington area, according to recent reports.

The N.C. Department of Health and Human Services (NCDHHS) is investigating after David Argay contracted vibriosis and died at the Raleigh-based WakeMed hospital Thursday.

The NCDHHS and the N.C. Division of Marine Fisheries (DMF) confirmed that the bacteria Vibrio vulnificus caused Argay’s death. Vibrio is one of several bacteria species known to cause illness in humans.

“We do know that that the oysters were not a North Carolina product,” said Tricia Smith, a spokesperson for the DMF.