Vibrio parahaemolyticus and Vibrio vulnificus in South America: water, seafood and human infections

The bacterial species, Vibrio parahaemolyticus and Vibrio vulnificus, are ubiquitous in estuaries and coastal waters throughout the world, but they also happen to be important human pathogens. They are concentrated by filter-feeding shellfish which are often consumed raw or undercooked, providing an important potential route of entry for an infective dose of these bacteria. Vibrio parahaemolyticus can cause abdominal cramping, nausea, diarrhoea, vomiting, chills and fever. Vibrio vulnificus can cause similar gastrointestinal-related symptoms, but can also spread to the bloodstream, resulting in primary septicaemia, and it can also cause disease via wound infections. The objective of this article is to summarize, for the first time, the incidence and importance of V.parahaemolyticus and V.vulnificus in South America, in environmental waters and seafood, especifically molluscan shellfish, as well as human infection cases and outbreaks. It appears that infections from V.parahaemolyticus have been more strongly related to shellfish ingestion and have been more frequently reported on the Pacific coast of South America. Conversely, V.vulnificus has been more frequently acquired by water contact with open wounds and its presence has been more heavily reported along the Atlantic coast of South America, and while documented to cause serious mortality, have been relatively few in number. The impacts of El Nino Southern Oscillation (ENSO) have been observed to cause an increase in V.parahaemolyticus outbreaks on the Pacific coast of South America. The implementation of a regulated monitoring approach, along with the use of faster, more accurate and virulence-specific detection approaches, such as PCR confirmation, should be considered to detect the presence of pathogenic Vibrio strains in environmental and seafood samples for protection of public health. Furthermore, improved clinical surveillance with suspected cases should be implemented. This review highlights the need for more research and monitoring of vibrios in South America, in water, shellfish and clinical samples.