Norovirus popularly known as "cruise-ship flu", "stomach flu" or "winter vomiting flu", is one of the world's most common causes of gastrointestinal distress according to New York Times. Now a new study published in the journal of "Applied and Environmental Microbiology" last month links oysters as the source of the dreadful virus.
Researchers analyzed 1,077 samples of noroviruses found in oysters. Files from genetic database since 1983 were also reviewed. The scientists then found out that 80 percent of documented human noroviruses saw a match in oysters found mostly on coastal waters contaminated by human sewage.
Noroviruses mutate very fast much like influenza viruses and big outbreaks usually begin after a new strain develops. And these oysters act like an incubator for the virus to mutate in between outbreaks. These new strains of Norovirus are mostly found in raw oysters, which how most people eat oysters. The new strains found in oysters and the strains currently circulating in humans seem to converge according to researchers.
Yongjie Wang, food science specialist at Shanghai Ocean University and lead author of the study came to a conclusion that oysters are important reservoir for human noroviruses. Further studies need to be done to find a way to detect noroviruses in oysters and in the beds where they grow.
Noroviruses are often painful and highly infectious. Although some patients recover after a few days of misery, the virus can be lethal to infants, older people and those with weak immune system. In most cases where outbreaks occur in cruise ships, it can spell disaster to your paradise vacation.
How it has been transmitted remains a mystery. In the past, unsanitary preparation of food has been blamed. Unwashed hands of food workers for example. Another source has been found in a study recently conducted at North Carolina State. Scientist built a "vomiting machine" that showed droplets of infected vomit can also fly through the air and infect people the way a sneeze and cough might.
