Raw-fish-eating behavior and fishborne zoonotic trematode infection in people of northern Vietnam.

Raw fish consumption in restaurants, for example, Sashimi style, is popular worldwide. In Vietnam, raw fish dishes are also traditionally prepared and consumed in private households. However, the habits of eating raw or otherwise inadequately cooked fish can be associated with risks of acquiring fishborne zoonotic trematode (FZT) infection. The present study was done in a fish-farming community in Nam Dinh, Vietnam, to obtain information about habits of eating raw fish dishes and risks for human FZT infection. Discussions were held in different groups divided by gender and age on raw-fish-eating behavior. A total of 180 household members were interviewed and their stool samples analyzed to identify risk factors of FZT infection. There was awareness about the risk of liver fluke infections from eating raw fish. However, many older people accepted these risks and continued eating raw fish, as they know effective drug treatment is available. Raw fish dishes are consumed at social gatherings from shared plates and dipping sauces using the same chop sticks. This is likely to pose risks of crosscontamination with FZT metacercariae to different food items as indicated by the finding that 25.8% of household members that stated not to have eaten raw fish were infected. In total, 32.2% fish farm household members were infected with FZT. The odds of FZT infection was 2.3 times higher (p = 0.013) for those eating raw fish than for those who did not eat raw fish. Among the people eating raw fish, those eating raw fish in restaurants had 3.6 times higher odds of FZT infection (p = 0.009) than people eating raw fish at home. A successful program to control FZT must be based on in-depth knowledge on the social and anthropological determinants of people's raw-fish-eating behavior and hygiene practices as well as production of FZT-free fish for human consumption.

Morphometric discriminant analysis for the classification of Diplectanum (Monogenea: monopisthocotylea), parasites of Sphyraena flavicauda.

The authors have examined the morphology of Diplectanum cazauxi and Diplectanum bauchotae through the observation of 23 specimens (10 of D. cazauxi and 13 of D. bauchotae) found during May 2003 on the gills of 2 specimens of Sphyraena flavicauda Rüppell, 1838 collected at Ras Mohammed National Park, Egypt. A discriminant analysis was performed on the morphometric data of opisthaptor to determine which parameters more accurately distinguish the two species. The best discriminant parameters resulted to be the copulatory apparatus and the central bar, which determined the absence of misclassification in the model. The discriminant functions are reported for the two species.