Occurrence of human enterovirus in tropical fish and shellfish and their relationship with fecal indicator bacteria

Aim: Human enteroviruses in fish and shellfish are a health concern worldwide. Human infections occur due to the consumption of raw or insufficiently cooked fish or shellfish. The objective of this study was to determine the occurrence of human enteric viruses belonging to Enterovirus (EV) group in seafood in Mumbai and to correlate their occurrence with the bacterial indicators of fecal contamination. Materials and Methods: Samples of fresh fish and shellfish collected from fish landing centers and retail fish markets were analyzed by virus concentration, nucleic acid extraction, and reverse transcription-polymerase chain reaction (RT-PCR). Bacterial indicators of fecal contamination were estimated by the most probable number technique. The relationship between the presence of virus and fecal indicators was determined by statistical analysis. Results: A total of 89 samples comprising of fish, shrimps, oysters, clams, and mussels were screened in this study. EV was detected in 32 (35.95%) samples, and all the virus-positive samples belonged to bivalve molluscan group. None of the finfish and crustacean shellfish samples was positive for the enteric viruses. Clams were found to be the most contaminated with 48.4% of the samples being positive for EV. The prevalence of enteric viruses in seafood samples showed a strong positive correlation with the bacteriological indicators of fecal contamination, suggesting that fecal coliform bacteria are good indicators of EVs in tropical seafood. Conclusion: The presence of EVs in seafood is a public health hazard. Increasing level of coastal water contamination from anthropogenic sources is the primary reason for the contamination of seafood with EVs. Continuous monitoring of coastal waters and seafood for enteric viruses will help to ensure the safety of fish and shellfish for human consumption.