PREVALENCE OF ZOONOTIC TREMATODES IN FISH FROM A VIETNAMESE FISH FARMING COMMUNITY.
June 27th, 2008 | by admin |PREVALENCE OF ZOONOTIC TREMATODES IN FISH FROM A VIETNAMESE FISH FARMING COMMUNITY.
The prevalence of fish borne zoonotic trematodes (FZT) metacercariae was investigated in fish farmed by rural households in Nghe An Province, located in northern Vietnam. A total of 716 fish, including tilapia (Oreochromis niloticus) and six carp species, Grass carp (Ctenopharyngodon idellus) Bighead carp (Aristichthys nobilis), Mrigal ( Cirrhinus mrigala), Common carp (Cyprinus carpio), Silver carp (Hypophthalmychthys molitrix), and Roha (Labeo rohita) collected from 53 fish farms were examined. The overall prevalence of FZT metacercariae was 44.6%, ranging from 12.5 to 61.0% in fish species collected from grow-out ponds, which are the production system for growing fish from fingerling size to market size. The overall prevalence was (43.6%) in fingerlings cultured in nurseries, ranging from 7.4 to 62.8% for different fish species. The FZT species recovered were heterophyids and echinostomatids and included Haplorchis pumilio, H. taichui, H. yokogawai, Centrocestus formosanus, Stellantchasmus falcatus and Echinochasmus japonicus, all of which are intestinal flukes in humans, other mammals and birds. This is the first report of H. yokogawai and E. japonicus in fish in Vietnam, and the first record for S. falcatus in northern Vietnam. Although a previous cross-sectional survey of the people living in these fish farm households revealed a very low prevalence of FZT (<1%), our results demonstrate that intestinal flukes are common in farmed fish in this area, suggesting that reservoir hosts such as dogs, cats, pigs, etc., are more important in sustaining the life cycles of these flukes in fish farms than human hosts. This has implications for the effectiveness of control programs focused mainly on treatment of humans.
Chi T, Dalsgaard A, Turnbull J, Tuan P, Murrell KD.