Freshwater aquaculture nurseries and infection of fish with zoonotic trematodes, Vietnam.
Residents of the Red River Delta region of northern Vietnam have a long tradition of eating raw fish. Fish-borne zoonotic trematodes (FZTs) are estimated to infect ≈1 million persons in Vietnam. It remains uncertain at what stages in the aquaculture production cycle fish become infected with FZTs. Newly hatched fish (fry) from 8 hatcheries and juveniles from 27 nurseries were therefore examined for FZT infection. No FZTs were found in fry from hatcheries. In nurseries, FZT prevalence in juveniles was 14.1%, 48.6%, and 57.8% after 1 week, 4 weeks, and when overwintered in ponds, respectively. FZT prevalence was higher in grass carp (p<0.001) than in other carp species. Results show that nurseries are hot spots for FZT infections in fish. Thus, sustainable FZT prevention strategies must address aquaculture management practices, particularly in nurseries, to minimize the risk of distributing infected juveniles to grow-out ponds and, subsequently, to markets for human consumption.
Centre for Environment Disease Monitoring in Aquaculture-Research Institute for Aquaculture No.1, Bac Ninh, Vietnam. phanvan@ria1.org
Van Thi
VT
Phan
Annette Kjær
AK
Ersbøll
Thanh Thi
TT
Nguyen
Khue Viet
KV
Nguyen
Ha Thi
HT
Nguyen
Darwin
D
Murrell
Anders
A
Dalsgaard
D000818:Animals; D017756:Aquaculture; D003430:Cross-Sectional Studies; D005393:Fish Diseases / Q000453:epidemiology / Q000469:parasitology*; D005399:Fishes / Q000469:parasitology; D005618:Fresh Water / Q000469:parasitology*; D006801:Humans; D058488:Metacercariae / Q000302:isolation & purification; D010270:Parasite Egg Count; D014200:Trematoda / Q000254:growth & development*; D014201:Trematode Infections / Q000453:epidemiology* / Q000635:transmission*; D014744:Vietnam / Q000453:epidemiology; D015047:Zoonoses / Q000453:epidemiology / Q000469:parasitology*