A cross-sectional study was applied in oder to evaluate the situation of metacercariae infections in freshwater fishes in six communes of Bac Giang and Binh Dinh province from 2016 to 2017. The sample size was of 400 freshwater fishe samples. The results showed that: (1) In Bac Giang province, metacercariae was found in 70% of Hypophthalmichthys molitrix, 62.5% of Carassius auratus, 25% of Hemiculter leucisculus, 95% of Toxabramis houdemeri, 85% of Cultrichthys erythropterus, 12.5% of Ctenopharyngodon idellus and 62.5% of Cyprinus carpio samples; and (2) In Binh Dinh province, metacercariae was found in 42.5% of Hypophthalmichthys molitrix, 95% of Carassius auratus, and 20% of Hemiculter leucisculus samples.

Polyclonal antibodies from vaccinated mammalian have made a significant contribution to scientific research and diagnosis. The fact that recent technologies allow the production of antibodies in egg yolks laid by hens has led to the development of an alternative to antibody production that is less dangerous to animals. The results of this study showed that it is possible to produce a large amount of IgY antibody to bovine serum albumin (BSA), content of about 8 mg/mL of egg yolk emulsion. The anti-BSA IgY antibodies with high purity and anti-BSA activity.