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The aims of this study were to investigate the prevalence of Moniezia spp. in domestic ruminants in central Vietnam and to develop a polymerase chain reaction (PCR) technique to distinguish M. expansa from M. benedeni. Among 2040 examined domestic animals (540 cattle, 800 goats, 700 sheep) Moniezia was recovered from 5.4% of cattle, 16.4% of sheep and 20.6% of goats. A set of primers for PCR was designed to classify M. expansa and M. benedeni based on the amplification of DNA corresponding to the internal transcribed spacer of 5.8S rRNA. The 457 specimens (75 from cattle, 162 from goats, 150 from sheep, 30 from horses, 30 from chickens and 10 from dogs) were subjected to PCR for classification of Moniezia spp. PCR products with the expected sizes were amplified from bovine, ovine and caprine specimens. No specific PCR products were found for specimens from horses, chickens and dogs. Of the 75 specimens from cattle, nine were classified as M. expansa and 66 were M. benedeni. Among 162 caprine specimens, 138 were M. expansa and 24 were M. benedeni. The distribution of M. expansa and M. benedeni in 150 ovine specimens was 132 and 18, respectively. These results show that M. expansa is dominant in goats and sheep, whereas M. benedeni is more common in cattle; PCR can be used for classification of these two species.

The aims of this study were to investigate the prevalence of natural Fasciola infections in both the definitive hosts (cattle) and the intermediate hosts (Lymnaea snails) in central Vietnam. A total of 1,075 fecal samples, randomly collected from cattle in Binh Dinh, Khanh Hoa, and Phu Yen provinces, were examined for Fasciola eggs by a sedimentation method. The overall prevalence of Fasciola was 45.3 %. A subset of the animals (235) was also screened for antibodies against Fasciola by an enzyme-linked immunosorbent assay. Overall, 46.3 % of these animals were shedding Fasciola eggs while 87.2 % were Fasciola seropositive. A lower prevalence of Fasciola was observed in calves ≤ 2 years of age (37.6 %) compared to that in cattle >2 years of age (53.7 %) (p < 0.05). The prevalence in the rainy season (50.8 %) was significantly different to that in the dry season (38.1 %) (p < 0.05). Of the 3.269 Lymnaea viridis and 1.128 Lymnaea swinhoei examined, 31 (0.95 %) and seven (0.62 %), respectively, were found to be infected with Fasciola. This appears to be the first epidemiological survey of the prevalence of Fasciola in cattle and snails in these three provinces in central Vietnam.

No abstract

Fasciola spp. were collected from naturally infected cattle at a local abattoir of Khanh Hoa province, Vietnam, for morphological and genetic investigations. Microscopic examination detected no sperm cells in the seminal vesicles, suggesting a parthenogenetic reproduction of the flukes. Analyses of sequences from the first and second internal transcribed spacers (ITS1 and ITS2) of the ribosomal RNA revealed that 13 out of 16 isolates were of Fasciola gigantica type, whereas three isolates presented a hybrid sequence from F. gigantica and Fasciola hepatica. Interestingly, all the mitochondrial sequences (partial COI and NDI) were of F. gigantica type, suggesting that the maternal lineage of the hybrid form is from F. gigantica. No intra-sequence variation was detected.