Antibody Levels against Newcastle Disease Virus, Infectious Bursal Disease Virus and Avian Influenza Virus in Rural Chickens in Viet Nam

Abstract

A serological survey on the prevalence of antibodies to Newcastle Disease (ND) virus, Infectious Bursal disease (IBD) virus and Avian Influenza (AI) virus was carried out in two communes of the Hue District, Middle Viet Nam. The villages in each commune and the households in each village included approximately 10% scavenging and 20% backyard chickens. The main objectives were to determine the prevalence of antibodies against ND virus at different seasons of the year, the prevalence of antibodies against IBD and AI virus, and a comparison of the situation of ND, IBD and AI in scavenging and backyard chickens. The results showed that there was no statistically significant difference in NDV titres between the seasons and between ND vaccinated and unvaccinated birds but there was a significant difference between the unvaccinated scavenging (33.9%) and the unvaccinated backyard birds (21.6%). Both ND vaccinated and unvaccinated birds in the 2-<6 months-old groups had a significantly lower NDV antibody titre than the > 6 month-old age group. There was no overt correlation between NDV-HI-and IBDV-ELISA titres. A statistical analysis was precluded due to inadequate data sets. There were 5 reactors in the AI-ELISA but they were negative in the HI test with H and H HA antigens. This study showed that in the selected chicken population 5 7 the level of protection of vaccinated birds was unsatisfactory. It further showed that there was no seasonal difference between rainy and dry season, that IBDV existed but did not appear to be associated with NDV. There were no specific antibodies against the H /H subtypes of AIV.

Serological Investigation of Newcastle Disease in Selected Districts of Buno Bedelle Zone, Ethiopia

“…The variation could be multifactorial like management, season, unequal proportions of breeds sampled during sampling. 36 Seroprevalence was also assessed by age and the difference in the seroprevalence between young and adult chickens was statistically insignificant (p>0.05), which does not agree with the finding of Vui et al, 37 which stated that young chickens had a significantly lower NDV antibody titer than adults. Overall, in Buno Bedele, seroprevalence was high in old age chickens and this can be hypothesized to be due to more frequent exposure of older birds to field virus, which means they might have survived the disease at an earlier age.…”

A Review of Pathogen Transmission at the Backyard Chicken–Wild Bird Interface

“…NDV is also often endemic among the backyard flocks of developing nations (187). For example, in Vietnam, up to 34% of unvaccinated backyard chickens tested positive for antibodies against NDV (188). In Bushehr province, Iran, 40% of unvaccinated chickens tested positive for antibodies against NDV (189).…”

“…Illegally trapped and transported individuals were found to have been exposed to NDV, avian poxvirus, and Chlamydia spp. ; pathogens were also found in backyard chickens (188,(225)(226)(227). In Burkina Faso, three hooded vultures (Necrosyrtes monachus), a western plantain-eater (Crinifer piscator), and an Ovambo sparrowhawk (Accipiter ovampensis) were infected with various combinations of HPAI, NDV, and IBV (228).…”