Veterinary Research Forum

Abstract Experimental infection of Muscovy ducks with V4 strain of Newcastle disease virus was undertaken to determine the response of the ducks to the virus and the possibility of virus transmission to ducks and chickens in village like conditions. Twelve ducks were randomly and equally divided into three groups of control, inoculated and in-contact. Additionally, the chickens were placed into two groups of four animals each, namely in-contact and control. The inoculated and in-contact ducks and in-contact chickens were kept together. The eye drop route was used for inoculation and hemagglutination inhibition (HI) antibodies were measured for assessment of antibody response and cloacal and pharyngeal swabs were used for detection of the virus. The primary antibody response of inoculated ducks was very high and rapid (geometric mean titers [Log base 2] of up to 5.75 ± 0.50). The in-contact ducks showed antibody response with the same pattern but lower titers than the inoculated ducks (geometric mean titers [Log base 2] of up to 3.25 ± 1.70). The in-contact chickens showed a slight increase of HI antibody (geometric mean titers [Log base 2] of up to 2.25 ± 1.25) while the control chickens did not show any increase. The antibody response indicated the transmission of the virus to contact ducks and chickens. A single isolation of virus confirmed the ability of ducks to excrete the virus. It was concluded that the V4 strain of Newcastle disease virus was highly antigenic for ducks, and ducks can transmit it to other ducks and also in-contact chickens.

Abstract Torque teno virus (TTV) is prevalent worldwide and has been extensively studied in human and some wild and domestic animals. As the studies on TTV in chickens was rare and there was no information about the infection of domestic village chickens with TTV and also structural resemblance of this virus to chicken anemia virus, the frequency of the infection in domestic village chickens in different villages in Isfahan (Iran) was investigated. Sera were collected from 50 chickens. Viral DNA was extracted and subjected to polymerase chain reaction (PCR) using the previously described T801 and T935 primers that were used for amplification of a highly conserved non-coding region (UTR) of the viral genome in a single round of PCR and Set B primers of conserved region in a nested PCR reaction. Using T801 and T835 primers TTV or viruses of TTV family were detected in 16 out of 50 sera tested (32%). Fourteen out of the same 50 sera (28%) were positive for TTV using Set B primers. Totally 20 sera were positive using both primers (40%). Ten sera were detected with both sets of primers, six sera with T801 and T935 primers and only four sera were positive using Set B primers for TTV. Different patterns of the detection of the virus with the two different sets of primers suggests the possibility of the presence of different genotypes of TTV in domestic village chickens and the possibility of the transmission of the virus from human to village chickens and vice versa. This necessitates further investigations.