Although wild ducks are considered to be the major reservoirs for most influenza A virus subtypes, they are typically resistant to the effects of the infection. In contrast, certain influenza viruses may be highly pathogenic in other avian hosts such as chickens and turkeys, causing severe illness and death. Following in vitro infection of chicken and duck embryo fibroblasts (CEF and DEF) with low pathogenic avian influenza (LPAI) viruses, duck cells die more rapidly and produce fewer infectious virions than chicken cells. In the current study, the morphology of viruses produced from CEF and DEF cells infected with low pathogenic avian H2N3 was examined. Transmission electron microscopy showed that viruses budding from duck cells were elongated, while chicken cells produced mostly spherical virions; similar differences were observed in viral supernatants. Sequencing of the influenza genome of chicken- and duck-derived H2N3 LPAI revealed no differences, implicating host cell determinants as responsible for differences in virus morphology. Both DEF and CEF cells produced filamentous virions of equine H3N8 (where virus morphology is determined by the matrix gene). DEF cells produced filamentous or short filament virions of equine H3N8 and avian H2N3, respectively, even after actin disruption with cytochalasin D. These findings suggest that cellular factors other than actin are responsible for the formation of filamentous virions in DEF cells. The formation of elongated virions in duck cells may account for the reduced number of infectious virions produced and could have implications for virus transmission or maintenance in the reservoir host.

The aim of this study was to detect influenza A virus in broiler chickens and wild ducks in different geographical regions of Basrah and Wasit provinces, Iraq. This study was authenticated by analysing the viral genome and designing a set of universal primers for the detection of all influenza A subtypes in a single enzymatic reaction through the amplification of a highly conserved region of viral M gene. A total of 157 and 155 oropharyngeal and cloacal swabs from broiler chickens and wild ducks, respectively, were analysed. The study shows that influenza A viruses were prevalent in these birds in all study regions with a significantly higher percentage in wild ducks compared to broiler chickens. The results showed that 92/157 samples (54/75 wild ducks and 38/82 broiler chickens) and 96/155 samples (38/75 wild ducks and 58/80 broiler chickens) in Basrah and Wasit, respectively, were positive for the viral M gene. In addition, there was no significant difference in virus prevalence between Basrah and Wasit provinces.

Orf which is commonly referred to as contagious ecthyma is a viral infectious disease that infects small ruminants. Little is known about the disease status in our geographical region. This study aimed to determine the seroprevalence of Orf virus in sheep in Basrah province, southern Iraq. Serum samples were randomly collected from 380 sheep of different age and sex groups from 4 different regions in Basrah province, which were Zubair, Abulkhasib, Shatt Al-Arab, and Qurnah. The samples were tested by ELISA for the presence of IgG antibodies to the Orf virus. Out of 380 animals screened, 98 animals were found positive for ELISA, which reveals an overall prevalence of 25.7%. There was no significant difference in the seropositivity between male and female animals. On the other hand, the seropositivity was significantly higher in lambs of the age group 1-6 months in comparison with the other age groups (6-12 months and more than 12 months). This finding indicates that the virus is highly prevalent in Basrah province as confirmed by the ELISA test.