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Avian Influenza is a contagious zoonotic disease that can be transmitted from birds to mammals. In this study, we conducted a systematic review and meta-analysis to investigate and summarize the occurrence of avian influenza H9N2 in humans and other mammals in Iran. Data were collected systematically until July 1 2023 from four English and two Persian databases. According to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and inclusion criteria, 14 eligible studies were obtained. Occurrences of AI H9N2 are reported in humans, dogs, and water buffaloes (Bubalus bubalis) in Iran. The pooled prevalence of AI H9N2 using a random model among humans was 0.15 (95% CI, 0.12-0.18). Pooled prevalence using the HI test was 0.16 (95% CI, 0.13-0.20). The pooled prevalence by different cut-offs for the HI test was equal to 0.34, 0.11, 0.02, and 0.01, respectively for cut-offs 1:20 to 1:160. Pooled prevalence using the HI test, among persons with possible exposure, hospitalized persons and hospital staff (0.20, 0.31, and 0.30) was higher than the prevalence in apparently healthy individuals (0.01). The group of individuals with possible exposure revealed the highest pooled prevalence of 0.25 (95% CI, 0.17-0.33) using the HI test. This was observed predominantly in slaughterhouse workers. The pooled prevalence using the ELISA test was 0.27 (95% CI, 0.23-0.31). These results can help policymakers to create prevention and control programs for possible epidemics in the future and can help researchers to tailor the design and objectives of future studies in this area. [ABSTRACT FROM AUTHOR]

Newcastle disease virus (NDV) is considered one of the most devastating avian viral pathogens affecting the avian population, and it causes a significant economic burden on the poultry industry worldwide. The study aimed to gain deeper understanding of the molecular and phylogenetic analyses of the complete hemagglutinin-neuraminidase (HN) coding region among NDV isolates. The samples were obtained from different parts of Iran from July 2017 to February 2020, were used for phylogenic analysis in this study. The results confirmed the predominance ofsub-genotypeVII.1.1,previouslyknownassub-genotypeVIIL, whichiscirculatingincommercial broiler farms of Iran. Identification of (a) an additional N-glycosylation site (NIS) at position 144; (b) mutations S315P and I369V which are related to increasing the viral thermostability; (C) cysteine residues at positions 123; (d) amino acid substitutions in the HN antigenic sites, especially the mutations I514V and E347Q, as well as the other mutant within HN binding sites of the VII.1.1 sub-genotype, suggests the idea that this new sub-genotype of NDV may possess a high level of pathogenicity and virulence compared to other NDV sub-genotypes. In conclusion, the results indicate the presence of an additional NIS at position 144, which may alter the virulence of the isolates. Furthermore, the presence of the thermostable mutations (S315P and I369V) and the other amino acid substitutions among the VII.1.1 sub-genotype isolates may have an impact on the vaccine immunity against this new NDV sub-genotype. [ABSTRACT FROM AUTHOR]

Since its first detection in 1998, avian influenza virus (AIV) subtype H9N2 has been enzootic in Iran. To better understand the evolutionary history of H9N2 viruses in Iran, we sequenced 15 currently circulating H9N2 viruses from domestic poultry during 2017–2019 and performed phylogenetic analysis of complete genome sequences. Phylogenetic analyses indicated that the Iranian H9N2 viruses formed multiple well‐supported monophyletic groups within the G1‐lineage of H9N2 virus. Our analysis of viral population dynamics revealed an increase in genetic diversity until 2007, corresponding to the multiple introductions and diversification of H9N2 viruses into multiple genetic groups (named Iran 1–4 subgroups), followed by a sudden decrease after 2008. Only the Iran 4 subgroup has survived, expanded, and currently circulates in Iran. The H9N2 viruses possessed many molecular markers associated with mammalian adaption in all gene segments, except neuraminidase gene. Considering the presence of mammalian host‐specific markers, the public health threat of H9N2 viruses continues. Molecular analysis showed that Iranian H9N2 strains have continued to evolve and recent strains have multiple amino acid changes and addition of potential N‐glycosylation on the antigenic sites of haemagglutinin. Continued antigenic and molecular surveillance of H9N2 viruses in poultry and mammals would be required to monitor further increments in viral evolution and their potential threat to public health. [ABSTRACT FROM AUTHOR]