Abstract:
Newcastle disease (ND) is among the most important poultry diseases worldwide. It is the major threat to poultry production
in Africa and causes major economic losses for both local and commercial chickens. To date, half of ND class II genotypes
have been reported in Africa (I, IV, V, VI, VII, XI, XIII, XIV, XVII, XVIII, and XXI). The information on the circulating
NDV genotypes is still scarce despite the endemic nature of ND in most countries on the African continent.A total of 659
oro-cloacal swabs were collected from local chickens in Mawenzi live bird market located in Morogoro, Tanzania, between
June 2020 and May 2021. Newcastle disease virus was detected by using reverse transcription real-time polymerase chain
reaction (RT-qPCR) and conventional PCR followed by sequencing of PCR products. The prevalence of NDV in the surveilled
live bird markets was 23.5%. Sequencing and phylogenetic analysis revealed the presence of sub-genotype VII.2.
The detected sub-genotype VII.2 has phylogenetic links to Zambian NDV strains implying a Southeast dissemination of the
virus, considering that it was first detected in Mozambique. This study underscores the need of active NDV surveillance to
determine the distribution of this NDV genotype in the country and monitor its spread and contribution to the emergence
of new ND viruses.
