Preliminary characterization of avian metapneumovirus subtype B in the U.S.

Authors: Kapczynski, Darrell; BRIGGS, KELSEY - Orise Fellow; PARKER, MOLLY - Orise Fellow; GORAICHUK, IRYNA - Orise Fellow; MO, JONGSUK - Orise Fellow; Spackman, Erica; Suarez, David

Submitted to: American Association of Avian Pathologists
Publication Type: Abstract Only
Publication Acceptance Date: 7/12/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Avian metapneumovirus (aMPV) is the causative agent of turkey rhinotracheitis, an acute upper respiratory tract infection of turkeys, and is associated with swollen head syndrome in chickens. The disease is usually accompanied by secondary bacterial infections that can increase morbidity and mortality. aMPV infection of turkeys was first reported in the late 1970s in South Africa, and viruses were subsequently isolated in Europe, the U.S., Asia, Central and South America. aMPV belongs to the Metapneumovirus genus within the Pneumovirinae subfamily of the Paramyxoviridae family. It is a single-strand, nonsegmented, negative-sense RNA virus that contains eight genes. Currently only one serotype of aMPV has been described; however, nucleotide sequence analysis has identified four subtypes A, B, C and D. Until recently only subtype C had been identified in the U.S. Here we report on the isolation and characterization of aMPV B in turkeys from North Carolina that were demonstrating respiratory distress and drops in egg production. Swab samples obtained from turkey hens produced a positive reaction by quantitative real-time RT-PCR to aMPV B. Following passage on Vero cells, cytopathic effect was observed that was consistent with metapneumovirus infection. Subsequently, a virus was isolated and its characterization will be discussed. In addition, testing of field samples from North Carolina demonstrated that the virus could first be detected in September of 2023. Taken together these studies report on the first isolation of aMPV B in the U.S.