Trends and Challenges in the Surveillance and Control of Avian Metapneumovirus

Abstract

Among the respiratory pathogens of birds, the Avian Metapneumovirus (aMPV) is one of the most relevant, as it is responsible for causing infections of the upper respiratory tract and may induce respiratory syndromes. aMPV is capable of affecting the reproductive system of birds, directly impacting shell quality and decreasing egg production. Consequently, this infection can cause disorders related to animal welfare and zootechnical losses. The first cases of respiratory syndromes caused by aMPV were described in the 1970s, and today six subtypes (A, B, C, D, and two more new subtypes) have been identified and are widespread in all chicken and turkey-producing countries in the world, causing enormous economic losses for the poultry industry. Conventionally, immunological techniques are used to demonstrate aMPV infection in poultry, however, the identification of aMPV through molecular techniques helped in establishing the traceability of the virus. This review compiles data on the main aMPV subtypes present in different countries; aMPV and bacteria co-infection; vaccination against aMPV and viral selective pressure, highlighting the strategies used to prevent and control respiratory disease; and addresses tools for viral diagnosis and virus genome studies aiming at improving and streamlining pathogen detection and corroborating the development of new vaccines that can effectively protect herds, preventing viral escapes.

Geographical Expansion of Avian Metapneumovirus Subtype B: First Detection and Molecular Characterization of Avian Metapneumovirus Subtype B in US Poultry

“…There are contradictory reports on the evolution of aMPV, with some studies reporting that aMPV is a relatively slow-evolving virus when compared to other avian RNA viruses and others estimating that its rate of viral evolution is within the normal range [ 41 , 42 , 43 ]. However, viral evolution is based on both the pressure exerted by vaccine programs and on the type of host and environment; therefore multiple strains of the same subtype can phenotypically circulate in different portions of the world [ 5 ]. The genetic diversity in the study sequences highlights the urgent need to carry out more whole genome sequencing of this virus in order to better understand the variants circulating in the field as well as to understand the evolution of this virus over time.…”

“…The aMPV is a single-stranded, non-segmented, enveloped, and negative-sense RNA virus (~13.3-14 kb in size) in the family Pneumoviridae, genus Metapneumovirus [4]. The genome contains eight genes: 3 ′ -Nucleoprotein (N), Phosphoprotein (P), Matrix (M), Fusion (F), Matrix 2 (M2), Small hydrophobic (SH), attachment (G), and large polymerase (L)-5 ′ , Viruses 2024, 16, 508 2 of 15 in this order, with leader and tailer sequences at both ends: 3 ′ -le-N-P-M-F-M2-SH-G-Ltr-5 ′ [5]. The L and P are non-structural proteins involved in genome replication, while the others code for nucleocapsid, matrix, and envelope structural proteins.…”

Tracing the Flight: Investigating the Introduction of Avian Metapneumovirus (aMPV) A and B

“…The virus is primarily associated with upper respiratory infections, predisposing birds to opportunistic bacterial pathogens, which can result in severe respiratory disease, high morbidity, and mortality rates. Furthermore, aMPV can infect the reproductive system, leading to lower egg production and decrease in quality [ 4 ].…”

“…aMPV subtype A was first identified in South Africa in the 1970s and subsequently spread to several European countries [ 9 , 10 ]. Around the same time, another subtype, aMPV-B, was recognized and gradually became dominant in the Old World [ 1 , 4 , 8 ]. The U.S. was unaffected until 1996, when aMPV subtype C emerged in turkeys and wild birds [ 11 , 12 , 13 ].…”

An affordable detection system based on RT-LAMP and DNA-nanoprobes for avian metapneumovirus

“…Avian metapneumovirus (aMPV) infection is considered one of the most economically important upper respiratory tract diseases in poultry (Kaboudi and Lachhbeb 2021 ; Salles et al 2023 ). Early described as the turkey rhinotracheitis (TRT) virus, it primarily affects turkeys but can also trigger the onset of swollen head syndrome (SHS) in chickens.…”