Avian Metapneumovirus subtype B around Europe: a phylodynamic reconstruction

Abstract

Avian Metapneumovirus (aMPV) has been recognized as a respiratory pathogen of turkey and chickens for a long time. Recently, a crescent awareness of aMPV, especially subtype B, clinical and economic impact has risen among European researchers and veterinarians. Nevertheless, the knowledge of its epidemiology and evolution is still limited. In the present study, the broadest available collection of partial G gene sequences obtained from European aMPV-B strains was analyzed using different phylodynamic and biostatistical approaches to reconstruct the viral spreading over time and the role of different hosts on its evolution. After aMPV-B introduction, approximatively in 1985 in France, the infection spread was relatively quick, involving the Western and Mediterranean Europe until the end of the 1990s, and then spreading westwards at the beginning of the new millennium, in parallel with an increase of viral population size. In the following period, a wider mixing among aMPV-B strains detected in eastern and western countries could be observed. Most of the within-country genetic heterogeneity was ascribable to single or few introduction events, followed by local circulation. This, combined with the high evolutionary rate herein demonstrated, led to the establishment of genetically and phenotypically different clusters among countries, which could affect the efficacy of natural or vaccine-induced immunity and should be accounted for when planning control measure implementation. On the contrary, while a significant strain exchange was proven among turkey, guinea fowl and chicken, no evidence of differential selective pressures or specific amino-acid mutations was observed, suggesting that no host adaptation is occurring.

Establishment and application of a quadruple real-time RT-PCR for detecting avian metapneumovirus

“…Avian metapneumovirus (aMPV) has been detected for a long time [ 1 ]. aMPV can cause both respiratory and reproductive disorders in a variety of poultry, including turkeys, chickens, guinea fowls and pheasants [ 2 ].…”

Research Note: Detection of Avian metapneumovirus subgroup C specific antibodies in a mallard flock in Italy

“…This is the first evidence of aMPV-C presence in Italy, where only aMPV-B has been accounted to circulate in recent years. Subgroup B has been reported to be by far the dominant subgroup in Europe ( Franzo et al., 2020 ). However, this prevalence only relates to aMPV in turkeys and chickens as almost all studies have been conducted uniquely on these 2 species.…”

Serological and Molecular Characterization of Avian Metapneumovirus in Chickens in Northern Vietnam

“…Simultaneous circulation of multiple subgroups is known in many countries such as Japan [19], Israel [51], Brazil [52], Nigeria [53], and China [53][54][55]. In contrast, some European countries (Italy, Romania, and Greece) have not detected subgroup A, but only subgroup B since 2017 [43,44,56]. Therefore, detecting only aMPV subgroup B circulating in northern Vietnam was not exceptional.…”

“…To date, several reports [35,56] have classified aMPV subgroup B based on the partial G gene (about 171-300 nucleotides at the 3 end) and not involving the highly diverse genomic regions of this gene as shown in Figure 3 (nucleotides 460-976). By comparing the phylogenetic tree based on the partial G gene (Figure 4) and nearly full-length G gene (Figure 5), this study suggests that the highly divergent region of the G gene must be included for genetic characterizations and classification.…”