Surveillance of avian paramyxovirus in migratory waterfowls in the San-in region of western Japan from 2006 to 2012

First detection and biological characterization of an avian metaavulavirus 8 isolated from a migratory swan goose in Qinghai Lake, Northwest China

Avian metaavulavirus 8 (AMAV-8), formerly known as avian paramyxovirus 8 (APMV-8), has been detected sporadically in wild birds worldwide since it was first identified in a Canadian goose in 1976. However, the presence of AMAV-8 in birds has never been reported in China. To understand the epidemiological situation of AMAV-8 and its ability to infect chickens, we conducted a surveillance study and in vivo analysis of the AMAV-8 isolate identified in total of 14,909 clinical samples collected from wild and domestic birds from 2014 to 2022 in China. However, in 2017, only one AMAV-8 virus (Y7) was successful isolated from the fresh droppings of a migratory swan goose in Qinghai Lake in Northwest China. Thereafter, we report the complete genome sequence of the Y7 strain with a genome length of 15,342 nucleotides and the Y7 isolate was genetically closely-related to wild bird-origin AMAV-8 viruses previously circulated in the United States, Japan, and Kazakhstan. Furthermore, AMAV-8 infections of one-day-old specific pathogen-free (SPF) chicks did not induce any clinical signs over the entire observation period but was associated with viral shedding for up to 8 days. Interestingly, although all birds infected with the Y7 strain seroconverted within the first week of infection, virus replication was only detected in the trachea but not in other tissues such as the brain, lung, or heart. Here, we report the complete genome, genetic and biological characterization, replication and pathogenicity analysis in vivo and first detection of AMAV-8 in China.

Avian paramyxovirus serotype-1 isolation from migratory birds and environmental water in southern Japan: An epidemiological survey during the 2018/19-2021/2022 winter seasons

Newcastle disease caused by highly pathogenic viruses of avian paramyxovirus serotype-1 (APMV-1) is a highly contagious poultry disease. Although a large-scale epidemic of Newcastle disease had occurred in Japan between the 1950s and the 2000s, there have been no outbreaks anywhere since 2010. In addition, there are no reports of epidemiological surveys of APMV-1 in wild birds in Japan in the last 10 years. We conducted the first epidemiological survey of APMV-1 in the Izumi plain, Kagoshima prefecture of southern Japan from the winter of 2018 to 2022. A total of 15 APMV-1 strains were isolated, and isolation rates from roosting water and duck fecal samples were 2.51% and 0.10%, respectively. These results indicate that the isolation method from environmental water may be useful for efficient surveillance of APMV-1 in wild birds. Furthermore, this is the first report on the success of APMV-1 isolation from environmental water samples. Genetic analysis of the Fusion (F) gene showed that all APMV-1 isolates were closely related to virus strains circulating among waterfowl in Far East Asian countries. All isolates have avirulent motifs in their cleavage site of F genes, all of which were presumed to be low pathogenic viruses in poultry. However, pathogenicity test using embryonated chicken eggs demonstrated that some isolates killed all chicken embryos regardless of viral doses inoculated (10² -10⁶ 50% egg infectious dose). These results indicated that APMV-1 strains, which are potentially pathogenic to chickens, are continuously brought into the Izumi plain by migrating wild birds.

An early warning system for highly pathogenic viruses borne by waterbird species and related dynamics of climate change in the Caspian Sea region: Outlines of a concept

Aim. Formulation of the outlines of the concept of ViEW (Viral Early Warning) which is intended as a long term system of multidisciplinary transboundary cooperation between specialist institutions of all five Caspian region states to research, regularly monitor and share data about the generation, transmission and epidemiology of avian‐borne pathogens and their vectors in the region, and the ways climate change may affect these processes.

Material and Methods. The concept is based on the multidisciplinary experience of the authors in researching the processes incorporated in the ViEW concept and on an in‐depth survey of the literature involved.

Results. The outlines of the ViEW concept are presented in this study for review and comment by interested parties and stakeholders.

Conclusion. Review of activities and opinions of specialists and organizations with remits relating to the development, establishment and maintenance of ViEW, indicates that such a system is a necessity for global animal and human health because of the role that the Caspian region plays in the mass migration of species of waterbird known as vectors for avian influenza and the already evident impacts of climate change on their phenologies. Waterbirds frequenting the Caspian Sea littorals and their habitats together constitute a major potential global hotspot or High Risk region for the generation and transmission of highly pathogenic avian influenza viruses and other dangerous zoonotic diseases.

Sero-detection of antibodies to Avian metaavulavirus 2 in peri-domestic birds, Nigeria

Avian metaavulavirus 2 (AMAV-2) previously known as the avian paramyxovirus-2 causes mild to severe respiratory disease, reduced hatchability and infertility of eggs, including increase in white-shelled eggs in chickens and Turkey breeders. When exacerbated by secondary pathogens and environmental stresses, infection is more severe leading to significant economic losses. This study was conducted to determine, if any, the presence of antibodies to Avian metaavulavirus 2 (AMAV-2) in peri-domestic birds in Bauchi State, Nigeria. In all, one hundred sera samples from pigeons (n = 10) and doves (n = 90 were collected in Bauchi, Nigeria. Based on hemagglutination-inhibition (HI) test, overall seroprevalence of 27.0% (27/100) was recorded. In pigeon, the seroprevalence was 80.0% while 21.1% was recorded for dove with HI antibody titers ranging from 3log₂ to 8log₂. There was statistical significance obtained between dove and pigeon sera tested (p < .05). Until now and to the best of our knowledge, there are no reports on AMAV-2 in poultry or wild birds in Nigeria. This study, thus, provides preliminary information on AMAV-2 seroprevalence in Nigerian peri-domestic birds. The need to conduct further studies in other avian species and wild birds in Nigeria is highlighted.

The Emergence of Avian Orthoavulavirus 13 in Wild Migratory Waterfowl in China Revealed the Existence of Diversified Trailer Region Sequences and HN Gene Lengths within this Serotype

Avian orthoavulavirus 13 (AOAV-13), also named avian paramyxovirus 13 (APMV-13), has been found sporadically in wild birds around the world ever since the discovery of AOAV-13 (AOAV-13/wild goose/Shimane/67/2000) in a wild goose from Japan in 2000. However, there are no reports of AOAV-13 in China. In the present study, a novel AOAV-13 virus (AOAV-13/wild goose/China/Hubei/V93-1/2015), isolated from a wild migratory waterfowl in a wetland of Hubei province of China, during active surveillance from 2013 to 2018, was biologically and genetically characterized. Phylogenetic analyses demonstrated a very close genetic relationship among all AOAV-13 strains, as revealed by very few genetic variations. Moreover, pathogenicity tests indicated that the V93-1 strain is a low virulent virus for chickens. However, the genome of the V93-1 virus was found to be 16,158 nucleotides (nt) in length, which is 12 nt or 162 nt longer than the other AOAV-13 strains that have been reported to date. The length difference of 12 nt in strain V93-1 is due to the existence of three repeats of the conserved sequence, “AAAAAT”, in the 5′-end trailer of the genome. Moreover, the HN gene of the V93-1 virus is 2070 nt in size, encoding 610 aa, which is the same size as the AOAV-13 strain from Japan, whereas that of two strains from Ukraine and Kazakhstan are 2080 nt in length, encoding 579 aa. We describe a novel AOAV-13 in migratory waterfowl in China, which suggests that diversified trailer region sequences and HN gene lengths exist within serotype AOAV-13, and highlight the need for its constant surveillance in poultry from live animal markets, and especially migratory birds.

Genetic characterization of one duck-origin paramyxovirus type 4 strain in China

Avian paramyxovirus type 4 (APMV-4) has been frequently reported from wildfowl and waterfowl in recent year. However, few studies have reported on the molecular characteristics and regional transmission of APMV-4, knowledge of which is important for understanding the genetic diversity and epidemiology of avian paramyxovirus. Herein, we report the isolation of one APMV-4 strain, designated as QY17, from the duck in eastern China. The determined complete genome of the isolate with six gene segments 3'-N-P-M-F-HN-L-5' was 15,054 nt in length. Genetic analysis of the whole-fusion gene of this isolate showed that QY17 was derived from a Eurasian lineage. Further phylogenetic analysis showed that the duck-origin strain QY17 had a highly genetic relationship with representative APMV-4 strains from wildfowl in neighbouring regions. These genetic results suggested that APMV-4 viral exchange may occur in wildfowl and poultry via wild bird migration.

Biological and phylogenetic characterization of a novel hemagglutination-negative avian avulavirus 6 isolated from wild waterfowl in China

Up to now only nine whole genome sequences of avian avulavirus 6 (AAvV‐6) had been documented in the world since the first discovery of AAvV‐6 (AAvV‐6/duck/HongKong/18/199/77) at a domestic duck in 1977 from Hong Kong of China. Very limited information is known about the regularities of transmission, genetic and biological characteristics of AAvV‐6 because of the lower isolation rate and mild losses for poultry industry. To better further explore the relationships among above factors, an AAvV‐6 epidemiological surveillance of domestic poultry and wild birds in six provinces of China suspected of sites of inter‐species transmission and being intercontinental flyways during the year 2013–2017 was conducted. Therefore, 9,872 faecal samples from wild birds and 1,642 cloacal and tracheal swab samples from clinically healthy poultry of live bird market (LBM) were collected respectively. However, only one novel hemagglutination‐negative AAvV‐6 isolate (AAvV‐6/mallard/Hubei/2015) was isolated from a fresh faecal sample obtained from mallard at a wetland of Hubei province. Sequencing and phylogenetic analyses of this AAvV‐6 isolate (AAvV‐6/mallard/Hubei/2015) indicated that this isolate grouping to genotype I were epidemiological intercontinentally linked with viruses from the wild birds in Europe and America. Meanwhile, at least two genotypes (I and II) are existed within serotype AAvV‐6. In additional, this novel hemagglutination‐negative AAvV‐6 isolate in chicken embryos restored its hemagglutination when pre‐treated with trypsin. These findings, together with data from other AAvV‐6, suggest potential epidemiological intercontinental spreads among AAvV‐6 transmission by wild migratory birds, and reveal potential threats to wild birds and domestic poultry worldwide.

Molecular Characterization of Avian Paramyxovirus Types 4 and 8 Isolated from Wild Migratory Waterfowl in Mongolia

Avian paramyxoviruses (APMVs) constitute some of the most globally prevalent avian viruses and are frequently isolated from wild migratory bird species. Using 1,907 fresh fecal samples collected during the 2012 avian influenza surveillance program, we identified two serotypes of APMV: APMV-4 ( n=10) and APMV-8 ( n=1). Sequences for these isolates phylogenetically clustered with Asian APMV-4 and APMV-8 recently isolated from wild birds in Korea, Japan, China, and Kazakhstan. Analysis by DNA barcoding indicated that the Mongolian APMV-4 and APMV-8 strains were isolated from Anseriformes species including Mallards ( Anas platyrhynchos) and Whooper Swans ( Cygnus cygnus). The close genetic relatedness to Asian isolates, and to similar host species, suggested that wild bird species in the Anatidae family might play an important role as a natural reservoir in the spread of APMV-4 and APMV-8. However, we did not find conclusive evidence to support this hypothesis owing to the limited number of strains that could be isolated. Enhanced surveillance of poultry and wild bird populations in Asia is therefore crucial for the understanding of global AMPV transmission, ecology, evolution, and epidemiology.

Next-generation sequencing of five new avian paramyxoviruses 8 isolates from Kazakhstan indicates a low genetic evolution rate over four decades

Five avian paramyxoviruses of serotype 8 (APMV-8) were isolated during a study monitoring wild birds in Kazakhstan in 2013 and each was further characterized. The viruses were isolated from three White-fronted geese (Anser albifrons), one Whooper swan (Cygnus cygnus), and one Little stint (Calidris minuta). Before our study, only two complete APMV-8 sequences had been reported worldwide since their discovery in the USA and Japan in the 1970s. We report the complete genome sequences of the newly detected viruses and analyze the genetic evolution of the APMV-8 viruses over four decades.

Complete Genome Sequence of a Novel Avian Paramyxovirus (APMV-13) Isolated from a Wild Bird in Kazakhstan

A novel avian paramyxovirus was identified during annual viral surveillance of wild bird populations in Kazakhstan in 2013. The virus was isolated from a white fronted goose (Anser albifrons) in northern Kazakhstan. Here, we report the complete genome sequence of the isolate, which we suggest should constitute a novel serotype.

Circulation of avian paramyxoviruses in wild birds of Kazakhstan in 2002-2013

BACKGROUND

Screening wild birds for avian paramyxoviruses is of increasing importance. 6913 samples of tracheal and cloacal swabs were collected during 2002-2013 and tested to study the prevalence of APMVs in wild avifauna of Kazakhstan. As a result, 45 isolates were obtained during this period and their ecological niches and genetic relationships were defined.

METHODS

Tracheal and cloacal samples from wild birds were collected using sterile swabs placed in viral transport medium and kept in liquid nitrogen until delivery to the laboratory. Samples were inoculated into 10-day-old embryonated chicken eggs and reverse transcription PCR (RT-PCR) assays were performed via a one-step protocol. The PCR products were sequenced and phylogenetic trees were constructed using the 'Neighbour Joining' method.

RESULTS

Six thousand nine hundred thirteen samples from 183 bird species were investigated and 45 isolates belonging to four different serotypes APMV-1, APMV-4, APMV-6 and APMV-8 were identified. All APMVs were isolated predominantly from birds belonging to Anatidae family (ducks and geese) and only one APMV-4 isolate was obtained from shorebird (Curlew) on the Caspian seashore. Genetic studies showed that the recovered APMV-1 strains had highest homology with European isolates. APMV-4 strains isolated in 2003, and APMV-6 and APMV-8 isolated in 2013 were 99 % identical to isolates from Far East.

CONCLUSION

This is the first reported characterization of avian paramyxoviruses from wild birds isolated in Kazakhstan. These data confirm the wide distribution of APMV-1, APMV-4 and APMV-6 in the Asian subcontinent. The obtained data contribute to the accumulation of knowledge on the genetic diversity and prevalence of APMVs in wild bird populations.

Genetic characterization and evolutionary analysis of Newcastle disease virus isolated from domestic duck in South Korea

Domestic ducks are considered a potential reservoir of Newcastle disease virus. In the study, a Newcastle disease virus (NDV) isolated from a domestic duck during surveillance in South Korea was characterized. The complete genome of the NDV isolate was sequenced, and the phylogenetic relationship to reference strains was studied. Phylogenetic analysis revealed that the strain clustered in genotype I of Class II ND viruses, has highly phylogenetic similarity to NDV strains isolated from waterfowl in China, but was distant from the viruses isolated in chickens and vaccine strains used in South Korea. Pathogenicity experiment in chickens revealed it to be a lentogenic virus. The deduced amino acid sequence of the cleavage site of the fusion (F) protein confirmed that the isolate contained the avirulent motif (112)GKQGRL(117) at the cleavage site and caused no apparent disease in chickens and ducks. With phylogeographic analysis based on fusion gene, we estimate the origin of an ancestral virus of the isolate and its sister strain located in China around 1998. It highlights the need of continuous surveillance to enhance current understanding of the molecular epidemiology and evolution of the pathogenic strains.

Phylogenetic analysis of avian paramyxovirus serotype-1 in pigeons in Japan

To understand the epidemiology of Avian paramyxovirus serotype-1 (APMV-1) in pigeons in Japan, phylogenetic analysis was comprehensively conducted based on partial fusion protein gene using isolate from the surveillance of this virus with previously known Japanese pigeon strains. This surveillance was conducted using feces obtained from domestic pigeons collected in 40 prefectures throughout Japan from June 2011 to March 2013. From a total of 1,021 samples, a single virus (APMV1/pigeon/Japan/Kanagawa/2013: JP/Kanagawa-pg/2013) was isolated. All Japanese pigeon APMV-1 strains were clustered into a single genetic lineage, which was termed VIb/1 by phylogenetic analysis based on the F gene including the sequence of the cleavage site. These APMV-1 strains were further subdivided into four subgroups identified over 4 separate timeframes: 1984–1995 (group 1), 1995–2000 (group 2), 2001–2007 (group 3) and the novel subgroup isolated in 2013 (group 4). Each subgroup has specific amino acid motifs at a cleavage site of the F protein, namely, ¹¹²GRQKR-F¹¹⁷(except for one strain), ¹¹²RRKKR-F¹¹⁷, ¹¹²RRQKR-F¹¹⁷ and ¹¹²RRQKR-F¹¹⁷, respectively. Our data suggest that Japanese APMV-1 strains from pigeons were diverse and reinforced the possibility that there were multiple introduction routes from foreign countries into Japan.

Surveillance of avian paramyxovirus serotype-1 in migratory waterfowls in Japan between 2011 and 2013

To further understand the epidemiology of avian paramyxovirus serotype-1 (APMV-1) in migratory waterfowls in Japan, we conducted the surveillance of this virus from feces derived from the migratory waterfowls collected in 41 Japanese prefectures between October 2011 and March 2013. Six APMV-1 viruses were isolated from total 661 samples. All isolates were identified as the avirulent (lentogenic) type on the basis of intracerebral pathogenicity tests. Genetic analysis showed that these viruses possessed the deduced amino acid sequence of ¹¹²GKQGR-L¹¹⁷ or ¹¹²ERQER-L¹¹⁷ at the cleavage site of the F0 protein, which was identical to the motif in the avirulent type. Phylogenetic analysis based on the partial fusion protein gene classified these APMV-1 isolates into 2 major genetic groups. Four isolates were classified as class II genotype I, and they were genetically closely related to strains isolated in Asian countries, including Japan. In contrast, two isolates were classified as class I, and they were genetically closely related to strains mainly isolated in the U.S.A.

Avian paramyoxvirus-8 immunization reduces viral shedding after homologous APMV-8 challenge but fails to protect against Newcastle disease

BACKGROUND

Protection against infection by Newcastle disease virus (NDV), also designated as avian paramyxovirus subtype-1 (APMV-1), is mediated by immune responses to the two surface glycoproteins, hemagglutinin-neuraminidase (HN) and fusion (F) protein. Thus, a chimeric APMV-1 based vaccine that encodes APMV-8 HN- and F-proteins and expresses the hemagglutinin of avian influenza virus (AIV) H5N1, is able to protect against HPAIV H5N1 but fails to protect against NDV [PLoS One8:e72530, 2013]. However, it is unclear whether avirulent APMV-subtypes, like APMV-8 can induce subtype-specific immunity and protect from a homologous challenge.

FINDINGS

APMV-8 infections of 3- and 6-weeks-old specific pathogen free (SPF)-chickens did not induce any clinical signs but was associated with virus shedding for up to 6 days. Viral replication was only detected in oropharyngeal- and never in cloacal swabs. Upon reinfection with homologous APMV-8, viral shedding was restricted to day 2 and in contrast to naive SPF-chickens, only RNA but no infectious virus was recovered. No protection was induced against virulent NDV challenge, although morbidity and mortality was delayed in APMV-8 primed chickens. This lack of protection is in line with a lack of reactivity of APMV-8 specific sera to APMV-1 HN-protein: Neither by hemagglutin-inhibition (HI) test nor immunoblot analyses, cross-reactivity was detected, despite reactivity to internal proteins.

CONCLUSIONS

Immune responses mounted during asymptomatic APMV-8 infection limit secondary infection against homologues reinfection and facilitates a delay in the onset of disease in a subtype independent manner but is unable to protect against Newcastle disease, a heterologous APMV-subtype.