Unexpected infection outcomes of China-origin H7N9 low pathogenicity avian influenza virus in turkeys

Slomka, Marek J.; Seekings, Amanda H.; Mahmood, Sahar; Thomas, Saumya S.; Puranik, Anita; Watson, Samantha; Byrne, Alexander M. P.; Hicks, Daniel; Núñez, Alejandro; Brown, Ian H.; Brookes, Sharon M.

doi:10.1038/s41598-018-25062-y

Cited by 28 publications

(72 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the clinical outcome was much milder than in the previous study when infection of turkeys with the same AIV H9N2 strain was exacerbated by concomitant respiratory pathogens [10]. Infections with LPAIV in gallinaceous poultry are usually asymptomatic if uncomplicated, but in turkeys the clinical disease caused by the virus alone is often observed [9,42]. The long duration of respiratory shedding and the robust antibody response indicate that the H9N2 virus may readily infect turkeys and induce only non-specific clinical signs, enabling the spread of the virus within a flock.…”

Section: Discussionmentioning

confidence: 71%

A Turkey-origin H9N2 Avian Influenza Virus Shows Low Pathogenicity but Different Within-host Diversity in Experimentally Infected Turkeys, Quail and Ducks

Świętoń

Tarasiuk

Olszewska-Tomczyk

et al. 2020

Viruses

View full text Add to dashboard Cite

Avian influenza virus (AIV) is a highly diverse and widespread poultry pathogen. Its evolution and adaptation may be affected by multiple host and ecological factors, which are still poorly understood. In the present study, a turkey-origin H9N2 AIV was used as a model to investigate the within-host diversity of the virus in turkeys, quail and ducks in conjunction with the clinical course, shedding and seroconversion. Ten birds were inoculated oculonasally with a dose of 106 EID50 of the virus and monitored for 14 days. Virus shedding, transmission and seroconversion were evaluated, and swabs collected at selected time-points were characterized in deep sequencing to assess virus diversity. In general, the virus showed low pathogenicity for the examined bird species, but differences in shedding patterns, seroconversion and clinical outcome were noted. The highest heterogeneity of the virus population as measured by the number of single nucleotide polymorphisms and Shannon entropy was found in oropharyngeal swabs from quail, followed by turkeys and ducks. This suggests a strong bottleneck was imposed on the virus during replication in ducks, which can be explained by its poor adaptation and stronger selection pressure in waterfowl. The high within-host virus diversity in quail with high level of respiratory shedding and asymptomatic course of infection may contribute to our understanding of the role of quail as an intermediate host for adaptation of AIV to other species of poultry. In contrast, low virus complexity was observed in cloacal swabs, mainly from turkeys, showing that the within-host diversity may vary between different replication sites. Consequences of these observations on the virus evolution and adaptation require further investigation.

show abstract

Section: Discussionmentioning

confidence: 71%

A Turkey-origin H9N2 Avian Influenza Virus Shows Low Pathogenicity but Different Within-host Diversity in Experimentally Infected Turkeys, Quail and Ducks

Świętoń

Tarasiuk

Olszewska-Tomczyk

et al. 2020

Viruses

View full text Add to dashboard Cite

show abstract

“…On the other hand, there have been LPAI outbreaks where clinical signs and even increased mortality were reported. Turkeys are more susceptible to LPAIV infection than broilers and laying hens (Mutinelli et al, 2003;Slomka et al, 2018). Similarly, the first signs in a Canadian outbreak of H7N3 LPAI were a sudden drop in feed consumption and a slight increase in mortality (Bowes et al, 2004).…”

Section: 2mentioning

confidence: 99%

“…Experimental infections with LPAI H7N9 strain A/Anhui/ A/2013 revealed that the virus is highly tropic for the upper respiratory tract in poultry (Pantin-Jackwood et al, 2014). However, Slomka et al (2018) have detected systemic dissemination of the LPAIV H7N9 subtype to multiple organs beyond the respiratory and digestive tracts, including skeletal muscles and feather follicles in experimentally infected turkeys. The presence of the virus was detected by immunohistochemistry and mostly in specimens collected from turkeys infected with a high dose of the virus (8 log 10 EID 50 ).…”

Section: Assessment Of Lpaiv Transmission Via Raw Poultry Meatmentioning

confidence: 99%

“…In layer flocks infected with H7N2 LPAIV (Pennsylvania, 1997(Pennsylvania, -1998, the mortality rate rose to even 10 times the baseline with a cumulative mortality of 4% (Ziegler et al, 1999;Lu et al, 2004). Turkeys are more susceptible to LPAIV infection than broilers and laying hens (Mutinelli et al, 2003;Slomka et al, 2018). Nevertheless, the severity of clinical signs and the capacity to recover appeared to be primarily agerelated and oldest turkeys recovered within one week of the onset of clinical signs.…”

Section: 2mentioning

confidence: 99%

See 1 more Smart Citation

Assessment of low pathogenic avian influenza virus transmission via raw poultry meat and raw table eggs

Gonzáles¹,

Roberts²,

Śmietanka³

et al. 2018

EFS2

View full text Add to dashboard Cite

A rapid qualitative assessment has been done by performing a theoretical analysis on the transmission of low pathogenic avian influenza (LPAI) via fresh meat from poultry reared or kept in captivity for the production of meat (raw poultry meat) or raw table eggs. A predetermined transmission pathway followed a number of steps from a commercial or non‐commercial poultry establishment within the EU exposed to LPAI virus (LPAIV) to the onward virus transmission to animals and humans. The combined probability of exposure and subsequent LPAIV infection via raw poultry meat containing LPAIV is negligible for commercial poultry and humans exposed via consumption whereas it is very unlikely for non‐commercial poultry, wild birds and humans exposed via handling and manipulation. The probability of LPAIV transmission from an individual infected via raw poultry meat containing LPAIV is negligible for commercial poultry and humans, whereas it is very unlikely for non‐commercial poultry and wild birds. The combined probability of exposure and subsequent LPAIV infection via raw table eggs containing LPAIV is negligible for commercial poultry and humans and extremely unlikely to negligible for non‐commercial poultry and wild birds. The probability of LPAIV transmission from an individual infected via raw table eggs containing LPAIV is negligible for commercial poultry and humans and very unlikely to negligible for non‐commercial poultry and wild birds. Although the presence of LPAIV in raw poultry meat and table eggs is very unlikely to negligible, there is in general a high level of uncertainty on the estimation of the subsequent probabilities of key steps of the transmission pathways for poultry and wild birds, mainly due to the limited number of studies available, for instance on the viral load required to infect a bird via raw poultry meat or raw table eggs containing LPAIV.

show abstract

“…In addition, a more recently designed RT-qPCR which amplifies elsewhere within the MP-segment was validated [24] and featured successfully in subsequent AIV outbreaks and wild bird investigations [25][26][27][28], AIV in vivo studies [29,30] and SwIV field investigations [31][32][33][34]. The importance of appropriate test validation has been emphasised in a veterinary context [35], with an MP-segment RT-qPCR for generic detection of contemporary H1N1, H1N2 and H3N2 SwIV subtypes in European pigs having been also validated [36].…”

Section: Introductionmentioning

confidence: 99%

A universal RT-qPCR assay for “One Health” detection of influenza A viruses

Nagy

Černíková

Kunteová

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

AbstractThe mutual dependence of human and animal health is central to the One Health initiative as an integrated strategy for infectious disease control and management. A crucial element of the One Health includes preparation and response to influenza A virus (IAV) threats at the human-animal interface. The IAVs are characterized by extensive genetic variability, they circulate among different hosts and establish host-specific lineages. The four main host reservoirs are: avian, swine, human and equine, with occasional transmission to other mammalian species. The host diversity is mirrored in the range of the RT-qPCR assays for IAV detection. Different assays are recommended by the responsible health authorities for generic IAV detection in birds, swine or humans. In order to unify IAV monitoring in different hosts and apply the One Health approach, we developed a single RT-qPCR assay for universal detection of all IAVs of all subtypes, species origin and global distribution. The assay design was centred on a highly conserved region of the IAV MP-segment identified by a comprehensive analysis of 99,353 sequences. The reaction parameters were effectively optimised with efficiency of 93-97% and LOD95% of approximately ten IAV templates per reaction. The assay showed high repeatability, reproducibility and robustness. The extensive in silico evaluation demonstrated high inclusivity, i.e. perfect sequence match in the primers and probe binding regions, established as 94.6% for swine, 98.2% for avian and 100% for human H3N2, pandemic H1N1, as well as other IAV strains, resulting in an overall predicted detection rate of 99% on the analysed dataset. The theoretical predictions were confirmed and extensively validated by collaboration between six veterinary or human diagnostic laboratories on a total of 1970 specimens, of which 1455 were clinical and included a diverse panel of IAV strains.

show abstract

Unexpected infection outcomes of China-origin H7N9 low pathogenicity avian influenza virus in turkeys

Cited by 28 publications

References 53 publications

A Turkey-origin H9N2 Avian Influenza Virus Shows Low Pathogenicity but Different Within-host Diversity in Experimentally Infected Turkeys, Quail and Ducks

A Turkey-origin H9N2 Avian Influenza Virus Shows Low Pathogenicity but Different Within-host Diversity in Experimentally Infected Turkeys, Quail and Ducks

Assessment of low pathogenic avian influenza virus transmission via raw poultry meat and raw table eggs

A universal RT-qPCR assay for “One Health” detection of influenza A viruses

Contact Info

Product

Resources

About