First human case of avian influenza A(H5N1) in Europe

Following an outbreak of extraordinarily pathogenic avian influenza A(H5N1) in a flock of spherical 125 Muscovy geese in a house setting in South West England on 22 December 2021, the virus was later moreover confirmed throughout the asymptomatic flock proprietor.

While transmission of avian influenza viruses from birds to folks is generally unusual, these viruses might adapt and purchase the flexibleness to moreover unfold from particular person to particular person. Timely identification of human an an infection is thus essential to forestall further unfold.

In their speedy communication, Oliver et al. [1] describe the medical epidemiological and virological options of this major human case of avian influenza A(H5N1) in Europe. In Great Britain, the autumn/winter 2021/22 season has seen a very powerful ever number of extraordinarily pathogenic avian influenza A(H5N1) wild chook detections and poultry outbreaks since 2003 [2].

Influenza A(H5N1) was confirmed in 19 out of 20 sampled keep birds from the flock on 22 December 2021. The flock proprietor had been in shut contact with the contaminated birds with none non-public defending instruments nonetheless remained asymptomatic all through an extended treatment course of antiviral medication (oseltamivir) for 10 days until two consecutive Polymerase chain response (PCR) exams have been unfavourable. During that time, the effectively being authorities initiated full contact tracing amongst 11 human contacts. Among these contacts no additional main situations or secondary transmissions have been seen.

During the investigation, the sequences of all gene segments from the human virus strain have been in distinction with these of the duck virus and the analysis confirmed that the H5N1 throughout the flock proprietor’s respiratory supplies was equal in all segments to the avian sequence, apart from 4 nucleotide (nt) mutations.

According to the authors, ’the circumstances regarding publicity to birds have been unusual, with a extreme diploma of shut contact with quite a lot of contaminated birds and a virus-contaminated enclosed house ambiance which resulted in an an infection. The spill-over an an infection to the human contact did not lead to any detected genetic changes throughout the virus that’s maybe associated to elevated zoonotic menace. This case demonstrates the elevated menace posed by one of these shut contact nonetheless does not change the overall analysis that the hazard to most people from avian influenza virus stays very low.’

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References/notes to editors:
[1] Oliver Isabel, Roberts Jonathan, Brown Colin S, Byrne Alexander MP, Mellon Dominic, Hansen Rowena DE, Banyard Ashley C, James Joe, Donati Matthew, Porter Robert, Ellis Joanna, Cogdale Jade, Lackenby Angie, Chand Meera, Dabrera Gavin, Brown Ian H, Zambon Maria. A case of avian influenza A(H5N1) in England, January 2022.
Available from: https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2022.27.5.2200061

[2] Wild water birds are the reservoir for avian influenza. Domestic poultry are inclined to spill-over an an infection from migratory wild birds, with outbreaks repeatedly reported in farm settings along with a contemporaneous large outbreak in Great Britain. In Great Britain, the autumn/winter 2021/22 season has seen a very powerful ever number of HPAI H5N1 wild chook detections and poultry outbreaks since 2003, when this avian virus started to unfold from Asia to Europe and Africa. Human avian influenza infections are unusual. However, some viruses, resembling goose/Guangdong lineage H5Nx or Asian lineage H7N9 viruses, have been associated to human sickness with extreme case fatality costs

[3] Since 2014, over 50 laboratory-confirmed situations of human an an infection with influenza A(H5N6) virus have been reported from China. The amount elevated all through 2021, with ca 25 situations reported and 10 fatalities, emphasising the persevering with extreme case fatality value of zoonotic transmissions associated to H5 influenza subtypes.

[4] Read the entire Eurosurveillance problem: https://bit.ly/EUS275