{"id":2853,"date":"2023-03-14T18:04:54","date_gmt":"2023-03-14T23:04:54","guid":{"rendered":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/?p=2853"},"modified":"2023-03-14T18:04:58","modified_gmt":"2023-03-14T23:04:58","slug":"controlling-avian-influenza","status":"publish","type":"post","link":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/2023\/03\/14\/controlling-avian-influenza\/","title":{"rendered":"Controlling avian influenza"},"content":{"rendered":"
\n

BMJ Editorial<\/a><\/p>\n\n\n\n

A One Health approach that links human, animal, and environmental health is essential<\/em>

Global reports of highly pathogenic avian influenza
A(H5N1) in birds are increasing, with cases reported
from every region except Australasia and Antarctica
since 2020.1 The global spread of these avian
influenza outbreaks is unprecedented, exacting large
economic losses to poultry industries and tourism,
and posing a substantial threat to global health
security and animal ecology.
In Europe, 2520 H5N1 outbreaks were reported in
poultry between October 2021 and September 2022,
and the virus was also detected in 3867 dead wild
birds.2 The US reported 131 mammalian H5N1
infections among bears, foxes, raccoons, skunks, and
seals between May 2022 and February 2023.3
In October 2022, an H5N1 outbreak among Spanish
farmed minks was reported for the first time,4
triggering concerns that the virus might soon become
transmissible between humans (mink are
physiologically similar to ferrets, the animal model
used to study transmissibility of influenza viruses
among humans).
<\/p>\n\n\n\n

On 24 February 2023, an 11 year old girl died from an
H5N1 avian flu infection in Cambodia and her father
was admitted to hospital with the same infection.6
On the same day, China reported another human
H5N1 case: in a 53 year old woman from Jiangsu
province who became ill after exposure to poultry.7
Genetic analysis showed that the strain in the
Cambodian cases belongs to the localised clade
2.3.2.1c, whereas the strain in the Chinese case
belongs to clade 2.3.4.4b, which has been causing
the recent poultry outbreaks across the world.6 -9
These new cases in Asia were probably the result of
transmission from poultry, not between humans, but
they do highlight the importance of a \u201cOne Health\u201d
approach to viral threats. This approach understands
and jointly considers human, animal, plants,
environment, and planetary health as fundamentally
connected.<\/p>\n\n\n\n


Although routine active surveillance among poultry,
wild birds, and other animals can track virus
evolution, outbreaks need to be investigated using
bespoke techniques to decipher the transmission
dynamics and identify underlying driving forces of
evolution.11 12 Furthermore, all data and virus isolates
should be shared widely among expert laboratories
so that the potential threat of evolving strains to
global health can be comprehensively assessed. A
pilot One Health programme implemented in
Thailand in 2016 showed that transparent sharing of
human, animal, and environmental surveillance data
among all stakeholders is essential for effective
surveillance and control. <\/p>\n\n\n\n

With robust human, animal, and environmental
surveillance data shared across all stakeholders,
epidemiological studies can characterise the interplay
between wild birds and the live poultry markets that
act as reservoirs of avian influenza viruses and inform
the design of interventions to control transmission
and spill-over. For example, after an outbreak of H5N1
in 1997, Hong Kong developed and implemented a
multipronged approach, including monthly closures
of live poultry markets for deep cleaning, a ban on
keeping live poultry overnight in both wet markets
and wholesale markets, and continued viral testing
of poultry and market samples. Since then, no
major avian influenza outbreaks have been reported
in Hong Kong,and similar control measures have
been implemented in other affected South East Asian
countries.

Vaccinating poultry<\/strong>
Several countries are now vaccinating poultry or
considering vaccination to help control avian
influenza. Although existing vaccines reduce deaths
among infected birds, vaccinated birds can still be
infected and transmit the virus. Nevertheless,
vaccination of poultry against H5 and H7 avian
influenza has been compulsory in China since 2017,
and there have been no nationwide outbreaks for
several years.17 18 Authorities in Mexico approved
emergency vaccination of poultry against H5N1 in
November 2022, and the US will shortly begin testing
new vaccines in response to its worst ever H5N1
outbreak.
Without systematic viral testing in poultry, imperfect
vaccine effectiveness means that ongoing viral
transmission might be difficult to detect if symptoms
are mild or absent. \u201cSilent circulation\u201d of the virus
under selective pressure might facilitate mutations
and increase the risk of a variant emerging that can
transmit between humans. Scientists are already
testing mRNA poultry vaccines that might reduce
infections and transmission and calling for the
development of more effective human vaccines.9 21
A One Health approach to surveillance and control
of avian influenza needs high level commitment and
substantial investment. In particular, eliminating
vulnerable bird populations would be costly for the
poultry sector and damaging to human food supply.
Over 58 million birds in the US were slaughtered
during January 2022 to February 2023 from more than
300 affected farms in Japan, 14.8 million birds have
also been culled, causing egg prices to surge
nationwide.22 To deliver its intended benefits, the
One Health approach must be implemented in
collaboration with all stakeholders, including
governments, local farmers, and the poultry industry,
to ensure the continuation of a viable poultry industry
and maintain food security.<\/p>\n<\/div><\/div>","protected":false},"excerpt":{"rendered":"

BMJ Editorial A One Health approach that links human, animal, and environmental health is essential Global reports of highly pathogenic avian influenzaA(H5N1) in birds are increasing, with cases reportedfrom every region except Australasia and Antarcticasince 2020.1 The global spread of these avianinfluenza outbreaks is unprecedented, exacting largeeconomic losses to poultry industries and tourism,and posing a […]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":false,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[37,21],"tags":[],"class_list":["post-2853","post","type-post","status-publish","format-standard","hentry","category-avian-influenza","category-featured"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts\/2853","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/comments?post=2853"}],"version-history":[{"count":1,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts\/2853\/revisions"}],"predecessor-version":[{"id":2854,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts\/2853\/revisions\/2854"}],"wp:attachment":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/media?parent=2853"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/categories?post=2853"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/tags?post=2853"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}