versión impresa ISSN
Bull World Health Organ vol.92 no.4 Genebra abr. 2014
Epub 16-Dic-2013
http://dx.doi.org/10.2471/BLT.13.125989
Lessons from the Field
Early response to the emergence of influenza A(H7N9) virus in humans
in China: the central role of prompt information sharing and public
communication
Réponse précoce à
l'émergence du virus de la grippe A(H7N9) chez
l'homme en Chine: le r?le central du partage rapide des
informations et de la communication publique
La respuesta temprana en la aparición del
virus de la gripe A(H7N9) en humanos en China: el papel central del
intercambio de información y la comunicación pública a
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A(H7N9) ???
中国人群出现甲型H7N9流感病毒的早期响应：迅速的信息共享和公众沟通的核心作用
Ранний
ответ на
появление
вируса
гриппа A (H7N9) у
населения
в Китае:
центральная
оперативного
обмена
информацией
информирования
общественности
Sirenda Vong
, Michael O’Leary
, Zijian Feng
aWorld Health Organization Office in China,
401 Dongwai Diplomatic Office Building, 23 Dongzhimenwai Dajie, Chaoyang
District, Beijing 100600, China
bChinese Centre for Disease Control and
Prevention, Beijing, China
In 2003, China’s handling of the early stages of the epidemic of
severe acute respiratory syndrome (SARS) was heavily criticized and
generally considered to be suboptimal.
Following the SARS outbreak, China made huge investments to improve
surveillance, emergency preparedness and response capacity and strengthen
public health institutions. In 2013, the return on these investments was
evaluated by investigating China’s early response to the emergence of
avian influenza A(H7N9) virus in humans.
Local setting
Clusters of human infection with a novel influenza virus were detected in
China – by national surveillance of pneumonia of unknown etiology
– on 26 February 2013.
Relevant changes
On 31 March 2013, China notified the World Health Organization (WHO) of the
first recorded human infections with A(H7N9) virus. Poultry markets –
which were rapidly identified as a major source of transmission of A(H7N9)
to humans – were closed down in the affected areas. Surveillance in
humans and poultry was heightened and technical guidelines were quickly
updated and disseminated. The health authorities collaborated with WHO in
risk assessments and risk communication. New cases were reported promptly
and publicly.
Lessons learnt
The relevant infrastructures, surveillance systems and response capacity need
to be strengthened in preparation for future emergencies caused by emerging
or existing disease threats. Results of risk assessments and other data
should be released promptly and publicly and such release should not
jeopardize future publication of the data in scientific journals.
Coordination between public health and veterinary services would be stronger
during an emergency if these services had already undertaken joint
preparedness planning.
En 2003, la gestion des premiers stades de
l'épidémie du syndrome respiratoire aigu
sévère (SRAS) par la Chine a été fortement
critiquée et généralement considérée
comme non optimale.
Après l'épidémie de SRAS, la Chine a investi
massivement pour améliorer sa surveillance, sa préparation aux
situations d'urgence et sa capacité de réponse, et pour
renforcer les établissements de santé publique.
En 2013, le retour sur ces investissements a été
évalué par l'examen de la réponse précoce
de la Chine à l'émergence du virus de la grippe aviaire
A(H7N9) chez l'homme.
Environnement local
Des cas d'infection humaine au nouveau virus de la grippe ont
été détectés en Chine
le 26 février 2013 par le système de
surveillance nationale des pneumonies d'étiologie inconnue.
Changements significatifs
Le 31 mars 2013, la Chine a notifié à
l'Organisation mondiale de la Santé (OMS) les premières
infections humaines au virus A(H7N9) enregistrées. Les marchés
de volaille – qui ont été rapidement identifiés
comme des sources majeures de transmission du virus A(H7N9) à
l'homme – ont été fermés dans les zones
touchées. La surveillance a été renforcée chez
l'homme et les volailles, et les recommandations techniques ont
été rapidement mises à jour et diffusées. Les
autorités sanitaires ont collaboré avec l'OMS dans les
domaines de l'évaluation des risques et de la communication des
risques. Les nouveaux cas ont été signalés rapidement
et publiquement.
Le?ons tirées
Les infrastructures concernées, les systèmes de surveillance et
la capacité de réponse doivent être renforcés en
prévision des futures urgences causées par les menaces de
maladies émergentes ou existantes. Les résultats des
évaluations des risques et les autres données doivent
être communiqués rapidement et publiquement, et ces
communications ne doivent pas compromettre la publication ultérieure
des données dans les revues scientifiques. La coordination entre les
services de santé publique et les services vétérinaires
serait plus forte pendant une situation d'urgence si ces services
avaient déjà engagé une planification préalable
Situación
En 2003, la gestión de China de las primeras etapas de la epidemia del
síndrome respiratorio agudo severo (SRAS) se criticó duramente
y se consideró insuficiente por lo general.
Tras el brote de SRAS, China realizó grandes inversiones para mejorar
la vigilancia, la preparación para emergencias y la capacidad de
respuesta, así como para fortalecer las instituciones de salud
pública. En 2013, se evaluó la rentabilidad de estas
inversiones mediante una investigación sobre la respuesta temprana de
China a la aparición del virus de la gripe aviar A(H7N9) en
Marco regional
El 26 de febrero de 2013 se detectaron grupos de infecciones humanas con el
nuevo virus de la gripe en China mediante la vigilancia nacional de la
neumonía de etiología desconocida.
Cambios importantes
El 31 de marzo de 2013, China comunicó a la Organización
Mundial de la Salud (OMS) las primeras infecciones humanas del virus A(H7N9)
registradas. Los mercados de aves de corral, que se identificaron de
inmediato como una fuente importante de transmisión del virus A(H7N9)
a los humanos, se cerraron en las zonas afectadas. Se reforzó la
vigilancia en humanos y aves de corral a la vez que se actualizaron y
difundieron las directrices técnicas con rapidez. Las autoridades de
salud colaboraron con la OMS en la evaluación de los riesgos y la
comunicación de los riesgos. De inmediato, se anunciaron los nuevos
casos públicamente.
Lecciones aprendidas
Deben reforzarse las infraestructuras pertinentes, los sistemas de vigilancia
y la capacidad de respuesta como preparación a las futuras
emergencias causadas por la amenaza de enfermedades nuevas o existentes. Los
resultados de las evaluaciones de riesgo y el resto de datos deben
divulgarse rápida y públicamente, pero dicha
divulgación no debe poner en peligro la futura publicación de
los datos en las revistas científicas. La coordinación entre
la salud pública y los servicios veterinarios sería más
fuerte durante una emergencia si estos servicios planificaran de antemano la
preparación conjunta.
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2003年，中国对非典（SARS）流行早期阶段的处理广受诟病，普遍被认为是次优的处理。
SARS爆发事件后，中国投入巨资来改善监测、应急准备和响应能力以及加强公共卫生机构。2013年，通过调查中国应对人群中出现甲型H7N9禽流感病毒的早期响应来评估这些投资的回报。
日，通过全国对不明原因肺炎的监测，检测到感染新型流感的人群。
日，中国向世界卫生组织（WHO）通报了第一例记录在案的人感染甲型H7N9禽流感病毒。在发病地区，关闭了被迅速认定为人类感染甲型H7N9禽流感主要传染源的鸡鸭市场。增强了人群和家禽监测，快速更新和分发了技术指南。卫生当局与世卫组织协作进行风险评估和风险沟通。新病例得到迅速公开的报告。
为应对未来因新出现或现有疾病威胁引起的突发事件，需要加强相关的基础设施、监测系统和反应能力。风险评估的结果和其他数据应及时和公开地发布，这种发布不应妨碍未来数据在科学期刊上的发表。如果公共卫生和兽医部门已落实了共同的准备计划，这些部门之间的协调就会更有力。
Проблема
В 2003 году
подход
Китая к
лечению
населения
на ранних
стадиях
эпидемии
тяжелого
острого
респираторного
синдрома
(ТОРС)
подвергся
жесткой
критике и
считался
неоптимальным.
Подход
После
вспышки
ТОРС Китай
направил
крупные
инвестиции
укрепление
институтов
общественного
здравоохранения,
улучшение
качества
эпиднадзора,
готовность
чрезвычайным
ситуациям
и скорость
реагирования.
В 2013 году
эффективность
инвестиций
оценена
путем
исследования
стратегии
раннего
реагирования
Китая на
появление
населения
вируса
птичьего
гриппа
типа А (H7N9).
Местные
условия
26 февраля
2013 года
Агентством
национального
эпиднадзора
случаями
пневмонии
неизвестной
этиологии
в Китае
обнаружены
кластеры
инфицирования
людей
новым
вирусом
гриппа.
Осуществленные
перемены
31 марта 2013
года Китай
уведомил
Всемирную
организацию
здравоохранения
(ВОЗ) о
первых
зарегистрированных
случаях
инфицирования
людей
вирусом A (H7N9).
инфицированных
районах
закрыты
птичьи
рынки,
которые
быстро
идентифицированы
основной
источник
передачи
гриппа A (H7N9)
человеку.
Был усилен
эпиднадзор
среди
населения
и домашней
птицы, а
также
обновлены
распространены
соответствующие
технические
инструкции.
Органы
здравоохранения
сотрудничали
с ВОЗ в
оценке
рисков и
информировании
о них. О
выявлении
новых
случаев
заболевания
сообщалось
быстро и
публично.
Выводы
Соответствующие
инфраструктуры,
системы
эпиднадзора
и ответные
должны
усилены
подготовке
к будущим
чрезвычайным
ситуациям,
вызванным
новыми или
существующими
заболеваниями.
Результаты
оценки
риска и
прочие
данные
должны
сообщаться
немедленно
и публично,
и такие
сообщения
не должны
препятствовать
будущей
публикации
данных в
научных
изданиях.
Координация
между
общественным
здравоохранением
ветеринарными
службами
была бы
более
эффективной
чрезвычайных
ситуациях,
если бы эти
службы
осуществили
совместное
планирование
мероприятий
на случай
чрезвычаных
ситуаций.
Severe acute respiratory syndrome is a zoonotic viral infection that probably first
occurred, in late 2002, in the south of China’s Guangdong province. Although the syndrome eventually
spread to more than 30 countries – with more than 8000 probable cases
and more than 800 deaths reported worldwide – most of the probable cases
occurred in mainland China.
In March 2003, the World Health Organization (WHO) issued a global alert and travel
advisory following the identification of clusters of cases of “severe
atypical pneumonia” in hospitals in Guangdong and the Hong Kong Special
Administrative Region in China and Hanoi in Viet Nam. By April 2003, a coronavirus had been identified as the
infectious agent responsible for this pneumonia and the pneumonia itself had been
called severe acute respiratory syndrome (SARS).
The early stages of the SARS epidemic went largely unnoticed. Many clinicians were
unaware of the epidemic threat posed by the “atypical pneumonia”;
cases went undetected because of poor surveillance and an inadequate network of
clinical laboratories, and poor information transfer meant that the epidemic had
gained considerable strength before it was recognized. China’s delayed detection of the outbreak and
– in particular – its poor level of communication during the response
to the emergency probably led to many avoidable cases of SARS and damaged
China’s economy and reputation.
Heavy criticism of China’s response in the early stages of the SARS outbreak
led to huge investments in public health by the Chinese government. There has been
substantial investment in public health infrastructure, such as new buildings,
improvements in Internet connectivity and the purchase of technically advanced
equipment. The government has also supported the development of the national Centre
for Disease Control and Prevention (China CDC) and the provincial and county-level
Centres for Disease Control and Prevention. China CDC has remodelled its
surveillance of infectious diseases – with an emphasis on severe respiratory diseases
and the development of a national influenza surveillance network. The Chinese health
authorities have initiated training programmes in field epidemiology – at the
national, provincial and municipality levels – and strengthened emergency
preparedness and response capacity. The detailed investments that the Chinese
government has made to improve the surveillance and control of
“high-priority” infectious diseases have been well documented.
The aims of China’s post-SARS investments in public health were to improve
disease surveillance and make the country’s response to future disease
outbreaks both swift and effective. To see if these aims had been achieved, we
investigated China’s early response to the emergence of avian influenza
A(H7N9) virus in humans during April 2013. We compared the chronology of
A(H7N9)-related events and responses with the level of A(H7N9)-related public
attention. The latter variable was evaluated using Sina Weibo (SINA Corp., Shanghai,
China), which is the largest social media network in China. Sina Weibo –
which offers services similar to those of Twitter (Twitter Inc., San Francisco,
United States of America) but in Chinese – is used by more than 30% of
Chinese Internet users. In December 2012, Sina Weibo had more than 500
million registered users and dealt with about 100 million new messages each
day. For our study, we
searched Sina Weibo daily – during the outbreak – for new
A(H7N9)-related postings, by using the Chinese words for “H7N9” and
“bird flu” as the search terms.
Local setting and relevant changes
On 31 March 2013, China’s National Health and Family Planning Commission
notified WHO of three human infections with A(H7N9): two in the city of Shanghai and
one in Anhui province. By 7 November
confirmed cases of human
infection with A(H7N9) – including 45 fatal cases – had been reported
in mainland China – in 10 provinces and two municipalities. Although the animal reservoir of
A(H7N9) infection involved in this outbreak has yet to be confirmed, it is probably
poultry and most transmission to humans probably occurs in markets selling live
poultry. The Chinese Ministry of Agriculture has already tested more than 1.2
million birds and other animals – from more than 69 000 different
sites – for A(H7N9). By 9 December 2013, only 68 non-human samples had been
found positive for the virus. The 68 positive samples – which were all
collected in markets selling live poultry – came from poultry, a pigeon or
feathers, bird faeces, cages or other “environmental” sources within
the market.
Although the investigation of more than
3000 close contacts of the confirmed
cases has not revealed any evidence of sustained human-to-human transmission of the
A(H7N9) virus, there is evidence of some human-to-human transmission among at least
three family clusters.– China’s National Health and Family Planning
Commission and WHO remain concerned about the threat posed by the A(H7N9) virus
because it is an avian virus that seems to have recently infected humans, causes
serious disease in humans and has genetic characteristics that indicate that it has
enhanced capacity for mammalian infection., It remains unclear, however, if A(H7N9) is common in
poultry. It has been difficult to detect the virus in poultry or other birds because
the virus causes little avian pathogenicity – and may therefore spread
undetected within and between flocks of birds.
As with A(H5N1), new sporadic
cases and small clusters of human infection with A(H7N9) infection are likely to
continue. WHO remains alert to any changes in the behaviour of the A(H7N9) virus in
humans and poultry and the resistance of the virus to antiviral drugs will be
carefully monitored. More or larger clusters of human cases – or evidence of
sustained human-to-human transmission – could indicate that the virus is
acquiring qualities compatible with pandemic potential.
The 2013 outbreak of human infection with A(H7N9) appears to have begun when a family
cluster of three cases of severe pneumonia – which was recognized as abnormal
by astute clinicians – triggered an alert to the Shanghai Centre for Disease
Control and Prevention on 26 February 2013. The influenza A virus found in the cluster did not
match any known subtype. Within 4 weeks of the cluster being reported, staff
at the China CDC – the WHO Collaborating Centre for Reference and Research on
Influenza (WHO CCRRI) in Beijing – had discovered that the virus belonged to
a novel strain: A(H7N9). This viral strain was identified much more quickly than
SARS coronavirus or A(H5N1), which took about 5 and 3 months to identify,
respectively., The viral genomic sequences from
the first three known human cases of A(H7N9) infection were published, via the
Global Initiative on Sharing Avian Influenza Data, on 31 March 2013. On the
following day, the National Health and Family Planning Commission enhanced
surveillance of pneumonia of unknown etiology and influenza-like illnesses across
China. Two days later, molecular diagnostic kits were distributed to the National
Veterinary Services, the laboratories in provincial Centres for Disease Control and
Prevention and clinical pathology laboratories in major hospitals. By 3 April
2013 – just 4 days after WHO had been notified of this family cluster
– the relevant guidelines regarding infection control, clinical management
and surveillance had been updated and the updated guidelines had been issued. On the
same day, the national government established a taskforce – for the control
of A(H7N9) – that included representatives from 16 ministries and was led by
the National Health and Family Planning Commission. Staff at the Shanghai Centre for
Disease Control and Prevention quickly identified markets that sold live poultry to
be the main locations of human infection with A(H7N9). On 6 April 2013, the
city’s mayor ordered all such markets in Shanghai to be closed. Isolates of
the virus were sent to other WHO CCRRIs on 10 April 2013. This sharing led to the
investigation of viral mutations and the development of new probes and primers for
use in diagnostic tests. As the number of cases continued to increase, China CDC
conducted a series of rapid risk assessments to address the likelihood of sustained
human-to-human transmission and further cases of human infection. Although these
initial assessments were disseminated to all of China’s Centres for Disease
Control and Prevention – and were generally similar to the risk assessments
that were made, independently, by WHO – they were not released publicly.
By the second week of April 2013, the China CDC was regularly sharing data –
on the human infections with A(H7N9) – with WHO’s Regional Office for
the Western Pacific, WHO’s headquarters in Geneva and other members of the
Global Outbreak Alert and Response Network. New cases of human infection and the
type and collection site of each A(H7N9)-positive animal sample were promptly
reported on official websites. This allowed members of the public to follow the
epidemic situation. There was an initial delay in the collection and sharing of the
detailed information needed to evaluate the risks of human-to-human transmission
accurately and determine the underlying medical conditions of patients with
symptomatic A(H7N9) infections. Nonetheless, the first detailed virological and
epidemiological results of investigations on the outbreak were published in
scientific journals in mid-April 2013.,
To improve clinical management of severely ill patients and to plan for appropriate
research, WHO facilitated discussion between key Chinese clinicians and
international experts on influenza. WHO and China’s National Health and
Family Planning Commission jointly coordinated a mission by
internationally-recognized influenza experts, who visited Beijing and Shanghai from
19 to 25 April 2013 to assess the A(H7N9) situation. The main aims of this mission were to provide expert
opinions on the level of the A(H7N9) threat and encourage investigators to close any
relevant gaps in our critical knowledge and understanding.
From the first recognition of the outbreak, WHO participated – with
China’s National Health and Family Planning Commission – in national
risk assessments and press conferences. Some outbreak-related events appeared
related to increases or decreases in the daily numbers of A(H7N9)-related messages
posted on Sina Weibo. The first main surge in the number of cases reported daily
– on 4 April 2013 – and the report of the first case to be
identified in Beijing – on 13 April 2013 – were followed by dramatic
rises in the number of A(H7N9)-related postings. In contrast, a press conference on
8 April 2013 – presented jointly by WHO and the National Health and
Family Planning Commission – and a public announcement on 17 April 2013
– on the WHO’s experts’ mission to China – each appeared
to be associated with a subsequent fall in the daily number of such postings ().
Fig. 1 Events during emergence of A(H7N9) virus as human pathogen and numbers of
related postings on social media network, China, 2013
Lessons learnt
The main lessons learnt are summarized in . China’s prompt communication and collaboration with
WHO in assessing and responding to human infections with the novel influenza A(H7N9)
virus were the result of sound preparedness and close and continuing international
collaboration. Above all, China’s apparently effective response to the
A(H7N9) outbreak in 2013 should be perceived both as one of the major returns on the
investment that China has made in public health since the SARS epidemic in 2003 and
as a useful – if still not optimal – model for responses to similar
outbreaks in the future. The International Health Regulations that were formulated
in 2005 – partly in response to the emergence of SARS – have helped
catalyse a standardized international framework in which WHO provides a system to
enable prompt information sharing.
Summary of main lessons learnt
Countries should invest in preparedness to respond to emerging and
existing disease threats by strengthening the relevant infrastructures,
surveillance systems and response capacity.
Risk assessments should be released publicly and should not jeopardize
authors’ plans to publish in scientific journals.
Coordination between public health and veterinary services would be
stronger during an emergency if these services had already undertaken
joint preparedness planning.
Epidemics caused by emerging infectious diseases often generate substantial public
concern. By publicly communicating about the risks – from the early stages of
a possible epidemic – health authorities can help to build trust in
governments, public health workers and the public. The public needs to have prompt
access to appropriate public health information.
The use of Sina Weibo and similar social networks to monitor public interest in a
health threat – or any other health topic – and also, perhaps, to
disseminate health education merits further research. In our study, certain major
events during the outbreak were associated with major increases in A(H7N9)-related
postings but some more formal announcements about the outbreak appeared to reduce
public interest. It seems possible that the formal announcements simply reduced
public concern about the outbreak.
Risk assessment is a systematic process that can be used to assess the level of
threat and facilitate the selection of the most appropriate interventions in an
often-complex situation. Such assessment often helps to identify gaps in our
critical knowledge and weaknesses in the relevant infrastructure. It may also help
to identify the better strategies for closing the knowledge gaps and strengthening
infrastructures. As the A(H7N9) virus emerged as a public health emergency of
international concern, the public health community and the threatened public
expected to be kept informed of all of the relevant data. The findings of national
risk assessments should therefore be rapidly released publicly and – in due
course –published in full in scientific journals. Journal editors should be
willing to publish articles based on data that – for public benefit –
have already been released to the public in summary form.
China’s prompt response to the emergence of the A(H7N9) virus as a human
pathogen – which spanned multiple governmental departments and ministries at
national, provincial and municipal level – was mainly the result of strong
leadership in a critical situation. We believe that strong and well integrated
coordination between veterinary and public health services can be best sustained by
joint preparedness planning and the creation of joint response systems – as
already promoted by international health organizations under the “One
Health” approach.
References
Parashar UD, Anderson LJ. Severe respiratory syndrome: review and
lessons of the 2003 outbreak Int J Epidemiol
–34.PMID: doi: http://dx.doi.org/10.1126/science.279.
PMID:9430591
WHO issues global alert about cases of atypical pneumonia: cases of
severe respiratory illness may spread to hospital staff [Internet]. Geneva:
World Health O 2003. Available from:
http://www.who.int/csr/sars/archive/en/ [accessed 9 December
Peiris JS, Lai ST, Poon LL, Guan Y, Yam LY, Lim W et al.; SARS study
group. Coronavirus as a possible cause of severe acute respiratory syndrome.
Lancet 9–25. doi:
http://dx.doi.org/10.-77-2 PMID:
Feng D, de Vlas SJ, Fang LQ, Han XN, Zhao WJ, Sheng S et al. The
SARS epidemic in mainland China: bringing together all epidemiological data.
Trop Med Int Health 2009;14(Suppl 1):4–13. doi:
http://dx.doi.org/10.1111/j.08.02145.x
Yang W, Li Z, Lan Y, Wang J, Ma J, Jin L et al. A nationwide
web-based automated system for outbreak early detection and rapid response in
China. Western Pac Surveill Response J
–5.http://dx.doi.org/10.5365/WPSAR..009
Wang L, Wang Y, Jin S, Wu Z, Chin DP, Koplan JP et al. Emergence and
control of infectious diseases in China. Lancet
8–605. doi: http://dx.doi.org/10.-65-3
Ong J. China’s Sina Weibo grew 73% in 2012, passing 500 million
registered accounts [Internet]. Amsterdam: The Next W 2013. Available from:
/asia//chinas-sina-weibo-grew-73-in-2012-passing-500-million-registered-accounts
[accessed 22 September 2013].
Human infection with influenza A(H7N9) virus in China – update
[Internet]. Geneva: World Health O 2013. Available from:
http://www.who.int/csr/don//en/index.html [accessed 9 December
Updates on national surveillance of A(H7N9) influenza virus in
animals [Internet]. Beijing: Ministry of A 2013. Available from:
http://www./zwllm/zwdt/1497.htm [accessed 9
December 2013]. Chinese.
Rudge JW, Coker R. Human to human transmission of H7N9. BMJ
30. doi: http://dx.doi.org/10.1136/bmj.f4730
Li Q, Zhou L, Zhou M, Chen Z, Li F, Wu H et al. Preliminary report:
epidemiology of the avian influenza A (H7N9) outbreak in China. N Engl J
Med .Epub 2013 Apr 24. doi:
http://dx.doi.org/10.1056/NEJMoa1304617 PMID:
Qi X, Qian YH, Bao CJ, Guo XL, Cui LB, Tang FY et al. Probable
person to person transmission of novel avian influenza A (H7N9) virus in eastern
China, 2013: epidemiological investigation. BMJ 52.
doi: http://dx.doi.org/10.1136/bmj.f4752 PMID:
Gao R, Cao B, Hu Y, Feng Z, Wang D, Hu W et al. Human infection with
a novel avian-origin influenza A (H7N9) virus. N Engl J Med
8–97. doi: http://dx.doi.org/10.1056/NEJMoa1304459
Chen Y, Liang W, Yang S, Wu N, Gao H, Sheng J et al. Human
infections with the emerging avian influenza A H7N9 virus from wet market
poultry: clinical analysis and characterisation of viral genome.
Lancet 6–25. doi:
http://dx.doi.org/10.-03-4 PMID:
Risk assessment summary for H5N1 [Internet]. Geneva: World Health
O 2013. Available from:
http://www.who.int/influenza/human_animal_interface/HAI_Risk_Assessment/en/index.html
[accessed 9 December 2013].
Subbarao K, Klimov A, Katz J, Regnery H, Lim W, Hall H et al.
Characterization of an avian influenza A (H5N1) virus isolated from a child with
a fatal respiratory illness. Science –6. doi:
http://dx.doi.org/10.1126/science.279. PMID:9430591
China–WHO joint mission on human infection with avian influenza
A(H7N9) virus. 18–24 April 2013. Manila: World Health O 2013.
[Internet]. Available from:
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/ChinaH7N9JointMissionReport2013.pdf
[accessed 26 May 2013].
One Health Initiative will unite human and veterinary medicine
[Internet]. One Health I 2013. Available from:
[accessed 30 September
Correspondence to Sirenda Vong (e-mail: ).}