4월 10일자 ProMED-mail

차례

1) H7N9 조류독감 바이러스의 기원 : 중국 장강 삼각주 가금류와 한국에서 날아온 야생 철새의
                                                                   유전자 재조합

2) 돌연변이율 :  H7N9 조류독감 바이러스는 평균적인 독감 바이러스보다 돌연변이가 8배나
                            더  빠름. haemagglutinin을 조사한 결과 단백질의 560개 아미노산 가운데
                            9개에서 변화가 발생. 전형적인 독감 바이러스에선 1~2개에서 변화 발생함.
                           연구팀은 유럽과 아시아에서 발생한 H7N9 조류독감 바이러스와 이번에
                           중국에서 발생한 바이러스를 비교했는데, 중국 정부 당국의 발표와 다른 견해를
                           제시함. 이번 바이러스는 중국내에서 발생했던 H9N2, H11N9, H7N3 바이러스와
                           헤마글루티닌(HA) 유전자가 유사함. 연구팀은 H7N9 조류독감 바이러스가
                           야생철새에 의해 중국 대륙에 유입되었을 가능성을 완전히 배제하지는 않았
                           지만, 중국 내에서 발생했을 가능성이 더 높다는 견해를 밝힘.
                           이 연구는 선진(Shenzhen)에 소재한 중국 과학기술대학(South University of
                            Science and Technology of China)의 면학학자 He Jiankui 교수팀에 의해
                          이루어졌음.(http://www.linkedin.com/pub/jiankui-he/17/175/a19)

3) 발생건수 : 33건 발생, 9명 사망(4월 10일자)
                           
4) 세계보건기구의 업데이트 : 28건 확진, 9명 사망(4월 10일자). 14건 중증, 5건 경증.
                                                     접촉자 600여명 중국 정부 당국 모니터링 중.                    

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Subject: PRO/AH/EDR> Avian influenza human (39): China (SH, JS, ZH) H7N9 update
Archive Number: 20130410.1636073

Published Date: 2013-04-10 16:56:02
http://www.promedmail.org/?p=2400:1000:2512817876171869:::::

AVIAN INFLUENZA HUMAN (39): CHINA (SHANGHAI, JIANGSU, ZHEJIANG) H7N9 UPDATE
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A ProMED-mail post
http://www.promedmail.org
ProMED-mail is a program of the
International Society for Infectious Diseases
http://www.isid.org

In this update:

[1] Origin

[2] Mutation rate

[3] Case count

[4] WHO update



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[1] Origin

Date: Wed 10 Apr 2013

Source: Xinhua News Agency [edited]

http://news.xinhuanet.com/english/china/2013-04/10/c_132299005.htm

A top Chinese biology lab has ascribed the H7N9 avian influenza to genetic reassortment of wild birds from east Asia and chickens from east China. The researchers found that no genes in H7N9 were traceable to pigs, thus excluding pigs as intermediate hosts for the deadly new strain of bird flu, the Chinese Academy of Sciences’ Key Laboratory of Pathogenic Microbiology and Immunology said on Wednesday [10 Apr 2013]. According to the researchers, the genetic reassortment is likely to have occurred in east China’s Yangtze River Delta areas covering Shanghai, Zhejiang, and Jiangsu [provinces]. They found that a virus carried by wild birds from the Republic of Korea and other east Asian regions mingled with the avian influenza virus carried by ducks and chickens in the Yangtze River Delta during migration. The lab’s research shows the H7 and N9 gene segments in H7N9 [outbreak strain] are similar to those in avian influenza samples collected from wild birds from east Asia, while the other 6 genes are traceable to chickens in China’s Shanghai, Zhejiang, and Jiangsu.

As to why the H7N9 is less harmful to animals than to humans, researchers said it’s because of viral mutation, adding that they had monitored mutation of the N9 genes. Animal experts and scientists have stepped up monitoring of bird migration paths to prevent the H7N9 from spreading, according to the China Wildlife Conservation Association.
The new bird flu has killed 9 of the 33 people infected with H7N9 in the country. Some have speculated that the new virus is related to the dead pigs found floating along Shanghai’s Huangpu River last month [March 2013], though local government has repeatedly underlined that this is not the case. On Wednesday [10 Apr 2013], police in southwest China’s Guizhou Province announced they have detained 3 people for fabricating rumors online that the deadly virus had been detected locally.
[Editor: An]
–

Communicated by:

ProMED-mail

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[2] Mutation rate

Date: Wed 10 Apr 2013

Source: The South China Morning Post [summ., edited]

http://www.scmp.com/news/china/article/1211077/h7n9-bird-flu-may-mutate-8-times-faster-regular-flu-study-finds
The new bird flu [A/(H7N9) influenza virus] could be mutating up to 8 times faster than an average flu virus around [that is, in] a protein that binds it to humans, a team of research scientists in Shenzhen says. Dr He Jiankui, an associate professor at South University of Science and Technology of China, said yesterday [9 Apr 2013] that the authorities should be alarmed by the results of their research and step up monitoring and control efforts to prevent a possible pandemic.

With genetic codes of [H7N9] viruses obtained from mainland authorities, the team scrutinised the haemagglutinin, a protein that plays a crucial rule in the process of infection. The researchers found dramatic mutation of haemagglutinin [gene] in one of the four flu strains released for study by the central government. 9 of the protein’s 560 amino acids had changed. In a typical flu virus, only one or 2 amino acids could change in such a short period of time, he said. The fast mutation [rate] makes the virus’ evolutionary development very hard to predict. “We don’t know whether it will evolve into something harmless or dangerous,” He said. “Our samples are too limited.
The origin of the virus was puzzling due to its novelty, but his research suggested some clues that differ from the mainland authorities’ theories. His team compared the new virus strain to all other H7N9 viruses identified in Europe and in other Asian countries that were cited by the Ministry of Agriculture as possible origins of the new bird flu, but found them all very different. In fact, the [HA of the] new bird flu was quite similar to [the HA genes] of some familiar domestic viruses such as H9N2, H11N9, and H7N3 found in Zhejiang and Jiangsu.
He said researchers could not rule out the possibility that the new virus was carried into China by wild birds, but it was more likely to be of local origin.
[Byline: Stephen Chen]
–

Communicated by:

ProMED-mail Rapporteur Mary Marshall
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[3] Case count

Date: Wed 10 Apr 2013

Source: Xinhua News Agency [edited]

http://news.xinhuanet.com/english/china/2013-04/10/c_132298870.htm
Two more human cases of H7N9 bird flu were reported on Wednesday [10 Apr 2013] in Shanghai Municipality, bringing the total number of infected people in the country to 33, health authorities said.

A local [76-year-old retired woman] developed a cough, sore throat and weakness on 1 Apr 2013. On 2 Apr 2013 she developed a high fever and went to the hospital on 5 Apr 2013. Doctors confirmed Tuesday night [9 Apr 2013] that she has H7N9 avian flu, according to a statement issued by the city’s health and family planning committee. The patient is now in stable condition, said the statement. An 81-year-old woman, who is a farmer, went to the hospital with symptoms of diarrhea and fever of unknown origin, and was subsequently diagnosed with acute enteritis and pneumonia. On Tuesday night [9 Apr 2013], the city’s disease prevention and control center confirmed that she has H7N9 bird flu, it said. 9 people who came into contact with the 2 women have so far shown no abnormal symptoms.
Apart from the 2 cases reported in Shanghai, 3 other new cases were also reported in Jiangsu and Zhejiang provinces Wednesday [10 Apr 2013], bringing the country’s total H7N9 infection count to 33 as of 5 pm. Wednesday [10 Apr 2013]. 9 of these individuals have died.
A 4-year-old boy, who had been hospitalized for H7N9 influenza, was discharged from a Shanghai hospital Wednesday [10 Apr 2013] after fully recovering.
[Editor: An]
–

Communicated by:

ProMED-mail

and ProMED-mail Rapporteur Kunhiko Iizuka

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[4] WHO update

Date: 10 Apr 2013

Source: WHO Global Alert and Response

http://www.who.int/csr/don/2013_04_10/en/index.html
Human infection with influenza A(H7N9) virus in China – update 10 Apr 2013

————————

As of 10 April 2013 (18:00 CET), the National Health and Family Planning Commission notified WHO of an additional 4 laboratory-confirmed cases of human infection with influenza A(H7N9) virus. Of the laboratory-confirmed cases, 2 are from Shanghai and 2 from Zhejiang.

The 1st patient is a 62-year-old man from Shanghai who became ill on [1 Apr 2013], the 2nd patient is a 77 year-old man from Shanghai who became ill on [3 Apr 2013], the 3rd patient is a 51 year-old woman from Zhejiang who became ill on [13 Mar 2013], and the 4th patient is a 79 year-old man from Zhejiang who became ill on [29 Mar 2013].
In addition, 2 patients earlier reported from Jiangsu (83-year-old man) and Anhui (35-year-old woman) have died.
To date, a total of 28 cases have been laboratory confirmed with influenza A(H7N9) virus in China, including 9 deaths, 14 severe cases and 5 mild cases.
More than 600 close contacts of the confirmed cases are being closely monitored. In Jiangsu, investigation is ongoing into a contact of an earlier confirmed case who developed symptoms of illness.
The Chinese government is actively investigating this event and has heightened disease surveillance. Retrospective testing of recently reported cases with severe respiratory infection may uncover additional cases that were previously unrecognized. An inter-government task force has been formally established, with the National Health and Family Planning Commission leading the coordination along with the Ministry of Agriculture and other key ministries. The animal health sector has intensified investigations into the possible sources and reservoirs of the virus.
WHO is in contact with national authorities and is following the event closely. The WHO-coordinated international response is also focusing on work with WHO Collaborating Centres for Reference and Research on Influenza and other partners to ensure that information is available and that materials are developed for diagnosis and treatment and vaccine development. No vaccine is currently available for this subtype of the influenza virus. Preliminary test results provided by the WHO Collaborating Centre in China suggest that the virus is susceptible to the neuraminidase inhibitors (oseltamivir and zanamivir).
At this time there is no evidence of ongoing human-to-human transmission.
WHO does not advise special screening at points of entry with regard to this event, nor does it recommend that any travel or trade restrictions be applied.
About this Disease Outbreak News
1. WHO is currently publishing information on laboratory confirmed cases received through the official notification from the Chinese National International Health Regulations (IHR) Focal Point once a day. This formal notification and publication follows verification of the information, and may therefore come after, or not include, some cases reported through public media and other sources.
2. To date, there is limited information to determine whether the reported number of cases represents some or all of the cases actually occurring. As some relatively mild cases of illness have now been reported, it is possible that there are other such cases that have not been identified and reported.
3. If the current pattern of sporadic infections continues, WHO will cease frequent reporting of case numbers, and focus its Disease Outbreak News on new developments or changes in the pattern or presentation of infections.
–

Communicated by:

ProMED-mail Rapporteur Marianne Hopp
[There have been significant advances in determining the origin and genetic characteristics of the A/(H7N9) influenza virus responsible for human disease in eastern China. From genome sequence data it has been deduced that no genes in H7N9 were traceable to pigs, thus excluding pigs as intermediate hosts. Rather the H7 and N9 gene segments in the H7N9 outbreak strain are similar to those in avian influenza samples collected from wild birds from east Asia, while the other 6 genes are traceable to chickens in China's Shanghai, Zhejiang, and Jiangsu provinces. Other research, focussing on the sequence of the HA gene, suggests that the HA gene new bird flu virus could be mutating up to 8 times faster than the HA of an average flu virus. 
Human cases of the H7N9 virus continue to be reported, mainly involving the middle-aged and the elderly. There has still been no confirmed transmission of this virus from person to person.
Currently the number of confirmed human cases is 33, and the number of fatalities is now 9. - Mod.CP]
[The discrepancies between the media reports of numbers of cases and the WHO official report on numbers of cases is explained at the bottom of the WHO update from today (10 Apr 2013).  The WHO numbers reflect those cases that have been laboratory confirmed and are reported through official channels. At present we reflect a difference of 5 cases between the WHO report and the newswire tallies. - Mod.MPP]

See Also