Featured Research

from universities, journals, and other organizations

First probable person to person transmission of new bird flu virus in China; But H7N9 is not able to spread efficiently between humans

Date:
August 6, 2013
Source:
BMJ-British Medical Journal
Summary:
The first report of probable person to person transmission of the new avian influenza A (H7N9) virus in Eastern China has been documented. The findings provide the strongest evidence yet of H7N9 transmission between humans, but the authors stress that its ability to transmit itself is "limited and non-sustainable."

The first report of probable person to person transmission of the new avian influenza A (H7N9) virus in Eastern China has just been published. The findings provide the strongest evidence yet of H7N9 transmission between humans, but the authors stress that its ability to transmit itself is "limited and non-sustainable."
Credit: © chuugo / Fotolia

The first report of probable person to person transmission of the new avian influenza A (H7N9) virus in Eastern China has just been published.

Related Articles


The findings provide the strongest evidence yet of H7N9 transmission between humans, but the authors stress that its ability to transmit itself is "limited and non-sustainable."

Avian influenza A (H7N9) virus was recently identified in Eastern China. As of 30 June 2013, 133 cases have been reported, resulting in 43 deaths.

Most cases appear to have visited live poultry markets or had close contact with live poultry 7-10 days before illness onset. Currently no definite evidence indicates sustained human-to-human transmission of the H7N9 virus.

The study reports a family cluster of two patients (father and daughter) with H7N9 virus infection in Eastern China in March 2013.

The first (index) patient -- a 60 year old man -- regularly visited a live poultry market and became ill five to six days after his last exposure to poultry. He was admitted to hospital on 11 March.

When his symptoms became worse, he was transferred to the hospital's intensive care unit (ICU) on 15 March. He was transferred to another ICU on March 18 and died of multi-organ failure on 4 May.

The second patient, his healthy 32 year old daughter, had no known exposure to live poultry before becoming sick. However, she provided direct and unprotected bedside care for her father in the hospital before his admission to intensive care.

She developed symptoms six days after her last contact with her father and was admitted to hospital on 24 March. She was transferred to the ICU on 28 March and died of multi-organ failure on 24 April.

Two almost genetically identical virus strains were isolated from each patient, suggesting transmission from father to daughter.

Forty-three close contacts of both cases were interviewed by public health officials and tested for influenza virus. Of these, one (a son in law who helped care for the father) had mild illness, but all contacts tested negative for H7N9 infection.

Environmental samples from poultry cages, water at two local poultry markets, and swans from the residential area, were also tested. One strain was isolated but was genetically different to the two strains isolated from the patients.

The researchers acknowledge some study limitations, but say that the most likely explanation for this family cluster of two cases with H7N9 infection is that the virus "transmitted directly from the index patient to his daughter." But they stress that "the virus has not gained the ability to transmit itself sustained from person to person efficiently."

They believe that the most likely source of infection for the index case was the live poultry market, and conclude: "To our best knowledge, this is the first report of probable transmissibility of the novel virus person to person with detailed epidemiological, clinical, and virological data. Our findings reinforce that the novel virus possesses the potential for pandemic spread."

So does this imply that H7N9 has come one step closer towards adapting fully to humans, ask James Rudge and Richard Coker from the London School of Hygiene and Tropical Medicine, based in Bangkok, in an accompanying editorial?

Probably not, they say. Limited transmission between humans "is not surprising, and does not necessarily indicate that the virus is on course to develop sustained transmission among humans."

Nevertheless, they point to several traits of H7N9 are of particular concern, and conclude that, while this study might not suggest that H7N9 is any closer to delivering the next pandemic, "it does provide a timely reminder of the need to remain extremely vigilant: the threat posed by H7N9 has by no means passed."

Dr Zhou says that the reason for carrying out this study was because there was "no definite evidence to show that the novel virus can transmit person-to-person," plus she and her co-authors wanted to find out whether the novel avian influenza virus possesses the capability to transmit person-to-person. She concludes that "the infection of the daughter is likely to have resulted from her father during unprotected exposure" and suggest that the virus possesses the ability to transmit person-to-person in this cluster. She does add however that the infection was "limited and non-sustainable as there is no outbreak following the two cases."


Story Source:

The above story is based on materials provided by BMJ-British Medical Journal. Note: Materials may be edited for content and length.


Journal Reference:

  1. X. Qi, Y.-H. Qian, C.-J. Bao, X.-L. Guo, L.-B. Cui, F.-Y. Tang, H. Ji, Y. Huang, P.-Q. Cai, B. Lu, K. Xu, C. Shi, F.-C. Zhu, M.-H. Zhou, H. Wang. Probable person to person transmission of novel avian influenza A (H7N9) virus in Eastern China, 2013: epidemiological investigation. BMJ, 2013; 347 (aug06 2): f4752 DOI: 10.1136/bmj.f4752

Cite This Page:

BMJ-British Medical Journal. "First probable person to person transmission of new bird flu virus in China; But H7N9 is not able to spread efficiently between humans." ScienceDaily. ScienceDaily, 6 August 2013. <www.sciencedaily.com/releases/2013/08/130806203509.htm>.
BMJ-British Medical Journal. (2013, August 6). First probable person to person transmission of new bird flu virus in China; But H7N9 is not able to spread efficiently between humans. ScienceDaily. Retrieved March 31, 2015 from www.sciencedaily.com/releases/2013/08/130806203509.htm
BMJ-British Medical Journal. "First probable person to person transmission of new bird flu virus in China; But H7N9 is not able to spread efficiently between humans." ScienceDaily. www.sciencedaily.com/releases/2013/08/130806203509.htm (accessed March 31, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Tuesday, March 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Solitair Device Aims to Takes Guesswork out of Sun Safety

Solitair Device Aims to Takes Guesswork out of Sun Safety

Reuters - Innovations Video Online (Mar. 31, 2015) — The Solitair device aims to take the confusion out of how much sunlight we should expose our skin to. Small enough to be worn as a tie or hair clip, it monitors the user&apos;s sun exposure by taking into account their skin pigment, location and schedule. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Soda, Salt and Sugar: The Next Generation of Taxes

Soda, Salt and Sugar: The Next Generation of Taxes

Washington Post (Mar. 30, 2015) — Denisa Livingston, a health advocate for the Dinι Community Advocacy Alliance, and the Post&apos;s Abby Phillip discuss efforts around the country to make unhealthy food choices hurt your wallet as much as your waistline. Video provided by Washington Post
Powered by NewsLook.com
UnitedHealth Buys Catamaran

UnitedHealth Buys Catamaran

Reuters - Business Video Online (Mar. 30, 2015) — The $12.8 billion merger will combine the U.S.&apos; third and fourth largest pharmacy benefit managers. Analysts say smaller PBMs could also merge. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
S. Leone in New Anti-Ebola Lockdown

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015) — Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins