This article is more than 5 years old. Information may no longer be current.

H7N9 case count, deaths continue 
to rise

Issue: May 2013

Add topic to email alerts

Receive an email when new articles are posted on

Please provide your email address to receive an email when new articles are posted on .

Subscribe

Added to email alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

Back to Healio

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Back to Healio

The case count for influenza A(H7N9) has passed the triple-digit mark, with 122 confirmed cases and 23 deaths in China as of April 29, according to WHO.

WHO China representative Michael O’Leary, MD, MPH, said recently that WHO and the China National Health and Family Planning Commission are leading a joint mission of experts to visit areas affected by H7N9 and make recommendations to prevent and control the spread of the disease.

“This is not because of changes in the scope or scale of the event,” O’Leary said during a media briefing. “There continue to be sporadic cases reported every day, but our risk assessment has not changed. Nor is it because of concerns about the investigation itself, as Chinese authorities have been demonstrating their capacity for this investigation. This mission is a concrete example of international cooperation in action.”

Researchers from the Chinese CDC isolated the novel reassortant influenza A(H7N9) virus from three patients who died in the outbreak in China, according to a report in The New England Journal of Medicine. Six internal genes were from avian influenza A(H9N2) viruses.

Another recent NEJM study on the epidemiology of H7N9, led by Qun Li, MD, and 
colleagues from the Chinese CDC, indicated the virus has affected patients in a wide age spectrum and caused severe lower respiratory tract illness. The median age of patients in the study (n = 82) was 63 years (range: 2 to 89 years), and 77% of cases with available data reported exposure to poultry or swine.

O’Leary said poultry continues to be the suspected source of transmission, but there is not yet a strong epidemiological link. Only a small number of chicken and birds tested have been positive for H7N9, and none of those animals were sick. This is in contrast to the more common influenza A(H5N1), which caused illness in birds.

There have been three small clusters of illness in which close contacts of cases became ill: two have been a parent and child and one was a husband and wife. However, human-to-human transmission has not yet been confirmed.

“These might be cases of one person passing the disease to another, or they may have been exposed to the same source of infection,” O’Leary said. “Even though we are concerned if the disease can pass from one person to another, it still seems that this does not happen easily, or we would see many such cases.”

WHO does not advise special screening at points of entry, nor does it recommend any travel or trade restrictions.

See a video perspective by Eric Toner, MD, from the Center for Biosecurity of UPMC in Baltimore. http://www.upmc-biosecurity.org/website/resources/perspectives/H7N9_04182013.html

References:

Gao R. N Engl J Med. 2013;doi:10.1056/NEJMoa1304459.
Li Q. N Engl J Med. 2013;doi: 10.1056/NEJMoa1304617.
Uyeki T. N Engl J Med. 2013;doi:10.1056/NEJMp1304661.