Zhejiang Province – Credit Wikipedia
# 8239
We’ve a terse statement from the Zhejiang Ministry of Health this morning announcing their investigation into a family cluster of H7N9 cases. Details are scant at this time, but what we know is 3 members of a family in Hangzhou all contracted the virus.
Whether this was due to a common environmental exposure, or human-to-human transmission is unknown at this time.
As we’ve discussed before, when it comes to proving human-to-human (H-2-H) transmission of an emerging virus, the bar is set pretty high. When there are other, equally plausible explanations (e.g. shared environmental, or live bird exposures), then H-2-H cannot be assumed.
Since we’ve seen suspected limited H-2-H transmission of the H7N9 virus in the past (see BMJ: `Probable Person-to-Person Transmission’ Of H7N9), another occurrence – while of epidemiological interest - wouldn’t be a game changer. We take notice primarily because it could be the first visible step in a chain of transmission.
First the (machine translated) statement, then I’ll be back with a bit more.
Release date :2014-01-29
January of this year, I appointed people infected with H7N9 reported confirmed cases of avian influenza have occurred in Xiaoshan District, a family clusters of cases, three people sick. In three patients before the onset of the existence of a common environmental exposure, there are close contacts, the exact cause of the infection, the national and provincial experts are studying, one has the final official results announced immediately to the public.
Additional reportage indicates this cluster consists of a couple and their daughter. This from AFP news.
Three H7N9 cases in same Chinese family: Xinhua
January 29, 2014 12:53 pm
SHANGHAI - Three members of the same Chinese family have contracted H7N9 bird flu in the province worst-affected by the current spike in cases, the official Xinhua news agency reported. A couple and their daughter in Hangzhou, the capital of the eastern province of Zhejiang, were infected one after another, Xinhua said late Tuesday, without giving further details.
In 2006, we saw large clusters of H5N1 infection in both Indonesia and Turkey, and yet, it never managed to gain enough momentum to spark a pandemic (see 2006 Karo Cluster Involved H2H Transmission). Similarly, a family cluster in Pakistan in 2007 raised concerns, but once again failed to catch fire (see EID Journal: Unraveling Pakistan’s H5N1 Outbreak).
Should we begin to see evidence of efficient and sustained H-2-H transmission (ie. 3rd, 4th, 5th generation transmission) - then things begin to get more interesting.
But for now, we’ve no indications of that happening.
