The Lancet this Friday publishes an editorial, a correspondence and a World report on the H7N9 outbreak in China. All these articles affirm that the Chinese government has handled this outbreak a lot better than the SARS epidemic ten years ago - an opinion that I concur. While the probability of the virus being transmitted from human to human is (very) low, experts raise concern over its potential spread among many birds across a large geographical space. Quoting Ted Alcorn in his World report,
Chinese authorities are attempting to identify the bird reservoir that is the source of the disease so they can reduce human exposure to it. But the task is complicated because the virus seems to have low pathogenicity among birds, which means it spreads silently among them without causing noticeable illness or deaths to indicate its presence.And the geographical distribution of human cases suggests that the virus may have already spread too far to contain. People have contracted the disease in seemingly independent incidents across a 1000 km stretch of coastal China, from Shanghai to Beijing.
So, my personal guess is that this H7N9 outbreak may take a while before it dies out.
***
Also, as you may know, Case-fatality ratio = (Total number of death due to the infection) / (Total number of people infected)
Whilst many are concerned with its apparent high case-fatality ratio among infected persons, it is important to highlight the fact that we simply do not know exactly how many people are infected and that some people who are critically ill right now may die in the future.
Apparently - at least from my own perspective - there are at least two potential hypotheses:
Hypothesis A is that the number of people infected are small. The number observed and reported by the public health authorities in China is not far from the true. In this case, the case-fatality ratio is certainly a lot higher than seasonal flu.
Hypothesis B is that there may be many people out there who are infected but are asymptomatic, just like the Beijing kid who was tested H7N9 positive but developed no symptoms at all. If that is the case, then we would have a larger denominator for the Case-fatality ratio, and therefore, a lower case-fatality ratio.
Which hypothesis is true? I honestly do not know. I know some scientists who believe in A while other scientists believe in B.
No matter what, I hope that the public health and agricultural authorities in China and the Chinese physicians, veterinarians, and scientists will work hard to contain the outbreak. Not only those who were unfortunately infected with this virus might die of the infection, the farmers who raise poultry also suffer a heavy financial loss. According to the Chinese Ministry of Agriculture (see press release (April 16, 2013)), the Chinese agricultural sector has already lost an estimated total of 16.7 billion Chinese yuan from the announcement of the outbreak (Mar 31) to April 15, due to poultry culling, reduction in sales and dropped price of poultry.
Perhaps, in the long run, the Chinese people need to re-think about their way of raising, handling and eating poultry.
Recent Comments