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Monday, April 15, 2013

H7N9 - The world is not ready for this

If Dr Timothy Uyeki and Dr Nancy Cox from the Center for Disease Control have it right, the human species is sitting on the edge of biological catastrophe.

The subject of epidemic surveillance has featured before on this blog [LINK] but this time our posting is far less academic and a lot more preemptive in its warning. From early analysis, H7N9 is a major risk threat which needs wider attention. Let's take a brief look at what appears to be very concerning, even though it is only a matter days since H7N9 has entered our world.
Comparison in perspective
Bird Flu is nothing new or so it seems, but the bird flu of 2013 or H7N9 is a pandemic in the making. Well it is certainly showing itself to be this if you read what the scientists are writing. 

H5N1 Cumulative Statistics | World Health Organisation [Click Image to Enlarge]

H5N1 (your "common" bird flu) is comparatively harmless when compared against H7N9, the new strain of avian flu and numerically speaking; the number of cases of H5N1 over half a decade in China, is less than the number of reported and current infections of H7N9 in China over the last sixty days.

H7N9 Cumulative Statistics Apr 10 | World Health Organisation [Click Image to Enlarge]

It may be early days in the surveillance of this new contagion but as it stands, the numbers are stacking up against us. Additionally, it appears that this new disease is showing itself to be potentially very infectious with low survival rates and there are difficulties testing patients who may have become infected.

Why you need to worry
Statistically speaking, the world is overdue for a pandemic and the odds seem to be working in the favor of H7N9 being that next pandemic trigger. A summary sheet extracted from the Dr Uyeki and Dr Cox paper on this emerging pathogen is shown below and their original research can be found at the following [LINK].

H7N9 Summary Sheet [Click Image to Enlarge]

In effect, H7N9 has all the necessary elements in a viral pathogen to present us with a full-blown global pandemic. The virus results in high fatality rates, extremely severe symptoms in humans but none in the source reservoir, it has a tendency to adapt or mutate and is likely to be very contagious through droplet infection.

H7N9 Infectious Case Reports | Click here for full map

As one can see, the H7N9 main cluster is focused on the city of Shanghai in China with some cases of infection being particularly concerning. It is understandable that adults working with birds or poultry products are at much higher risk of infection but a two year old in transit should not be threatened. Such cases are a leading indicator that human-to-human transmission may already be occurring, as well as potential evidence for high adaptability of the virus. Error in diagnosis and reporting are of course feasible reasons, perhaps optimistic reasons for explaining these disturbing results. 

Within 60 days, clusters form

Other indicators that the infection is anchored in the human population is that the growth rate of infection persists and new cases form clusters. This is especially the case, if corridors between case load clusters start to develop. 

Some clusters may be an outcome of the virus having an extremely long incubation period or that the pathogen is still contagious from the source reservoir. However, if new clusters continue to form or if cross boarder occurrence is detected, then the disease is likely to become endemic.

Google Map Tracking H7N9
A Google map that is tracking H7N9 has been created and can be viewed below.

H7N9 Google Tracker | Click here for full map

Additional information on this pandemic threat can be found at the World Health Organisation statistics and news pages [LINK].

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