Tuesday, April 10, 2012

Global H5N1 Blind Spots

 

 

 

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Hong Kong Wild Bird H5N1 Detections 1/1/12 – 4/4/12 – Source Govt. of Hong Kong

 

# 6270

Today the Government of Hong Kong has announced positive lab results from another wild bird discovered to have died from the H5N1 virus. This makes the 19th such case thus far in 2012 (see map for locations).

 

First the latest press release, and then I’ll return with more.

Bird carcass H5N1 positive

April 10, 2012

The carcass of an Oriental magpie robin found near 19 Station Lane in Hung Hom on April 4 was confirmed to be H5N1-positive, the Agriculture, Fisheries & Conservation Department said today.
The Oriental magpie robin is a common resident bird in Hong Kong.

 

The department will continue to conduct inspections of poultry farms to ensure that proper precautions against avian influenza have been implemented.

In the past the Hong Kong government has attributed poultry outbreaks in the region to introduction of the virus from wild and migratory birds (see Wild Birds Eyed As Likely Source Of Hong Kong Bird Flu Outbreak).

 

Each year Hong Kong generally sees a couple of dozen dead birds test positive for the H5N1, so today’s report is neither unusual nor particularly alarming.

 

Hong Kong is, admittedly, one of the few places in the world where public health authorities take notice of (and test) something as seemingly inconsequential as a single dead bird.

 

Hong Kong’s surveillance, reporting, and ability to respond to an outbreak of disease is as good as it gets.  Which is why I am more comforted by these reports than alarmed.

 

As good as Hong Kong’s surveillance is, it serves as a reminder that neighboring China - with a land area 8,700 times larger than the SAR of Hong Kong - rarely reports the discovery of H5N1 in either wild birds or in poultry.

 

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Hong Kong in relation to China - Credit Wikipedia

 

We do hear unofficial, usually anecdotal reports of large poultry outbreaks or wild bird die off from the dissident press. But official confirmation rarely comes.

 

Given that most of the migratory birds that arrive in Hong Kong either originated from, or recently passed through mainland China, it is a reasonable assumption that the virus can be found among the bird population there as well.

 

But if anyone is actually testing for the virus in China, the results are not generally made available for public consumption.

 

And this is illustrative of one of the great concerns surrounding the H5N1 virus. Many of the countries where the virus is most active are either unable, or unwilling, to provide surveillance or reporting.

 

While we get good reporting out of Hong Kong, Korea, Japan, and Vietnam (among others) we can do little more than guess at how the virus is behaving in places like China, Myanmar, Cambodia, Iran, Laos, and parts of Africa.

 

Today’s H5N1 surveillance system is analogous to the the state of hurricane forecasting 50 years ago, before we had weather satellites providing us with 24 hour global coverage.


Meteorologists were dependent on scattered ship’s reports, and reports from islands, to try to piece together what was going on far out to sea. And back then, it wasn’t unusual for  hurricanes to get `lost’, only to turn up a day or two later threatening a populated coastline with very little warning.

 

Compared to 2006-2007, the amount of bird flu activity around the world appears to have declined, and that has led many to believe that the pandemic threat has somehow lessened.

 

But given the number of `blind spots’ we have around the world, we are dealing with huge gaps in our knowledge of what is actually going on.

 

And when you are dealing with a constantly mutating, highly pathogenic virus that is endemic in countries with inadequate surveillance and reporting, one must remember that no news isn’t always good news.