Monday, March 12, 2012

ICEID: Another H5N1 Seroprevalence Study To Ponder

 

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# 6218


This week I hope to highlight some of the ICEID 2012 abstracts (see ICEID 2012: Abstracts & Program) of particular interest to Flublogians.

 

With the recent controversy over the seroprevalence of H5N1 virus (see Science: Peter Palese On The CFR of H5N1 & mBio: Mammalian-Transmissible H5N1 Influenza: Facts and Perspective) we’ve seen estimates ranging from there being relatively few undetected human cases of H5N1 infection to `millions’.

 

If there are mild or subclinical infections with the virus going undetected, the best way to find them is to look for antibodies in the blood of those who have had substantial exposure to poultry.

 

Which is precisely what researchers at International Centre for Diarrhoeal Disease Research Bangladesh (ICDDR,B), Bangladesh’s Institute of Epidemiology, Disease Control and Research (IEDCR), and the CDC did.

 

They performed microneutralization assays on workers from 89 poultry farms with confirmed H5N1 outbreaks and 3 live bird markets reporting high poultry mortality to detect neutralizing antibodies in sera using A/Bangladesh/207095/2008 (H5N1).

 

The following abstract can be found on page 116 of the 2012 ICEID Abstract, I’ve just excerpted the conclusion.

 

Board 183. Sero-prevalence of H5N1 Antibodies among Poultry Workers in Bangladesh, 2008–2009


S. Nasreen, S.U. Khan, E. Azziz-Baumgartner, K. Hancock, J.M. Katz, V Veguilla, D. Wang , M. Rahman, A. Alamgir, E.S. Gurley, K. Sturm-Ramirez T.M. Uyeki , S.P. Luby

Conclusions: Despite extensive poultry
exposures, no serological evidence of H5N1 virus infection was found among farm or market poultry workers during 2008-09.

However, the recent cases of human H5N1 infection detected in Bangladesh and the continued circulation of H5N1 among poultry warrants continued surveillance among a larger cohort of poultry workers to monitor the risk of avian-to-human H5N1 virus transmission.

 

 

It should be noted that since the beginning of the year, Bangladesh has detected 3 H5N1 infections among live poultry market workers through routine surveillance (see IEDCR On The Bangladesh H5N1 Cases).

 

All appear to have had mild to moderate illness, and have recovered.

 

With multiple clades of the H5N1 virus in circulation around the world - and constantly mutating - what may have been true in 2009 may not hold true today. 


So ongoing seroprevalence studies in Bangladesh, and other regions where the virus is endemic, are sorely needed.