Testing Limits Confirmed H5N1 in West Bengal
Recombinomics Commentary 01:11
January 22, 2008
The HSADL, Bhopal has confirmed a positive result for Avian Influenza (H5) in respect of samples from Chachal-I block of Malda district, Nakashipara block of Nadia district and Mejia block of Bankura district of West Bengal on the basis of rapid tests.
A total of 22 samples have been sent to the HSADL, Bhopal from North 24 Parganas,
South 24 Parganas, Hooghly, Nadia, West Midnapur and Birbhum districts on 20.01.2008.
The above official numbers for yesterday demonstrate that the spread of confirmed H5N1 poultry outbreaks in West Bengal is limited by sample collection and testing.
The reported 107,881 poultry deaths represents an increase of 9627 over the prior day. However, of the almost 10,000 bird deaths, 22 samples were sent to Bhopal for testing. Consequently, only 7 of the 18 districts in West Bengal have confirmed positives, while virtually all have reported excess poultry deaths. The lag in testing leads to lags in culling, while H5N1 continues to extend its reach at an alarming rate.
If adequate testing was being done, H5N1 would be found in virtually all districts and in multiple blocks per district, as seen in the satellite map of confirmed and suspect outbreaks.
The explosion of cases is now just beginning to show suspect cases. Five cullers are in isolation and on Tamiflu, as samples are being tested for H5N1. Similarly one fatal case is highly suspect, based on circumstances and proximity to positive poultry and the five suspect cullers.
The failure to find addition suspect cases among villagers who ate H5N1 infected birds or had exposures through collection of playing with infected birds, raises additional questions about the testing in general. Interviews with parents of children exposed to H5N1 suggest that those with fever are not being tested or hospitalized. The government appears to have a watchful waiting program fro such cases. Tamiflu is largely limited to cullers and health care workers, although this approach does not appear to have been successful for the five suspect cullers.
Clearly the spread of confirmed cases of H5N1 in birds and patients is limited by testing, which should be dramatically increased.
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