Commentary
H5N1
Culling Accelerates In Bangladesh
Recombinomics Commentary
13:36
December 24, 2008
The above headline on H5N1 in Bangladesh is somewhat misleading. In the past month there have been multiple outbreaks in Bangladesh, which signals a significant H5N1 expansion in the upcoming weeks and raises questions about the recent lack of confirmations in Assam and West Bengal in neighboring India (see updated map).
The spread of H5N1 in Bangladesh has been well documented in updates from the Ministry of Fisheries and Livestock, as well as situation updates from WHO, and OIE reports.
After the outbreak in Naogaon in October, which was detailed in an OIE report, the South-East Asia Regional Office of WHO issued a December 8 situation update describing the Naogaon outbreak as well as unnatural poultry deaths in Rangpur, which was influenza A confirmed but not yet sero-typed. However, MOFL issued a December 3 update which indicated culling had taken place at two farms in Rangpur, indirectly confirming H5N1(255 birds culled and confirmed in OIE report).
That was followed by December 13 update with three outbreaks north of Dhaka (3540 birds culled), followed by a December 16 outbreak that was also north of Dhaka (4440 birds culled). WHO SEARO then issued a December 20 update describing these outbreaks (Rangpur, Narsingdi, Gazipur, Natore).
MOFL then issued a December 20 update with the Natore culling ( (665 birds , which was followed by a December 23 update which included culling (945 birds) in Gaibandha and Kurigram.
The three most recent outbreaks are near the confirmed outbreaks in Malda in West Bengal, as well as western Assam outbreaks. However, as the reporting in Bengladesh accelerates, India is claiming that the poultry deaths in adjacent areas are due to Newcastle Disease instead of H5N1. Over 30,000 birds were culled in Malda (Englishbazar and Old Malda blocks) and hundreds of crows died, but excessive poultry deaths 5-10 miles away in other Malda blocks (Ratua I, Gajole, Manikchak) were said to be due to Newcastle Disease. Sera were collected for routine testing, but sera are rarely positive for high path H5N1 because birds die before antibody levels rise to the detectable level. Similar results were reported in adjacent districts in West Bengal, raising serious questions about testing and reporting H5N1 in India.
Thus, confirmed H5N1 in Bangladesh is on the rise, as expected as the temperature drops and more birds migrate south, yet India is claiming that the bird deaths in Assam and West Bengal are not due to H5N1. Almost exactly one year ago birds began dying in Birbhum, but H5N1 was not confirmed until mid-January, when over 100 villages in Birbhum were H5N1 infected (see 2008 map) and H5N1 in West Bengal and Bangladesh rose to record levels.
The latest news from India suggests a significant increase in H5N1 outbreaks in the near term.
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