Commentary
H5N1
Spread to Tripura and Mizoram India?
Recombinomics Commentary
03:54
December 10, 2008
The above comments suggest H5N1 may have spread to Tripura and Mizoram (see updated map). However, there has been a large number of reports on confirmed H5N1 cases in Assam, and most media reports describe alerts by Tripura and Mizoram. These alerts are said to be based on concerns that H5N1 will be smuggled across the border from Bangladesh, which was blamed for the confirmed H5N1 in Tripura last season. This season only one confirmed H5N1 case has been reported in Bangladesh (see map), but media reports have described rumored outbreaks in northern Bangladesh as well as West Bengal.
Determining where H5N1 is in India and Bangladesh is problematic. Last season India reported confirmed H5N1 in West Bengal on January 15. However, villagers indicated poultry had been dying since December, and villagers had been eating the dead poultry. Moreover videos of the early outbreaks showed piles of dead crows, yet India never confirmed H5N1 in any host other than domestic poultry.
Culling was ordered after H5N1 was confirmed, but testing was limited and delays in confirmatory results led to culling in regions where there were excessive poultry deaths. Moreover, the rapid spread of H5N1 led to culling in regions adjacent to West Bengal. OIE reports were limited to outbreaks in West Bengal, which were then followed by the Tripura outbreak. No confirmation of H5N1 in excessive poultry deaths in regions outside of West Bengal or Tripura was reported.
The rapid spread of H5N1 was blamed on smuggling of birds from Bangladesh, even though borders were ordered closed. Rumors on under-reporting of H5N1 in Bangladesh were widespread, but confirmations of H5N1 in Bangladesh increased and 287 outbreaks in 2007 and 2008 were detailed in OIE reports. In contrast, India reported 40 outbreaks in 2008, prior to the current outbreak in Assam, and all prior 2008 outbreaks were in West Bengal or Tripura.
However, the outbreaks were widespread (see map here here here), and limitation to the borders of West Bengal and Tripura is doubtful. Although the outbreak began later last season, the spread was rapid and was facilitated by wild birds, as evidenced by the H5N1 confirmed crows in Bangladesh, and frequent reports or wild resident and migratory birds in close approximation to H5N1 confirmed poultry.
Thus, although all confirmed H5N1 outbreaks remain in Assam, reports of unnatural poultry deaths in Tripura, Mizorum, West Bengal, and Bangladesh are not unexpected.
Additional spreads of H5N1 in the region is expected.
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