It is not long since India was declared free of highly pathogenic avian influenza (HPAI) after the last outbreak in north-east India (Imphal area of Manipur state) in July 2007. The Government subsequently formulated a comprehensive action plan for H5N1, which is now being used sooner than envisaged.
Numerous reports in the first two weeks of January 2008 said up to 35,000 backyard birds had died in and around Margram village of Birbhum district in the state of West Bengal (250km from Calcutta). Further significant mortality was reported at south Dinajpur, 350km from Calcutta. Birbhum district is close to Bangladesh and south Dinajpur has a common border with Bangladesh.
In fact, the town of Dinajpur was partitioned between India and East Pakistan (now Bangladesh) in 1947. Dinajpur district in Bangladesh features prominently in the pandemic now affecting that country. It first erupted in June 2007 with further outbreaks in November and in the last week of December, just days before the outbreak on the other side of the border in South Dinajpur in India.
Preliminary tests on samples from Margram village and South Dinajpur in India showed infection with the HPAI virus. “The preliminary tests showed the birds died from bird flu, but we still don't know whether it is the deadly H5N1 strain,” Sunil Kumar Bhowmik, chief medical officer of Birbhum told Reuters on 13 January. “We will quarantine people if we find anybody sick and intensify culling tomorrow morning (14 January) until we get confirmation in a few days.”
Indian authorities were hopeful that H5N1 was not involved but mindful of the endemic status of the virus in neighbouring Bangladesh where at least 73 farms in 23 out of 64 districts have recorded the disease. Samples were sent to the High Security Animal Disease Laboratory in Bhopal for testing. On 14 January, director of the Bhopal laboratory S.C. Dubey, said, “There is no need to panic. We have received samples from Margram and Dinajpur. Our scientists are conducting tests and it will take six days to arrive at any conclusion.” He denied reports that either he or his lab had indicated existence of the deadly H5N1 virus in the samples, adding “We work according to WHO guidelines and, therefore, are in no position to confirm anything till the entire process has been completed.”
There was a period of equivocation and confusion with different officials saying different things and it looked like July 2007 all over again when the authorities took several weeks to confirm the H5N1 outbreak in Manipur. Clearly mindful of the seriousness of this new outbreak and the confusion being caused, the Indian government confirmed H5N1 in West Bengal within hours. “The strain is deadly enough to kill the birds," Federal Health Secretary Naresh Dayal told Reuters. “Our teams are already there. Now people will be monitored for flu-like symptoms.” From West Bengal itself, minister of animal husbandry Anisur Rahman said, “It [H5N1] has been confirmed and we have instructed district health officials to start culling.”
And cull they did. Reports the following day suggest that 350,000 birds were to be slaughtered around the Margram and a further 50,000 at South Dinajpur. Over 300 veterinary workers plus volunteers started to cull birds, according to a report from Reuters (India).
These new outbreaks in India are almost certainly linked to the ongoing poultry pandemic in Bangladesh where H5N1 has is now endemic less than a year since first outbreak in February 2007. New outbreaks continued to be reported in Bangladesh as the West Bengal outbreak in India was revealed. First was an outbreak in Maulvibazar district in Sylhet division. This was reported by Reuters on same day as first reports from West Bengal were released.
As culling got underway in India, a flood of outbreaks in Bangladesh hit the headlines with poultry dying and culled at Barguna, a southern coastal district of Barisal division, Jessore district of Khulna division also in the south and Rangpur and Rajshahi districts (Rajshahi division) in north-west Bangladesh. There are 150,000 poultry farms in Bangladesh with an annual turnover of US$750 million. H5N1 has already caused loss of 300,000 chickens (from disease or slaughter) in Bangladesh.
H5N1 had been concentrated in northern Bangladesh districts mostly on the western side close to and sometimes actually bordering India’s West Bengal state. Maulvibazar district (Sylhet Division) is in north-eastern Bangladesh and borders the Indian states of Assam and Tripura, to the east and south, respectively. Outbreak in Barisal was a first for this south coastal region of Bangladesh.North-eastern India is hemmed in by Bangladesh, Burma and China where H5N1 appears entrenched if not endemic. International borders are remote and often rugged, with poultry smuggling an everyday occurrence. India is particularly sensitive to AI outbreaks in this area because central authorities have much less control than over most other parts of the country. Endemic H5N1 in Bangladesh – with its long and difficult border with India – has led some officials to suggest that West Bengal may already be riddled with H5N1.