The avian flu scare and after

The outbreak of the H5N1 influenza has sent authorities into a tizzy even as the cause remains a mystery

Eleven days after the outbreak of the highly pathogenic avian influenza (AI) - a subtype H5N1 - was reported at the Central Poultry Development Organisation (CPDO) farm at Hesaraghatta near here, the unit has no more birds.

The authorities, under the supervision of appropriate personnel, have culled all the birds in the farm following the Centre’s Action Plan-2012 for control and containment of AI.
Thousands of birds, including chicken, duck and emu, having been culled; and the process of disposing them of and sanitising the 50-odd units that are a part of the farm having begun, the focus now is on how to contain the spread of the virus.

A prohibitory order banning the sale and marketing of poultry and poultry products in a 10-km radius of the CPDO is in place till November 15, as a precaution.

While the officials concerned and doctors are on the prevention job, the cause and the spread of the virus is still undetermined. Almost 200 samples have been sent to the high-security Animal Disease Laboratory, Bhopal, and another laboratory, but the State departments are still awaiting the reports.

A well-placed source said that even the reports might not be able to identify the cause accurately. Thereby, the way it spread will go undetermined if one depends completely on the reports. Theories are afloat about migratory birds having caused it. There is, however, no confirmation.

In an attempt to find out the source of the virus, the authorities have, besides blood samples, begun checking bird-feed, litter, feather samples and water, sources said. The focus, however, is on bird litter which spreads the virus faster.

While no fresh cases of bird deaths due to the flu have been reported in and around Hesaraghatta, or in Bangalore, caution is prescribed by almost everybody involved in detecting and solving the problem.

Most AI viruses do not infect humans. Some, including H5N1, have, however, caused serious infections in the past. Experts believe that the case fatality rate for H5N1 virus infections is much higher compared with other seasonal influenza infections.

According to the World Health Organisation (WHO), “The disease caused by the H5N1 virus follows an unusually aggressive clinical course with rapid deterioration, and has high fatality.”

The incubation period for H5N1 avian influenza may be longer than that for normal seasonal influenza, which is around two to three days. Data with the WHO shows that H5N1 infection indicates an incubation period ranging from two to eight days and possibly as long as 17 days.

Further, the authorities, who are confident of containing the virus from spreading to other birds in the vicinity and to humans, are busy with sanitation work. According to experts, the sanitisation process is expected to take at least eight to 10 days more as no prescribed procedure, given the nature of the virus, can be ignored.

“We also need to take care of disposing of the birds that have been culled and those that will be culled to prevent the disease from spreading further,” a senior official from the Department of Animal Husbandry and Veterinary Sciences (AH&VS) said.

Dead birds, including those culled, have to be buried in a four-layered pit filled with different kinds of chemicals at every layer in order to ensure containment of the disease.
Besides, the equipment in the farm have to be sanitised and there are different procedures to sanitise plastic, iron and steel equipment.

While sanitisation of the 50-odd units at the farm is a headache, authorities also have to worry about the scientific disposal of the litter, the paddy husk used in the sheds, the seeds, et al; and officials point out that this is a more difficult task than disposing of dead birds. Given the complexities, the AH&VS department has to take sufficient care of the personnel involved in such tasks.

On whether or not the personnel involved in surveillance, sanitisation, culling and disposal are protected and quarantined, Aravind Jannu, Principal Secretary AH&VS, said, “Everything is being taken care of scientifically.”

“All the staff members involved in culling and disposing of the birds have been provided with special equipment and clothing as prescribed by the Centre and all measures are being taken,” the officer said.

He said the staff are being sanitised before and after they begin the activity and that they have all been administered a specific kind of prophylactic, a drug used to prevent spread of any disease.

About 25 rapid response teams are involved in culling and disposing of 19,235 chickens, 13,673 ducks, 369 emu birds, and sanitisation of 52 poultry sheds in the CPDO farm. No unusual death of birds has been noticed in the surveillance zone or in any part of the State.