Avian influenza outbreak

Why in news?

After India declared itself free from avian influenza 3 months earlier, new cases of avian influenza subtypes have been reported now.

Where are the cases reported?

• Four States — Rajasthan, Madhya Pradesh, Himachal Pradesh and Kerala -are the epicentres in this outbreak.
• In Haryana, Jharkhand & Gujarat, thousands of poultry birds have died but the cause of death is still unknown.
• The two subtypes (H5N1 & H5N8) have targeted different birds — crows in Rajasthan & Madhya Pradesh, migratory birds in Himachal Pradesh and poultry in Kerala.
• H5N1 has caused deaths of over 2,000 migratory birds in Himachal Pradesh.
• H5N8 led to the death of thousands of poultry in Kerala, hundreds of crows in Rajasthan and Madhya Pradesh.

How did the virus transmit?

• Migratory birds have been largely responsible for long-distance transmission of the virus into India.

• It also spreads through local movement of residential birds and poultry.
•  Movement of men and material from poultry farms too has been a cause for further spread.

What are the measures undertaken to control the outbreak?

• On Wednesday over 69,000 birds, including ducks and chickens, were culled in Alappuzha & Kottayam as per India’s 2015 National Avian Influenza Plan.
• Other States have been asked to be vigilant of any unusual deaths or disease outbreak signs amongst birds, particularly migratory ones.
• States have been asked to strengthen bio security of poultry farms, disinfection and proper disposal of dead birds.

How was the global outbreak?

• As per European Food Safety Authority 561 avian influenza were reported in 15 European countries and the U.K between August-December.
• H5N1 and H5N8 were two of three subtypes found in Europe & it was predominantly found in wild birds, and a few in poultry and captive birds.
• Genetic analysis confirmed that spread from Asia to west-central Europe likely to cause persistent circulation of this virus strain in wild birds in Asia.

Does it transmit to humans?

• Though avian influenza virus cross the species barrier and occasionally infecting humans, but human-to-human spread is reported rarely.
• Mutations of an avian influenza A virus and a human influenza A virus in a person can create a new influenza A virus.
• This can result in sustained transmission between humans thus increasing the risk of a pandemic influenza.
• Hence efforts should be taken to control the outbreaks & genome sequencing of virus samples helps in tracking the evolution of the virus.

Source: The Hindu