DH Deciphers | Should we fear the latest outbreak of bird flu?

The latest outbreak of bird flu has heightened fears at a time when the threat of the Covid-19 pandemic remains high due to the discovery of a new variant of novel coronavirus. Ten states have reported the deaths of poultry birds, crashing the prices of chicken and eggs during the peak winter season. But what exactly is bird flu and how does it spread? And should you worry about consuming chicken and eggs? Let's find out:

What is bird flu? When was the first outbreak reported?

Bird flu or avian influenza is a highly contagious viral disease that affects both domesticated and wild birds. It refers to infections caused by the Type A virus in the intestines and respiratory tracts of wild aquatic birds, which usually do not get sick. Avian influenza A viruses are, however, very contagious among birds and some of them can even kill domesticated bird species such as chickens, ducks and turkeys.

The first outbreak of the virus was reported in China in 1996. In India, the first cases were reported in Nandurbar, Maharashtra, in 2006.

How does the disease spread?

The infections spread through bird faeces, the primary source of getting the disease. The virus can spread through direct contact with bird excreta from infected birds, especially through faeces or contaminated feed and water. The bird flu viruses are resistant in nature, can survive for long periods when temperatures are low and spread easily from farm to farm. They can also be carried on farm equipment.

Also read — Bird flu: Centre asks states to maintain sufficient stock of PPE kits

Wild birds can normally carry bird flu viruses in their respiratory or intestinal tracts but they do not commonly get sick. This allows them to carry the viruses on long distances along their migration flyways.

Is bird flu caused by a single virus or are there different strains?

There are many bird flu virus strains, which are usually classified into two categories according to the severity of the disease in poultry: low pathogenic (LPAI) strains, which typically cause few or no clinical signs in poultry, and highly pathogenic (HPAI) strains, which can cause severe clinical signs and potentially high mortality rates in poultry. Differentiation between low and high pathogenicity is based on the results of laboratory tests.

Does the disease spread from birds to humans?

People in close contact with infected birds risk acquiring avian influenza. While many human cases are limited to conjunctivitis or the mild respiratory disease, some viruses tend to cause severe illnesses.

Can eating chicken and eggs cause bird flu?

There is no evidence to suggest that the consumption of poultry or eggs could transmit the bird flu virus to humans. But scientists recommend cooking the poultry at temperatures upwards of 70 degrees Celsius.

Also read — Explained: How Bird Flu spreads

As a precautionary and regulatory measure, birds are culled (slaughtered en masse) to prevent the bird flu outbreak from entering the human food and the animal feed chain.

What is the status of the current outbreak?

The current outbreak in India was reported this month and has spread to Kerala, Rajasthan, Madhya Pradesh, Himachal Pradesh, Haryana, Maharashtra, Delhi, Uttarakhand, Gujarat and Uttar Pradesh.

The Department of Animal Husbandry and Dairying has issued a testing advisory to states, encouraging them to undertake screening and ensure suitable biosecure facilities.

What are the measures to prevent an outbreak?

If the infection is detected in animals, a policy of culling the infected and contact animals is normally used in an effort to rapidly contain, control and eradicate the disease. When outbreaks are detected, culling is generally carried out at the infected farm or within a short radius of the infected premises in conjunction with active surveillance.