Veterinary workers are hard at work in India and Bangladesh to collect and slaughter hundreds of thousands of animals, mostly chickens, in an effort to keep the recent outbreak from spreading, officials said this week.

Health authorities in Bangladesh and India have one reason for optimism: no human cases have been reported over the terrible past week which saw a reemergence of bird flu.

The Associated Press reports that the disease is creating havoc among the two countries’ poultry, with nearly 56,000 birds dead in eastern India, and another 400,000 animals, mostly chickens, awaiting slaughter, and 20 birds dead in Bangladesh, with an additional 1,700 slaughtered as a precautionary measure.

The outbreak in Bangladesh is the H5N1 strain of the disease, according to the AP. The outbreak has spread to several locations in India and authorities say they are still conducting tests to determine the strain of flu that killed animals. The World Health Organization has called this the worst bird flu outbreak in India.

Reuters reports that the latest outbreak in India’s West Bengal has affected three districts, but it could be spreading. The state’s animal husbandry minister, Anisur Rahman, told the Associated Press that the suspected bird flu could actually be Newcastle disease, known locally as Ranikhet, a fatal respiratory disease that does not affect humans. He added that samples will nevertheless be tested for bird flu.

Veterinary workers are having some troubles as they strive to collect birds in West Bengal because locals believing their poultry is not infected are letting their ducks and chickens free, according to Reuters.

Health workers are going door-to-door, looking for people with high fevers or breathing trouble, officials were quoted by the AP as saying.

Western India had an H5N1 virus outbreak in 2006 but hundreds of thousands of chickens were sacrificed at the time and the country declared itself free of the bird flu. No human cases were reported at the time.

There was another smaller outbreak in northeastern India last year but it was contained.

Since February 2007, when bird flu was first detected in Bangladesh, hundreds of thousands of chickens have been killed on dozens of farms across the country.

New deaths are being reported around the clock, reigniting fears of bird fu mutating into a form that spreads easily among humans. Such a situation could lead to a pandemic and experts have been working to create a vaccine that would be effective.

The vaccine does not exist yet and most of the human deaths which have occurred over the past 5 years around the world have been linked to contact with infected birds. More than 200 people have died since 2003.