Avian influenza in Delhi Zoo: Surveillance, bio-security measures ramped up

Surveillance and bio-security measures have been intensified at the National Zoological Park after avian influenza infection led to the death of 12 birds, an official said on Monday (September 1, 2025).

Surveillance teams are surveying the premises twice a day, and others are cleaning and disinfecting enclosures, water ponds, and foraging grounds of migratory birds.

The health and behaviour of animals are being monitored by keepers and through CCTV cameras. Staff have been provided with gloves, masks, protective suits, and shoe covers, the official said.

Three painted storks and one black-necked ibis have been segregated for treatment and are under observation.

Delhi zoo closed due to bird flu in New Delhi on August 30, 2025.
| Photo Credit:
Shashi Shekhar Kashyap

Till Sunday, six painted storks and two black-necked ibises had died in the water bird aviary, while four migratory painted storks had died in ponds.

Samples from two painted storks and two ibises tested positive for H5N1, officials said.

According to a zoo statement, the two black-necked ibises died last Thursday and their samples were sent to the National Institute for High Security Animal Diseases (NIHSAD), Bhopal.

The reports confirmed that they were positive for the H5N1 avian influenza virus.

After the painted storks also tested positive for bird flu on Friday, the zoo authorities closed the premises temporarily to the public.

Prevention measures taken by Delhi Zoo

A statement released by zoo director Sanjeet Kumar on Friday said a plan had been rolled out to prevent the flu’s spread to other animals and birds, and to safeguard staff at the zoo. The initiative had been taken in accordance with the “Guidelines for Zoological Parks of the Action Plan for Preparedness, Control and Containment of Avian Influenza (revised 2021)” issued by the Ministry of Fisheries, Animal Husbandry and Dairying, he said.

“All necessary precautionary measures are being taken, with close observation of all birds and animals. A close watch is being kept on mammals, especially big cats like lions and tigers, who are vulnerable during such outbreaks.

“As per protocol, we will be keeping a close watch on the situation and conducting regular random testing of birds for the next 21 days, provided there are no deaths in between. Once the deaths stop, tests are conducted every 15 days for at least three rounds to confirm that the zoo is completely virus-free. If there are deaths in between, the timeline will reset accordingly, and further action will be taken depending on the situation,” the official said.

Meanwhile, the zoo remains closed to visitors until further notice.