Arignar Anna Zoological Park in Vandalur near Chennai will not be allowing visitors on October 22 and 23 as a precautionary measure following confirmation of H5N1 avian influenza infection in water birds by the National Institute of High Security Animal Diseases (NIHSAD), Bhopal, on October 2, 2026.

According to Forest Department officials, seven water birds in the zoo had died between October 3 and 7. Of them four were painted storks, one grey pelican, one grey heron and one oriental darter. As soon as the first bird died on October 3, the zoo officials cordoned off the area.

Immediate preventive measures, including disinfection, sanitisation, and strict implementation of biosecurity protocols, were undertaken in accordance with the Government of India’s guidelines, officials said. However, the zoo remained open as no further bird mortality or sickness has been reported since October 9.

Now that the confirmation has come, the zoo management has to follow the protocols laid out by the Centre and so the zoo would remain closed on Thursday and Friday, officials said.

This temporary measure is intended to facilitate intensive sanitisation, strengthen biosecurity measures, and ensure close monitoring of the situation. The public are requested to cooperate with the precautionary measures, a press release from the zoo said.

According to the protocol, as soon H7 avian influenza is confirmed, visitors’ entry needs to be stopped forthwith.

The movement of the vets and labourers should be restricted and in no case they should move from infected pens to healthy pens. The management of the healthy sheds should be done by a separate team. Maximum possible number of birds is to be sampled, while sampling a water body, birds arriving at different locations be taken into consideration, it should be ensured that different species are proportionately represented.

In addition to sampling of birds, environment samples like water, soil are to be collected and sent for testing, the guidelines state. The control actions to be initiated are same as for domestic poultry. However, endangered and precious captive birds confirmed as non-infected could be exempted from culling, say officials.

Sampling has to be repeated every 15 days for at least four times and if consecutive two samplings from the last positive result are found negative then the opening of the zoo for public could be considered by the competent authority, according to the action plan for prevention, control and containment of avian influenza.