A team from the Centre for Wildlife Studies at the State Institute for Animal Diseases (SIAD), Palode, that visited the Thiruvananthapuram zoo on Saturday to look into the deaths of 37 blackbucks and 14 spotted deer from tuberculosis over the past 10 months is likely to suggest more strategies, including biosecurity measures, to control the spread of zoonotic disease though it does not think the situation is alarming.
Tuberculosis caused by mycobacterium bovis had been detected in all samples and deer carcasses sent to the SIAD for necropsy, and confirmed by laboratory procedures. Samples were also sent to the Microbiology department of the College of Veterinary and Animal Sciences, Mannuthy, Thrissur, for further confirmation.
The SIAD team that visited the zoo spent considerable time taking a look at the animal enclosures, particularly those of the spotted deer, blackbucks, and the sambar deer.
Though some measures have been put in place by the zoo authorities, biosecurity measures will be recommended so that the pathogen does not spread to the remaining spotted deer and blackbucks or from one enclosure to another.
The level of exposure within the zoo is low, but the disease can spread to human beings. Though the animal handlers are adopting precautions, awareness classes will be held for them. The zoo authorities should also be on the lookout for ailing animals if any. Culling will be the last resort to control the disease spread, the team said.
Minister for Zoos and Animal Husbandry J. Chinchurani, in a statement, said the spread of tuberculosis among the deer was being viewed seriously. As the safety of animal handlers and visitors is top priority, the SIAD team had been directed to conduct investigations and submit recommendations. Their report would be available within a few of days, and action taken on its basis in a time-bound manner.
Last year, the SIAD had sent a letter to the zoo director pointing out that tuberculosis was a chronic disease that could spread to other animals. As humans too were at risk, there was need to adopt steps to control the disease. However, it is alleged that not enough was done by the zoo authorities.
Employees claim that they did not come to know about the confirmation of tuberculosis till recently. High number of deer deaths continued to be reported even in December. The zoo had not reported any tuberculosis infection in recent memory till now, they say.
Zoo director S. Abu, however, said tuberculosis was not rare in zoos. He claimed that rain, cold and stress had increased the death rate of deer here. There was no treatment for it, but the zoo had taken steps to increase animal immunity.
All animal keepers were provided with gloves and masks as precautions. Carcasses were incinerated to prevent infection. The waste from the enclosures was deviated into a separate drain so that it did not flow into other enclosures. Disinfection was being conducted regularly, he said.