Captive elephants of Chitwan National Park have once again started dying from tuberculosis, bringing back the memories of deaths among elephants due to TB at a worrying rate.

Three domestic elephants belonging to the national park have died so far this fiscal year. The park has confirmed TB as the reason behind the death of two elephants while the cause of the third death has yet to be ascertained. The latest casualty is also linked to TB as the elephant had been sick for a long time and was once diagnosed with TB earlier.

“The elephant had been weak and ailing for a long time. The elephant died on Sunday. We believe that it also died due to TB infection, but we are waiting for the final report,” Ashok Kumar Ram, information officer at the Chitwan National Park, told the Post over the phone.

“If this elephant is also confirmed to have died from TB, then the lung disease would have killed three elephants this fiscal year alone, which is a worrying sign.”

Chitwan National Park has nearly 60 domesticated elephants which support the park officials in day-to-day conservation activities. The three deaths have worried park officials about the danger of TB among the animals.

“TB was once a major threat to these elephants during 2006-07 when many elephants were diagnosed with TB. After medication, the disease was neutralised within years. But the return of the disease among captive elephants has once again emerged as a challenge for us,” said Ram.

TB can transmit from elephants to other elephants, as well as other human beings.

Tuberculosis in elephants is caused primarily by Mycobacterium tuberculosis—the same bacterium that is responsible for pulmonary diseases in humans. Domesticated elephants pick up the bacterium from humans who get close while taking care of these tuskers, among other activities.

Concerned with the latest infections among captive elephants, the park has begun random testing of elephants to detect the zoonotic disease. For now, the Rapid Diagnosis Test (RDT) is being conducted randomly among elephants, which look sick and old. However all the five dozen elephants can be screened if needed, according to Ram.

By 2007, TB had emerged as a major health hazard for the elephants kept by private owners, who use them for safari in Sauraha, and protected areas. Tests done among 200 elephants in 2012 showed that around 23 percent of elephants belonging to the national parks and tourism entrepreneurs had TB.

According to the Chitwan National Park statistics, 61 elephants were diagnosed with TB and they were treated. Out of the total 61 infected with TB, 16 had died. Another test done in 2016 showed that nine of the 93 animals examined had got the TB bacterium.

Over the years, with timely interventions the TB infection rate among the elephants used in protected parks and by tourism entrepreneurs had declined rapidly. But the threat seems to be returning with three elephants from the Chitwan park succumbing to TB last fiscal year and at least two deaths blamed on the disease within the first three months of the current fiscal year.

Haribhadra Acharya, spokesperson for the Department of National Parks and Wildlife Conservation, the government authority responsible for management of protected parks and wildlife, is also concerned about the deaths of elephants due to TB.

“In the latest case, the elephant had been sick and weak for a long time. However, this is worrisome,” Acharya, who is also an ecologist with the department, told the Post. “When TB posed a major threat to these domesticated elephants around 2006-07, we saw encouraging recoveries and control in spread.”

Old age, workload and insufficient diet make elephants prone to TB, Acharya said.