First case of human-to-animal drug-resistant TB transmission suspected in Karachi’s elephants

Two female elephants at Karachi’s Safari Park, Malaika and Madhubala, have been diagnosed with drug-resistant tuberculosis (TB), which infectious disease experts believe they contracted from their caregivers at the Karachi Zoo.

This could be the first documented case of human-to-animal transmission of drug-resistant TB in Pakistan, raising serious concerns about zoonotic diseases and the health risks posed to both animals and humans.

“There is a strong suspicion that all four elephants, including the two that died earlier, contracted drug-resistant TB from their caregivers at Karachi Zoo. Malaika and Madhubala have also been infected, and they now require at least one year of treatment to recover,” said Dr Naseem Salahuddin, head of infectious diseases at Indus Hospital, while speaking to The News on Tuesday.

Multiple tests confirmed that both elephants are infected with Mycobacterium tuberculosis complex (MTBC), a bacterial strain responsible for TB in humans and animals. According to Dr Naseem Salahuddin, MTBC is one of the leading causes of mortality worldwide, affecting both humans and wildlife. Current research suggests that the bacteria can persist in the environment, indirectly infecting both species and leading to severe health complications.

A panel of infectious disease specialists tested the caregivers of the elephants but did not find any active TB cases among them. However, they strongly recommended screening the entire staff of the Karachi Zoo to identify any asymptomatic carriers who might have transmitted the bacteria to the animals.

“Normally, cattle are infected with Mycobacterium bovis, which causes bovine TB, but in the case of Karachi’s elephants, we have found drug-resistant TB that appears to have jumped from humans to animals. We know that this type of TB has already caused the deaths of the previous two elephants,” Dr Salahuddin explained.

Following the confirmation of TB among the elephants, the Karachi Metropolitan Corporation (KMC) sought assistance from senior infectious disease specialists from Indus Hospital, Aga Khan University Hospital, and other institutions to devise a treatment plan for the infected animals.

The experts, who had no prior experience treating TB in elephants, reached out to the World Health Organization (WHO) in Islamabad, which connected them with Dr. Rajapaksalage Chandana Rajapaksha, Director General of the Department of National Zoological Gardens in Sri Lanka, who has extensive experience in treating elephants with TB.

“We have prepared a prescription for the treatment of Malaika and Madhubala and sent it to Dr Rajapaksha in Sri Lanka for review. Once he approves it, we will begin making arrangements for the drugs and the logistics of administering them to the sick elephants,” Dr Salahuddin said.

She noted that each elephant would require a daily dose of at least 300 tablets of anti-TB medication, along with additional treatments such as anti-parasitic drugs, antibiotics, and improved nutrition. The course of treatment is expected to last at least one year, making it a challenging and resource-intensive process.

“Treating these elephants will be an uphill battle because we have never handled a case like this before, and no one in Pakistan has experience treating TB in elephants. We are consulting with Sri Lankan experts daily and trying to develop a strategy, but it remains unclear how the authorities will arrange the medications and other necessary resources for the treatment,” she added.

Officials at the National Institute of Health (NIH) in Islamabad acknowledged that humans can transmit TB to animals, but they currently have no documented evidence of zoo animals or cattle in Pakistan being infected with Mycobacterium tuberculosis complex.

However, the situation has highlighted the urgent need for a One Health approach, which addresses the interconnected health risks between humans, animals, and the environment. “The federal Ministry of Health has recently launched a project titled One Health Workforce Development Project to train a skilled workforce to combat zoonotic diseases, antimicrobial resistance (AMR), and climate-related health risks. Zoonotic diseases, which can spread between animals and humans, pose a real and growing threat that requires a multi-sectoral response,” an NIH official said.

The case of Karachi’s elephants has not only raised alarms about animal health but also underscored the risks of cross-species transmission of drug-resistant infections, emphasizing the need for better infection control measures, improved zoo management, and enhanced veterinary healthcare for captive animals in Pakistan.