9 monkeys kept at Hong Kong zoo died from melioidosis bacterial infection
Hong Kong Free Press
The nine monkeys which died at the Hong Kong Zoological and Botanical Gardens have been found to have contracted melioidosis, the government has said. The disease can infect both humans and animals, though the incident is believed to be an isolated infection within the zoo.
Secretary for Culture, Sports, and Tourism Kevin Yeung said on Friday evening that the monkeys tested positive for melioidosis following necropsies and toxicological diagnosis.
“Under normal circumstance, a melioidosis infection is [contracted] through contact with contaminated soil and surface water, but not person-to-person or animal-to-person [contact],” Yeung said in a press conference.
Yeung said experts suspected the infection was due to soil digging work in the garden in early October, where staff caring for the monkeys may have accidentally brought contaminated soil to the primate cages on their shoes.
The disease could also have been transmitted among the monkeys, he said.
Yeung added that the incubation period for melioidosis infection was approximately a week, which matched the period between the monkeys’ death and the soil digging work.
Authorities revealed that eight monkeys, including three critically endangered cotton-top tamarins, died on Sunday. Another white-faced saki died on Monday while a De Brazza’s monkey was put in isolation for displaying abnormal appetite and behaviours.
Common in Asia
Thomas Sit, the assistant director on inspection and quarantine at the Agriculture, Fisheries and Conservation Department, said possible viral infections, such as the Influenza A virus, Mpox, and Covid-19, tested as negative. Government laboratorians also could not find pesticide or rat poison on the monkeys.
But the necropsy of a dead white-faced saki found high levels of Burkholderia pseudomallei, the bacteria that causes melioidosis, Sit said, adding that necropsies of the eight other animals showed the same infection.
Authorities concluded that the monkeys died from sepsis induced from the infection, he said.
Sit added that the bacteria is common in Asia and the Pacific, where it normally lives in soil and water.
Animals living in zoos in other countries had suffered cases and there were also individual cases in Hong Kong before, Sit said.
‘Isolated’ incident
Edwin Tsui, the controller of the Centre for Health Protection of the Department of Health, said 17 samples collected from the monkeys tested positive for melioidosis.
10 food samples and nine water samples tested negative, while 25 soil samples collected in the cage were also negative, Tsui said. But the Department of Health was performing inoculation testing and it will take a few days before results come back, he added.
Tsui also said staff at the gardens were in good health.
“This event is an isolated infection that happened in an individual zoo. We believe it will have a small impact on residents and people should not be overly worried,” he said in Cantonese.
Tsui added that doctors in the city were required by law to notify the authorities of any melioidosis infections.
The Department of Health recorded 19 cases of human melioidosis infections this year, compared with 17 cases last year, Tsui said, adding that the figures did not show an upward trend.
But he warned that melioidosis is endemic to Hong Kong and residents should wear protective gear when they are in contact with soil and contaminated water.
When asked about the conditions of the De Brazza’s monkey under monitoring, Yeung said it was stable but was still separated from other animals.
He said that the gardens had closed off the mammals section and conducted thorough disinfection of animal cages.
The monkeys found dead on Sunday included three cotton-top tamarins, a De Brazza’s monkey, a common squirrel monkey, and three white-faced sakis.
Cotton-top tamarins, found only in northwestern Colombia, are critically endangered according to the International Union for Conservation of Nature’s Red List. De Brazza’s monkeys, common squirrel monkeys, and white-faced sakis are considered of least concern.
The Hong Kong Zoological and Botanical Gardens are home to about 158 birds, 93 mammals and 21 reptiles, living in about 40 enclosures, according to the website.
Support HKFP | Policies & Ethics | Error/typo? | Contact Us | Newsletter | Transparency & Annual Report | Apps
Help safeguard press freedom & keep HKFP free for all readers by supporting our team
HKFP has an impartial stance, transparent funding, and balanced coverage guided by an Ethics Code and Corrections Policy.
Support press freedom & help us surpass 1,000 monthly Patrons: 100% independent, governed by an ethics code & not-for-profit.