An 11th monkey from the Hong Kong Zoological and Botanical Gardens was found dead on Sunday whilst under quarantine, the government has said.
In a statement issued on Sunday evening, the government said a common squirrel monkey died while being placed under isolated surveillance. It followed the death of another monkey of its kind the previous day.
It is the 11th monkey that has died since last Sunday. A De Brazza’s monkey is currently being quarantined and has been given medication, according to Sunday’s statement.
Authorities will perform a necropsy on the animals to ascertain if the cause of death was the same as earlier cases. Last Friday, the government said nine monkeys were found to have died from melioidosis infections.
Earlier on Sunday, Secretary for Culture, Sports, and Tourism Kevin Yeung said the 70-odd animals kept at the zoo were in a normal condition.
“Apart from the monkeys that were isolated earlier, all the other animals in the gardens are normal… On the whole, we all think that the work done in the gardens is adequate for the time being, so we will continue to work in this direction,” he told reporters in Cantonese.
Yeung on Friday joined a group of experts from the government’s Department of Health and the Agriculture, Fisheries and Conservation Department at a press conference, where they announced the cause of death of the nine monkeys based on necropsy and toxicology analysis.
At that time, the officials did not disclose that two common squirrel monkeys were under quarantine. When asked why, Yeung said: “All along, it is normal for animals to undergo quarantine, and sometimes – when they are not feeling well – they may undergo different medical procedures.”
Staff working at the zoo were in normal health, the government said on Sunday.
‘Precious animals’
Michael Rivera, a biological anthropologist at the University of Hong Kong, told HKFP that there had been cases of fatal melioidosis infection in animals reported in different parts of the world, with recent cases including two captive orangutans in Malaysia in 2022, and one cynomolgus macaque from Cambodia being transported to the US, also in 2022.
“The occurrence of this infection is common in Southeast Asia, but both infections and deaths are more common among captive primates,” Rivera said in an emailed reply to HKFP.
“This is because captive primates may have weakened immune response[s] due to the stresses of confinement, less of their natural social stimulus, and the lack of a natural environment,” he added.
The incubation period of the disease – which is typically less than a month – and the confined environment of zoos could be contributing to the spread of the infection, Rivera said.
“It is clear an outbreak happened here given the sudden deaths of nine all within 48 hours. The different species are located very close to one another, in adjoining cages or cages that are only a stone’s throw away. Because infection usually occurs through surface water and soil, spread is more likely to occur here (especially in rainy seasons),” he said.
“I worry about the buff-cheeked gibbon, the ring-tailed lemurs, the De Brazza’s monkeys, the orangutans and many others. Each of these are precious animals.”
But the scholar also said catching the infection early and making the public informed should have allowed authorities to protect other wild and captive animals in the city.
He said the authorities should quarantine all animals and test whether the infection had spread to the remaining primates before allowing humans to enter their proximity, referring to the measures taken by the US regarding a similar infection in 2013.
The government experts had said the disease would not spread from animals to humans in normal circumstances and urged residents not to worry.
The mammals section of the garden had been closed since last Monday for disinfection.
Yeung said earlier that the infection was believed to be related to a soil digging work in the gardens in early October, which had since been completed.
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 garden’s website.
