HONG KONG – Necropsies show that the bacterial infection Melioidosis was behind the abrupt death of nine monkeys in two days at a Hong Kong zoo, authorities said on Friday.

The official necropsies revealed that the monkeys died from sepsis caused by Melioidosis, a disease caused by the bacterium Burkholderia pseudomallei, which can infect both humans and animals.

Ruling out the possibility of food poisoning, Secretary for Culture, Sports and Tourism Kevin Yeung Yun-hung assured the public that there is no need to worry about the spread of the diseases as the diseases will not be transmitted via person-to-person or animal-to-human transmission.

READ MORE: HK zoo partially closed after 8 monkeys found dead

Meeting the media on Friday, Yeung said humans can become infected through contact with contaminated soil and surface waters.

Eight monkeys — including one De Brazza’s monkey, one common squirrel monkey, three cotton-top tamarins, and three white-faced sakis — were found dead on Sunday at the Hong Kong Zoological and Botanical Gardens in Central; another one died the following day. Following the incident, the mammals section of the zoo was closed from Monday for disinfection and cleaning while tests were conducted.

Among the dead animals, cotton-top tamarins are a critically endangered species, mainly found in Costa Rica and northwestern Colombia.

Yeung said the incident may stem from renovation work of the irrigation hoses under the flowers, which may dug up the contaminated soil and subsequently got attached to the shoes of the staff. One of the monkeys was found to have a high level of the bacterium and have had close contacts with other monkeys contracting the diseases, he added.

The Centre for Health Protection carried out PCR testing on 17 monkeys within the park, revealing that all samples tested positive for the Burkholderia pseudomallei, indicating the presence of the bacterium in their bodies.

The center conducted tests on food, water, and soil samples from these animals. While the initial results for the soil samples were negative, further bacterial culture examinations are planned.

In response to the affected monkeys, Yeung said the park has taken measures to isolate the infected ones from the healthy ones and thoroughly cleaned the affected areas. Future efforts will focus on intensifying disinfection measures to reduce the risk of similar incidents occurring again.

Thomas Sit Hon-chung, assistant director of the Agriculture, Fisheries and Conservation Department of Hong Kong, said that the incubation period varies, usually from two to four weeks, but can range from a day to few years.

READ MORE: CE stresses ensuring HK zoo safety as another monkey dies

Currently, there is no vaccine available for melioidosis. The public is advised to wear appropriate protective clothing or footwear when participating in activities with possible contact with soil or water.

According to the CHP website, Melioidosis can be spread by contaminated soil and water during and after typhoons and storms. The public should remain indoors during typhoons and storms to avoid contact with muddy water and soil.

Hong Kong Zoological and Botanical Gardens, the city’s oldest park, was opened to the public in 1871. The park occupies an area of 5.6 hectares and houses about 158 birds, 93 mammals and 21 reptiles in about 40 enclosures.