Man who had unpasteurised milk daily is only known bovine TB case in Singapore
Yap Wei Qiang
The Straits Times
Dec 29, 2025
A man who had been a dairy farmer for 28 years and had drunk unpasteurised cow's milk every day in the past was identified as Singapore's first case of human bovine tuberculosis (TB) infection by the bacterium which is most commonly found in cows.
In response to queries from The Straits Times, the Communicable Diseases Agency (CDA) confirmed that the case was reported and identified in 2021, and the 73-year-old man had completed treatment with the usual TB medications.
Transmission, prevention and treatment of TB are effectively the same, regardless of the bacteria causing it.
None of his close contacts tested positive for TB, following investigations and contact tracing. CDA did not reveal how many close contacts were tested.
The Indian man remains the only known bovine TB case in Singapore.
TB remains a global public health threat, though it is curable and the spread is preventable. In 2023, there were more than 10.8 million cases of active TB globally, with 1.25 million deaths.
In Singapore, TB is endemic. Based on statistics released by the Ministry of Health (MOH), there were 1,156 new cases of active TB disease among Singapore residents in 2024, slightly lower than the 1,201 in 2023.
Associate Professor Lim Poh Lian, group director for CDA's communicable diseases programmes, told ST that a case of pulmonary TB was reported to the National TB Programme in 2021, with the man's symptoms, chest X-ray and medical tests consistent with the ailment.
Whole genome sequencing (WGS) confirmed that he was infected by Mycobacterium bovis (M. bovis).
Tuberculosis is caused by Mycobacterium tuberculosis complex (MTC), the group of genetically related mycobacteria that can cause TB in humans or animals.
Among the various MTC species, M. bovis is most commonly found in cattle, as well as bison, elk and deer, according to information on the US Centers for Disease Control and Prevention (CDC) website.
Another MTC species is Mycobacterium tuberculosis (M. tuberculosis), which is the bacterium that causes most human TB cases.
Prof Lim said M. bovis can be transmitted by unpasteurised milk and dairy products, and it has become rare in Singapore, given that milk products are generally required to be pasteurised.
The process involves heating the milk products above a certain temperature to inactivate bacteria, including M. bovis.
A team of researchers from Tan Tock Seng Hospital, the National Public Health Laboratory (NPHL) and Singapore General Hospital presented information on this first and only bovine TB case in the Republic in their letter to the editor of the Singapore Medical Journal published in December.
The information revealed the infected man had no known exposure to other pulmonary TB cases.
Further inquiries revealed he had been a dairy farmer for 28 years until 1990, during which he drank at least one glass of raw cow's milk daily.
He presented symptoms of poor appetite and weight loss. According to the US CDC, TB caused by M. bovis or M. tuberculosis has similar symptoms, which include prolonged coughing, fever, night sweats and weight loss.
A 2013 study by researchers from the South African Stellenbosch University estimated that bovine TB accounted for an insignificant minority of human TB cases globally, with cases estimated to make up less than 1.4 per cent in regions outside Africa, and 2.8 per cent in Africa.
Since 2020, Singapore has adopted the use of WGS for a comprehensive analysis of the genetic make-up of the TB bacteria and precise identification of related cases, said MOH in a 2024 parliamentary reply.
WGS has helped to identify TB clusters in Singapore, including a Bukit Merah cluster, added MOH.
In 2024, it revealed that WGS used in 10 TB cases detected between February 2022 and July 2023 showed the bacteria in all the cases were genetically similar to those of the cluster of seven TB cases linked to Block 2 Jalan Bukit Merah in 2022.
It subsequently conducted mandatory TB screening for those who live and work in Block 1 and Block 3 Jalan Bukit Merah, employees at ABC Brickworks Market and Food Centre, as well as clients and staff of a senior activity centre at Block 3, as the 10 cases were detected in this area.
More than 97 per cent of the more than 2,500 people tested were found to be non-infectious, and at least two active TB cases were picked up by the screening.
CDA said its NPHL has analysed more than 7,000 TB positive samples since November 2020, and the identification of this bovine TB case shows that Singapore's existing systems for TB surveillance, diagnosis and treatment are robust and effective.
Prof Lim said: "Uncommon cases, such as this, demonstrate our capabilities to detect and confirm rare TB species and to manage them appropriately."
