With the latest detection of a fourth case of tuberculosis (TB) at national train operator SMRT, a reliable source with inside information on train operations raised concerns about whether this might turn out to be a broader health issue, and if SMRT has been doing due diligence in conducting checks on its train drivers.
He related to TISG that “more than 300 train drivers from the three crew rooms (in Tanah Merah, Ang Mo Kio and Jurong) are sharing the same driving cabs in the trains”, which means that the risk of cross infection of TB among train officers is high.
He also pointed out that “the air conditioning in the train is shared by other saloon cars”, which means that should a train driver be infected, it also carries the risk of infection to train commuters.
The reliable source tells TISG that staff screening will only start this week at Ang Mo Kio and Jurong crew rooms.
However, all four published cases were from Tanah Merah.
He also said that the annual medical check-up for train drivers has been discontinued, for reasons he did not share, which suggests that TB cases might not be picked up until a case has been discovered and might be spreading.
TISG wrote in to both SMRT and the Ministry of Health (MOH) to clarify on the above issues. And asked them the following questions:
- We understand that there are up to 300 drivers sharing the crew rooms, who have access to the driving cabs in the trains. Has SMRT and/or MOH taken any precautions to prevent cross-infection from taking place, and if so what are these measures?
- We understand that the air conditioning in the train is shared by other saloon cars. Can SMRT and/or MOH verify if this is true, and if so, given that TB is transmitted by air, what are the precautions taken to prevent infection from spreading to train passengers?
- We understand that medical screening for Tanah Merah station have yet to commence, and that Ang Mo Kio and Jurong stations will be screened first. Can MOH and/or SMRT confirm if this is true, and if so, why the delay when the cases of active TB have been found at Tanah Merah?
- We also understand that annual medical check-up for SMRT train drivers has been discontinued. Can MOH and/or SMRT verify if this is true? If so, when was it discontinued, and why was it discontinued?
- Can MOH please confirm the number of TB cases nation-wide since January 2016 and indicate steps that you have taken to prevent it spreading?
SMRT responded to our questions and said:
“Sharing with you previously issued statements to media queries:
On 6 August 2016 (Saturday): “An SMRT crew manager was diagnosed with active Tuberculosis (TB) and is currently receiving treatment. He is not infectious and cannot spread TB to others. Immediately upon discovering that the staff had contracted TB, SMRT worked closely with the TB Control Unit to carry out contact tracing. Contact tracing amongst his contacts is ongoing. Two SMRT staff had earlier in the year been diagnosed with latent TB. These two cases are not linked to the active TB case, and have been cleared by the TB Control Unit after completing treatment and are back at work. We have worked closely with the TB Control Unit to ensure that all fellow workers who are close contacts undergo screening, and have carried out extensive sanitisation of staff work areas. We will also ensure and support our staff who have TB to complete their treatment successfully. SMRT takes healthcare concerns very seriously and will spare no effort in taking the necessary steps to keep our staff and commuters safe.” – Mr Patrick Nathan, Vice President of Corporate Information and Communications, SMRT Corporation Ltd
On 11 August 2016 (Thursday): “Another SMRT staff has been diagnosed with active Tuberculosis (TB) on 11 August 2016. Contact tracing is being carried out by the Tuberculosis Control Unit to identify close contacts, such as family members and co-workers, so that they undergo TB screening. We will also ensure and support our staff who have TB to complete their treatment successfully. In addition, we have shared health advisories to our staff informing them of the actions we have taken as well as exhorting them to continue practising good personal hygiene. SMRT takes healthcare concerns very seriously and will spare no effort in taking the necessary steps to keep our staff and commuters safe.” – Mr Patrick Nathan, Vice President of Corporate Information and Communications, SMRT Corporation Ltd
On 12 August 2016 (Friday): “We have sent our staff for Tuberculosis screening in batches and are awaiting the final results.” – Ms Margaret Teo, Head of Corporate Marketing & Communications, SMRT Corporation Ltd”
MOH responded to our questions and said:
“TB is endemic in Singapore and is spread through close and prolonged contact with an infectious individual. Such infections usually result in latent TB infection (LTBI). Persons with LTBI do not have symptoms of TB (e.g. cough) and they do not spread TB to others. The vast majority of healthy persons with LTBI do not develop active TB disease. About 5% of persons with LTBI develop active TB disease within 2 years after infection while another 5% may develop TB many years later, over a lifetime.
As transmission of the TB bacteria usually requires prolonged exposure (days to weeks, rather than minutes to hours), the risk of getting TB from brief casual contact is very low. Screening is thus generally not necessary for commuters should public transport staff be infected with TB.
Singapore has the second lowest incidence of TB in Asia. In 2015, a total of 2,704 new cases of active TB were notified. The Singapore TB Elimination Programme (STEP), managed by the TB Control Unit leads national efforts to promote early diagnosis and effective treatment of patients with TB.”