One of the residents having X-ray screening (Photo Straits Times)

MOH concludes screening of TB cluster at Ang Mo Kio Ave 3

July 4 – The Ministry of Health (MOH) announced that residents of the Tuberculosis (TB) cluster at Block 203 Ang Mo Kio Avenue 3, have progressively received their results from the on-site TB screening exercise from June 16 to 19,  since June 30.

MOH held the four-day precautionary screening after the discovery of the new cases at the foot of the blocks so as to ascertain if there are any undiagnosed cases. There are about 350 residents who live in the blocks, and 223 of them has taken the tests.

From MOH’s announcement, it is said,

  • Majority (164) tested negative for TB and do not require follow-up action.
  • 45 residents diagnosed with latent TB (they do not have symptoms and cannot spread TB)
  • 3 residents had previously contracted TB earlier in life and had completed treatment. Not related to TB cluster.
  • 2 possibly have active TB.
  • 9 residents have only completed either a chest x-ray or blood test.

MOH stated that the two new residents from the TB cluster were shown to be possibly infected by active tuberculosis (TB) through through their chest X-ray scans. It is said that the health officials are going to follow up the case so they will get necessary treatment. The two will be monitored closely for MOH to be able to perform contact-tracing.

MOH said that they will also take DNA fingerprinting analysis which would take some time to specify if their cases are related to the cluster of six MDRTB in the public housing board.

Though the tests had already ended on June 19, but health officials still visited the blocks on July 2 to encourage those who have no taken the tests and offered to collect blood samples to make it more convenient for residents.

Earlier on June 16, MOH held a press conference and revealed that there were 6 cases of multi-drug-resistant tuberculosis (MDRTB) emerged from Ang Mo Kio Block 203, and the first case were found back in 2012.

Even though the cases happened from years ago, it was only on May this year that the cases were being reported to MOH. The investigation found that the six people were Singaporeans ranging in age from early 20s and 70, and were infected with the same strain of MDRTB, which takes longer to treat, about 20-24 months instead of 6-9 months because less effective medicines are needed.

Of the six who are infected with MDRTB, three lived in a same apartment, and the first one were diagnosed with MDRTB in February 2012. The members of his household were being monitored. Then two other were diagnosed in May 2012 and October 2015. As for the other three, they do not live in a same apartment. One were diagnosed in April 2014, another in October 2015 and the last one were diagnosed just last month. No history of contact by the three were found through the interview, making this a very unusual case.

The director of medical services at MOH, Professor Benjamin Ong said, “It is highly unusual to find cases of the same strain of the MDRTB who do not share common activities with one another. Other than the three cases in the same household, there was no common link to other cases except for the residential block.”

As TB is spread through air. People need to inhale the bacteria from an infected individual in close range and over a prolonged period of time to become infected. So this disease is more likely to spread to the family members, friend, co-workers and schoolmates.

No new updates on the diagnosis of the two residents and the situation at Ang Mo Kio’s TB cluster as of July 10.