6 drug resistant TB cases in AMK
Six residents of Block 203, Ang Mo Kio Avenue 3have contracted multidrug-resistant tuberculosis (MDR TB).
While three of them, including Patient Zero, live in the same flat, the other three are from different units.
Announcing this at a press conference last evening, Associate Professor Benjamin Ong, director of medical services at the Ministry of Health (MOH), said this makes it "highly unusual to find cases of the same strain of the MDR TB who do not share common activities with one another".
TB is spread through the air and a person needs to inhale the germs in a close and prolonged period to become infected.
So people with TB are most likely to spread it to family members, friends, and co-workers or schoolmates. (See report, above.)
"Other than the three cases in the same household, there was no common link among the other cases except for the residential block," Prof Ong said.
Patient Zero was diagnosed with MDR TB in February 2012 and his household members were monitored.
Two were later diagnosed with active MDR TB, one in May 2012, and the other in October last year.
Three others who were not from the same household were detected: one in April 2014, another in October last yearand the third was the most recent - last month.
"They did not know or interact with one another, or congregate at the same common areas, making it the first unusual case which does not fit the usual pattern of TB spread," Prof Ong said.
He added that while the lift is a common facility that the residents would have used, "the probability that TB could be transmitted by this mode is low".
The detection of this cluster was made especially difficult because of the long latent period of TB and the absence of known common activities or exposure.
It was due to the vigilance of a doctor from the Tuberculosis Control Unit at Tan Tock Seng Hospital that the cases surfaced.
She had noticed that the block number of the most recent MDR TB case was the same as earlier cases and reported the matter to MOH last month.
This led to an investigation that established that the six individuals were infected with the same MDR TB strain.
Prof Ong also said that all six cases are no longer contagious.
"Three have already completed treatment, while the other three are currently undergoing treatment.
"All six individuals are no longer infectious and cannot transmit MDR TB and are therefore not an ongoing public health risk," he said.
To assure and protect the residents of the block, MOH is offering TB screening to residents "who are living or have lived there since July 2011" from today until Sunday.
Screening will be held at the void deck of the block between 9am and 9pm. Those with positive screening results will be offered appropriate advice and follow-up.
Prof Ong said that former residents will be contacted with help from the Housing Board.