TB in AMK: 2 possible infectious cases
TWO more people may have active tuberculosis infections in the same Ang Mo Kio block where a cluster of drug-resistant cases was recently found, said the Health Ministry (MOH) yesterday.
This follows a four-day precautionary screening exercise - held at the foot of Block 203 along Avenue 3 - three weeks ago to pick up undiagnosed TB cases among residents there.
In its statement about the two potentially infectious cases, MOH said: "They are currently being followed up for treatment, monitoring and contact tracing."
It added that it will carry out DNA fingerprinting to see if they are related to the cluster of six drug-resistant cases although "this may take some time".
Some 223 residents and former residents went for screening - which was not compulsory - over the four-day period. An estimated 350 people live in the block.
Another round of screening was also conducted on Saturday although results are not yet in.
The first round of screening tests turned up 45 people with latent TB infections.
Unlike those with the active form of the disease, they cannot spread it to other people.
Latent TB is not uncommon among Singaporeans, especially the older population.
For example, it affects only 2 per cent of people aged 18 to 29 but nearly 30 per cent of those aged between 70 and 79.
In yesterday's statement, MOH said the baseline prevalence of TB in the affected block is expected to be up to 23 per cent, after considering factors such as its demographic profile.
"The rate of latent TB among those who were screened on-site... is about 22 per cent, within the upper end of the expected baseline prevalence range," it noted.
Another three who had previously contracted TB but already completed treatment were also found. These were unrelated to the "highly unusual" cluster found between 2012 and May this year.
MOH is also following up with nine people who completed only part of the screening, which involves both an X-ray and a blood test.
To date, ministry officers, grassroots volunteers and staff from Tan Tock Seng Hospital's TB Control Unit have reached out to nine in 10 households in the block.
During these house visits, they have also checked with residents if anyone in their households had been coughing for more than three weeks.
All those who had have been screened to exclude TB.
It is continuing to encourage everyone to go for screening and will send a letter to households where residents have not yet been screened.