The six pose no ongoing public health risk as they have either completed or are undergoing treatment.
Monica Kotwani Channel NewsAsia 16 Jun 16;
SINGAPORE: The detection of an unusual cluster of six multi-drug resistant tuberculosis (MDRTB) infections at a block of flats in Ang Mo Kio has prompted health authorities to offer free TB screenings to the block's residents starting Thursday (Jun 16) until Sunday (Jun 19).
In a statement, the Health Ministry assured the public that the six pose no ongoing public health risk, as they have either completed or are receiving treatment.
DISCOVERY OF THE CLUSTER
The six individuals with MDRTB come from four separate units at Block 203 Ang Mo Kio Avenue 3. The first three cases come from the same household, with the first individual in that unit diagnosed in February 2012. The rest of the household was subsequently monitored for the infection. Two were later diagnosed with active MDRTB in May 2012 and October last year.
In that period, two more diagnoses were made of individuals in separate units within the same block, in April 2014 and October last year. The last individual was diagnosed in May, and brought to the attention of authorities after a doctor at Tan Tock Seng Hospital's TB Control Unit (TBCU) noticed that the block number of the last patient was the same as the earlier cases.
A "genetic fingerprinting" carried out this month revealed that the six individuals were infected with the same MDRTB strain. Channel NewsAsia understands that all six are Singaporeans and range from their early 20s to 70 years old. Five of them are males.
MOH said they do not pose an ongoing public health risk as they are either receiving or have completed treatment. This means they can no longer spread the infection.
SPREAD OF CASES IS 'UNUSUAL'
The discovery of the infection has baffled TB experts here, as the transmission does not follow the usual pattern of spread.
Associate Professor Benjamin Ong, the Health Ministry's Director of Medical Services, said it is the first time experts here are seeing instances where they are unable to trace the link between the spread - authorities have not been able to find a common activity between the individuals in the different units who were subsequently diagnosed.
Assoc Prof Ong said: "Just being in the vicinity without close contact is not a known way in which TB spreads. When you find TB cases, you would look at where they may have potentially gotten it. We would go to the contacts within their home, workplace, social context and we have to depend on the recall that the individual has and in these cases, we were searching for the possible link to the index (first) case and his family. I believe the TBCU could not identify any obvious link from what they've done as well."
Assoc Prof Ong said providing free screening to the more than 350 residents in the block would not only act as a precautionary measure, but might lead to more evidence of a link between the infections.
MULTI-DRUG RESISTANT TUBERCULOSIS
MDRTB is transmitted the same way as the usual TB infection, in that it requires close and prolonged contact - hours, days or even weeks - with an infectious individual. This is partly the reason why experts say it is highly unlikely that the infection was transmitted within the common lift in the block.
Professor Sonny Wang, director of TTSH's Tuberculosis Control Unit, said that when infected with TB, individuals go through a stage of "latent infection". "It does not immediately manifest as active disease. This latent state can remain latent forever and in which case, there is no impact on the person's health or the health of people around him."
Prof Wang said only one in 10 people with a normal immune system will get active TB. The risk period also happens in subsequent years. "MDRTB behaves in exactly the same way. The only difference is that it is harder to treat because it is resistant to the two most important drugs which are used to treat TB. When you lose these two drugs, the effectiveness of TB treatment falls considerably. That's why you have to use so many other drugs for such a long time - 20 to 24 months."
MONITORING OTHER RESIDENTS
Prof Wang said while there is no cause for alarm, authorities want to ensure early action is taken for prompt diagnosis.
MOH is offering free screening, including at the void deck of Block 203, to detect any undiagnosed latent or active TB cases. It started spreading word of the screening among residents from Wednesday night. Children under the age of five have to be taken to the TBCU for a separate skin test.
MOH said it is working with relevant authorities to contact former residents, who lived in the block between July 2011 and May this year, to also get screened.
Residents who miss the on-site screening will be screened for free at any SATA clinic until the end of the month.
- CNA/mo
'High alert’ after 3rd case in same HDB block: Doctor who flagged TB cases
Dr Cynthia Chee from the Tuberculosis Control Unit at Tan Tock Seng Hospital raised the alarm after tracing a series of cases of multi-drug-resistant tuberculosis to a block in Ang Mo Kio, prompting the Health Ministry to offer free screenings for residents from the block.
Lee Li Ying, Channel NewsAsia 16 Jun 16;
SINGAPORE: The doctor who first alerted the Ministry of Health to the unusual cluster of six multi-drug-resistant tuberculosis (MDRTB) cases in a HDB block in Ang Mo Kio said the team at the Tuberculosis Control Unit (TBCU) at Tan Tock Seng Hospital (TTSH) had been on “high alert” after a case diagnosed in October 2015 raised warning signs.
Dr Cynthia Chee, senior consultant at TBCU, told Channel NewsAsia on Thursday (Jun 16) that after the third case in the same block of flats was diagnosed last year, her team looked at the data carefully and discovered that the patient shared the same block address as some other cases diagnosed a few years before.
"From that time, we were on very, very high alert for any subsequent cases of MDRTB should they come from this particular block," she explained.
“At that time, we were not clear as to the actual significance of this finding, but when the latest case surfaced in May, we decided we had to tell the Ministry of Health about it to see what more could be done,” added Dr Chee.
The alert prompted health authorities to offer free TB screenings to the block's residents as a precaution from Thursday until Sunday.
Earlier in the day, Member of Parliament (MP) for Ang Mo Kio GRC Koh Poh Koon had called Dr Chee's connection of six MDRTB cases over four to five years a "very astute observation".
MDRTB is harder to treat than regular strands of TB because it is resistant to the two most important drugs typically used to treat TB. As such, other drugs have to be used to treat the patient over a longer period of time of about 20 months.
Less than 10 cases of MDRTB are diagnosed a year and, by law, the Singapore TB Elimination Program Registry under TBCU is notified of all TB cases. TBCU sees more than 80 per cent of TB cases in Singapore and all the MDRTB cases, it said.
“Because MDRTB is such a difficult condition to treat, and we do not want it to spread in Singapore, we are on very high alert every time there is a new case of MDRTB diagnosed,” said Dr Chee.
- CNA/mz
Residents of affected Ang Mo Kio block undergo tuberculosis screening
The Ministry of Health is providing the screening after six cases of multi-drug-resistant tuberculosis cases were found at the block in Ang Mo Kio.
Justin Ong Channel NewsAsia 16 Jun 16;
SINGAPORE: Tuberculosis screening is being offered to residents of Block 203 Ang Mo Kio Avenue 3 after six cases of multi-drug-resistant tuberculosis (MDRTB) were found there.
Member of Parliament (MP) for Ang Mo Kio GRC Koh Poh Koon was on site on Thursday (Jun 16), speaking to residents to share information about TB. Dr Koh also applauded Dr Cynthia Chee, the clinician who first made the connection between the TB cases.
“All of us have seen many patients on a daily basis, and the amazing thing is how she connects six patients over a four to five year period... Many of us would link patients by name, maybe by surname or family name, but to link addresses over a period of four years I think is a very astute observation.”
Dr Koh noted that while the screening was not mandatory, he cautioned that it is “important for residents to understand the disease process of TB” and to visit a doctor should they experience symptoms such as having a cough or fever.
Dr Koh also said that grassroots volunteers and MOH officials posted pamphlets under the doors of those who had not been at home last night, and would continue to make visits over the next few nights.
“I guess there will be no way we can cover this one hundred percent because some might be overseas and some may not be home the time we visit. But we will make sure that the information is put under their door, so as and when they are home, they can read it at their leisure,” he said.
Residents Channel NewsAsia spoke seemed reassured that the necessary measures were being taken.
Odd job worker Mohamed Ali said: “I’m happy with what they are doing. We don’t have to wait for a long queue.”
Taxi driver Ani said that she would bring her four-year-old daughter to the hospital for a skin test as recommended by officials last night. While she was unconcerned for herself, she said: "I think it's best if we just stay at home and not go out at all.”
Retail assistant Sherry Ng, who also has a four-year-old son, said: "I know about the tuberculosis cases but I had no idea there was screening downstairs. But I'm definitely concerned and yes I will go for the screening. I may ask my mum and son to wear masks. For myself I'm not scared but I worry for my kid."
- CNA/ww
About 70 residents from affected Ang Mo Kio block screened for TB so far
The results from the on-site screening will be out within two weeks, added the ministry.
Channel NewsAsia 16 Jun 16;
SINGAPORE: The Ministry of Health (MOH) said that about 70 residents and former residents of Block 203 Ang Mo Kio Avenue 3 had been screened on-site for tuberculosis (TB), as of 5pm on Thursday (Jun 16).
Results of the screening will be out within two weeks, said the ministry.
MOH added that its public health officers and grassroots leaders have engaged more than half of the households in the block by going door-to-door and we will continue to do so over the next few nights.
The screenings started Thursday morning after an unusual cluster of six multi-drug resistant tuberculosis (MDRTB) infections were detected at the block in Ang Mo Kio.
While the six no longer pose a health risk to the public, the free screening was provided to the more than 350 residents as a precautionary measure. They also might lead to more evidence of a link between the infections, said Associate Professor Benjamin Ong, the Health Ministry's Director of Medical Services.
According to Assoc Prof Ong, this is the first time experts in Singapore are seeing instances where they are unable to trace the link between the spread.
Dr Cynthia Chee, who first alerted the MOH to the unusual cluster, said the team at the Tuberculosis Control Unit (TBCU) at Tan Tock Seng Hospital (TTSH) had been on “high alert” after a case diagnosed in October 2015 raised warning signs.
The senior consultant at TBCU told Channel NewsAsia that after the third case in the same block of flats was diagnosed last year, her team looked at the data carefully and discovered that the patient shared the same block address as some other cases diagnosed a few years before.
Earlier in the day, Member of Parliament (MP) for Ang Mo Kio GRC Koh Poh Koon applauded Dr Chee for making the connection between the six cases over a span of four to five years, calling it a "very astute observation".
MDRTB is harder to treat than regular strands of TB because it is resistant to the two most important drugs typically used to treat TB. As such, other drugs have to be used to treat the patient over a longer period of time of about 20 months.
- CNA/ek
Disease now rarely fatal, but cases on an uptick
KELLY NG Today Online 17 Jun 16;
Tuberculosis (TB) was recognised as a major public health problem in Singapore since the city’s founding in the 19th century, and was a major cause of death in the 1940s.
To help treat and stamp out the disease, the Singapore Anti-Tuberculosis Association (Sata) was set up in 1947. A year later, the Tuberculosis Clinic at Tan Tock Seng Hospital (TTSH) opened its doors.
The BCG vaccine for tuberculosis was introduced in the 1950s together with a mass vaccination campaign for newborns, which reduced deaths from TB among young children.
As hygiene and housing conditions improved in Singapore, the rate of occurrence of the disease fell significantly over the next three decades, from 307 cases per 100,000 population in 1960 to 56 cases per 100,000 in 1987.
It fell further to a low of 35 per 100,000 resident population in 2007, after the launch of the Singapore Tuberculosis Elimination Programme in 1997. The programme aims to eliminate TB here by diagnosing and treating all infectious cases, tracing and treating infected contacts, and preventing the emergence of multi-drug-resistant tuberculosis.
The programme incorporated a national surveillance registry that tracks the treatment progress of each TB case until an outcome is achieved. The registry also alerts physicians if patients default on treatment or do not respond to treatment as expected.
In recent years, Singapore has witnessed a “resurgence” of the disease, with the incidence of TB per 100,000 population hovering between 36.9 and 41.5 since 2008. Three in 10 cases diagnosed in 2014 emerged in foreigners who live in Singapore.
This increase corresponds with the global rise of multi-drug-resistant TB (MDR-TB), which cannot be treated with conventional first-line drugs.
Drug resistance may be due to inefficient treatment protocols and poor patient compliance.
In Singapore, 131 cases of MDR-TB (22 home-born, a term that refers to residents born in Singapore, and 109 foreign-born) were reported from 2010 to 2014 — up from 93 cases (14 home-born, 79 foreign-born) in the previous period from 2005 to 2009.
In March, a report from the Health Ministry showed that all nine cases diagnosed to date of extensively drug-resistant TB cases — a rare type of MDR-TB resistant to a wider range of first- and second-line drugs — were among foreigners who reside here.
Drug-resistant TB ‘takes longer to cure, poses more risk’
SIAU MING EN Today Online 16 Jun 16;
SINGAPORE — Compared with patients diagnosed with tuberculosis (TB), those infected with the multi-drug-resistant strain of the disease will have to take more medicines a day, and the types of medication they consume also put them at risk of side effects such as kidney, liver or psychiatric problems.
Doctors TODAY spoke to also noted that patients diagnosed with such multi-drug-resistant strains will take more time to be completely cured. The doctors were commenting after the Ministry of Health (MOH) said on Wednesday that there was an unusual cluster of six multi-drug resistant TB cases at a public housing block on Ang Mo Kio Avenue 3.
The inappropriate treatment of TB and patients’ poor adherence to the treatment increases the likelihood that drug-resistant strains will develop. The use of antibiotics has also led to the rise of such strains
of the disease.
But these strains remain in the minority: Of the 1,498 new TB cases among Singapore residents, less than 1 per cent were multi-drug-resistant.
Dr Ong Kian Chung, a respiratory specialist at Mount Elizabeth Hospital, said that while a normal TB patient will have to take three to four types of medication each day, those with drug-resistant strain of TB will have to take more, about four to six types of medication each day.
He added that the treatment for patients diagnosed with the drug-resistant strain also varies widely, depending on the number of drugs the patient is resistant to and the patient’s tolerance for certain types of medication.
These patients tend to experience more side effects as they are taking second- or third-line medication, which are “less tolerable” and could result in kidney, liver, neurological or psychiatric problems.
The full treatment for normal TB patients takes about six to nine months, while those with the multi-drug-resistant strains will need between 20 to 24 months to recover, noted the MOH on Wednesday. With a longer treatment period, there is a higher chance of developing complications during the process,
added Dr Ong.
Dr Leong Hoe Nam, an infectious disease specialist at Mount Elizabeth Novena Specialist Centre, said those with TB and the multi-drug-resistant strain will no longer become infectious after two weeks of treatment. On the effectiveness of BCG vaccinations, he noted that they may only work against two rare forms of TB — TB in the brain and in the blood.
To date, there are no effective vaccinations against TB in the lungs, added Dr Leong.
