The Online Citizen

TB Resurgence and Screening of Foreign Workers In Singapore

May 04
13:35 2012

~ By Dr Vincent Chia Wei Meng ~

With reference to the Straits Times on 28th April 2012, "tuberculosis (TB) is making a resurgence after some years in decline [in Singapore]." (1)

I am increasingly concerned with the way foreign workers are screened for tuberculosis in Singapore, which could have contributed to this resurgence.

According to Khin Mar Kyi Win et al, due to the “liberalization of the immigration policy in Singapore in 2005, there was an influx of migrant workers and immigrants from countries with high incidences of TB and a corresponding increase in TB notifications among this population. Of these persons with TB, >75% came from 5 of the 7 countries (India, China, Indonesia, Bangladesh, and the Philippines) with highest incidences of TB.” (2)

The work permit health screening for foreign workers uses the Chest X-ray as the screening tool for pulmonary tuberculosis. It does not include a Mantoux test or any other test for the detection of TB in these foreign workers.

However, the Chest X-ray is notoriously known for its inability to detect early disease or recurrences. (3) Although the Chest X-ray is commonly used for the diagnosis and screening of active TB, it has poor sensitivity, specificity, and reproducibility. (4)

One likely reason for the delay in diagnosis of TB is an over-reliance on X-rays. “In Hong Kong, general practitioners' practice was reviewed, and it became clear that they depend too much on X-rays rather than sputum examinations, and that they were slow in referring tuberculosis patients to the government tuberculosis service.” (5)

Some cases of active pulmonary tuberculosis could be missed in early disease as X-ray changes have no begun to show. To compound the diagnostic problem further, scarring from previously cured disease seen on X-rays might sometimes be difficult to distinguish from current active tuberculosis.

Furthermore, pregnant foreign workers are exempted from Chest X-rays, which really is the only – albeit inadequate – means of detecting active TB in the work permit health screen.

In conjunction with radiological evidence, the Centres for Disease Control and Prevention (CDC) recommend at least a TB Skin test (Mantoux test) or a TB blood test (interferon-gamma release assays or IGRAs) for the diagnosis of TB. (6) Suspicious cases are also sent for further laboratory tests such as sputum smears and cultures. This is reasonable since “[sputum] culture-positive pulmonary TB with a normal CXR is not uncommon, and the incidence of this presentation is increasing.” (7) In other words, a patient with a normal Chest X-ray could actually have active TB, and this would go undiagnosed if no other tests were done.

If the foreign worker does not declare his symptoms accordingly, clinical suspicion would hence be lowered in clinicians performing the work permit health screening.

Combining a simple Mantoux test with the Chest X-ray would enhance the quality and effectiveness of TB screening in foreign workers. Suspected cases would then be referred for further diagnostic tests (e.g. sputum smears and cultures) to delineate those with latent TB infection from those with active TB disease.

Shouldn't the Ministry of Manpower change her current practice of using merely a Chest X-ray for the screening of TB in foreign workers?


(1) “Health Ministry working to dispel myths about TB.”

(2) Kyi Win KM, et al., “Tuberculosis among foreign-born persons, Singapore, 2000–2009,” Emerg Infect Dis 17, no. 3 (2011), (accessed April 28, 2012).

(3) Ito K, “Limits of chest X-ray investigation in the diagnosis of recurrent pulmonary tuberculosis,” Kekkaku 80 (2005): 521-6.;.

(4) Toman K. 1979. Tuberculosis—Case-Finding and Chemotherapy: Questions and Answers. World Health Organization, Geneva.

(5) Christoph Lange and Toru Mori, “Advances in the diagnosis of tuberculosis,” Respirology 15 (2010): 220-40

(6); also see

(7) Darcy D. Marciniuk et al, “Detection of Pulmonary Tuberculosis in Patients With a Normal Chest Radiograph,” CHEST 115 (1999): 445-52.


  • jameson

    singapore won't have to worry about overcrowding pretty soon. once this TB is imported along with foreign workers, people will soon be dropping like flies. daaammn, pap better wake up cuz those people voting for them may longer be alive next general election.

  • iAMahMENG

    when a foreign maid come to singapoor..she must be screen for TB and aids before approval of work permit
    why other foreign workers are xempted? when i was a quitter in britain..if i dont produced a health certificate from way would i be granted entry into the UK


     'compulsive' contradcitory behaviour seems to be the habit of the MIWs without exception.
    on the one hand,every of the MIWs,from the most old-uncle 'dogs' to the most junior and even some ft-grassroots kind,kept shouting so loudly that SG needs new immigrants of face 'labour' shortage in the midst of an aging populace BUT in the same breadth,they keep brining all sorts of tom and hairy dickies here without even proper healh due diligence?
    at this rate and manner,the population will dwindle even quicker than if we allow for NORMAL AGING of the populace???
    what kind of  'superb' thinking indeed that they ask to be paid in the MILLIONS?

  • vision

    Sinkies are the hardest hit by this inconsiderate decision by the inapt govt to open the floodgate to any foreigner just to jack up the GDP and mock growth.This is a suicidal step that not only affect the society and the infrastructures at large but will also cause their downfall soon.

  • PingPong

    Unless the cases increase at an alarming rate or something unfortunate happened, our gahmen will not be on the panic mode.
    Didn't Amy Khor boast that spore has 1 of the lowest TB rates in Asia?

  • agongkia

    Thanks to Dr Vincent Chia .
    Walao Oy,I mingle with these FWs every day  without knowing that  X ray test is not effective enough to test whether they got TB.
    I think the HIV test should also be conducted 6 month before approval of their arrival as they may also go for HIV test within the window period and they may not be detected for aids even if the disease too.
    Should not bring in FWs blindly.Citizen's safety first.

  • iTBscreamer

    PingPong4 May 2012

    Unless the cases increase at an alarming rate or something unfortunate happened, our gahmen will not be on the panic mode.
    what to panick? in the event of an outbreak..leekinyou would be in Emirate tryin to get a camel lisence while the primeister himself would be in moscow to attained his KGB lisence


  • joker

    1. why world class city cannot detect TB of FT?
    2. until what stage will elites stop doing harmful things to sg folks?
    3. CHANGE now!

  • mice is nice

    wow, S'pore now an importer & exporter of TB? would that not scare the high net worth foreigners out to take the 1st flight out?
    there is no scare like health scare. this wan i think is sabotage…

  • mel

    According to looes74 who posted in another thread there is no TB in singapore and we have the PAP to thank for that.. Rolleyes.

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  • Entire Population

    Now the put the ENTIRE SINGAPOREAN RACE at stake cos of the INTEREST IN growing THEIR OWN POCKET.
    We NEED to reclaim WHAT BELONGS to US.
    We NEED to fight,.

  • citizen

    The "growth at all cost open door wide to foreigners" policy have saddled us with lots of problems and brought along lots of unhappiness.
    Growth because of cheap labour killed productivity, which citizens will have to pay back.
    Unabated, unchecked inflow of foreigners resulted in over-crowdedness, resulting in transport, and housing woes.
    Over-crowdedness help to spread the diseases which foreigners brought along.  
    Inflation, too many people chasing for too little or the same goods, lower income suffer most.  Just look at the COEs.  Population has increased by soooo much, car population needed to be curbed, how does that work? 

  • Libran

    The PAP govt. is committing a heinous crime against true blue Singaporeans with its liberal immigration policy.

  • Which health/immigration Minister to blame?

    'Tuberculosis, is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria.
    Tuberculosis typically attacks the lungs but can also affect other parts of the body. It is spread through the air when people who have an active TB infection cough, sneeze, or otherwise transmit their saliva through the air.
    When people with active pulmonary TB cough, sneeze, speak, sing, or spit, they expel infectious aerosol droplets 0.5 to 5 µm in diameter.
    A single sneeze can release up to 40,000 droplets. Each one of these droplets may transmit the disease, since the infectious dose of tuberculosis is very low (the inhalation of fewer than 10 bacteria may cause an infection).'
    MOH should send back the thousand foreigners diagnosed with the major disease. Maybe give them a full course of drug to bring back.
    No Minister has spoken on this poyentially seriously health issue facing Singapore. There is no sense of urgency.

  • Tony

    A friends ‘s friend was told us in a pub how many in their kffice was found positive for TB. Once their colleague from near indian ocean was diagnosed in sg hospital with TB, a disease no singaporean has heard before or for decades.

    Thanks to the influx, some smart alec called it a few flies fliwn i , so be it, so many Tb cases found now.

    Singaporeans, you are not a STUPID INNOCENT SIMPLETON BLUR FCUK. Because you know that TB is usually inactive in the body of the infected until its triggered. Its asymptomatic and when active, its a CDC type of risk. Its COMMUNICABLE DISEASE.

    Singaporeans, you are not DAFT because you know you will do nothing about it and continue to Accept and not be Subservient, self censored highly educated, cpf paying and extra cost to employer , first world son of a gun.

    No first world like you full of 3rd world people.

    A third world first world?

    There are lotentially more infected with TB than is known based on the law of asymptomatic diseases.

    Singaporeans, tell me are you a fool?

    The answer is clear.

  • John Sperm

    Does any singaporean here know :
    1. How is Singapura Government or Ministry of Health Responsible for TB infection in Singapore?
    2. How many singaporeans are actually infected?
    How do you know if not all have been tested?
    The fact is, one can be having it without knowing it.
    TB has been unheard of in singapore for a long time.
    Its now Back.
    I am sure no one is responsible.
    How do i know?

  • Lee Tao

    One person ever said about influx.
    "If a few flies come in, so be it."
    I wonder does any of the flies include TB ?
    Many singaporeans are daft not knowing what TB is and how it can be infecting without the person ever knowing until it errupts.
    The only way to know for sure how many singaporeans are now Infected, even if dormantly, is a nation wide Screening .
    I urge the opposition alliance to put the government responsible for this mess.
    Push for nation-wide screening .
    Educate the Daft about  the Reality of TB .
    Dafts need to be Educated, although it would be a futile attempt anyway to enlighten a DAFT. A daft is a daft.  

  • David

    Most of the problems in Singapore are the result of reckless flood of foreigners.  I see as cost  more than benefit to this supposedly peaceful and healthy society.  PAP should not shun all these problems created by them and pretend nothing is serious until it get extremely out of hand that force the doctor to come out and speak for Singaporeans like what Lim Chong Yah did.

  • May

    TB is a highly-contagious bacterial infection, spread from one person to another, thru' droplets in the air, when talking to an infected person, via coughing or talking.
    TB is known as a lung disease, BUT TB, a bacterial infection can spread to other organs in the body- ie- spine, brain, kidneys.
    Get medical checkup if you don't feel well. Also checkup on kids is vital.

  • Taxi Driver

    What a real mess created my the so-called self-proclaimed "best self-paid millions salaried govt in the whole wide world" with its FT policy; There are so many Foreign Trashes on our land causing ever increasing social and health problems without remedy!

  • agongkia

    @mice is nice4 May 2012

    wow, S'pore now an importer & exporter of TB? 
    If TB patients cab generate wealth and  income for the health industry …why not? Usually  40 % mix more with FWs.With TB maybe result in 35 %.


  • Pusinderen

    With more TB patients, hospitals, both pubic and private, will be making tons of dollars to help boost GDP. So it’s good to grow GDP at all cost. But dont forget:
    Greed Doesn’t Pay.
    End up losing more.

  • mice is nice

    maybe some foreigners working in healthcare industry are TB carriers themselves…? the "best" thing is they have been here for years.
    let's not forget they are everywhere, they are simply unavoidable…

  • The Sperm from Arizona

    Does the Government of Singapura know how to handle TB?
    Did they know that you cannot just any how influx as many people as you suka?
    You first should seek the People's Referendum.
    What happens when old man  retires, which is an INEvitability in every sense of the word where no PhD or Queens counsel , senior Council, Rear Admiral or Deep Blue super computer can stop? Not even god.

  • Doc

    Singapore does not know how to combat TB. The TB department is so small! There is no evidence people who refuse treatment are imprisoned or force in any way!

  • CECA

    Since 2005 when the CECA between sg and india was signed, the number of Indians influxed here has grown Exponentially. The number of foreigners here is in excess of 1 million. Many singaporeans are still DAFT , Naive and Ignorant of the exact level of extreme influx.
    TB is a by-product of this influx which foreigners contributed in the spread here.
    IT professionals of singapore need to know :
    1. For how long does the CECA last? Anyways, I will be voting Lee Kuan Yew's party out in 2016.
    2. While sg is said to be the 8th Investor of india (ref : )
    its clear indians have benefitted tremendously from singapore. But how come i do not feel any benefit received from Indians? One thing for sure, my rice bowl tremendously affected and countless job opportunities lost over the last almost a decade.
    3. Am i right to say there is no way to stop the influx due to the CECA that was signed? Was it GY who signed it?
    GY, why not you come out from your defeat and take on HG once more?
    Come !

  • crisis

    this reminds me of sars.. Which country was it from again?

    • iSARnoMORE

      sars came from china…leekingyou blamed the peasants ole aged for goin to china(as though the ole aged knew SAR is comin)

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  • James Mc Sperm

    The over 1500 cases are not all that are infected.
    Potentially, these' family members could also be infected asymptomatically.
    We not only embrace influx, we embrace diseases so EASILY Communicable.
    Hi, my name is Sperm, James Sperm. James Mc Sperm to be exact.

  • Zhang

    IF you have to travel in packed buses and/or MRT trains, then you better worry about contracting TB from the workers from the sub-continent, etc. BUT if you are one of the elites i.e. Ministers, Perm Secs, Judges etc…why worry!!! You are not using public transport and therefore practically there is no chance of  rubbing elbows with a foreign worker with TB.

  • Zhang

    Productivity? Who measures their(MIW) productivity? Did they EVER talk about their Productivity when they raised their pay? NO! They claimed that they deserved the obscene pay otherwise nobody would come forward to serve! They need such a bloated cabinet ( imagine the PMs office need 2 Ministers w/o Portfolio) to run a country of 680 sq km and a then 4 million people.
    BUT  there are ACTUALLY morons who believed that they deserved their pay. Pay them fairly yes; but not obscenely.
    When Gerard Ee said that the ministers pay for their own security when they travel, either Gerard is lying or he was talking co-k.  Gerard Ee has NO credibility.How pathetic!!

  • Anton

    A stranger told me, his office has1 confirmed TB foreigner.
    This led to contact tracing by TB CONTROL UNIT.But the screening started after quite some time after the diagnosis.

    Many chinese singaporeans tested positive indications from the Mantoux test.

    Likewise many india indians too.

    A substantial proportion are found to have reaction.

    My question is why moh using this not very accurate test ?

    Now, everyone is worried .

    We are paid peanuts and have to suffer like this?

    How can claims be made against the company or who?

    If so many are found to show reaction,how many singaporeans potentially can be found positive?

    They have to take antibiotics for 6 mths.
    I wonder what side effects can they be inflicted from long term daily intake of antibiotics?

    What legal recourse do they have? Should they not be given more conclusive tests before being forced to take meds?

    Why so many TB nowadays?

    Is moh not responsible? Or am i responsible?

  • Desmond Choo Choo

    I do not understand how a PR can have TB if he was tested flr TB each time he travels to other countries or if moh requires them to go for annual screening.

    Else the initial job screening is useless if he works there many years and travels back home regularly.

    How many may be infected if he sneeze in congested mrt or bus or expo ?

    Why no singaporean doctor fart any concern about this? CDC employees? TTS , TBCU, GPs, ang yong guan, pap doctors?

    • mice is nice

      why no one makes in health care makes a sound, cos its such a huge can of worms…?

      • little voice

        What can MOH and MOM say? That they are daft and had been letting in FTs with TB with their liberal immigration policies?
        Let's see if anyone from MOM/MOH/Parliament say anything this year. I think media will turn the attention to Hougang re-election or to some sex scandal.

        • mice is nice

          maybe they will say something when the department is helmed by new people. "i just took over, anything before my time, i dun have the details.".
          its quite normal for top people to buy time to think of ways to wriggle free from liability.  :(

  • Amin

    Oh no, this article is relegated to not so easily spotted area. Most citizens wont notice.

  • Language fun

    Mice is Nice
    Bravo! Agree with the can of worms.

    1. Many will be found positive, more than a layman would believe.

    2. The bacteria is Latent infection.

    3. EP need health check but PR also foreigner, also annually flies back not required.


    4. I have heard that many tested positive with latent infection .

    5. Xray cannot tell all if any latent infection.

    6. So many can easily be infected in mrt. Everyday taking trains. As long as in 1 year, your immunity drops low and bacteria in air you breath, high chance.

    7. If you have not been tested , you cannot say you definitely do not have it.

    No one knows how many carriers exist now in sg and infected due to overcrowding.

    Been to EXpo?

    Ignorance is not bliss. Its living in denial.

    8. More definitive tests cost money.

    9. Public education insufficient as even highly educated may not know what tb is.
    Costly to educate public also.

    So, i do not think anyone is responsible. Business as usual.

    • mice is nice

      yap, ignorance is bliss, knowing cost money.
      any places where there is a crowd TB will spread. not just public transport systems, but also, consumer travel & trade fairs, pubs, mass sports event (marathons, triathelons), schools, movie threatres, workplaces, NDP, etc. as i have mentioned foreigners are unavoidable.
      they have permeated every level of society some years now. they come into contact not just with the poor but the rich. i wonder if any MIWs will ever raise a voice about the downsides of lax immigration…

  • Prolitico Inconvenience

    Yes TB is spread by air vapor and many cough in public places.
    While not all contains TB, some can be TB.

    given so many cases of TB in sg now, it shows they cannot stop TB from entering.

    Xray is only useful if TB erupted. Latent tb is not visible.

    I doubt anyone knows clearly how many are infected as most people in sg are never screened for latent infection. Xray, yes, but not latent infection. They are different.

    I am not optimistic current system and policy can handle pandemic of tb.

    Sg economy can collapse if people really understand what is tb.

    Which doctor like to challenge me, a sec 5 failure?

    • mice is nice

      like the many state infrastructure, i also think healthcare cannot cope.
      as much as a person can opt for a Mantoux test, seek treatment for TB if found to be positive. personally i find it rather futile as one may get TB again & again & again as one cannot live a life of a hermit.
      only i can't recall the amount of time & effort S'pore went through to rid TB in the past. if one takes the current healthcare costs & the current population size in consideration, how much would it be? wait someone say Negerian scam again… *shudders*