Tuberculosis and Job Security

A colleague pointed out that the preschool teacher diagnosed with pulmonary tuberculosis could have her contract terminated early, according to news reports, although this part was not clear from the Todayonline report.

A screenshot from an earlier version of the ST report; also found on the mypaper.sg report


I hope that this does not happen. TB-infected patients are generally not infectious after just 2 weeks of appropriate therapy, and the vast majority are cured after completing 6 to 9 months of anti-TB therapy. Transmission of TB virtually always happens prior to starting therapy, when the patient with pulmonary infection is still coughing away.

Firing a person, or early termination of the work contract because of an infectious disease such as TB, further perpetuates the stigma of the disease, and has the counterproductive effect of deterring people from seeking early medical attention (for prolonged cough, for example), going for TB diagnostic testing, or even persisting with completing the long treatment regimen.

Is the employee with TB protected by law from being fired for the sole reason of his/her infection? In the United States, TB is considered a “disability” during the time of treatment, and the Americans with Disability Act covers employees with TB from any form of discrimination including demotion, sacking, or generation of a hostile work environment. I could not find a similar law or regulation in Singapore. Although we have ratified the UN Convention on the Rights of Persons with Disabilities, it is not clear that TB is viewed as a “disability” here. The Employment Act has a section that covers sick leave, but this is general and hardly covers for the duration of TB therapy, including directly observed therapy (DOTS). We have a tripartite guideline on fair employment practices, but the “discrimination” described does not extend to illnesses.

Therefore employees with TB appear to largely depend on the good graces of their employers with regards to keeping their jobs, and may have no legal recourse if dismissed after the sick leave period. Hopefully someone with a better understanding of the law (or a news report in the next few days) will clarify this and prove this wrong.

(More) Local News About Tuberculosis

The latest to make the news is that of a pre-school teacher (Little Greenhouse, Bukit Batok) who was diagnosed with pulmonary TB last Wednesday, leading to planned screening of all 104 pre-schoolers 20 staff.

Web clipping of the pre-school teacher with TB news article from Today online


This follows news of the elderly resident from Peacehaven Bedok Day Centre who was diagnosed with TB in June, leading to a round of screening of residents and staff; Tanah Merah MRT TB “outbreak”, and the Ang Mo Kio multidrug-resistant TB cluster. All in fairly rapid succession.

The incidence of TB has not increased dramatically in Singapore, although it has sort of been inching up since 2008. In the past, such news reports were rare (but such events did happen). But having more of such cases reach the public attention can only be a good thing, despite the potential trouble it brings to the authorities, the companies involved, and the TB control programme in Singapore. They provide opportunities for repeated public education about tuberculosis – many online commentators seem to believe we hardly had TB in Singapore in the past, which is patently erroneous – as well as prevent TB from reaching the state of being a neglected disease in Singapore (with cuts in funding to operational and research programmes). This last is particularly important, because TB resurgence in many countries have occurred as a consequence of policy makers’ attention moving to other more newsworthy diseases, falsely believing that TB elimination was merely a matter of time.

Hard Targets for Antimicrobial Resistance Control

A month from now (21st September), the UN General Assembly will convene a one day high level meeting on antimicrobial resistance (AMR) in New York.


The purpose is to “summon and maintain strong national, regional and international political commitment in addressing antimicrobial resistance comprehensively and multi-sectorally, and to increase and improve awareness of antimicrobial resistance.” In general, a positive development, particularly as the important roles played by the agricultural and animal husbandry industries are also recognised.

In last week’s Policy Forum in the journal Science, Prof Woolhouse and co-authors from USA and China argued the case for specific global concrete targets for AMR control to arise from the September UN meeting, coupled with adequate financing and governance. One example given was to set national antibiotic consumption per capita targets. I think few would disagree with the need for hard targets, but to get global buy in and compliance is a difficult thing, and even then, targets are often missed, as in the case of global warming and climate change.

Targets will also have to be chosen carefully. Sometimes, cause and effect can be difficult to ascertain, and the collateral damage from policies can be considerable. One of the most famous AMR control targets was the Labour Party’s 2004 election pledge to reduce MRSA bloodstream infections by 50% in all UK trusts over 5 years. And they were wildly successful, reducing the rates by 57% by March 2008, and the fall in MRSA infections have continued since. I have yet to meet a U.K. hospital senior executive from those years who did not complain about the raft of penalties imposed by the UK government (although they did not complain about the increased funding received to tackle the problem), but however it happened, MRSA control worked. In Singapore, when antimicrobial stewardship programmes (ASPs) were first put up for governmental funding in 2009/2010, one of the KPI’s was to reduce the prevalence of certain drug-resistant hospital bacteria (ESBL-producing Enterobacteriaceae) by a small percentage. However, this target could not be met because of the increased prevalence of ESBL carriage in the community, and the importation and subsequent spread of carbapenemase-producing Enterobacteriaceae since 2010 compounded the perceived ineffectiveness of ASPs (thankfully not a lasting perception).

Clinical Vignette 64

A young odd-jobs man presented with cough for 3 months, associated with weight loss and fatigue at work. Finally seeking medical attention at a public hospital, he was found to have cavitation and infiltrates in the right upper lobe of the lung, with sputum microscopy showing high counts of acid-fast bacilli (AFB 4+). He was started on conventional anti-TB therapy and discharged. Subsequently, his cultures grew drug-susceptible Mycobacterium tuberculosis.

The young man postponed his hospital outpatient follow-up by a week, and on the following occasion, changed his appointment a few times owing to his work commitments. Unsure of his medication adherence, and perhaps tired of the administrative headaches, his doctor transferred him to the TB Control Unit (TBCU) for directly observed therapy (DOTS).

The old colonial-style house on Moulmein Road that houses the TB Control Unit in Singapore

At the TBCU, he was counselled again with regards to the importance of adherence to anti-TB medication, and started on DOTS at a polyclinic near his residence. However, over the next 3 weeks, he missed DOTS on 6 occasions, each time citing odd work schedules and fatigue from his long working hours.

Question: How should this matter be handled?

Non-adherence to TB treatment is both a clinical and public health concern. The patient risks both progression of TB infection, as well as the development of drug-resistant Mycobacterium tuberculosis that – in the worst case scenario – can be passed on to others. This is how the phenomenon of multidrug-resistant TB developed in many parts of the world.

In Singapore, the Infectious Diseases Act serves to prevent the transmission of infectious diseases. Therefore individuals who are persistently non-adherent to TB treatment can be compelled by the law to complete their treatment, failing which they will be deemed to have committed an offence, and are liable to be fined (not exceeding SGD10,000) or imprisoned (up to 6 months) or both.

However, most people who are initially non-adherent are not deliberate and wilful offenders. Some have experienced adverse effects (occasionally severe) to the anti-TB drugs, and are therefore leery of therapy that seems to make them worse than the disease. The majority fail to understand the implications of TB treatment, and/or find it difficult to fulfil occupational or social roles while undergoing daily treatment. There are multiple programs for counselling and social assistance at the TBCU, including provision of supermarket shopping vouchers to the destitute in exchange for achieving targets in TB treatment. So the heavy hand of the law has seldom been employed on patients who are non-adherent to TB therapy in Singapore.

Vancomycin-Resistant Enterococci, Singapore (Overview)

Vancomycin-resistant enterococci (VRE) belong to the current “pantheon” of “superbugs” causing human infections primarily in the hospital setting. Enterococci are a type of Gram-positive bacteria that are part of the intestinal flora. They are opportunistic pathogens, causing infections primarily in immunocompromised patients, especially when the gut mucosal barrier has been broken. Two species cause virtually all the enterococcal infections in humans – E. faecium and E. faecalis. In terms of propensity for causing human infections, they are far less virulent than other common bacteria such as Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and many others. For the sake of completeness, it is important to note that enterococci can also cause infections in healthy persons – urinary tract infections predominantly and very rarely, heart valve infection (endocarditis). This is a good thing because enterococci are hardy bacteria that are difficult to kill even when they are reported as being susceptible to the antibiotics tested against them. The term VRE is an anachronism, a throwback to a period – more than a decade ago – when vancomycin was the only antibiotic that could reliably treat severe infections caused by methicillin-resistant S. aureus (MRSA) and ampicillin-resistant enterococci. It was discovered that some versions of the van gene that made enterococci resistant to vancomycin (specifically vanA and vanB) could be transferred to MRSA, in effect creating VRSA that were virtually untreatable (this was more than a decade ago).

VRE were first isolated and identified in the UK in 1988, following which they were found in the USA and many other European countries before a more global dissemination. One of the causes for the emergence of VRE is the use of the antibiotic avoparcin (a glycopeptide related to vancomycin) in animal feed as a growth promoter in Europe (and to a lesser extent in Australia and New Zealand) since 1975. Banning avoparcin as a growth promoter in animals reduced but did not eliminate the prevalence of VRE in farmed animals (article behind a paywall).

How about Singapore? My colleague Dr Piotr Chlebicki from Singapore General Hospital (SGH) published an excellent review in 2008, documenting chronologically the sporadic reports of VRE causing local infections since 1994, prior to the bigger outbreaks at SGH in 2004 and 2005. The 2005 outbreak in particular made it to the public eye, generating a number of news pieces and also parliamentary questions. The “sanitised” part of outbreak control at SGH was published in the American Journal of Infection Control (AJIC) in 2008 (behind a paywall). It was an impressive effort championed principally by Dr Asok Kurup (an infectious diseases physician now in the private sector), screening thousands of patients, shutting wards, and stopping elective surgery for weeks. Including revenue loss, the whole operation must have cost millions of dollars for what was effectively fewer than 180 VRE carriers (there were only a handful with true infections).

VRE-AJIC-2005

VRE cases at SGH during the outbreak in 2005. Data derived from the American Journal of Infection Control publication in 2008.

However, there was a salutary effect to the SGH effort that is even now under-appreciated – VRE rates at all hospitals in Singapore remained low for the next five years! From the chart below, it is quite clear that the total number of VRE isolated – at least in the public hospitals – hardly crossed 100 each year between 2006 and 2010.

VRE-SG-2010

VRE in Singapore hospitals (case count). A black-and-white version of this was published in the Annals of Academy of Medicine, 2012.

Where are we with VRE today, more than 10 years after the SGH outbreak? Systematic hospital data are unfortunately not publicly available (although there are several good reasons why such data should be publicly available), but there have been sporadic publications from which an incomplete picture can be drawn. Researchers from Tan Tock Seng Hospital (TTSH) reported 243 VRE-colonised/infected cases from that hospital for the whole calendar year of 2012. Similarly, researchers from the National University Hospital (NUH) reported 405 VRE-colonised/infected cases over a period of 85 months (2008-2015), peaking in 2012 and declining over the next three years (paper behind a paywall). No data are publicly available from SGH since the 2008 AJIC paper. VRE rates have generally been far lower from the other public sector hospitals, probably because of the differing patient populations. But the suggestion from these papers is that the VRE “problem” has by no means gone away in Singapore, and may perhaps be worse than in 2005.

What should be done is another matter. The subject matter is controversial but I am of the opinion that there are far more important superbugs to focus on today. Carbapenem-resistant Enterobacteriaceae (CRE) rates are rising all over the country and the world, and patients infected/colonised by CRE necessarily compete with VRE-colonised/infected patients for hospital resources such as isolation rooms/cohort cubicles (along with patients with chickenpox, tuberculosis and MRSA). The concern with VRE has always been less about the bug itself than the fact that the vancomycin resistance gene can be transmitted to MRSA, a far more virulent bacteria. Lots of circulating VRE and MRSA in the same setting will increase the possibility of such events occurring. However, there are also far more antibiotics – albeit far more expensive ones – available for the treatment of VRE and MRSA, such that an “untreatable” VRE or VRSA infection is not a real concern today. Another convulsive effort, such as by SGH in 2005, seems to be less cost-effective compared to 2005 and – in the face of the CRE threat – also somewhat akin to rearranging deck chairs on the Titanic. Focusing on CRE, while continuing to improve overall hand hygiene compliance as well as overall prudence in antibiotic prescription, would be a pragmatic approach to VRE in the specific setting of Singapore hospitals.

Outbreaks (General) 2

Tuberculosis, Singapore

Curiously, a report of 2 SMRT train drivers and a crew manager being diagnosed with TB made it to the news today. Only one among them had active disease – the other two were diagnosed with latent tuberculosis which is non-infectious. Such cases are rarely highlighted in our mainstream media.

Screenshot from the Straits Times webpage


The risk of tuberculosis being transmitted on an MRT train or public bus is minimal. The risk of a road traffic accident is far higher.

Zika, Florida, USA

Aerial spraying against mosquitoes took place in Wynwood, Florida. A highly controversial method for controlling Aedes mosquitoes, because the chemical used – an organophosphate insecticide called Naled – may not reach all the mosquitoes or their breeding sites. There was a new case of Zika reported in Miami outside Wynwood.

mcr-1 in Salmonella, Scotland (ex Southeast Asia)

The plasmid-borne colistin resistance mcr-1 gene continues to be reported from more countries. The latest is Scotland, in a traveler who was diagnosed with Salmonella infection (the Salmonella carried the resistance plasmid). The traveler had recently returned from Southeast Asia, where the plasmid was likely acquired.

Clinical Vignette 63

A middle-aged man with sudden onset of painful lesions on both lower limbs. No prior significant exposures or clinical symptoms. No fever.


Questions:

  1. What is the clinical diagnosis?
  2. How should this person be worked up and treated?

This is a clear cut case of erythema nodosum. Skin biopsy would show panniculitis, but it is unnecessary to do one. It represents a hypersensitivity reaction, with women more prone to developing it than men. The causes are myriad and include infection (most commonly streptococcal infection and tuberculosis), pregnancy, drugs (sulphonamides among others), autoimmune conditions including Crohn’s disease, and malignancies.

A rather good review of EN can be found on the Emedicine website. The workup includes taking a detailed history, and doing various investigations to test for the common causes, including a chest X-Ray (tuberculosis), throat swab for Group A streptococcus or anti-streptolysin O titres, and other specific tests as dictated by the clinical history. Often, no cause for EN can be found (idiopathic EN).

Treatment is most commonly with NSAIDs and bed rest, although colchicine and certain anti-thyroid medications may help relieve symptoms as well. The condition is self-limiting and resolves in weeks.