Poor urban neighborhood in a large city in India. DRTB patient (squatting) in front of his house while coughing up bloody sputum. His relative (middle) holds his small daughter. The woman to the right is a research assistant. (photo by Jens Seeberg © 2016)
Is drug-resistant tuberculosis (DRTB) a special case of antimicrobial resistance (AMR)? The question has two parts. The first part would be, “is DRTB a case of AMR?” This may seem to be asking for the obvious, since the relation of DRTB to AMR is that of a part to the whole. AMR includes all forms of antimicrobial resistance, therefore also DRTB. Moving to the second part, then, why should it be a special case of AMR? This question is less trivial than it may seem at first. If one looks at the global health efforts involved in reduction of AMR compared to those involved in control of tuberculosis (TB) and its drug-resistant strains, collectively known as DRTB, the answer seems to be “yes” – so special that it is hardly considered as part of the general AMR problem. This special status may act for TB control as a barrier to addressing some of the structural dynamics that lead to AMR in society in general.
Why is drug-resistant tuberculosis a special case of TB?
DRTB is caused by strains of Mycobaterium tubercolusis resistant to Isoniazid and Rifampicin, two of the four first-line anti-tuberculosis drugs, but may also involve resistance to one or several second-line drugs. Although tuberculosis was nearly eliminated in western countries after World War II, only around 25% of the estimated number of DTRB patients around the world receive treatment (WHO, 2020). In 2014, the World Health Organization (WHO) launched the “End TB Strategy” (WHO, 2014) in response to not only the Sustainable Development Goals, but also because of the failure to halt the increase of DRTB worldwide. These efforts have been the topic of considerable political attention, resulting in the first ever UN high-level meeting on TB in 2018 (Herbert, 2018). On a parallel track, a UN high-level meeting held in 2016 adopted a political declaration on AMR (UN General Assembly, 2016). However, the logics of these two tracks are quite different.
TB control has a long public health history of being a “vertical”, or disease focussed programme, with its own ideology of paternalistic public health ethics, perhaps most clearly expressed in the DOTS strategy (Directly Observed Treatment – Short course), where patients were to be observed taking their medications to increase adherence. The vertical approach is reflected in the ambitious goal of ‘ending TB’, e.g. to achieve that TB is no longer a major public health concern through a 90% reduction of TB incidence and 95% reduction of TB deaths in 2035 compared to 2015 (WHO, 2014). In contrast to this disease focus, the recent global efforts of AMR control take a much more “horizontal” One Health approach, seeing AMR as a complex problem evolving in the complex dynamics of human, animal and environmental health and requiring interdisciplinary research and a wide range of interventions to limit excessive use of antibiotics, control environmental pollution with antibiotics, etc. An admittedly oversimplified yet telling articulation of the difference between DRTB and AMR policies could be that AMR policies seek to better control treatment based on the problem of resistance as the point of departure, whereas DRTB policies seek to better control disease based on a disease-specific point of departure.
Should drug-resistant TB be considered a special case of AMR?
On this background, it does indeed seem to that DRTB control is a special case. We may rephrase the question and ask, whether it ought to be considered as a special case. Here, the answer is much less obvious. Let us start with the observation that given a disease-specific point of departure, most if not all infections involving AMR are likely to present particular problems. The increase in infection with Methicillin-resistant Staphylococcus aureus (MRSA) linked to overuse of antibiotics in industrial pig production (Khanna et al., 2008; Voss et al., 2005) is different from, say, an epidemic of fluoroquinolone-resistant gonorrhoea linked to overuse of Ciprofloxacin in human healthcare (Harrell, 2014). Biosocial dynamics involved in the development of AMR – e.g. disease characteristics such as latency period and mode of infection; virulence; transmission, including possible zoonotic properties; access to effective treatment; duration of treatment; and severity of side effects – are just some of the factors that need to be taken into account when addressing any type of AMR. From this perspective, there is nothing special about TB. However, TB control policies have focused primarily on the public healthcare sector, which is the sector that directly responds to WHO policies. Strategies such as DOTS were developed in this political context and thus worked through public health systems. Realizing the de facto involvement of the private healthcare sector in TB control, WHO began, during the early 2000s, to establish policies to engage private practice in the DOTS programme while disregarding the fact that many private practitioners worked actively against the DOTS strategy (Ecks and Harper, 2013). In India, which holds approximately one quarter of the world’s TB cases, and where DRTB incidence is fast rising, attempts to include commercial healthcare in the national TB control strategy have failed (Seeberg, 2014; Udwadia, Pinto and Uplekar, 2010). It can be argued that this is so, in part because TB and DRTB are given “special case” status. After all, TB control and the development of drug resistance that it gives rise to are addressed as isolated problems without due consideration of the larger problem of AMR in society. Staying with the example of India (but noting, at the same time, that this problem is in no way limited to India), approximately 70% of TB treatment is provided outside the government TB control programme, i.e. in the commercial sector. Big variations in treatment regimens occur and incorrect and interrupted treatment are common (Udwadia, Pinto and Uplekar, 2010). Yet, within the TB control programme, these are seen as problems that are specific to TB treatment, with solutions that can be specific to TB (such as new DRTB drugs and better DRTB diagnostics) rather than as general AMR problems that undermine treatment of many infectious diseases, including TB.
It seems justified to argue that one of the greatest barriers to more effective DRTB prevention is linked to the understanding within global health policy, financing and infrastructure that DRTB, along with TB, is a special case, considered to be completely unlike other forms of AMR. This understanding is a reflection of the verticality of TB control. However, TB – and with it DRTB – is a profoundly biosocial disease (Seeberg, in press). It seems highly unlikely that it will ever be controlled based on medical technologies without seriously taking into consideration the need for improvement of the living conditions of poor populations at highest risk of TB infection and disease (Seeberg, in press). To the extent that a One Health approach to AMR control can be pushed in this direction by taking the biosocial dynamics of AMR fully into account, it may be time to remove the “special” status of DRTB and begin to see it as this: a kind of AMR.
Professor (mso) at the department of Anthropology, Aarhus University