by Anne Muendi Musuva (MD, MPH from Kenya) and Innocent Turate (MD, MScPH from Rwanda)
When Daniel and Patrick, residents of Kapsabet – a rural town in Kenya, were suspected of defaulting on their treatment for multi-drug resistant (MDR) tuberculosis in August 2010, they were arrested and thrown in jail for allegedly posing a threat to the health of the public. Amidst public outrage and pressure from human rights activists who filed a court case to challenge this imprisonment, the men were eventually released. This harsh jail term was meted out with no consideration of the difficulties faced by patients while undergoing treatment for MDR tuberculosis.
MDRtuberculosis is defined as tuberculosis that is resistant to the two key first line anti TB drugs Rifampicin and Isoniazid. It is a man-made problem brought about by interrupted, erratic, or inadequate TB treatment. Today, direct transmission of MDR-TB strains is on the increase, further augmenting the problem. Although progress has been made to reduce the global incidence of drug-susceptible TB, the emergence and spread of drug resistant TB threatens to reverse the gains made in the prevention and control of TB to date. The WHO estimates that in 2010, there were 650,000 cases ofMDR tuberculosis globally. MDR-TB is underdiagnosed and inadequately treated. Less than 6% of previously treated cases are tested for MDR-TB, and only 16% of MDR-TB cases notified in 2010 were enrolled on treatment. Indeed the management ofMDR TB is complicated.
Diagnosis of MDR tuberculosis is a challenge particularly in resource poor settings. Diagnosis requires culture labs since microscopy based diagnostics are unable to diagnose MDR-TB. The novel diagnostic assay GeneXpert, remarkably shortens the duration of diagnosis of tuberculosis and its resistance to rifampicin- to 2 hours – and can be used in peripheral facilities. However, this molecular equipment requires a steady supply of electricity, which is a pipe dream in many resource poor settings. Treatment is particularly problematic and very expensive. It involves daily injections, a cocktail of less effective and toxic drugs and takes a minimum of 18 months. Complications, such as irreversible hearing loss and imbalance, are common. There have been no new TB drugs developed in almost 50 years. Pharmaceuticals have been reluctant to develop drugs for MDR TB as this illness mostly affects patients who can ill afford the drug costs, leading to market failure.
During MDR TB treatment, balancing the rights of individual patients – to have freedom of movement – versus protecting the rights of the public – to be protected from dangerous infectious diseases- raises moral and ethical concerns, as seen in the case of Daniel and Patrick. Should patients be isolated, even if voluntarily? On the one hand, isolation of infectious patients would protect close contacts and the public from further exposure, but on the other hand how feasible and humane is long term isolation from loved ones? Moreover, studies on drug sensitive TB indicate that the vast majority of secondary infections in close contacts have occurred by the time a TB patient is diagnosed, and that transmission is interrupted on the day of starting effective antibiotics, suggesting that isolation of patients who start therapy is futile. And wouldn’t the threat of isolation be a major disincentive for patients to present for diagnosis and treatment?
All these challenges are faced against a back drop of weak health systems, unregulated private sectors and limited domestic and international funding for MDR TB. Moreover, further amplification of drug resistance, leading to extremely drug resistant (XDR) or totally drug resistant (TDR) TB, is emerging as an even more ominous threat.
Needless to say, there is an urgent need for further research on how to best improve the dire situation in the management and control of MDR TB. Diagnostics that can be used in resource poor settings with basic infrastructure are crucial. Simpler, shorter, cheaper, and safer oral treatment for MDR TB needs to be developed if countries are to scale up treatment to reach the WHO target of treating 80% of MDR TB cases by 2015.
All is not lost though. Ongoing research may provide solutions to some of these challenges. The development of a treatment regimen that would drastically reduce the duration of treatment from 24 months to 9 months is already underway, with very promising results. New drugs are in the pipeline, such as TMC 207 and PA 824. While these developments are very encouraging, much more still needs to be done. Evidence gaps in infection control, surveillance and supply chain issues need to be filled. Urgent investment is needed in infrastructure, diagnostics, care provision and in educating populations about MDR TB to decrease the social fear currently surrounding MDR TB. Early detection, diagnosis and treatment of TB patients remains a priority in the control of MDR-TB. Strong collaboration among health facilities, continuous and coordinated care, together with the development of clear, simple TB guidelines for healthcare providers and patients are key to success in the battle against MDR-TB.