The world’s most lethal infectious disease threatens a comeback
While over 11,000 people have died from Ebola virus disease during the most recent epidemic in West Africa, 1.5 million people die from tuberculosis (TB) each year. And now, estimates of TB burden are greater than ever before. While there have been some successful drug treatments for TB in the past, drug-resistant Tuberculosis is becoming more common and is poised to derail global control efforts.
In the piece below, authors from today’s Medical Journal of Australia article on multi-drug resistant tuberculosis explain why this highly contagious disease should be on everyone’s radar, and why Australia should be taking a leadership role on this issue.
Professor Allen Cheng and Dr James Trauer write:
MDR-TB is not a problem that will just go away
While the world continues to delay fully grappling with the greatest infectious disease killer of the modern age – tuberculosis – new drug-resistant strains of the disease have been emerging, including multidrug-resistant TB (MDR-TB).
As TB in Australia and other high income countries has been relatively uncommon, this disease does not generally register on the radar here. However, MDR-TB and even more resistant strains, such as the spectre of extremely drug-resistant TB (XDR-TB), have the potential to change this. This is not only because of the direct costs of patients with such strains being imported and transmitted within Australia, but also the huge costs to the healthcare systems in our nearest neighbours.
“Drug-resistant TB is a major global threat and Australia is well placed to support global initiatives towards achieving control in our region.”
Responding to MDR-TB in resource-limited settings is not easy
Initially, drug resistance occurs because of failure to complete treatment – and this is more common where systems to follow up patients are poor. Health systems require resources and trained personnel, which are in short supply in countries with the highest disease burden.
However, the assumption that the emergence of MDR-TB can be prevented simply by ensuring compliance to standard treatment for non-resistant strains needs to be overturned. Not only does this risk blaming patients with MDR-TB for their own condition, but it is increasingly clear that this view is wrong. The large majority of cases of MDR-TB now occur through direct community transmission – passing drug-resistant strains from one person to another.
A failure to sufficiently grasp this means patients who have no prior history of treatment are rarely tested for resistance, and instead are treated with drugs that don’t work.
The treatment of MDR-TB presents a further challenge
Retaining patients on toxic treatment regimens for two years to ensure treatment completion is a difficult undertaking – and one that is critically dependent on the strength of the underlying health system, including consistent drug supply chains, laboratory capacity, human resources and operating procedures.
The treatment of drug-resistant TB is much more expensive and requires more resources to ensure treatment completion, further exacerbating the problem.
Despite these challenges, we know success is possible. The rapid and effective response to MDR-TB outbreaks in the remote Pacific Island of Chuuk and success stories in regional neighbours such as Cambodia – despite its relative poverty – demonstrate how considered programs can reduce the burden of disease.
Australia now has an opportunity to take a leadership role in combating the MDR-TB epidemic in the Asia-Pacific – a region home to well over half of all MDR-TB cases globally.
Why get involved?
The strongest argument for responding is the human right to TB treatment and to protect the health of the most marginalised and neglected populations of the world.
However, the principle of “enlightened self-interest” applies here too: investing in TB control programs is clearly in Australia’s interest from a biosecurity perspective. Failure to respond to MDR-TB will also lead to worsening of the problem in years to come, placing a huge burden on the health systems of developing countries and stifling economic development in our region.
The response needs to be taken to a global scale and – with the announcement of highly ambitious post-2015 END-TB Targets to replace the modest Millennium Development Goals – now is the time to do it.
Collaboration with affected countries
If fully funded, the US National Action Plan for Combating MDR-TB, which calls for partnership between international agencies and affected communities, is an example of the leadership vision required.
As a high-income country of the Asia-Pacific, Australia is ideally placed to support such action, which should be targeted on the basis of need and linked to broader health system development. As described in the US National Action Plan, pillars of the response should include working with highly affected communities and countries, improving international collaboration and accelerating research.
Broader interventions that go beyond health systems and aim to improve human development and living standards are also essential. TB is a disease of poverty, and poverty alleviation limits the spread of TB.
Australia has the expertise and capacity to work with countries in our region to lead the implementation of these initiatives and support global efforts towards halting the spread of drug-resistant TB. We must rise to the challenge.
Dr Allen Cheng will be presenting on MDR-TB at the Australasian Society for Infectious Diseases (ASID) Annual Scientific Meeting 2016 on Thursday April 21 in Launceston.
Professor Allen Cheng and Dr James Trauer are from the School of Public Health and Preventive Medicine at Monash University