New vaccines, drugs and diagnostics urgently needed to halt the spread of tuberculosis
Drug-resistant TB can take two years to treat, leave patients with frightening side-effects, such as hearing loss and psychosis, and cost up to a million dollars in health care costs per case. Jamie Triccas and Ben Marais argue that Australia needs to play an important role in finding better solutions to stop the spread of one of the world’s oldest and deadliest diseases.
A young woman from Papua New Guinea has sought treatment at Cairns Base Hospital for extensively drug-resistant tuberculosis (XDR-TB), a difficult and expensive disease to treat. After five months in isolation, she is likely to stay in hospital care for the next two years, and her chances of being cured are frighteningly low. Patients with drug-resistant TB must endure a long course of treatment (24 months or longer) with harsh side effects, such as permanent hearing loss and temporary psychosis.
Treatment for one case of XDR-TB can cost $500,000 to $1 million, with no guarantee of cure. Our methods of treatment and control for TB are not sustainable in the face of highly drug-resistant TB that is as transmissible as drug-susceptible strains; investments must be made into better solutions.
New vaccines, drugs and diagnostics are urgently required to ultimately eliminate one of the world’s oldest and deadliest infectious diseases. Unlike other major diseases such as HIV and malaria, TB is transmitted via airborne particles, complicating infection control measures. TB spreads through air just like the common cold and most people are completely unaware when TB exposure occurs. Although treatable, the TB germ is becoming more deadly as it evolves to dodge our current medicines.
In 2011, there were an estimated 78,000 cases of multidrug-resistant TB (MDR-TB) in the Western Pacific Region. From 2001-2010, 59 cases of MDR-TB have been diagnosed by the Cairns Regional TB Control Unit, which encompasses Far North Queensland and Torres Strait. XDR-TB has been reported in 84 countries. The World Health Organization estimates that each year there are 440,000 new cases of MDR-TB globally. Last year, only 13% of these patients were diagnosed and enrolled in treatment. This means hundreds of thousands of people worldwide are going untreated and continuing to spread drug-resistant forms of the disease. India has now reported TB cases so difficult to treat that some have labeled them totally drug-resistant TB (TDR-TB).
MDR-TB continues to be a threat to Australia’s citizens who work or travel throughout the region. Eleven countries in the Asia Pacific region – Afghanistan, Bangladesh, Cambodia, China, India, Indonesia, Myanmar, Pakistan, the Philippines, Thailand and Vietnam – are among the 22 countries that carry 80% of the global TB disease burden. Each report high rates of drug-resistant TB. Last year, MDR-TB reached crisis levels in Papua New Guinea, inciting former Health Minister Jamie Maxtone-Graham to pronounce it a greater health emergency than HIV/AIDS. Australia’s aging population and high numbers of people with chronic health conditions increase our vulnerability as a nation.
Vaccines are one of the most cost-effective tools in the fight against infectious diseases. There is broad consensus that the development of an
effective TB vaccine is a key global health priority. Twelve TB vaccine candidates are currently in clinical trials and research groups within
Australia are leading the development of additional promising candidates.
We applaud the Australian government for the time and effort spent developing AusAID’s Medical Research Strategy for the Asia Pacific region. A contribution of $10 million for malaria research highlights the Australian government’s commitment to lead through innovation. We hope that there is a similar vision for funding research and development of new tools to fight TB. We are especially glad that TB vaccines have been included in the Medical Research Strategy. Vaccine research and development is a lengthy process involving large-scale clinical trials with thousands of
participants over multiple years. Australian participation alongside other donors in funding the TB vaccine development effort would help accelerate progress, and build on AusAID’s leadership role in tackling the Asia Pacific region’s major health challenges.
Jamie Triccas is Associate Professor and Head of the Microbial Pathogenesis and Immunity Group, Department of Infectious Diseases and Immunology at the University of Sydney. Ben Marais is Deputy Director and Patrick de Burgh Associate Professor at the Sydney Institute for Emerging Infections and Biosecurity, University of Sydney.