Recent reports about the emergence of Extreme Drug-Resistant TB in South Africa are disquieting reminders of fundamental concerns in international public health: fragile health systems in developing countries, stretched to the breaking point as they struggle to respond to health needs today, have the potential to incubate infectious diseases that are tomorrow's global threat. While the new strains of TB that are untreatable with any of current medications affect only small numbers at the moment, the insurgent microbes cannot be ignored.
Resistant strains arise when individuals with infectious diseases are incompletely treated, leaving the hardier bugs -- those not killed off by the first part of the treatment -- to flourish. Incomplete treatment, in turn, reflects serious but common breakdowns in health systems: stock-outs of drugs or diagnostics because of a broken supply chain, an inability of patients to obtain timely and continuous care, health workers who don't have the wherewithal to follow up
assiduously and make sure patients are completing a course of treatment, non-existent surveillance systems, the widespread availability of fake drugs, and more. And the root causes of these problems have to do with insufficient and unpredictable financing, human resources shortfalls (among both service delivery and managerial ranks), and dysfunctional incentives.
Preventing or slowing drug resistance is a public policy challenge that implies tough trade-offs between responding to short-term needs, on the one hand, and devoting resources to avoid problems over the long term, on the other. Instead of following only the politically expedient route of pushing the drugs out the door, those providing the finance and technical advice have an enormous responsibility to consider the unintended consequences and to design mechanisms to avert or deal with them.
Part of the solution lies in increased investment in R&D for the next generation of treatments. So, for example, as second-line treatments for AIDS are starting to be made available in developing countries, pharmaceutical companies are at work developing the third line; with subsidies from public-private partnerships, several large companies and biotechs are working on new TB medications and better diagnostics. Another part of the solution can be found in ensuring that prices faced by patients are set at levels that are affordable but discourage over-use of drugs. The high-level subsidy for antimalarials, first proposed by an Institute of Medicine panel and now being moved toward implementation under the International Drug Purchase Facility, is another important strategy to slow the emergence of resistant organisms. But this is not anything close to the full picture of what needs to be done.
With ever greater attention and money devoted to getting drugs to people, we need to think far more comprehensively about the higher levels of spending on support systems that need to be made whenever drugs are introduced and access is scaled up: the real bottom line = the price of the product + the cost of the range of complementary investments in the delivery system. And it's worth considering whether donors could and should condition access to funds for pharmaceutical procurement on whether the most basic parts of the delivery system are in place and functioning at an adequate level.
Update: The New York Times has published an editorial that provides further information regarding extreme TB.