PHILADELPHIA, PA- Without new tools, soon, to address multidrug-resistant tuberculosis, TB control efforts made over the last two decades will be defeated, Dr. Carol Dukes Hamilton said this week, in an IDWeek presentation. Hamilton, co-chair of the Infectious Diseases Society of America Center for Global Health Policy called drug-resistant TB a runaway train.
New tools are slow to develop, she noted. In the meantime, a step in the right direction would be to update the World Health Organization’s Directly Observed Treatment Strategy, or DOTS, to address drug resistant TB, HIV-TB co-infection, and other factors that complicate the global TB response.
“The WHO DOTS strategy represents the bare minimum of what’s needed,” she said. Originally, she said, it provided “an excellent foundation for getting TB programs up and going in countries with weak or non-existent government-wide TB programs.”
But the initial strategy was only focused on addressing smear-positive pulmonary TB in adults, she noted, and an emphasis on microscopy for diagnosis and not on culture means 40 to 60 percent of cases are missed. Microscopy also fails to detect drug resistance, which has contributed to an increase in transmission of multidrug resistant TB, she said.
Once it became apparent that DOTS isn’t enough, the Stop TB strategy was created in 2010. This strategy is meant to address gaps, including failures to detect and treat drug-resistant TB, to address TB in children and in vulnerable groups that include prison populations, to address HIV-TB co-infection, and to address extrapulmonary TB.
Additional barriers to addressing TB include the lack of an effective vaccine, and low access and uptake of preventive therapy of latent TB infection. Inadequate healthcare facilities in resource-limited areas with few infection control efforts add, rather than limit opportunities for disease to spread, while current TB treatment regimens are lengthy and inadequate to address negative drug interactions with antiretrovirals for treating HIV infection, she said. All of these factors fuel drug resistance.
“Tuberculosis is often the nail in the coffin for people who are already poor,” she said, adding that people who are barely getting by go from a situation of poverty to extreme poverty after being infected with TB.
The way forward is to borrow tools, processes, and ideas from other disease responses, including from the HIV, malaria, and neglected tropical disease worlds, she said. “We need to use the data available to advocate for more resources,” she said.
She recalled the resurgence of TB in the U.S. in the early 1990s when reduced public health funding, the emergence of HIV, and an epidemic of crack cocaine use in American cities contributed to an unprecedented TB epidemic. While that epidemic led to better infection control efforts and major reforms in public health, she said, developing countries are still way behind in their TB control efforts because of their gaps in resources.