The World Health Organisation's (WHO) strategy to control the worldwide rise of tuberculosis (TB) has not worked, say Harvard researchers in the Journal of Epidemiology and Community Health. It is time to go beyond simply treating people with active disease, which has been the cornerstone of its strategy, they say.
The WHO declared TB a global health emergency in 1993: a third of the world's population was thought to be infected at the time, with 7.5 million new cases and 2.5 million deaths from the disease every year. One in four preventable deaths in adults around the world was attributable to TB.
In the same year, the WHO introduced its 'directly observed therapy short course' (DOTS), in a bid to halve TB deaths over the next decade and curb the global epidemic.
Yet, say Dr Timothy Brewer and Jody Heymann from Harvard University, Massachusetts, USA, TB cases continue to rise, despite the introduction of 'DOTS-Plus', a programme aimed to tackle multiple drug resistance to TB strains. Where HIV is endemic, cases of TB have soared.
There is no historical precedent for the successful global elimination of an infectious disease based solely on treating people with known active disease to prevent transmission, the authors write.
Although some authorities believe that increased resources and political will for DOTS programmes would lead to global TB control, Drs Brewer and Heymann review recent figures that "show that DOTS at best leads to modest declines in TB case rates and in some regions is unable to contain TB at all."
Epidemiological data suggest that combinations of preventive and active treatment strategies are likely to be more effective than DOTS at controlling TB, they suggest. Preventive treatment should be extended to those who are HIV negative and positive, and better surveillance systems should be put in place.
The authors acknowledge that DOTS programmes have improved the effectiveness of treatment and helped prevent the emergence of drug resistant strains.
"However, controlling TB will require much more than treating people diagnosed with smear positive disease. To substantially reduce TB worldwide, we will have to do much more than connect the DOTS," they conclude.