The Styblo model 20 years later: what holds true?

The Styblo model is the result of international collaboration aimed at the expansion of national tuberculosis (TB) programs in partner countries. This model is the foundation of the DOTS strategy launched in the 1990s and which was subsequently expanded as a global strategy. This paper discusses the impact and relevance of this body of work. The basic principles supporting the model still hold. There is a tendency to be all-inclusive when global strategies are devised, which increases the complexity of such strategies. Whereas it is relatively easy to standardize diagnosis and surveillance, this is not the case with patient care and treatment where, as recent experiences in TB programs show, universal recommendations can be controversial. It may be unwise to put forward global strategies when the terrain is as variable as it is in different parts of the world. Since the conception of the model, the human immunodeficiency virus (HIV) pandemic has been gaining force in Africa. As a result, TB control efforts on the continent have been severely undermined. The relevance of the model in this setting is questioned. Although HIV infection has contributed to outbreaks of drug-resistant TB, it has also facilitated the control of outbreaks of multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. Where MDR-TB has reached critical proportions in the absence of HIV, it has proven difficult to control. Technological development has not kept up with the need for new tools. Whereas many policy analysts agree that a revised strategy is required, a convincing breakthrough has yet to appear.