Pertussis in developing countries: definition of the problem and prospects for control.

Pertussis is a distinct clinical syndrome caused by Bordetella pertussis. The disease has been well characterized and largely controlled in the industrialized countries. Studies of pertussis in developing countries have been much more limited, in large part because of difficulty in culturing the organisms. Conventional whole-cell vaccine is being widely used in developing countries but without clear epidemiologic measures of efficacy. The introduction of new acellular pertussis vaccines has focused attention on the need to define the impact of pertussis in the developing world and to explore the optimal approach to control of this illness.