whooping cough

Acute infectious disease, seen mainly in children, caused by colonization of the air passages by the bacterium Bordetella pertussis. There may be catarrh, mild fever, and loss of appetite, but the main symptom is violent coughing, associated with the sharp intake of breath that is the characteristic ‘whoop’, and often followed by vomiting and severe nose bleeds. The cough may persist for weeks.

Although debilitating, the disease is seldom serious in older children, but infants are at risk both from the illness itself and from susceptibility to other conditions, such as pneumonia. Immunization lessens the incidence and severity of the disease: the whole cell (or ‘killed’) vaccine has been replaced by an acellular version, which is made up from the bacteria Bordetella pertussis, and has fewer side effects than its predecessor.

According to World Health Organization (WHO) figures, there are 20–40 million cases each year, leading to up to 400,000 deaths, of which 90% occurred in developing countries (2003).