The severity of whooping cough in hospitalised children--is it declining?

Four hundred and sixty admissions for whooping cough to three hospitals between 1974-9 were reviewed. Many children had a long illness. More than half of them had severe or moderately severe coughing spasms and a quarter had pronounced feeding difficulties. The incidence of clinical pneumonia and convulsions was low and there were no deaths. The disease continues to be much more severe in infancy. There was some evidence that the disease declined in severity over the period studied. A number of factors including increased use of erythromycin may have contributed to this change.