Pertussis, usually referred to as whooping cough, is caused by the gram-negative bacteria, Bordetella pertussis. The younger a person is upon contracting pertussis, the more severe the symptoms and complications. Fatal disease almost only occur in infants less than 6 months of age, while adults usually only experience nonspecific symptoms. For the prophylaxis of infection, children are repeatedly inoculated in infancy with DTP (diphtheria, tetanus, pertussis). Because of the decreasing protection from the inoculation over the years, pertussis appears more and more often in adulthood. The effectiveness of antibiotic therapy could not be clearly established.
The incubation period is 12 to 20 days. After a two week prodromal phase consisting of non-specific symptoms such as rhinitis, conjunctivitis and fever, the characteristic cough attacks follow, which normally end after 6 weeks.
A leukocytosis occurs due to a lymphocytosis and not a neutrocytosis, although it is a bacterial infection. In children and adolescents, leukocyte values between 15 and 30 x 109/L are usually observed. In adults on the other hand, this phenomenon is not observed. Lymphocytes are mostly small and inconspicuous. Only a few reactive atypical lymphocytes can be observed.