Pertussis is a highly contagious infection of the respiratory tract caused by the gram-negative bacterium Bordetella pertussis, which is only pathogenic in humans. The disease is transmitted by contact with droplets from infected individuals. It starts with symptoms similar to a cold and is followed by characteristic coughing fits that may last up to several weeks before they slowly subside. Small children may experience severe complications such as pneumonia, seizures and encephalopathy. Though infection is possible at any age, infants and small children have a higher risk of severe and potentially deadly disease progression.
In recent years, an increase in infections with B. pertussis has been observed in unvaccinated as well as vaccinated individuals. Depending on an individual's immune status, its clinical progression may vary widely and be uncharacteristic especially in adolescents and adults. This makes laboratory diagnosis highly important in order to prevent transmission with quick antibiotic treatment. It must be assumed that pertussis is underdiagnosed not only in Europe but globally, especially in countries with few resources.