Analysis index

PCR: Nasopharyngeal swab, bronchial secretion, BAL, tracheal secretion, sputum, nasopharyngeal aspirate, at least 400 µl each.

Antibody-demonstration: 2 ml serum

IgG (Toxin and filamentous hemagglutinin (FHA)): < 40 – 50 IU/ml

IgG toxin: < 40 – 100 IU/ml

IgA toxin: < 15 – 20 IU/ml

PCR: negative

Suspicion of infection with pertussis/parapertussis (Tracheobronchitis with convulsive coughing, in adolescents and adults possibly only dry coughs over a period of several weeks)

Serological detection of IgA-toxin antibodies > 15 IU/ml or of IgG-toxin antibodies > 100 IU/ml as well as the demonstration of bacterial DNA of Bordetella pertussis or parapertussis will be reported to the responsible health department by the laboratory, giving the patient’s name. Suspicion of disease, disease and death have to be reported by the treating physician.

Direct demonstration of Bordetella pertussis or parapertussis from a nasopharyngeal swab by PCR is only possible during the catarrhal stadium and early convulsive stadium, so approximately up to the third week in untreated infections. Up to the fifth week, the number of positive results decreases to approximately 50 %, after the fifth week to < 20 %. With the help of the PCR, differentiation between infections with pertussis respective parapertussis is possible in one step and from only one nasopharyngeal swab. Circulating antibodies against the Bordetella pertussis toxin can only be found from the 15^th to 25^th day of onset of clinical symptoms. The circulating antibodies reach their highest concentration about 8 to 10 weeks after disease outbreak and can remain detectable for years and even decades. IgG-antibodies can be detected after a vaccination as well as after an acute infection. IgA-antibodies against the pertussis toxin are usually only produced in acute infections and only in exceptional cases after vaccination (within the past three years). Children with suspected whooping cough should be kept away from community facilities. 5 days after therapy commencement, nursery or school may be visited again. Due to the limited duration of immunity, after both natural illness or after full vaccination, even immunized children, adolescents and adults can be re-infected. After basic immunization (babies and small children), booster vaccinations should be given at pre-school age, in the youth and in adulthood (please also refer to current STIKO recommendations).

Please also refer to “Respiratory tract pathogens” and “Multiplex-PCR”