Isolation of the causative agent remains the "gold standard" for the early diagnosis of pertussis. For this purpose, the nasopharynx is swabbed with a calcium alginate swab. Cephalexin-containing charcoal horse blood medium is used for the transport of the swabs to the bacteriology laboratory. As an alternative, the isolation of bordetellae can be performed at the paediatrician's office by direct inoculation of charcoal horse blood agar plates. Long-lasting cough of unknown aetiology is the main field for pertussis serology (ELISA). Even today, severe courses of whooping cough requiring hospitalization are not rare, especially in infants. Erythromycin (given in high doses for 14 days) is the antibiotic of choice for pertussis. As an alternative to the macrolides, cotrimoxazole may be administered or amoxycillin. Salbutamol and the corticosteroids have been shown to be useful for the symptomatic treatment of severe pertussis in infants.