“…Experience with the method is one of the most important variables. Attempts at isolating B. pertussis are most likely to be successful at the end of the incubation period, during the catarrhal stage, and at the beginning of the paroxysmal (convulsive) stage of the disease (9,26,42,52,59,102). Isolation rates are negatively correlated with increasing age (high rate in infants [121]; low rate in adults [116]), with effective antimicrobial pretreatment (macrolides, co-trimoxazole, and tetracyclines but not penicillin or ampicillin [8,42,59,102]), and with the number of pertussis vaccination doses received by the patient (lower isolation rate in completely vaccinated individuals [8,35,59,102]).…”