Bordetella pertussis (B. pertussis)

Pertussis (whooping cough) is a highly contagious bacterial infection caused by B. pertussis.21 B. pertussis attaches to the cilia of upper respiratory mucosa. The toxins produced paralyze the cilia and cause inflammation. B. pertussis is transmitted from person to person by direct contact with respiratory secretions or by airborne droplets generated by coughing or sneezing. The incubation period is about 5 to 10 days (may be as long as 3 weeks).

Clinical Features

Early symptoms such as runny nose, low-grade fever, occasional coughing is indistinguishable from those of other respiratory infections. The “hallmark” signs of pertussis are paroxysms (fits) of rapid coughs, followed by a high-pitched “whoop,” vomiting, and subsequent exhaustion. The period of infectivity starts with the early symptoms and extends into the paroxysmal stage (about 2 weeks) or until 5 days after the start of effective antibacterial chemotherapy.

Recovery is gradual, lasting about 2 to 3 weeks. Pertussis can cause serious and sometimes life-threatening complications in infants and young children, e.g., pneumonia, convulsions, apnea, encephalopathy, and death. Complications in adolescents and adults are often caused by the cough itself, e.g., weight loss, loss of bladder control, syncope, and rib fractures from severe coughing.


Pertussis is a vaccine-preventable infection. There are four combination vaccines used to prevent diphtheria, tetanus and pertussis: DTaP, Tdap, DT, and Td. Two of these (DTaP and DT) are given to children younger than 7 years of age, and two (Tdap and Td) are given to older children and adults. Vaccine protection fades with time. A booster that contains protection against tetanus, diphtheria and pertussis (Tdap) is recommended.

Medical Management

Pertussis is generally treated with antibacterial chemotherapy. The recommended antibacterial agents include azithromycin, clarithromycin, and erythromycin. Trimethoprim-sulfamethoxazole may also be effective. With early treatment (before coughing fits begin) pertussis is likely to be less severe. Early treatment is also likely to prevent the transmission of B. pertussis to close contacts.