Antigenic structure: . Pili: Adheres to ciliated epithelial cells of respiratory tract. . Filamentous haemagglutinin: Adheres to ciliated respiratory
. Pertussis toxin: . Lumphocytosis promoting factor . Histamine sensitizing factor . Insulin secretion enhancing factor . Adenylyl cyclase toxin . Dermonecrotic toxin . Hemolysin . Tracheal cytotoxin: Inhibits DNA synthesis in ciliated respiratory epithelial cells. . Lipipilysaccharide: Damages respiratory epithelial cells. Clinical features: Incubation period: 2 weeks Route of transmission is respiratory from early cases and possibly carries.
It has three stages:
During catarrhal stage, the patient is highlyinfectious but not very ill manifesting with mild coughing and sneezing. During paroxysmal stage, the patient presents with explosive repetitive cough with characteristic ‘whoop’ upon inhalation leading to exhaustion, vomiting, cyanosis and convulsion.