1. Bordetella (pertussis) (whooping cough) bacterial respiratory childhood infections B. Pertussis B. parapertussis

2. B.pertussis Small gram-negative bacilli Most fastidious Culture media containing charcoal ◦ bordet-Gengou medium ◦ Charcoal blood agar Strict aerobe Slow growth (3 days) 3 major agglutinogens ( attachment ) ◦ (1, 2 and 3) ◦ detected by specific antiserum ◦ Role in immunity ◦ Three serotypes  Type 1,2  Type1,3  Type 1,2,3

3. pathogenesis Non invasive infection of respiratory mucosa ◦ Ciliated epithelium of bronchi, trachea Human is the only natural host IP : 1 – 2 weeks Tracheal cytotoxin ( TC ) Pertussis toxin (PT) ◦ Lymphocytosis Filamentous haemagglutnin (FHA)

4. clinical Catarrhal phase ( preventable )-most infectious Paroxysmal phase ( sever cough) Convalescent phase Atypical cases Complications ◦ Bronchopneumonia ◦ Secondary infection ◦ Lung collapse ◦ Anoxia, convulsions

5. EPIDEMIOLOGY SOURSE ◦ Patients ( droplets ) – child or adults ◦ Atypical cases Cmunicable Epidemics Antibiotics reduce transmission Incidence and mortality ◦ All ages ◦ Cause of death ( < 2 years, infants )

6. Immunity One attack confers long lasting immunity ◦ (herd immunity) Infection with different serotype Passive protection from mother is incomplete 3 – injections of vaccine – effective active immunity

7. Diagnosis Clinical lymphocytosis Laboratory ◦ Nasopharynx (postnasal swab ) ◦ Pernasal swab ◦ Selective media ◦ Slid agglutinations ( antiserum)

8. Treatment No effect in well established infection Erythromycin ◦ Reduce severity if given before paroxysmal phase ◦ For 14- days ◦ Reduces transmission ◦ Prophylaxis of contacts

9. Control Vaccination is safe - > 90% effective ◦ Whole bacterial cell ( killed) – deep IM inj. ◦ Contain 3 – agglutinogens ◦ 3 – doses ◦ SE : neurological sequelae, crying, fever Acellular pertussis vaccine ◦ PT, FHA + agglutinogens