Mode of transmisison: droplets

Incubation: 7-10d (5-21d)

Period of infectivity: catarrhal stage - 3wk after onset of paroxysmal cough in case not treated with antimicrobials. If erythromycin: until 5d antibiotics.

R0 = 14

Vaccines:  acellular

• DTaP-IPV-HepB/Hib

• DTaP-IPV

• Tdap/Td

Schedule: 6wk, 3mo, 5mo, 4, 11, pregnancy

efficacy: 84% effective

precaution; children with evolving neurological disorder

Herd:

• Bordetella pertusis

  • gram negatvie bacillus

  • fastidious (special media)

  • often cleared by time typical cough appears

  • PCR

clincial

• Catarrhal ; 1-2 weeks

  • infectivity greatest

  • rhinorrhoea

  • irritating cough

• paroxysmal stage

  • coughing short expiratory bursts followed by inspiratory gast/whoop

  • and/or vomiintg

  • relatively well between paroxysms

• in young infants

  • apnoea/canosis may precede severe disesase

• in immunised children:

  • compared to other resp. illnesses

    • inspiratory whoop

    • post-tussive vomiting

    • absence of wheeze and fever

• cough generally worse @ night, paroxymasl

• complciatiosn

  • AOM

  • pneumonia

  • complciations of coughing

    • PTX

    • subconjunctival haemorrhages

    • petechiae

    • epistaxis

  • infants

    • 1/6 die or be left with brain or lung damage

• erythromycin reduce severity and duration of clinical disease but only if started during catarrhal phase

• once coughing paroxysms have begun - no effect on clinical course

  • reduce risk of spread to others

• Azithromycin = recommended treatment