Pertussis is an acute infection of the respiratory tract caused by B pertussis which is transmitted by respiratory droplets.
-It is most severe in the very young under the of two years
-Neither disease nor immunization provides last immunity to pertussis; so there is no long term immunity.
-adults are an important reservoir of the disease and facilitate its spread
-the bacteria attaches directly to respiratory cilia without invading the tissues
-it releases pertussis toxin which disrupts cell functions locally and systemically
Symptoms & Signs
-The symptoms last about 6 weeks
-they are characterized by three phases: the catarrhal phase, the paroxysmal phase, and the convalescent phase.
The Catarrhal stage: insidious onset, lacrimation, sneezing, coryza, anorexia, malaise, a hacking night cough that becomes diurnal
The Paroxysmal stage: Bursts of rapid, consecutive coughs followed by whoops (deep, high-pitched inspirations)
The Convalescent stage: decrease in the frequency and severity of paroxysms of cough
Labs: elevated WBC, lymphocytosis
Culture: nasopharyngeal specimen obtained; it is slow growing and requires a special selective medium for growth
Imaging: CXR may show thickened bronchi; ‘shaggy’ heart border
Macrolide antibiotics: Erythromycin, azithromycin, clarithromycin
Allergy to macrolides: trimethoprim-sulfamethoxazole
Azithromycin use in infants less than 1 month old: risk of pyloric stenosis
All infants: DTaP
Adults of all ages: Tdap
Pregnant women: A dose between 27 and 36 weeks of gestation
Q.What is the most communicable phase of pertussis? Catarrhal phase
Q.What is the most serious complication of pertussis? Bronchopneumonia due to superinfection