Field effectiveness of erythromycin prophylaxis to prevent pertussis within families.
To evaluate the field effectiveness of erythromycin prophylaxis for pertussis within families, a retrospective cohort study was conducted among 246 families. Overall 41% of the subjects (387 of 940) had been sick. The secondary attack rate was 65% for infants younger than 2 years, 54% for those 2 to 4 years old and 39% for children 5 to 9 years old, and it declined thereafter. The secondary attack rate decreased from 25% in families without prophylaxis to 17% in families with prophylaxis. The protection induced by prophylaxis did not vary with age or vaccination status. When prophylaxis was used before the onset of a secondary case, the secondary attack rate was 4% compared with 35% when given after a secondary case (P < 0.001). Erythromycin prophylaxis seems to be efficient in preventing secondary cases but is most useful when administered before the occurrence of the first secondary case.
De Serres
G
G
Centre de Santé Publique de Québec, Beauport, Canada.
Boulianne
N
N
Duval
B
B
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D004917:Erythromycin / Q000008:administration & dosage / Q000627:therapeutic use*; D005069:Evaluation Studies as Topic; D005190:Family; D006801:Humans; D007223:Infant; D016015:Logistic Models; D015999:Multivariate Analysis; D012189:Retrospective Studies; D016896:Treatment Outcome; D014917:Whooping Cough / Q000188:drug therapy / Q000517:prevention & control* / Q000635:transmission
D000900:Anti-Bacterial Agents; D004917:Erythromycin