Me. Nennig et al., PREVALENCE AND INCIDENCE OF ADULT PERTUSSIS IN AN URBAN-POPULATION, JAMA, the journal of the American Medical Association, 275(21), 1996, pp. 1672-1674
Objectives.-To determine the prevalence of Bordetella pertussis infect
ion among adults who have prolonged cough for 2 weeks or longer and to
estimate the incidence of B pertussis infection in adults in a define
d urban population. Design.-A prospective clinical study. Setting.-Kai
ser Permanente, San Francisco (Calif) Medical Center. Participants.-On
e hundred fifty-three referred and participating health plan members 1
8 years old or older with the complaint of cough:persisting for 2 week
s or longer and 154 health plan members 18 years old or older with no
cough for the past 3 months (controls) were enrolled. Medical records
for an additional 100 patients randomly sampled from 676 patients 18 y
ears old or older with an ambulatory diagnosis of cough (60 with prolo
nged cough) were also reviewed. Main Outcome Measures.-Prevalence of a
dult pertussis as determined by enzyme-linked immunosorbent assay IgG
antibody levers to pertussis toxin in individuals with prolonged cough
for 2 weeks or longer and the incidence of adult pertussis in San Fra
ncisco Kaiser health plan members. Results.-The prevalence of adult pe
rtussis was 12.4% of the participating referrals. The incidence of adu
lt pertussis was estimated to be 176 cases per 100 000 person-years (9
5% confidence interval, 97 to 255 cases). Conclusions.-Adult pertussis
is a significantly greater public health threat than previously suspe
cted, Booster doses of acellular pertussis vaccine after 7 years of ag
e may bean effective approach to minimize transmission and infection.