This study was conducted to evaluate age-specific seroprevalence of pertussis in Korea and to formulate a strategy to prevent and reduce the incidence of pertussis. Residual serum samples of healthy adolescents and adults 11 yr of age or older were collected between July 2012 and December 2012, and anti-pertussis toxin (PT) IgG titers were measured using a commercial ELISA kit. We compared the mean anti-PT IgG titers and seroprevalence of pertussis of the six age groups: 11-20, 21-30, 31-40, 41-50, 51-60, and > or = 61 yr. A total of 1,192 subjects were enrolled. The mean anti-PT IgG titer and pertussis seroprevalence were 35.53 +/- 62.91 EU/mL and 41.4%, respectively. The mean anti-PT IgG titers and seroprevalence were not significantly different between the age groups. However, the seroprevalence in individuals 51 yr of age or older was significantly higher than in individuals younger than 51 yr (46.5% vs 39.1%, P = 0.017). Based on these results, a new pertussis prevention strategy is necessary for older adults.
Adolescent ; Adult ; Aging ; Antibodies, Bacterial/*blood ; Bordetella pertussis/*immunology ; Child ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G/*blood/immunology ; Incidence ; Male ; Middle Aged ; Pertussis Toxin/blood/*immunology ; Pertussis Vaccine/immunology ; Republic of Korea/epidemiology ; Seroepidemiologic Studies ; Vaccination ; Whooping Cough/blood/*epidemiology ; Young Adult

INTRODUCTIONPertussis is a highly communicable, vaccine-preventable respiratory disease and a frequent but often underestimated cause of prolonged cough illness in adults. Protection after childhood vaccination is minimal after 10 years without boosting. The need for adult booster depends on the national epidemiology.

MATERIALS AND METHODSWe did a seroepidemiological survey amongst the adult population (aged 18 to 45 years) of Singapore. None had received pertussis booster vaccine in the preceding 10 years. We measured IgG antibodies to pertussis whole cell antigen.

RESULTSTwo hundred and seventy subjects with the median age of 30 years were enrolled. We found positive IgG antibody levels in 97% of the population. Seropositivity was not associated with age, gender or race.

CONCLUSIONThe seroprevalence in adults was much higher than the previously documented seroprevalence of around 50% in the adolescent age group in Singapore. The increase is most likely due to natural infection with B. pertussis. Pertussis booster vaccine for adolescents/young adults in Singapore would be indicated.

Adolescent ; Adult ; Antibodies, Anti-Idiotypic ; immunology ; Antibodies, Bacterial ; blood ; Bordetella pertussis ; immunology ; Cross-Sectional Studies ; Diphtheria-Tetanus-acellular Pertussis Vaccines ; pharmacology ; Female ; Humans ; Immunoglobulin G ; immunology ; Male ; Middle Aged ; Population Surveillance ; methods ; Prevalence ; Prognosis ; Retrospective Studies ; Seroepidemiologic Studies ; Singapore ; epidemiology ; Whooping Cough ; epidemiology ; immunology ; prevention & control