Bordetella pertussis ; immunology ; Consensus ; Humans ; Pertussis Vaccine ; therapeutic use ; Whooping Cough ; immunology ; prevention & control

We investigated the prevalence of pertussis in Korean adolescents and adults with persistent cough. Study population was adolescents (aged 11-20 yr) and adults (> or = 21 yr old) who showed persistent cough of 1-8 weeks' duration. Pertussis was diagnosed by culture, polymerase chain reaction (PCR), and serology. A total of 310 subjects participated in this study, and 76 cases (24.5%) met the criteria for laboratory-confirmed pertussis. The majority of the pertussis cases (66/76) were confirmed by serology, while 3 cases (1.0%) were diagnosed with culture, and 10 cases (3.2%) were detected with PCR. Of the 76 subjects diagnosed with pertussis, 20/86 cases were adolescents and 56/224 cases were adults. Neither adolescents nor adults received adolescent-adult booster against pertussis within the previous 5 yr. Pertussis can be a primary cause of persistent cough in Korean adolescents and adults.
Adolescent ; Adult ; Bordetella pertussis/immunology ; Child ; Cough/*epidemiology ; Diphtheria-Tetanus-Pertussis Vaccine/immunology/*therapeutic use ; Female ; Humans ; Immunization, Secondary/*utilization ; Male ; Republic of Korea/epidemiology ; Whooping Cough/*epidemiology/immunology ; Young Adult

A recent resurgence of pertussis has raised public health concerns even in developed countries with high vaccination coverage. The aim of this study was to describe the clinical characteristics of infant pertussis, and to determine the relative importance of household transmission in Korea. The multicenter study was prospectively conducted from January 2009 to September 2011. We identified the demographic and clinical data from these patients and performed the diagnostic tests for pertussis in their household contacts. Twenty-one patients with confirmed pertussis were included in the analysis. All infections occurred in infants younger than 6 months of age (mean age, 2.5 months) who had not completed the primary DTaP vaccination except for one patient. Infants without immunization history had a significant higher lymphocytosis and longer duration of hospital stay compared to those with immunization. All were diagnosed with PCR (100%), however, culture tests showed the lowest sensitivity (42.9%). Presumed source of infection in household contacts was documented in 85.7%, mainly parents (52.6%). Pertussis had a major morbidity in young infants who were not fully immunized. Household members were responsible for pertussis transmission of infants in whom a source could be identified. The control of pertussis through booster vaccination with Tdap in family who is taking care of young infants is necessary in Korea.
Bordetella pertussis/genetics ; Diphtheria-Tetanus-acellular Pertussis Vaccines/immunology ; Female ; Humans ; Immunization, Secondary ; Infant ; Length of Stay ; Lymphocytosis/etiology ; Male ; Parents ; Polymerase Chain Reaction ; Prospective Studies ; Republic of Korea ; Whooping Cough/diagnosis/immunology/*transmission

Pertussis is a representative vaccine-preventable disease. However, there have been recent outbreaks in countries where even higher vaccination against the disease. One reason is the emergence of antigenic variants, which are different to vaccine type. In Korea, reported cases have rapidly increased since 2009. Therefore, we analyzed genotype of strains isolated in 2011-2012 by multilocus sequence typing method. As expected, the genotype profiles of tested genes dramatically changed. The major sequence type changed from ST1 to ST2, and new sequence type (ST8) appeared. In the minimum spanning tree, recent isolates belonging to the ACC-I-ST3 subgroup were detected that were composed of ST2, ST3, and ST6. In particular, the ST2 frequency increased to 81%. The novel ST8 was linked to the increased frequency of ST2. In addition, toxic strains carrying the ptxP3 promoter type were confirmed. This ptxP3 type emerged from 2009 and its frequency had increased to 100% in 2012. Based on these results, it can be inferred that the genotypic changes in the currently circulating strains are strongly associated with the recent increasing of pertussis in Korea. Therefore, the surveillance system should be strengthened, and genetic characterization of the isolates should be expanded to the whole genome sequence level.
*Antigenic Variation ; Antigens/*genetics/immunology/metabolism ; Bacterial Proteins/genetics/metabolism ; Bordetella pertussis/*genetics/isolation & purification/*metabolism ; Genes, Bacterial ; Genotype ; Humans ; Pertussis Toxin/genetics/metabolism ; Promoter Regions, Genetic ; Republic of Korea ; Sequence Analysis, DNA ; Whooping Cough/immunology/*microbiology/pathology

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