OBJECTIVES: Bordetella pertussis circulates even in highly vaccinated populations. There is a considerable amount of infection in adults. For designing more effective vaccination schedules it is important to quantify the age-dependent relation between the number of notified cases and the number of infections. METHODS: We used a statistical relationship between the time since infection and the IgG antibody titers against pertussis toxin, derived from a longitudinal data set, to estimate time since infection for all individuals in a cross-sectional population-based study (1995-1996) based on their titers. Age-specific incidence of infection with B. pertussis was calculated and compared with the age-distribution of notified cases of pertussis in 1994-1996. RESULTS: Estimated incidence of infection was 6.6% per year for 3-79-year olds, annual incidence of notified cases 0.01%. Estimated age-specific incidence of infection was lowest for 3-4-year olds (3.3%) and increased gradually up to the age of 20-24 years (10.8%). The number of notified cases was highest for 3-9-year olds. CONCLUSIONS: In the Dutch population B. pertussis infections occur more frequently and in elder age-categories then suggested by notifications. Mathematical modeling could explore what booster vaccination strategies are most effective in reducing severe disease among not (completely) vaccinated infants.
OBJECTIVES: Bordetella pertussis circulates even in highly vaccinated populations. There is a considerable amount of infection in adults. For designing more effective vaccination schedules it is important to quantify the age-dependent relation between the number of notified cases and the number of infections. METHODS: We used a statistical relationship between the time since infection and the IgG antibody titers against pertussis toxin, derived from a longitudinal data set, to estimate time since infection for all individuals in a cross-sectional population-based study (1995-1996) based on their titers. Age-specific incidence of infection with B. pertussis was calculated and compared with the age-distribution of notified cases of pertussis in 1994-1996. RESULTS: Estimated incidence of infection was 6.6% per year for 3-79-year olds, annual incidence of notified cases 0.01%. Estimated age-specific incidence of infection was lowest for 3-4-year olds (3.3%) and increased gradually up to the age of 20-24 years (10.8%). The number of notified cases was highest for 3-9-year olds. CONCLUSIONS: In the Dutch population B. pertussis infections occur more frequently and in elder age-categories then suggested by notifications. Mathematical modeling could explore what booster vaccination strategies are most effective in reducing severe disease among not (completely) vaccinated infants.
Authors: Xuqing Zhang; Sara E Hester; Mary J Kennett; Alexia T Karanikas; Liron Bendor; David E Place; Eric T Harvill Journal: Infect Immun Date: 2010-10-25 Impact factor: 3.441
Authors: D Dilli; I Bostanci; Y Dallar; T Buzgan; H Irmak; M A Torunoğlu Journal: Eur J Clin Microbiol Infect Dis Date: 2008-01-09 Impact factor: 3.267
Authors: L C S Smallenburg; N A van Welie; L H Elvers; J C M van Huisseling; P F M Teunis; F G A Versteegh Journal: Eur J Clin Microbiol Infect Dis Date: 2014-04-23 Impact factor: 3.267