Cost-Effectiveness of Adolescent Pertussis Vaccination for The Netherlands: Using an Individual-Based Dynamic Model

BACKGROUND: Despite widespread immunization programs, a clear increase in pertussis incidence is apparent in many developed countries during the last decades. Consequently, additional immunization strategies are considered to reduce the burden of disease. The aim of this study is to design an individual-based stochastic dynamic framework to model pertussis transmission in the population in order to predict the epidemiologic and economic consequences of the implementation of universal booster vaccination programs. Using this framework, we estimate the cost-effectiveness of universal adolescent pertussis booster vaccination at the age of 12 years in the Netherlands. METHODS/PRINCIPAL FINDINGS: We designed a discrete event simulation (DES) model to predict the epidemiological and economic consequences of implementing universal adolescent booster vaccination. We used national age-specific notification data over the period 1996-2000--corrected for underreporting--to calibrate the model assuming a steady state situation. Subsequently, booster vaccination was introduced. Input parameters of the model were derived from literature, national data sources (e.g. costing data, incidence and hospitalization data) and expert opinions. As there is no consensus on the duration of immunity acquired by natural infection, we considered two scenarios for this duration of protection (i.e. 8 and 15 years). In both scenarios, total pertussis incidence decreased as a result of adolescent vaccination. From a societal perspective, the cost-effectiveness was estimated at €4418/QALY (range: 3205-6364 € per QALY) and €6371/QALY (range: 4139-9549 € per QALY) for the 8- and 15-year protection scenarios, respectively. Sensitivity analyses revealed that the outcomes are most sensitive to the quality of life weights used for pertussis disease. CONCLUSIONS/SIGNIFICANCE: To our knowledge we designed the first individual-based dynamic framework to model pertussis transmission in the population. This study indicates that adolescent pertussis vaccination is likely to be a cost-effective intervention for The Netherlands. The model is suited to investigate further pertussis booster vaccination strategies

Conclusions on (cost-)effectiveness of pertussis booster vaccination strategies highly dependent on selections made in evidence review

This letter reacts on a paper recently published in this journal, reviewing the effectiveness and (cost-)effectiveness of pertussis booster vaccination strategies. We argue that a different selection of (cost-)effectiveness data could validly be made than the one presented in the review as being considered most robust. In particular, we explicitly present an alternative set of (cost-)effectiveness data. (C) 2009 Elsevier Ltd. All rights reserved

IL-1 receptor type 1 gene-deficient mice demonstrate an impaired host defense against pneumococcal meningitis

The fatality rate associated with Streptococcus pneumoniae meningitis remains high despite adequate antibiotic treatment. IL-1 is an important proinflammatory cytokine, which is up-regulated in brain tissue after the induction of meningitis. To determine the role of IL-1 in pneumococcal meningitis we induced meningitis by intranasal inoculation with 8x10(4) CFU of S. pneumoniae and 180 U of hyaluronidase in IL-1R type I gene-deficient (IL-IR-/-) mice and wild-type mice. Meningitis resulted in elevated IL-1alpha and IL-1beta mRNA and protein levels in the brain. The absence of an intact IL-1 signal was associated with a higher susceptibility to develop meningitis. Furthermore, the lack of IL-1 impaired bacterial clearance, as reflected by an increased number of CFU in cerebrospinal fluid of IL-1R(-/-) mice. The characteristic pleocytosis of meningitis was not significantly altered in IL-1R(-/-) mice,, but meningitis was associated with lower brain levels of cytokines. The mortality was significantly higher and earlier in the course of the disease in IL-1R(-/-) mice. These results demonstrate that endogenous IL-1 is required for an adequate host defense in pneumococcal meningiti

Academic and behavioral limitations and health-related quality of life in school-age survivors of bacterial meningitis

The objectives of this study were to describe health-related quality of life of postmeningitic children and to examine the association between academic and/or behavioral limitations and health-related quality of life. One hundred and eighty-two children (mean age 9.7 years; range 5.3-14.2) were selected randomly from a cohort of 674 school-age children who recovered from non-Haemophilus influenzae type B bacterial meningitis. These children had neither meningitis with 'complex onset', nor prior cognitive or behavioral problems, nor severe disease sequelae. On average 7.4 years after meningitis, they were evaluated using an 'Academic Achievement Test' and their parents filled in the Child Behavior Checklist, the Child Health Questionnaire, and the Health Utilities Index. The long-term incidence of academic and/or behavioral limitations was 32%. Overall health-related quality of life of the postmeningitic children was decreased in comparison with that of a reference population of schoolchildren. The group of postmeningitic children with academic and/or behavioral limitations showed the most marked decrease in quality of life, especially concerning psychosocial health, cognition and family life. The negative effects on quality of life were not significantly influenced by age, gender, causative pathogen, presence of minor neurological impairment, or presence of hearing impairment. In conclusion, health-related quality of life of postmeningitic children is decreased, particularly of those with academic and/or behavioral limitations

Hearing Loss at School Age in Survivors of Bacterial Meningitis: Assessment, Incidence, and Prediction

Objectives. To establish the incidence of sensorineural hearing loss in children who survived non-Haemophilus influenzae type B (Hib) bacterial meningitis, to highlight the actual percentage whose hearing was evaluated, and to develop a prediction rule to identify those who are at risk of hearing loss. Methods. In 1999, we compiled a cohort of 628 school-aged children who were born between January 1986 and December 1994 and had survived non-Hib bacterial meningitis between January 1990 and December 1995. Presence of sensorineural hearing loss (>25 dB) was determined, based on information from questionnaires and medical records. Potential risk factors for hearing loss were obtained from medical records; independent predictors were identified using multivariate logistic regression analysis, leading to the formulation of a prediction rule. Results. The incidence of hearing loss was 7%. The hearing of 68% of the children was evaluated as part of their routine follow-up after bacterial meningitis, resulting in the detection of 75% of the cases of hearing loss. The remaining 25% were detected after this follow-up had ended. Using a prediction rule based on 5 factors-duration of symptoms before admission >2 days, absence of petechiae, cerebrospinal fluid glucose level ≤0.6 mmol/L, Streptococcus pneumoniae, and ataxia-62% of the postmeningitic children were selected as being at risk. All cases of hearing loss were in this at-risk group. Conclusions. Hearing loss can be predicted satisfactorily. When the hearing of children who are predicted to be at risk is tested as part of their routine follow-up, no children with hearing loss need be missed