Modeling and simulation of pertussis transmission in Argentina: effect of adding a booster in adolescents

G. FABRICIUS; P. BERGERO; M.ORMAZABAL; A.MALTZ; D.HOZBOR

Baltimore

Simposio; 9th International Bordetella Symposium Baltimore; 2010

Despite the widespread use of pertussis vaccine for more than five decades, this acute respiratory disease remains a public health problem. In recent years in different countries including Argentina, there has been seen a steady increase in reported cases not only in children but also in the adolescent-adults population. The reasons for this increase and the search for more accurate strategies for disease control are matters of debate in the scientific community. Under this context, mathematical models are being increasingly used as a tool not only for analysis but also for predictions in order to contribute to the knowledge of this complex problem. In the present study we evaluated the effect of the incorporation of a booster at 11 years of age on pertussis transmission. We designed and used a deterministic mathematical model. Since there are uncertainties in some parameters such as the duration of protective immunity, and infective contacts rate among individuals of different ages, we explored different parameterizations with the constraint that the model reproduces the local epidemiological data. Our study points out that the dose given at age 11 would decrease the incidence of the disease in the age group from 11 to 13 years old in between 40 and 70 percent. However, this reinforcement would have a much lower impact (less than 5 percent) for children under 1 year of age who are the most vulnerable group. The results obtained in our work also suggest that an effort directed towards improvement of current vaccination scheme coverage would produce a much higher impact in reducing pertussis incidence in infants.