The data used to build the models: Pertussis morbidity and mortality burden considering various Brazilian data sources

Abstract

Background: Pertussis is associated with significant disease burden in children worldwide. In addition to its cyclical nature, resurgences of pertussis cases, hospitalizations and deaths have been reported by many countries. We describe the dynamics of pertussis in Brazil, a middle-income country that has experienced a resurgence and that provides good quality data to allow building a dynamic transmission disease model.

Methods: We conducted a descriptive analysis of pertussis burden considering data from the national disease surveillance system, national hospitalization information system and national mortality registry. Study period was 2000-2016. Absolute numbers and rates per 100,000 inhabitants over time, by age sub-groups and geographical regions are presented.

Results: From 2000 to 2016, a total of 37,299 reported pertussis cases, 25,240 hospitalizations, and 601 deaths due to pertussis were reported. Although the outcomes - pertussis cases, hospitalizations, and deaths - come from independent information systems, our results document low disease burden with periodic increases every 3-4 years during the years 2000-2010, followed by a sharp increase which peaked in 2014. In both periods, disease burden is concentrated in young children, while its more serious outcomes - hospitalizations and deaths, are concentrated in infants. Pre-outbreak and outbreak disease burden as well as timing of peak during the outbreak period vary by states and within geographical regions, representing valuable resources of data for modelling purposes.

Conclusion: Consistent disease burden patterns were observed over time in Brazil using a variety of data sources. Given the scarcity of good epidemiological data on pertussis available from low- and middle-income countries, our reported data provide valuable information for the assessment of the public health impact and cost-effectiveness modelling studies of newer strategies to prevent and control pertussis. These data were used to build and calibrate a national dynamic transmission model, which was used to evaluate the cost-effectiveness of maternal immunization. Clinical Trial registry name and registration number: Not applicable.

Keywords: Disease disease burden; Epidemiology; Modelling; Mortality; Pertussis; Surveillance; Whooping cough.