Geographic analysis of pertussis infection in an urban area: A tool for health services planning

Objective. This study examined whether incident cases of pertussis cluster in urban census tracts and identified community characteristics that predict high-incidence areas. Methods. An ecological study design was used. The study population included all persons diagnosed with pertussis from January 1, 1986, through December 31, 1994. Maps of rates were constructed via a geographic information system and clustering was statistically confirmed. Associations between pertussis rates and community characteristics were tested. Results. Mapping and statistical analysis revealed spatial clustering of pertussis. Higher age-adjusted rates of pertussis infection were associated with higher proportions of residents below poverty level. Conclusions; In urban areas, pertussis infection clusters in areas of poverty.