Case fatality rate for meningococcal disease: study in the region of Campinas, SP, Brazil 1993 to 1998

Abstract

OBJECTIVE: To analyze the trends of the meningococcal disease cumulative incidence and case-fatality rate in the region of Campinas, Brazil, an area that encircles five cities and 1.2 million inhabitants, from 1993 to 1998. METHODS: A longitudinal retrospective study of all case records (375) obtained from the regional epidemiological surveillance system was carried out. A logistic regression analysis allowed identifying the risk factors related to fatal outcomes of meningococcal disease. RESULTS: The highest fatality rates (23.8%) were seen in the period of 1996 and 1997, coinciding with the incidence peaks of serogroup B Neisseria and a high percentage of septicemia cases. Also at the same period there was registered a poor etiological investigation of the cases. A seasonal pattern and the predomination of strains B:4:P1.15 and C:2b:P1.3 were observed. In the logistic regression analysis, the risk factors related to fatality were: septicemia with or without meningitis (adjusted odds ratio [ORa] = 13.88 and 95% confidence interval [CI] = 4.68--42.13); age over 30 years (ORa = 6.42; CI = 2.32--17.80); age under 1 year (ORa = 2.95; CI = 1.55--5.63); and serogroup B (ORa = 2.33; CI = 1.14--4.79). CONCLUSIONS: Septicemia, age and serogroup were predictive variables related to a fatal outcome. In 1996 and 1997, case-fatality rates were high, indicating the need to further assessment of the quality of the services delivered and their readiness to take preventive action. The lack of etiological identification in many cases precluded more accurate inferences about the epidemiological behavior of Neisseria meningitidis in the region.