Revista Española de Salud Pública
Print version ISSN 1135-5727
GOICOECHEA SAEZ, Mercedes et al. Evolution of Meningococcal Disease among the Infantile Population in the Autonomous Community of Valencia (1996-2000): Effectivity of A+C Meningococcal Vaccination. Rev. Esp. Salud Publica [online]. 2003, vol.77, n.1, pp. 125-142. ISSN 1135-5727. http://dx.doi.org/10.1590/S1135-57272003000100009.
Bacground: The increase in meningococcal disease caused by serogroup C in the Autonomous Community of Valencia during the 1996-1997 period gave rise to an A+C meningococcal vaccination campaign having been conducted targeting the population ranging from 18 months to 19 years of age. The purpose of this study is that of analyzing the impact of this campaign regarding the epidemiology, clinical aspects and evolution of meningococcal disease and the vaccination status of the youth population for the purpose of evaluating the efficacy of this vaccination. Methods: The data was taken from the clinical records of the children under 15 years of age who showed clinical signs and symptoms suggesting an invasive disease with isolation of Neisseria meningitidis and/or which meet the established case definition criteria which had been treated at all of the public hospital in the Autonomous Community of Valencia within the 1996-2000 period. The trend of incidence was evaluated by means of incidence rates. The clinical aspects and their progress (sequelae and lethality) by frequency and distribution by serogroup and age. The vaccination efficacy was calculated using the Orestein equation. Results: A total of 302 cases of invasive disease caused by N. Meningitidis were recorded. The rate of incidence by serogroup C in children under age 15 dropped following the vaccination campaign from 5.82/105 habitants in 1997 to 1.68/105 habitants in 1998. Rates similar to those prior to the time prior to the vaccination recorded three years subsequent to the campaign, showing an increase in the disease caused by serogroup B over the last 2 years. Sixty-one percent of the sequelae were among children under 5 years of age. Lethality was higher for serogroup C. Vaccination efficacy three years subsequent to the campaign was 83.7% for the 5-14 age range and 69.1% for the 19month-4 year age range. Conclusion: The polysaccharide vaccine was shown to be effective for halting the outbreak. The drop in the incidence of serogroup C can be attributed to the vaccination efficacy achieved.
Keywords : Neisseria meningitidis; Meningitis; Infant; Incidence; Bacterial vaccines; Effectiveness; A+C meningococcal vaccine.