ABSTRACT
A study of the chronological series of mortality due to meningococcal disease in children under one year old, the group of highest incidence during the last epidemy in Cuba, was carried out. Data were collected by doing a survey in an uniform way since 1983 throughout the country. More than 90% of the population between 3 months and 5 years old were vaccinated with VAMENGOC BC since the end of 1988 until April, 1990. The behaviour of this disease was studied in order to identify the influence of this vaccine. It is stressed that the mortality incidence reached its epidemic achme in 1986 and begins a slow descence which is accentuated in 1990 and 1991, with an annual relative decrease of 26.1 and 34.9%, respectively. The highest mortality rate was found in 1984, with a significant reduction in 1990 (-23.8%) and 1991 (-41.8%), after the culmination of the vaccination campaign with VA-MENGOC BC. It was detected that morbimortality, which is lower in children under one month because of the probable protection provided by maternal antibodies, started to increase until the fifth month of life, when it is observed a trend towards the reduction of morbidity and mortality. According to the present immunization chronogram, overall protection in only attained after the sixth mont of life.
Subject(s)
Bacterial Vaccines/administration & dosage , Meningitis, Meningococcal/mortality , Age Factors , Cuba/epidemiology , Humans , Incidence , Infant , Infant, Newborn , Meningitis, Meningococcal/prevention & control , Morbidity , Neisseria meningitidis/immunology , VaccinationABSTRACT
The assessment of the after-licensing efficacy of the Cuban vaccine VA-MENGOC-BC was performed one year after the mass immunization campaign was completed in children under 6 years of age in the Province of Holguín which had the second highest incidence rate of meningococcal disease during 1988 in Cuba. In the design of the study the following aspects were taking into account: case definition; case detection, determination of the state of vaccination, and comparability of exposure. The utilization of 2 case definitions with different sensitivity and specificity is introduced within the methodology, as well as 2 estimation methods. Incidence rates from exposed and nonexposed subjects, as well as the ratio of cases and of the vaccinated population are used. The impact of this prophylactic intervention was determined by the estimation of the percentual preventive population fraction. Among outstanding results, the high efficacy of more than 98% found in both variants of case definition is to be mentioned. It is evidenced that the effect of the vaccine accounts for more than 80% of the observed case reduction. Such reduction in the number of cases was obtained without changing diagnostic criteria since the isolation of the agents was hept at levels similar to the ones from previous years.
Subject(s)
Bacterial Vaccines/immunology , Neisseria meningitidis/immunology , Product Surveillance, Postmarketing , Child, Preschool , Confidence Intervals , Cuba , Humans , Incidence , Infant , Meningitis, Meningococcal/epidemiology , Meningitis, Meningococcal/prevention & control , Product Surveillance, Postmarketing/methods , Product Surveillance, Postmarketing/statistics & numerical data , Risk , Time FactorsABSTRACT
Children less than one year old behave as the group with the highest incidence of meningococcal disease during all the epidemic period in the past '80s decade in Cuba. There were used chronological series of monthly incidence rates between 1983 and 1990, in order to identify the behavior of seasonality, taking into account the clinical form and the insert of years 1989 and 1990 in the series: in both of them a massive antimeningococcal vaccination campaign took place. It is evident that seasonality has a different behavior in accordance with the clinical form: it is like the countries from the northern hemisphere with a moderate climate for the meningoencephalitis, and like the countries of the southern hemisphere with a warm climate for the meningococcal syndrome. Months of the rainy period have the lowest seasonal index. Modifications of these seasonal patterns are not found after executing the vaccination.