Role of schools in the transmission of measles in rural Senegal: implications for measles control in developing countries.
Patterns of measles transmission at school and at home were studied in 1995 in a rural area of Senegal with a high level of vaccination coverage. Among 209 case children with a median age of 8 years, there were no deaths, although the case fatality ratio has previously been 6-7% in this area. Forty percent of the case children had been vaccinated against measles; the proportion of vaccinated children was higher among secondary cases (47%) than among index cases (33%) (prevalence ratio = 1.36, 95% confidence interval (CI) 1.04-1.76). Vaccinated index cases may have been less infectious than unvaccinated index cases, since they produced fewer clinical cases among exposed children (relative risk = 0.55, 95% CI 0.29-1.04). The secondary attack rate was lower in the schools than in the homes (relative risk = 0.31, 95% CI 0.20-0.49). The school outbreaks were protracted, with 4-5 generations of cases being seen in the two larger schools. Vaccine efficacy was found to be 57% (95% CI -23 to 85) in the schools and 74% (95% CI 62-82) in the residential compounds. Measles infection resulted in a mean of 3.8 days of absenteeism per case, though this did not appear to have an impact on the children's grades. Among the index cases, 56% of children were probably infected by neighbors in the community, and 7% were probably infected at health centers, 13% outside the community, and 24% in one of the three schools which had outbreaks during the epidemic. However, most of the school-related cases occurred at the beginning and therefore contributed to the general propagation of the epidemic. To prevent school outbreaks, it may be necessary to require vaccination prior to school entry and to revaccinate children in individual schools upon detection of cases of measles. Multidose measles vaccination schedules will be necessary to control measles in developing countries. (+info)
nvited commentary: vaccine failure or failure to vaccinate?
aning of vaccine-induced immunity: is it a problem in Africa?
Outbreaks of gastrointestinal illness of unknown etiology associated with eating burritos--United States, October 1997-October 1998.
From October 1997 through October 1998, 16 outbreaks of gastrointestinal illness associated with eating burritos occurred in Florida, Georgia, Illinois, Indiana, Kansas, North Dakota, and Pennsylvania. All but one outbreak occurred in schools, and most of the approximately 1700 persons affected were children. This report summarizes investigations of two of these outbreaks and describes the collaborative efforts of CDC, the U.S. Department of Agriculture (USDA), and the Food and Drug Administration (FDA) to identify the etiologic agent(s); these outbreaks may have been caused by an undetected toxin or a new agent not previously associated with illness. (+info)
School and community influences on adolescent alcohol and drug use.
Social environment risk factors present in schools and communities have not been thoroughly investigated. This study cross-sectionally examined the social environments of schools and communities, and their influence on adolescent alcohol and drug use. Survey responses of eighth grade students (N = 2309), a random half of their parents (n = 943), community leaders (n = 118), school principals (n = 30), school counselors (n = 30) and chemical health providers (n = 14) were pooled to create indices of social environmental norms, role models, social support and opportunities for non-use of alcohol. Each index was examined for its association with prevalences from 30 schools of alcohol use onset, last-month alcohol use, heavy alcohol use and last-year marijuana use in univariate and stepwise regression analyses. Increases in the levels of norms, role models and opportunities for non-use predicted decreases in alcohol use prevalences. The explanatory power of the examined constructs in multivariate analyses was acceptably high (R2: 38-53%). These findings further support the notion that community-wide efforts need to be launched to affect changes in the normative, role model and opportunity structures of adolescents' social environments in order to curb adolescent alcohol and drug use. (+info)
The epidemic of obesity in American Indian communities and the need for childhood obesity-prevention programs.
American Indians of all ages and both sexes have a high prevalence of obesity. The high prevalence of diabetes mellitus in American Indians shows the adverse effects that obesity has in these communities. Obesity has become a major health problem in American Indians only in the past 1-2 generations and is believed to be associated with the relative abundance of high-fat foods and the rapid change from active to sedentary lifestyles. Intervention studies are urgently needed in American Indian communities to develop and test effective strategies for weight reduction. The poor success rate of adult obesity treatment programs in the general population points to the need to develop prevention approaches aimed toward children. Because eating and physical activity practices are formed early in life and may be carried into adulthood, prevention programs that encourage increased physical activity and healthful eating habits targeted toward young people need to be developed and tested. To be most effective, interventions must be developed with full participation of the American Indian communities. (+info)
Design and statistical analysis for the Pathways study.
We report the design, rationale, and statistical procedures used in Pathways, a randomized, school-based intervention for the primary prevention of obesity in American Indian children. The intervention, which is now being implemented in 7 American Indian communities around the country, includes a health-promotion curriculum, a physical education program, a school meal program, and a family involvement component. Forty-one schools serving American Indian children were randomly assigned to be either intervention or control groups. The intervention will begin in the third grade and continue through the end of the fifth grade. Efficacy of intervention will be assessed by differences in mean percentage body fat, calculated by a prediction equation, between intervention and control schools at the end of the fifth grade. Power computations indicate that the study has power to detect a mean difference of 2.8% in body fat. Data analysis will use intention-to-treat concepts and the mixed linear model. The study will be completed in 2000. (+info)
Body composition assessment in American Indian children.
Although the high prevalence of obesity in American Indian children was documented in several surveys that used body mass index (BMI, in kg/m2) as the measure, there is limited information on more direct measurements of body adiposity in this population. The present study evaluated body composition in 81 boys (aged 11.2+/-0.6 y) and 75 girls (aged 11.0+/-0.4 y) attending public schools in 6 American Indian communities: White Mountain Apache, Pima, and Tohono O'Odham in Arizona; Oglala Lakota and Sicangu Lakota in South Dakota; and Navajo in New Mexico and Arizona. These communities were participating in the feasibility phase of Pathways, a multicenter intervention for the primary prevention of obesity. Body composition was estimated by using a combination of skinfold thickness and bioelectrical impedance measurements, with a prediction equation validated previously in this same population. The mean BMI was 20.4+/-4.2 for boys and 21.1+/-5.0 for girls. The sum of the triceps plus subscapular skinfold thicknesses averaged 28.6+/-7.0 mm in boys and 34.0+/-8.0 mm in girls. Mean percentage body fat was 35.6+/-6.9 in boys and 38.8+/-8.5 in girls. The results from this study confirmed the high prevalence of excess body fatness in school-age American Indian children and permitted the development of procedures, training, and quality control for measurement of the main outcome variable in the full-scale Pathways study. (+info)