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Results of the evaluation of the anti-meningococcal BC Cuban vaccine based on routine epidemiological surveillance information of meningitis for the years 1990 to 1992, following mass-vaccination of 232,022 children aged between 3 months and 7 years in 1989/90 during an epidemic of serogroup B meningococcal disease in the State of Santa Catarina, Brazil, are presented. The protective efficacy of the vaccine was calculated from the incidence rates for the cohort of vaccinated and non-vaccinated children in 20 municipalities. Main results for cases confirmed by bacteriological tests were 59% (CI 95%: 23 to 78%) for children aged under 4 years and 78% (CI 95%: 54 to 90%) for children aged 4 to 7 years. Eighty-six percent of cases serogrouped (n = 29) were B, and in these cases efficacy increased to 66% (< 4 years) and 88% (4-7 years), but at 95% CI were wider. The protective efficacy based on death rates from the disease in children < 4 years was 76% (CI 95%: 41 to 91%). There was no evidence of decreasing protective efficacy in the three year follow-up, as shown by the yearly estimates. An interesting hypothesis arising from the findings is that the lower protective efficacy for children aged < 4 years, observed in studies in which only cases confirmed by laboratory tests are analysed, could be due to a selective effect of this procedure. More severe cases die shortly after the onset of the disease, often before medical care is provided. On the other hand, the attenuation of the disease by vaccination gives a better chance for medical intervention and collection of samples for laboratory analysis. Finally, the authors support the use of the vaccine in epidemics of serogroup B meningococcal disease. They also suggest that three, rather than two doses of vaccine should be tested in children under 2 years of age to further increase its efficacy.

This paper analyses the association between blood pressure and sodium excretion in 3975 individuals aged 20-74 years, selected in a probability sample survey of private households carried out in Rio Grande do Sul, Brazil. Sodium and creatinine titrations were performed in casual urine samples collected at the time of BP measurements. A subsample of 611 subjects provided 24 h urine collections. The regression slopes of systolic pressure on sodium excretion increased when diastolic level was higher. At the lowest levels of diastolic pressure the slope did not differ significantly from zero. The adjusted correlation coefficient then rose progressively to a maximum of +0.41 at diastolic pressures of 95-99 mmHg. Strikingly, at diastolic pressures of > or = 100 mmHg, there was no longer any significant association between systolic pressure and sodium excretion. These results could explain some earlier contradictory findings concerning the role of salt intake in hypertension and provide estimates of expected reduction on the prevalence of hypertension in each diastolic pressure group following a reduction on salt intake of a population.

A 1978 survey of 4,565 people in Rio Grande do Sul obtained interview and blood pressure data as well as casual urine specimens for subsequent sodium and creatinine titrations. Data derived from this survey have demonstrated a variety of complex relationships between blood pressure and sodium, a number of which are examined here. The main conclusion is that observed blood pressure differentials could reflect the kidney's ability to handle sodium, an ability subject to the influences of age, heredity, and the environment. As a consequence, it is suggested that the adoption of salt restriction by populations could bring them large health benefits.