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Biomedical subjects

F Simondon

Publications and source records attributed to F Simondon.

At least 55 records · Page 3Linked to original sources
PubMed1995

Non-specific beneficial effect of measles immunisation: analysis of mortality studies from developing countries.

OBJECTIVE: To examine whether the reduction in mortality after standard titre measles immunisation in developing countries can be explained simply by the prevention of acute measles and its long term consequences. DESIGN: An analysis of all studies comparing mortality of unimmunised children and children immunised with standard titre measles vaccine in developing countries. STUDIES: 10 cohort and two case-control studies from Bangladesh, Benin, Burundi, Guinea-Bissau, Haiti, Senegal, and Zaire. MAIN OUTCOME MEASURES: Protective efficacy of standard titre measles immunisation against all cause mortality. Extent to which difference in mortality between immunised and unimmunised children could be explained by prevention of measles disease. RESULTS: Protective efficacy against death after measles immunisation ranged from 30% to 86%. Efficacy was highest in the studies with short follow up and when children were immunised in infancy (range 44-100%). Vaccine efficacy against death was much greater than the proportion of deaths attributed to acute measles disease. In four studies from Guinea-Bissau, Senegal, and Burundi vaccine efficacy against death remained almost unchanged when cases of measles were excluded from the analysis. Diphtheria-tetanus-pertussis and polio vaccinations were not associated with reduction in mortality. CONCLUSION: These observations suggest that standard titre measles vaccine may confer a beneficial effect which is unrelated to the specific protection against measles disease.

Bangladesh↗
PubMed1995

Nutritional change and economic crisis in an urban Congolese community.

BACKGROUND: In 1986, the government of Congo undertook a structural adjustment programme to cope with the economic crisis. We present the results of a study whose objectives were to assess the evolution of nutritional status of an urban community between 1986 and 1991 and to identify specific groups for which the nutritional status may have worsened. METHODS: Two cross-sectional surveys were carried out on representative samples of Brazzaville children < 6 years old: 2295 children were surveyed in 1986 and 2373 in 1991. Anthropometric assessment of nutritional status was performed. For children, weight-for-height and height-for-age indices were used according to WHO recommendations. Wasting and stunting were respectively defined as indices under -2 z-scores. Body mass index of mothers was calculated and risk of chronic energy deficiency (CED) was defined as < 18.5 kg/m2. Socioeconomic data relative to the households were also collected. Multivariate statistical methods were used to obtain adjusted estimates of nutritional changes in the community. RESULTS: Data analysis led to several converging results: increase in the percentage of low birthweight (10.2% in 1985 versus 18.7% in 1990), increase in the percentage of CED (from 7.9% to 10.5%), and increase in the prevalence of wasting (from 2.9% to 4.2%). By contrast, the overall prevalence of stunting decreased from 13.9% to 11.0%. After statistical adjustment, the factors found to influence the evolution of anthropometric status were: age of child, age of mother, schooling of mother and household characteristics such as number of preschool children, economic level and head of household's occupation. CONCLUSIONS: The study enables the negative effects of the economic crisis to be quantified. Body mass index is shown to be sensitive to economic changes. It could be recommended as a possible indicator for monitoring the nutritional status at population level. The results also call for a new impetus in preventive health programmes and the implementation of nutritional surveillance activities.

Adolescent↗
PubMed1995

Serologic status and measles attack rates among vaccinated and unvaccinated children in rural Senegal.

During a measles vaccine trial in a rural area of Senegal, antibody status was examined within 10 days of exposure for 228 previously vaccinated and 313 unvaccinated children more than 12 months old who were exposed to measles at home. Thirty-six percent of the children developed clinical measles, the clinical diagnosis being confirmed for 135 of the 137 children from whom 2 blood samples were collected. Vaccine efficacy was 90% (95% confidence interval, 83 to 94%). The hemagglutinin-inhibiting antibodies (HI) or plaque neutralizing antibodies (PN) assays were equally efficient in predicting susceptibility and protection against measles. Vaccinated children who had no detectable HI or PN antibodies at exposure had significant protection against measles compared with seronegative unvaccinated children (HI vaccine efficacy, 49% (95% confidence interval, 21 to 68%); PN vaccine efficacy, 43% (95% confidence interval, 12 to 62%)). The attack rate was high for children with a titer of 40 to 125 mIU) 67% (4 of 6) of those with a positive hemagglutinin-inhibiting antibody test and 36% (13 of 36) of those with a positive PN test developed measles. Attack rates among children with HI or PN titers above 125 mIU were 2% (6 of 295) and 3% (7 of 258), respectively. Because titers of < or = 120 mIU have been found to offer little protection in another study, this antibody level may be the best screening value for assessing susceptibility and protection against measles. However, it should be noted that many seronegative vaccinated children are protected against measles infection.

Adolescent↗
PubMed1995

Infant feeding and nutritional status: the dilemma of mothers in rural Senegal.

OBJECTIVE: To describe infant feeding practices in rural Senegal in relation to age and nutritional status. The main hypothesis to be tested was whether mothers modulate feeding in response to growth and nutritional status of their infants. DESIGN: A cross-sectional survey using qualitative 24-h recalls and lifetime recalls to assess feeding practices, and using weight and recumbent length measurements to assess nutritional status. SETTING: Three health clinics in the Fatick region, a rural area of Senegal, West Africa, covering a population of 26,600. SUBJECTS: All 2-10-month-old infants attending four immunization sessions in 1991 (n = 1174; 80% of convoked infants). MAIN OUTCOME MEASURES: Prevalence of feeding with additional food (gruel, family diet and food of animal origin), weight-for-length and length-for-age. RESULTS: All infants were breastfed. A supplement had been given the day before the survey to 10% of infants aged 2-3.9 months, 30% of infants aged 4-5.9 months and 45% of those aged 6-6.9 months. The main food items were watery millet gruel and family diet (millet or rice). Gruel was given in response to perceived breast-milk insufficiency. Animal products were seldom eaten at any age. Length-for-age and weight-for-length were significantly lower among infants supplemented with millet gruel, when adjusted for age; while no such relationship was found with family diet. CONCLUSION: Mothers preferentially fed gruel to small, thin infants.

Adolescent↗
PubMed1994

Sex-specific differences in mortality after high-titre measles immunization in rural Senegal.

Administration of high-titre measles vaccine (Edmonston-Zagreb (EZ) at > 10(5) plaque-forming units (PFU) per dose) before the age of 9 months has been recommended in areas with high measles mortality before the routine age of immunization after 9 months. The study compares the long-term survival after high-titre measles immunization at 5 months of age with that following routine immunization with standard-titre vaccine at 10 months of age. At 5 months of age the high-titre group received Edmonston-Zagreb (EZ-HT, 5 months) or Schwarz (SW-HT, 5 months) at titres > 10(5) PFU per dose, while the standard-titre group received placebo at 5 months of age and < 10(4) PFU per dose of Schwarz vaccine at 10 months (SW-std, 10 months). All the children were followed up to at least 36 months of age. The mortality ratio (MR) for infants in the EZ-HT, 5 months and SW-HT, 5 months groups was 1.32 (P = 0.089) and 1.45 (P = 0.092), respectively, which did not differ significantly from that of recipients of the SW-std, 10 months. The higher MR among recipients of the high-titre vaccines was due to the significantly lower survival among females compared with the females who received SW-std vaccine (EZ-HT, 5 months MR = 1.76, P = 0.013; SW-HT, 5 months MR = 2.14, P = 0.017). For children aged 5-10 months the high-titre measles vaccine did not increase mortality relative to unvaccinated children who had received placebo.

Bias↗
PubMed1993

Divergent mortality for male and female recipients of low-titer and high-titer measles vaccines in rural Senegal.

The female/male mortality ratio among unimmunized children and children vaccinated with standard or high-titer measles vaccines was examined for all children born in the period 1985-1991 in a rural area of Senegal. The female/male mortality ratio from 9 months to 5 years of age for unvaccinated children was 0.94 (95% confidence interval (CI) 0.75-1.19), significantly different from the ratio of 0.64 (95% CI 0.48-0.85) for recipients of the Schwarz standard measles vaccine (p = 0.040). In the 4-year period, where high-titer measles vaccines were used in the study area, the female/male mortality ratio was 1.33 (95% CI 1.00-1.78) for recipients of high-titer Edmonston-Zagreb or Schwarz vaccines compared with 0.67 (95% CI 0.42-1.07) for recipients of the Schwarz standard vaccine (p = 0.013). Hence, the Schwarz standard and high-titer measles vaccines have divergent sex-specific effects on mortality throughout childhood. Further studies of the underlying mechanisms are needed.

Cause of Death↗
PubMed1992

[Urbanization and nutritional transition in sub-saharan Africa: exemplified by Congo and Senegal].

To evaluate the impact of urban life-style on nutritional status, body mass index (BMI) of mothers and indices of malnutrition of preschool children were calculated in four representative surveys in two rural areas and two main cities of Western and Central Africa. Mean BMIs were similar in both urban settings and were significantly higher than those of rural mothers. Distributions shifted significantly towards values over 25 kgs/m2 in towns, although, values lower than 18.5 were still present. Therefore chronic energy deficiency, largely prevalent in many rural areas of Africa, remains important in cities, where obesity also appears to have become a public health concern. Wasting was rare in young urban children, but the prevalence of stunting, although lower, indicates the persistence of nutritional deficiencies. This situation of nutritional transition generates a double burden to already limited health finances and requires an appropriate educational policy.

Adolescent↗
PubMed1991

The utility of infancy weight curves for the prediction of linear growth retardation in preschool children.

Routine weight measurements, recorded on health cards of 95 Congolese infants, were collected during a cross-sectional survey as the children were aged 1 to 5 years. The subjects were divided into two groups according to height-for-age (more or less than -2 SD of NCHS reference) at the time of the survey. Adjustment of a mathematical function to the infancy weight curves allowed comparison of groups using the means of the function's parameters: The stunted children had been significantly lighter than the healthy group during infancy. Predictive values of estimated weights and quarterly weight gains were assessed by discriminant analysis and cut-off points were computed. The weight gain between 3 and 6 months of age predicted stunting just as well as weight at age 1 year did. Sensitivity and specificity were at 77% and 74%, respectively. These results suggest that good prediction of stunting is possible from first-year weight measurements.

Body Height↗
PubMed1991

[Nutrition survey in the Republic of the Congo: results from a national survey conducted in 1987].

The objective was to evaluate the nutritional status of preschool children in the rural areas in order to establish a baseline for the measurement of the impact of a Government Nutrition Education Project (NUTED) in forthcoming years. The household cross-sectional survey was carried out on a representative sample of the rural population. The sample was stratified in order to portray the nutritional status of the children in the northern regions (more thinly populated) and in the southern regions: one stratum for small towns (between 2000 and 30,000 inhabitants) and 4 strata for rural localities. The sampling method used was by clusters of 30 children, distributed randomly in 20 zones per stratum. The nutritional indices of 2429 children were calculated and analysed according to WHO recommendations. The prevalence of the different types of malnutrition was 27.5% (95% confidence interval (CI), 24.2-30.8) for stunting (height-for-age retardation) and 5.5% (CI = 4.2-6.8) for wasting (weight-for-height retardation). Both types coexisted among 1.9% of the children; 23% of children were underweight for their age (CI = 21.6-26.2), and 15.8% (CI = 14.7-16.9) aged greater than 12 months had a mid-arm circumference below 135 mm. No sex difference was observed in the results. Stunting seems to appear in the second trimester of life (3-5 months), and wasting appeared between 9 and 23 months (highest rate between 12 and 17 months: 14.0% (CI = 9.3-18.8], which presents a real public health problem. The stratification did not show any significant differences in nutritional status among the children living in rural zones and those living in the small towns. However, the prevalence of malnutrition in the rural zones was 2 or 3 times higher than that observed in 1986 in Brazzaville. The division of the country into five main ecological zones allows some useful comparisons, e.g., the prevalence of stunting ranges from 15.5% (CI = 12.8-18.2) in the northern inundated forest zone to 38.8% (CI = 32.9-44.7) in the southern forests of Mayombe and Chaillu. The diet also varied, the frequency of animal protein consumption on the preceding day ranging from 76.3% to 59.1% in the different zones. The Republic of the Congo differs from other African countries in having relatively lower rates of stunting but an astonishingly high prevalence of wasting.(ABSTRACT TRUNCATED AT 400 WORDS)

Child Nutrition Disorders↗
PubMed1986

A simple model relevant to toxoplasmosis applied to epidemiologic results in France.

A simple mathematical model was applied to the results of a seroepidemiologic study of toxoplasmosis carried out in France in 1982-1983. An adequate fitting to the prevalence data observed on 7,605 women of childbearing age was obtained. Thus, the data were used to estimate the seroconversion rate, allowing the approach to and discussion of insights gained from the model, such as the risk of Toxoplasma infection during pregnancy, the age-related expected risks of maternal seroconversion, as well as an overall prediction of the yearly number of congenitally infected infants in the total population. In addition, the high prevalence of congenital toxoplasmosis in France and the excess risk encountered by young migrant women from lower prevalence areas were confirmed by the model. The model might therefore be useful for public health purposes in other countries.

Adolescent↗
PubMed1985

[Nutrition studies in the mid-valley of Senegal. 1. Evolution of food consumption since 1958 and current structure of rations].

A food consumption survey was performed in 5 villages in the Senegal mid valley, including 55 households. In order to study the situation on a lapse of 25 years, the results of this survey were compared with those of a survey done in 1958. Nutritional value of intakes did not change: the same deficiencies are noticed. Food origin have changed, meaning a deep social transformation. Food risk is already present.

Diet↗