Yves Martin-Prevel

Background Obesity and metabolic diseases represent a major health burden in the Caribbean, particularly since a large part of the population is disadvantaged. However, socioeconomic inequalities in chronic diseases are poorly explored in this region. We investigated the association between socioeconomic position and metabolic syndrome (MetS) prevalence and explored the contribution of diet quality to explain this association, among adults in the French West Indies. Methods This cross-sectional analysis included 1144 subjects (≥16 y) from a multistage sampling survey conducted in 2013–2014 on a representative sample of the Guadeloupean and Martinican population. MetS prevalence was assessed using the Joint Interim Statement. Dietary intakes were estimated from 24 h-dietary recalls, and diet quality was assessed through the Diet Quality Index-International (DQI-I). Associations between socioeconomic indicators (education, employment, social assistance benefits) and MetS prevalence, a...

Background The program “Santé Nutritionnelle à Assise Communautaire à Kayes” (SNACK) in Mali aimed to improve child linear growth through a set of interventions targeted to mothers and children during pregnancy and up to the child's second birthday. Distributions of cash to mothers and/or lipid-based nutrient supplement (LNS) to children 6–23 months of age were added to SNACK to increase attendance at community health centers (CHCs). Objectives The aim of this study, which was embedded in a cluster randomized impact evaluation of the program, was to assess the incentive value of the cash on CHC attendance. Methods We used a mixed methods approach. We collected quantitative data on cash receipt and CHC attendance in a midline survey of mother-child pairs (n = 3,443). A program impact pathway analysis guided qualitative data collection and analysis. Twelve CHCs were purposively selected in study groups that received cash. We conducted semi-structured, continuous observations of ca...

REtard de Croissance Intra-uterin et PALudisme (RECIPAL) is an original preconceptional cohort designed to assess the consequences of malaria during the first trimester of pregnancy, which is a poorly investigated period in Africa and during which malaria may be detrimental to the fetus. For this purpose, a total of 1214 women of reproductive age living in Sô-Ava and Akassato districts (south Benin) were followed up monthly from June 2014 to December 2016 until 411 of them became pregnant. A large range of health determinants was collected both before and during pregnancy from the first weeks of gestation to delivery. Five Doppler ultrasound scans were performed for early dating of the pregnancy and longitudinal fetal growth assessment. Pregnant women were identified at a mean of 6.9 weeks of gestation (wg). Preliminary results confirmed the high prevalence of malaria in the first trimester of pregnancy, with more than 25.4% of women presenting at least one microscopic malarial infe...

Women of reproductive age are at nutritional risk due to their need for nutrient-dense diets. Risk is further elevated in resource-poor environments. In one such environment, we evaluated feasibility of meeting micronutrient needs of women of reproductive age using local foods alone or using local foods and supplements, while minimizing cost. Based on dietary recall data from Ouagadougou, we used linear programming to identify the lowest cost options for meeting 10 micronutrient intake recommendations, while also meeting energy needs and following an acceptable macronutrient intake pattern. We modeled scenarios with maximum intake per food item constrained at the 75th percentile of reported intake and also with more liberal maxima based on recommended portions per day, with and without the addition of supplements. Some scenarios allowed only commonly consumed foods (reported on at least 10% of recall days). We modeled separately for pregnant, lactating, and nonpregnant, nonlactating...

The period from conception to 24 months of age is a crucial window for nutrition interventions. Personalized maternal counseling may improve childbirth outcomes, growth, and health. We assessed the effectiveness of facility-based personalized maternal nutrition counseling (from pregnancy to 18 months after birth) in improving child growth and health in rural Burkina Faso. We conducted a paired cluster randomized controlled trial in a rural district of Burkina Faso with 12 primary health centers (clusters). Healthcare providers in the intervention centers received patient-centered communication and nutrition counseling training. Pregnant women in the third trimester living in the center catchment areas and intending to stay for the next 2 years were prospectively included. We followed 2253 mother-child pairs quarterly until the child was aged 18 months. Women were interviewed about counseling experiences, dietary practices during pregnancy, and their child's feeding practices and...

Food-based approaches such as biofortification are meant to sustainably address micronutrient deficiencies in poor settings. Knowing more about micronutrient intakes and deficiencies is a prerequisite to designing and evaluating interventions. The objectives of the study were to assess biological status and dietary intakes of iron, zinc and vitamin A among women and children aged 36-59 months in rural Burkina Faso and to study relationships between intake and status to better inform future food-based interventions. A cross-sectional survey was carried out in two rural provinces of Burkina Faso on a random cluster sample of 480 mother-child pairs. Dietary data was obtained by 24-hour recalls repeated on a random sub-selection of 37.5% of subjects to allow calculation of nutrient's probability of adequacy (PA). Biomarkers were measured on a sub-sample of 180 mother-child pairs. Blood samples were analyzed for hemoglobin, serum ferritin, soluble transferrin receptors (sTfR), C-reac...

In 1990, the Unicef conceptual framework for nutrition recognised the role of care, along with household food security and health services and environment, as one of the three underlying factors of child survival, growth, and development. This model has been adopted at a policy level at the International Conference on Nutrition (Rome, 1992) and over the past ten years the concept of care has been refined through literature reviews, consultative meetings and empirical works. "Care is the provision in the household and the community of time, attention, and support to meet the physical, mental, and social needs of the growing child and other household members". Basically, care refers to the actions of caregivers (mainly, but not only mothers) that translate food and health resources into positive outcomes for the child's nutrition. Even under circumstances of poverty, enhanced caregiving can optimise the use of resources to promote good nutrition. Care practices have been grouped into six categories: care for women, breastfeeding and child feeding practices, psychosocial care, food preparation, hygiene practices, household health practices. They cover a wide range of behaviours, are often culturally specific and are daily, repetitive, and time-consuming activities. It must be underlined that the way care practices are performed (i.e., quality of care) is as important as the practices themselves. It has also been emphasised that children play a significant role in determining the quality of care that they receive, through an interactive process: an active child elicits more care from the caregiver, who is in turn more responsive. Care resources at household level have been described according to three categories: human (knowledge, beliefs, education, physical and mental health of the caregiver), economic (control on income, workload and time), and organisational (alternate caregivers, community support). But the availability of care also depends on support at the national or international level. As the mother is the primary caregiver, most of the obstacles to care are the constraints to the mothers, the most common characteristic of which being the low status of women in many societies. More studies are required to better understand the causal relationship between care and nutrition. Methods to measure the qualitative aspects of care and indicators that capture the complexity of care must be developed and cross-culturally tested. These will also be useful to design and monitor more effective interventions incorporating care. These programmes should first identify and support the good traditional care practices rather than simply ask for change; the activities proposed should not break the balance between the time women spend on care and the time they spend on work. Therefore one must be sure that enough resources are available. Finally, to achieve sustainable changes a participatory and comprehensive approach is definitely needed.

Previous studies investigating the association between an infant and child feeding index (ICFI) and length-for-age were based on a cross-sectional design and on the assumption that data collected with brief recalls could provide information about more enduring processes. The objectives were to test the stability of the individual ICFI values over time and to investigate how they relate to length-for-age z score (LAZ) and weight-for-length z score (WLZ) at the end of the study. This prospective cohort study included 363 children aged 6-17 mo who were visited 3 times over 6 mo. A cross-sectional ICFI (CS-ICFI) was constructed for each visit by using data on feeding practices and data from quantitative 24-h recalls. A longitudinal ICFI (L-ICFI) was constructed with use of the 3 CS-ICFIs. The stability of the CS-ICFI was assessed by using the variance of the repeatability coefficient (s(2)r). Stability of the CS-ICFI was shown by the value of 0.704 (95% CI: 0.625, 0.805) of the s(2)r, w...

Africa is currently the continent with the highest urbanization rate in the world. This demographic upheaval has sometimes been considered as an opportunity for modernization but as early as the 1980s experts called attention to its potential impact on nutrition. In recent decades, economic problems and structural reforms have had dire effects on urban populations. Today increasing poverty and the effects of globalization have revived concerns about urban nutrition. Retarded growth and emaciation are less common than in urban areas than in rural areas, but disparities between the rich and poor are much greater. However, in some cities, the incidence of emaciation progressed the more during the 1990s, and now equals that in rural areas. In cities the level of obesity in adult women is a sign of nutritional transition but emaciation has also increased. Despite the wide variety of urban conditions, analysis of the underlying factors reveals several constants. For most of these factors,...

The aim of this study was to describe the contribution of prematurity and small for gestational age (SGA) to low birth weight (LBW) as well as to identify risk factors associated with preterm birth and SGA and to explore their impact on birth weight. A cross-sectional study was carried out in southern Benin between June 2007 and July 2008. At delivery, women's characteristics and newborn's anthropometric measurements were collected. Gestational age was estimated using the Ballard method; SGA was defined using the William's reference curve. Analyses were performed by multiple logistic and linear regressions. In total, 526 mother-infant pairs were enrolled. LBW (<2500 g), prematurity (<37 weeks) and SGA accounted for 9.1%, 10.3% and 25.3% of the sample, respectively. Infant's male gender was associated with a lower risk of prematurity (p=0.03). Low maternal anthropometric status…

To measure the lipid content and the fatty acid (FA) composition of breast milk as part of a nutritional survey of the essential fatty acid (EFA) status of 5 months old Congolese infants. Cross sectional nutrition survey. A suburban district of Brazzaville (capital of the Congo). A random sample of nursing mothers and their 5 months old infants (n = 102). Data collection procedures: The mothers were questioned on their socio-economic status, dietary habits, and their body mass index (BMI) was measured. Breast milk samples were collected from each mother. Milk lipid content and fatty acid composition were determined. Compared with milk from various countries, Congolese women's mature breast milk was low in lipid (28.70+/-11.33 g/L) but rich in 8:0-14:0 FAs (25.97+/-8.17% of total FAs) and in polyunsaturated FAs (PUFAs), particularly n-3 PUFAs (2.39+/-0.68% of total FAs, mainly 18:3 and 22:6). This was associated with the frequent consumption of high-carbohydrate foods (processed cassava roots, wheat bread, doughnuts) known to enhance 8:0-14:0 FA biosynthesis, and with that of foods providing n-6 and n-3 EFAs such as freshwater and saltwater fish, vegetable oil, green leafy vegetables, and high-fat fruit (peanuts, avocado, bushbutter). These foods were traditionally and locally produced. Milk lipid content was negatively related with mothers' BMI (P < 0.01) and varied with the frequency of consumption of certain foods corresponding to distinct dietary patterns. Lipid content and FA composition of Congolese breast milk were dependent on mother's nutritional status. However, despite an adequate EFA composition of breast milk, partially breast-fed 5 months old Congolese infants probably did not get enough n-6 and n-3 EFAs from breast milk to meet their EFA requirements.

The 2007/2008 food prices hike has increased the interest in social safety nets programmes to fight food insecurity. Targeting the most in need is central to achieve effectiveness of such interventions. In 2009 in Ouagadougou, Burkina Faso, a food voucher (FV) programme targeted the 25 000 most vulnerable households (8.3% of the population). Targeting used a two-stage process: first geographical selection of poorest districts (∼90 000 households); then, in those districts, identification of the most vulnerable households according to a proxy-means test (PMT). Targeted households were entitled to receive FV for 1 year. A first survey was conducted at the beginning of the FV distribution on a representative sample of 2273 households drawn from the poorest districts. One year later a second survey, conducted on a subsample of same households (n = 901), identified those who actually received FV (beneficiary). The performance of the whole process was assessed against household food expenditure, used as the reference measure for vulnerability with a cut-off point of 1513 FCFA (corresponding to the 8.3th percentile of the distribution of expenditure). The 'normalized share of transfers going to vulnerable households' (NSTVH), i.e. proportion of FVs allocated to households below the cut-point, was the main criteria of judgement. Almost twice as many FV were allocated to vulnerable households as compared with a theoretical random distribution all over Ouagadougou (NSTVH = 1.85). When considering the sole targeted districts the NSTVH was only 0.84 (i.e. no more effective than a random distribution), meaning that the geographical stage was effective to select vulnerable districts while the PMT did not perform well to identify the most vulnerable households in those districts. Results could have been improved if only targeted households had received FV (NSTVH = 2.61 and 1.18 for the whole Ouagadougou and targeted districts, respectively). Improved targeting procedures or alternate targeting instruments are needed.

A seroepidemiological survey was conducted in a representative population of children aged 0-5 in Gabon. Breast-feeding appears to an important mode of HTLV vertical transmission. Owing to other epidemiological data in population of gabonese adults allow us to think that breast-feeding related transmission and sexual transmission seem to occur in equal proportion in the global HTLV transmission in that area of endemicity.

A Schistosoma intercalatum focus in south-east Gabon was studied between July 1989 and July 1990. Among the 356 permanent residents in the village, 354 provided stool specimens and 101 (28.5%) were excreting eggs (geometric mean of egg density = 101.4 eggs/g, with a range of 1-3200). The pattern of prevalence and intensity of infection with age showed the curve usually found in schistosomiasis, i.e. increasing during the first 2 decades of life and then gradually decreasing. The analysis by stepwise logistic regression of factors shown to be important in determining infection in other schistosomiasis clearly demonstrated the significant and independent effects of both age and water contact on infection by S. intercalatum. These similarities with other schistosomal infections could indicate that similar immune mechanisms were operating. Urine from 284 subjects, of whom 90 were egg excreters, was tested for circulating antigen by enzyme-linked immunosorbent assay using a Schistosoma genus-specific monoclonal antibody (Sm 10.27.12). The test was positive for 90 subjects but only 35 of these were egg excreters. Although S. intercalatum is usually considered of low pathogenicity in man, this study showed a relationship between egg excretion and both splenomegaly and lower haemoglobin levels, even after taking into account the confounding presence of Plasmodium falciparum.

A cluster sampling survey was performed in 1989 in Libreville, Gabon, to determine HTLV-I and HTLV-II prevalence and to compare the efficacy of polymerase chain reaction (PCR) and serology in detecting HTLV-I and HTLV-II infections. A total of 322 sera from adults were tested by ELISA and by Western blot (WB). The WB patterns were interpreted according to WHO criteria and those of the manufacturer. PCR analysis using primer pairs in the gag and pol region, with a specific probe for HTLV-I and HTLV-II, was performed on the lymphocytes of the 322 adults. In addition, 134/322 samples were re-tested with tax primers, in a second laboratory. Using WHO criteria, 8/322 (2.5%) samples were positive on WB and 25 were indeterminate; with the criteria of the kit, 26/322 (8.1%) were positive and 7 were indeterminate by WB. By PCR, 13 (4%) samples were positive, including 12 for HTLV-I (3.7%) and one for HTLV-II (0.3%). All 8 seropositive samples (by the WHO criteria) were positive by PCR, as were 4 out of 25 indeterminate samples. Only one out of 289 seronegative samples was positive by PCR. In contrast, only 12/26 positive samples by the kit criteria were confirmed by PCR. These results confirm the relatively high HTLV-I/II seroprevalence observed in Gabon. HTLV-I infection is preponderant, but HTLV-II is also present. The WHO criteria for WB give a better fit with PCR results than the kit criteria for WB. In the absence of a specific confirmatory test and based on the uncommon "seronegative" HTLV-I/II infection, the indication for PCR appears limited to the positive WB samples (to differentiate HTLV-I and II infection) and to the indeterminate WB samples.

In cross-sectional studies, to quantify the association between a risk factor and a disease (possibly adjusted for confounders), in the framework of the multiplicative model, the more obvious effect measure is a prevalence rate ratio with an associated confidence interval. The validity of this confidence interval requires an unbiased estimator and an appropriate estimate of the variance. In numerous epidemiological studies however, routine use is made of odds ratios and logistic regression. As the odds ratio per se is difficult to understand, prevalence odds ratios are often interpreted as prevalence rate ratios. But this latter approximation is valid only under the rare disease assumption. Moreover, in the logistic regression model, the variance of the estimates is based on the assumption of binomial variability, which is not always supported by the data; in the frequent case of overdispersion, this leads to under-estimation of the type I error rate. Yet, within the generalized linear model, it is easy to choose a link function other than the logit. For example, the log link (log-binomial model) is appropriate to directly estimate adjusted prevalence rate ratios. In case of overdispersion, it is also possible to achieve a better fit of the model, either by choosing another distribution in the exponential family or by estimating a dispersion parameter for the binomial distribution. Thus, there are no valid reasons for the systematic choice of odds ratio and of the logistic regression model to estimate prevalence rate ratios, unless the type of study imperatively requires their use.