Antoine Rachas

Infections in Infants during the First 12 Months of Life: Role of Placental Malaria and Environmental Factors

Background The association between placental malaria (PM) and first peripheral parasitaemias in early infancy was assessed in Tori Bossito, a rural area of Benin with a careful attention on transmission factors at an individual level. Methodology Statistical analysis was performed on 550 infants followed weekly from birth to 12 months. Malaria transmission was assessed by anopheles human landing catches every 6 weeks in 36 sampling houses and season defined by rainfall. Each child was located by GPS and assigned to the closest anopheles sampling house. Data were analysed by survival Cox models, stratified on the possession of insecticide-treated mosquito nets (ITNs) at enrolment. Principal Findings Among infants sleeping in a house with an ITN, PM was found to be highly associated to first malaria infections, after adjusting on season, number of anopheles, antenatal care (ANC) visits and maternal severe anaemia. Infants born from a malaria infected placenta had a 2.13 fold increased risk to present a first malaria infection than those born from a non infected placenta ([1.24–3.67], p<0.01) when sleeping in a house with an ITN. The risk to present a first malaria infection was increased by 3.2 to 6.5, according to the level of anopheles exposure (moderate or high levels, compared to the absence of anopheles). Conclusions First malaria infections in early childhood can be attributed simultaneously to both PM and high levels of exposure to infected anopheles. Protective measures as Intermittent Preventive Treatment during pregnancy (IPTp) and ITNs, targeted on both mothers and infants should be reinforced, as well as the research on new drugs and insecticides. In parallel, investigations on placental malaria have to be strengthened to better understand the mechanisms involved, and thus to protect adequately the infants high risk group.

Factors associated with growth patterns from birth to 18 months in a Beninese cohort of children

The aim of this study was to analyze factors influencing the growth pattern of children from birth to 18 months. A longitudinal prospective study was conducted in three maternity wards in Southern Benin. Inclusion took place between June 2007 and July 2008; children were followed-up until 18 months of age. Height-for-age and weight-for-height Z-scores were computed using the newborns anthropometric measurements taken at delivery, every month up to 6 months and then quarterly. Infant and young child feeding (IYCF) practices and malarial morbidity were recorded. Gestational age was estimated using the Ballard method; Williams sex-specific reference curve of birth weight-for-gestational-age was used to determine intrauterine growth retardation (IUGR). Analyses were performed on 520 children using a linear mixed model. Low birth weight (coef=-0.43; p=0.002), IUGR (coef=-0.49; p<0.001), maternal short stature (coef=-0.25; p=0.001) and maternal low weight status (coef=-0.19; p=0.006) were significantly associated with growth impairment. Only LBW (coef=-0.28; p=0.05) and maternal low weight status (coef=-0.23; p=0.004) were associated with wasting. A good IYCF score was positively associated with weight gain (coef=0.14; p<0.001) whereas we found a paradoxical association with length (coef=-0.18; p<0.001). Malaria morbidity was not associated with growth. LBW, IUGR and maternal low weight status and height were important determinants of childrens growth. These results reinforce and justify continuing public health initiatives to fight IUGR and LBW and break the intergenerational cycle of malnutrition.

Prematurity, intrauterine growth retardation and low birth weight: risk factors in a malaria-endemic area in southern Benin

BACKGROUND 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. METHODS A cross-sectional study was carried out in southern Benin between June 2007 and July 2008. At delivery, womens characteristics and newborns anthropometric measurements were collected. Gestational age was estimated using the Ballard method; SGA was defined using the Williams reference curve. Analyses were performed by multiple logistic and linear regressions. RESULTS 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. Infants male gender was associated with a lower risk of prematurity (p=0.03). Low maternal anthropometric status (p<0.001), primiparity (p=0.017) and infants male gender (p=0.015) were associated with an increased risk of SGA. Only low maternal anthropometric status and primiparity were associated with an increased risk of LBW, and their effect on LBW was mediated by SGA. CONCLUSIONS SGA was the main mechanism mediating the effect of risk factors on LBW. Maternal undernutrition (either short stature or low anthropometric status) was the most important of them.

Timeliness of Yellow Fever Surveillance, Central African Republic

During January 2007–July 2012, a total of 3,220 suspected yellow fever cases were reported in the Central African Republic; 55 were confirmed and 11 case-patients died. Mean delay between onset of jaundice and case confirmation was 16.6 days. Delay between disease onset and blood collection could be reduced by increasing awareness of the population.

Correction: Excess mortality and hospitalizations in transitional-age youths with a long-term disease: A national population-based cohort study

[This corrects the article DOI: 10.1371/journal.pone.0193729.].