RESUMO
OBJECTIVE: To examine environmental and human factors that affect the spatial and temporal dynamism of malaria in DRC's South-Kivu province. METHODS: In a cross-sectional study conducted between 1 January 2010 and 31 December 2015, spatial distribution was determined through thematic maps of malaria attack rate. SatScan ™ software and Monte Carlo test were used to identify spatial risk clusters. Temporal evolutions were analysed using the Cleveland algorithm. Generalized Additive Models for Location Scale and Shape and negative binomial regression were used to assess the independent human and environmental factors associated with incident malaria. RESULTS: The cumulative annual incidence of malaria increased from 10 968/100 000 in 2013 to 15 501/100 000 in 2015 (P for trend Ë0.001); malaria lethality increased from 0.1% in 2013 to 0.3% in 2015 (P for trend = 0.62). Between 2010 and 2015, 18 of 34 health zones consistently reported the highest attack rates, which ranged from 25 000 to 50 000/100 000. Four risk clusters areas were identified, with relative risk (RR) of 1.2 to 3.0, from which malaria was reported continuously during each year. Factors significantly associated with malaria cases were agro-pisciculture practices (Incidence Risk Ratio [IRR]: 1.96; 95% CI: 1.23-3.13) and the presence of a lake in the health zone (IRR: 2.48, 95% CI: 1.51-4.42). CONCLUSIONS: Malaria control in this setting must be intensified in peri-lacustrine areas and those in which the population is intensively engaged in standing water-associated activities.
OBJECTIF: Examiner les facteurs environnementaux et humains qui affectent le dynamisme spatial et temporel du paludisme dans la province du Sud-Kivu en RDC. MÉTHODES: Dans une étude transversale menée entre le 1er janvier 2010 et le 31 décembre 2015, la distribution spatiale a été déterminée à l'aide de cartes thématiques du taux de cas de paludisme. Le logiciel SatScan™ et le test Monte Carlo ont été utilisés pour identifier les grappes de risques spatiaux. Les évolutions temporelles ont été analysées à l'aide de l'algorithme de Cleveland. Des modèles additifs généralisés pour l'échelle et la forme de l'emplacement et la régression binomiale négative ont été utilisés pour évaluer les facteurs humains et environnementaux indépendants associés à l'incidence du paludisme. RÉSULTATS: L'incidence annuelle cumulée du paludisme est passée de 10.968/100 000 en 2013 à 15.501/100 000 en 2015 (p pour la tendance Ë0,001); la létalité du paludisme est passée de 0,1% en 2013 à 0,3% en 2015 (p pour tendance = 0,62). Entre 2010 et 2015, 18 des 34 zones de santé ont constamment rapporté des taux de cas les plus élevés, qui variaient de 25.000 à 50.000/100 000. Quatre zones de risques de grappes ont été identifiées, avec un risque relatif (RR) de 1,2 à 3,0 à partir desquelles le paludisme a été rapporté en continu chaque année. Les facteurs significativement associés aux cas de paludisme étaient: les pratiques agro-piscicoles (Ratio d'Incidence de Risque [IRR]: 1,96 ; IC95%: 1,23-3,13) et la présence d'un lac dans la zone de santé (TRI: 2,48 ; IC95%: 1,51-4,42). CONCLUSIONS: La lutte contre le paludisme dans ce contexte doit être intensifiée dans les zones péri-lacustres et celles dans lesquelles la population est intensément engagée dans des activités liées à l'eau stagnante.
Assuntos
Malária/epidemiologia , Antropometria , Estudos Transversais , República Democrática do Congo/epidemiologia , Meio Ambiente , Humanos , Incidência , Malária/etiologia , Fatores de Risco , Análise Espaço-TemporalRESUMO
BACKGROUND: Transfer of the trace metal cobalt (Co) from mother to foetus has not been documented in populations with high environmental exposure to Co, as is the case in the African Copperbelt mining region. We analysed data obtained from 246 mother-infant pairs included (at delivery) in a previously published case-control study on birth defects, done in Lubumbashi (Democratic Republic of Congo) between March 1, 2013, and Feb 28, 2015. METHODS: Co was measured by Inductively Coupled Plasma Mass Spectrometry in maternal blood, maternal urine, umbilical cord blood and placental tissue, as available. RESULTS: The Co concentrations [geometric mean (GM) with interquartile range (IQR)] in maternal blood (GM 1.77 µg/L, IQR 1.07-2.93) and urine (GM 7.42 µg/g creatinine, IQR 4.41-11.0) were highly correlated (Spearman r = 0.71, n = 166; p < 0.001) and considerably higher than reference values determined for general populations elsewhere in the world. The concentrations of Co in umbilical cord blood (GM 2.41 µg/L) were higher (Wilcoxon test, p < 0.001) than in maternal blood (GM 1.37 µg/L), with a correlation between both values (Spearman r = 0.34; n = 127, p < 0.001). Co concentrations in placental tissue (geometric mean 0.02 µg/g wet weight) correlated with concentrations in maternal blood (Spearman r = 0.50, n = 86, p < 0.001) and in neonatal blood (Spearman r = 0.23, n = 83, p = 0.039). CONCLUSION: This first study of maternal and neonatal Co concentrations in the African Copperbelt provides strong evidence of a high transfer of Co from mother to foetus.