Blood lead level in infants and subsequent risk of malaria: A prospective cohort study in Benin, Sub-Saharan Africa

Abstract

Lead and malaria both present significant health risks to children in Sub-Saharan Africa. Previous studies have shown that high blood lead levels in children act as a protective factor against subsequent malaria incidence. The main objective of this study was to investigate associations between blood lead level and malaria outcomes prospectively in Beninese children from 12 to 24 months of age. Two-hundred and four children were assessed for lead at 12 months and closely followed until 24 months for malaria; when symptoms and parasite density were also recorded. Univariate and multivariate negative binomial and linear regression models tested associations between blood lead level quartile and total episodes of malaria (total symptomatic and asymptomatic episodes) and parasite density, respectively. Median blood lead level among children measured at 12 months was 56.50 (4.81–578) μg/L. During the 12-month follow-up, 172 (84.31%) children had at least one malaria episode. Univariate and multivariate negative binomial and linear regressions did not reveal significant associations between blood lead level quartile and malaria outcomes. Iron deficiency was not found to be an effect modifier. Results from this prospective child-cohort study investigating associations between blood lead level and malaria did not confirm results from previous cross-sectional studies. Further research is needed to further explore this relationship and other co-morbidities due to malaria and lead.

Blood Lead Levels and Subsequence Risk of Malaria in the African Population: A Systematic Review and Meta-Analysis

“…The remaining 13 studies were assessed for full texts; then, seven studies were excluded with reasons: three reviews, one systematic review, one study without data on malaria and lead, one comment, and one case report. Finally, six eligible studies [11,[18][19][20][21]24] were included in the qualitative and quantitative syntheses (Figure 1).…”

“…The included studies were published between 2011 and 2020 and conducted between 2005 and 2013. Three studies were conducted in Nigeria (3/6, 50%) [11,19,20], two studies were conducted in Benin (2/6, 33.3%) [18,24], and one study was conducted in Uganda [21]. Three studies had cross-sectional design [18,19,21], while two studies were prospective observational design [11,20], and one study had a cohort design [24].…”

“…Three studies were conducted in Nigeria (3/6, 50%) [11,19,20], two studies were conducted in Benin (2/6, 33.3%) [18,24], and one study was conducted in Uganda [21]. Three studies had cross-sectional design [18,19,21], while two studies were prospective observational design [11,20], and one study had a cohort design [24]. Five studies enrolled children age between 1 and 9 years [18][19][20][21]24], while only one study enrolled pregnant women [11].…”

“…Three studies had cross-sectional design [18,19,21], while two studies were prospective observational design [11,20], and one study had a cohort design [24]. Five studies enrolled children age between 1 and 9 years [18][19][20][21]24], while only one study enrolled pregnant women [11]. Among studies that enrolled children, one study enrolled children with venous blood lead level (VBLL) >45 mg/dL before chelation [20], and one study enrolled children with malaria [21].…”

“…Among studies that enrolled children, one study enrolled children with venous blood lead level (VBLL) >45 mg/dL before chelation [20], and one study enrolled children with malaria [21]. Four studies aimed to investigate the correlation between malaria and BLL [11,18,19,24], while two studies aimed to determine the impact of both malaria and BLL on patients' complications, such as neurological complications [20] and severe anemia [21]. Three studies [11,18,21] used microscopy for malaria diagnosis, while others used both microscopy or rapid diagnostic test (RDT) [24], RDT alone [20], or did not specified the test method [19].…”