Fig 1.
S. haematobium epidemiology across age groups.
The epidemiological data indicated that children aged 11 to 15-years-old experienced both the highest S. haematobium prevalence (%) and intensity (eggs/10ml urine), and that the lowest levels were experienced by individuals 26-years-old and older. Error bars indicate SD.
Fig 2.
Linkage disequilibrium blocks for SNPs on chromosomes 1, 5, 9, 10, 12, 17 and X.
The values within each box indicate the D’ value associated with each pair of SNPs. Blocks indicate groups of two or more SNPs which were found to be in strong LD. Strongly red blocks represent higher degrees of LD (i.e., a higher D’), and whiter blocks represent lower degrees of LD. These results show four haplotype blocks between SNPs on chromosomes 1 (IL10 rs3024496 and IL10 rs1800872), 5 (IL13 rs1295686 and IL13 rs20541), 12 (IFNG rs2069727, IFNG rs2069718 and IFNG rs2069705), and X (FOXP3 rs2294021 and FOXP3 rs2232365), where there exists strong evidence of co-inheritance of SNPs. Plots produced using Haploview 2.
Table 1.
Minor allele frequencies of SNPs in Zimbabwean sample, and Chi-square comparative analysis of frequencies between Zimbabwean sample and African and European populations.
Table 2.
Linkage disequilibrium statistics of haplotype blocks.
Table 3.
Case-control analysis of SNP MAFs between schistosome-infected (N = 354) and–uninfected individuals (N = 442).
Table 4.
Case-control analysis of haplotype frequencies between schistosome-infected (N = 354) and–uninfected individuals (N = 442).
Fig 3.
A) Odds ratios of S. haematobium infection between genotypes of SNPs IL4 rs2070874 (N = 805) and B) IFNG rs2069727 (N = 810). Models are adjusted for the confounding variables of participant age, sex and village. These data indicate that the C:T and T:T genotypes and the T allele of IL4 rs2070874 was associated with protection from S. haematobium infection, and that the G:A genotype and the G allele of IFNG rs2069727 was associated with elevated risk of infection with S. haematobium. OR = odds ratio; CIs = confidence intervals. Genotypic and dominant models display ORs relative to the homozygous reference genotype; recessive models display ORs relative to the homozygous variant genotype.
Fig 4.
Mean cytokine concentrations between SNP genotypes.
Analysis of variance identified relationships between systemic or parasite specific cytokine levels and six SNPs: IL13 rs20541 (systemic IL-5), FOXP3 rs2232365 (systemic IL-5), FOXP3 rs2294021 (systemic IL-10), TBX21 rs16947078 (CAP-specific IL-4), GATA3 rs4143094 (SEA-specific IFNγ), and STAT6 rs324015 (SEA-specific IFNγ). Pairwise p-values are Bonferroni corrected. Error bars indicate SD. CAP = cercariae antigen preparation; SEA = soluble egg antigen).
Table 5.
Analysis of variance of mean cytokine concentrations between SNP genotypes.
Fig 5.
Regression scatterplots of systemic and parasite-specific cytokines against PC scores.
X axes show square-root (x+1) transformed values. Dashed line shows regression best line of fit, and shaded area shows 95% confidence intervals of the best line of fit. Regression analysis found significant relationships between systemic and parasite-specific cytokine levels and PC2 (CAP-specific IL-10), PC4 (systemic IL-5, SEA-specific IL-13), PC6 (CAP-specific IL-10), PC10 (systemic IL-4, WWH-specific IL-5, SEA-specific IFNγ) and PC14 (SEA-specific IL-4, CAP-specific IL-5). PC = principal component; CAP = cercariae antigen preparation; SEA = soluble egg antigen; WWH = whole worm homogenate.
Table 6.
Multiple linear regression of cytokine concentrations and PCs.