Table 3 Associations between RBC variants and prevalence of microscopic parasitaemia at the time of each routine visit
Age group | Red cell variants | Variant | Parasite prevalence | Unadjusted | Adjusted* | ||
|---|---|---|---|---|---|---|---|
PR (95% CI) | p-value | PR (95% CI) | p-value | ||||
Children | Haemoglobin variant | AA | 2488/15,830 (15.7%) | Reference | Reference | ||
AS | 597/3636 (16.4%) | 1.07 (0.89–1.30) | 0.46 | 0.95 (0.80–1.13) | 0.57 | ||
SS | 3/66 (4.6%) | 0.31 (0.14–0.68) | 0.004 | 0.31 (0.18–0.54) | <0.001 | ||
Alpha thalassaemia variant | Normal | 1621/11,664 (13.9%) | Reference | Reference | |||
alpha+ (α−/αα) | 1272/6397 (19.9%) | 1.45 (1.24–1.70) | <0.001 | 1.23 (1.06–1.43) | 0.008 | ||
alpha0 (α−/−α) | 127/937 (13.6%) | 0.96 (0.66–1.40) | 0.83 | 0.98 (0.66–1.44) | 0.91 | ||
G6PD genotype | Normal (male) | 1593/9147 (17.4%) | Reference | Reference | |||
Hemizygotes | 194/1030 (18.8%) | 1.09 (0.81–1.48) | 0.57 | 0.86 (0.65–1.14) | 0.30 | ||
Normal (female) | 887/7039 (12.6%) | Reference | Reference | ||||
Heterozygotes | 372/2062 (18.0%) | 1.35 (1.04–1.75) | 0.02 | 1.13 (0.87–1.45) | 0.36 | ||
Homozygotes | 46/243 (18.9%) | 1.38 (0.75–2.54) | 0.30 | 0.92 (0.53–1.59) | 0.76 | ||
Adults | Haemoglobin variant | AA | 187/3952 (4.7%) | Reference | Reference | ||
AS | 37/1050 (3.5%) | 0.72 (0.45–1.15) | 0.17 | 0.74 (0.45–1.22) | 0.24 | ||
Alpha thalassaemia variant | Normal | 128/3307 (3.9%) | Reference | Reference | |||
alpha+ (α−/αα) | 81/1332 (6.1%) | 1.59 (1.08–2.34) | 0.02 | 1.52 (1.04–2.23) | 0.03 | ||
α−/−α | 15/290 (5.2%) | 1.35 (0.76–2.42) | 0.30 | 1.16 (0.63–2.14) | 0.64 | ||
G6PD genotype | Normal (male) | 8/229 (3.5%) | reference | reference | |||
Hemizygotes | 7/79 (8.9%) | 2.48 (0.72–8.52) | 0.15 | 5.10 (0.58–44.9) | 0.14 | ||
Normal (female) | 173/3792 (4.6%) | Reference | Reference | ||||
Heterozygotes | 37/880 (4.2%) | 0.87 (0.58–1.31) | 0.51 | 0.77 (0.52–1.15) | 0.20 | ||
Homozygotes | 3/50 (6.0%) | 1.38 (0.42–4.50) | 0.59 | 1.34 (0.44–4.05) | 0.61 | ||