Background
Methods
Study site and population
The study design
Recombinant antigens
Antibody measurements
Multiplexed assay
Results
Pattern of Plasmodium falciparum infection and clinical malaria in the study area
Characteristics | Cumulative incidence of malaria | Child year at risk | No. of malaria episodes | Incidence rate per 100 child year (95% CI) |
---|---|---|---|---|
Age group | ||||
12 <24 months | 52.5% (21/40) | 34.9 | 28 | 80 (55, 116) |
24 <36 months | 31.5% (17/54) | 46.1 | 24 | 52 (35, 78) |
36 <48 months | 12.8% (10/78) | 75.1 | 12 | 16 (9, 28) |
48 <60 months | 10.3% (8/78) | 76.4 | 9 | 12 (6, 23) |
60 <73 months | 10.8% (7/65) | 62.2 | 7 | 11 (5, 23) |
Baseline P. falciparum parasitemia level | ||||
Negative | 41.4% (24/58) | 52.1 | 31 | 59 (42, 84) |
Positive | 15.2% (39/257) | 242.7 | 49 | 20 (15, 27) |
TOTAL | 20% (63/315) | 295.1 | 80 | 27 (22, 34) |
Association between antibody levels, age and clinical malaria
Antibody | Antigen | Crude IRR (95%CI) | IRR adjusted for age (95%CI) | P-value for adjusted IRR |
---|---|---|---|---|
IgG | GLURP-R0 | 0.76 (0.67, 0.86) | 0.85 (0.75, 0.96) | 0.01 |
GLURP-R2 | 0.65 (0.55, 0.78) | 0.77 (0.65, 0.91) | <0.01 | |
MSP1-3D7 | 0.72 (0.61, 0.85) | 0.79 (0.69, 0.91) | <0.01 | |
MSP1-FVO | 0.81 (0.63, 1.06) | 0.73 (0.58, 0.93) | 0.01 | |
MSP3-3D7 | 0.75 (0.63, 0.89) | 0.86 (0.74, 1.01) | 0.06 | |
AMA1-3D7 | 0.72 (0.63, 0.82) | 0.80 (0.71, 0.91) | <0.01 | |
AMA1-FVO | 0.72 (0.62, 0.83) | 0.81 (0.71, 0.93) | <0.01 | |
AMA1-LR32 | 0.74 (0.64, 0.85) | 0.85 (0.74, 0.96) | 0.01 | |
EBA-175 | 0.66 (0.56, 0.78) | 0.81 (0.68, 0.97) | 0.02 | |
LSA-1 | 0.79 (0.64, 0.98) | 0.89 (0.73, 1.09) | 0.26 |
Immunological variables | Adjusted IRR (95%CI) | Wald P-value | LR test | |
---|---|---|---|---|
MSP1-3D7 IgG | Values transformed to log base 2 | 0.84 (0.73, 0.97) | P = 0.02 | |
AMA1-3D7 IgG | Values transformed to log base 2 | 0.84 (0.74, 0.96) | P = 0.01 | |
Age group | 12 <24 months | 1 | χ2 = 21.24, p < 0.001 | |
24 <36 months | 0.94 (0.44,2.01) | P = 0.88 | ||
36 <48 months | 0.33 (0.14,0.77) | P = 0.01 | ||
48 <60 months | 0.21 (0.08,0.51) | p < 0.01 | ||
60 <73 months | 0.24 (0.09,0.66) | P = 0.01 |