Table II. Associations among Ab prevalence, age, and parasitemia.
| Ag | Region | No. Positive (%) | Age ≤9 y (no. [%]) | Age >9 y (no. [%]) | p Value | PCR−(no. [%]) | PCR+ (no. [%]) | p Value |
|---|---|---|---|---|---|---|---|---|
| Surface proteins (GPI anchored) | ||||||||
| MSP1 | MSP1–19 | 199 (96.6) | 85 (93.4) | 114 (99.1) | 0.024 | 62 (92.5) | 137 (98.6) | 0.025 |
| MSP1 | MSP1–42 | 191 (92.7) | 80 (87.9) | 111 (96.5) | 0.018 | 57 (85.1) | 134 (96.4) | 0.003 |
| MSP2 | Full length | 182 (88.4) | 74 (81.3) | 108 (93.9) | 0.005 | 51 (76.1) | 131 (94.2) | <0.001 |
| MSP4 | Full length | 194 (94.2) | 80 (87.9) | 114 (99.1) | 0.001 | 57 (85.1) | 137 (98.6) | <0.001 |
| MSP10 | Full ectodomain | 178 (86.4) | 71 (78.0) | 107 (93.0) | 0.002 | 50 (74.6) | 128 (92.1) | 0.001 |
| Pf12 | Full ectodomain | 196 (95.2) | 81 (89.0) | 115 (100.0) | <0.001 | 59 (88.1) | 137 (98.6) | 0.001 |
| Pf38 | Full ectodomain | 182 (88.4) | 77 (84.6) | 105 (91.3) | 0.137 | 53 (79.1) | 129 (92.8) | 0.004 |
| Surface proteins (non-GPI anchored) | ||||||||
| MSP3 | Full ectodomain | 180 (87.4) | 70 (76.9) | 110 (95.7) | <0.001 | 50 (74.6) | 130 (93.5) | <0.001 |
| MSP3 | LSP | 135 (65.5) | 48 (52.8) | 87 (75.7) | 0.001 | 34 (50.8) | 101 (72.7) | 0.002 |
| MSP6 | Full ectodomain | 182 (88.4) | 76 (83.5) | 106 (92.2) | 0.054 | 50 (74.6) | 132 (95.0) | <0.001 |
| MSP7 | Full ectodomain | 199 (96.6) | 85 (93.4) | 114 (99.1) | 0.024 | 63 (94.0) | 136 (97.8) | 0.157 |
| MSRP1 | Full ectodomain | 175 (85.0) | 68 (74.7) | 107 (93.0) | <0.001 | 50 (74.6) | 125 (89.9) | 0.004 |
| ABRA/MSP9 | Full ectodomain | 185 (89.8) | 75 (82.4) | 110 (95.7) | 0.002 | 53 (79.1) | 132 (95.0) | <0.001 |
| H103/MSP11 | Full ectodomain | 195 (94.7) | 82 (90.1) | 113 (98.3) | 0.010 | 58 (86.6) | 137 (98.6) | <0.001 |
| GLURP | R2 peptide | 185 (89.8) | 74 (81.3) | 111 (96.5) | <0.001 | 55 (82.1) | 130 (93.5) | 0.011 |
| SERA5 | Full ectodomain | 199 (96.6) | 85 (93.4) | 114 (99.1) | 0.024 | 61 (91.0) | 138 (99.8) | 0.002 |
| Pf41 | Full ectodomain | 183 (88.8) | 73 (80.2) | 110 (95.7) | <0.001 | 51 (76.1) | 132 (95.0) | <0.001 |
| MSPDBL1 | DBL domain | 193 (93.7) | 81 (89.0) | 112 (97.4) | 0.014 | 58 (86.6) | 135 (97.1) | 0.004 |
| MSPDBL2 | Full ectodomain | 186 (90.3) | 75 (82.4) | 111 (96.5) | 0.001 | 53 (79.1) | 133 (95.7) | <0.001 |
| Micronemal proteins | ||||||||
| AMA1 | Full ectodomain | 195 (94.7) | 81 (89.0) | 114 (99.1) | 0.001 | 58 (86.6) | 137 (98.6) | <0.001 |
| EBA140 | Region II | 176 (85.4) | 74 (81.3) | 102 (88.7) | 0.136 | 51 (76.1) | 125 (89.9) | 0.009 |
| EBA140 | Region III–V | 165 (80.1) | 66 (72.5) | 99 (86.1) | 0.016 | 47 (70.2) | 118 (84.9) | 0.013 |
| EBA175 | F2 | 186 (90.3) | 75 (82.4) | 111 (96.5) | 0.001 | 56 (83.6) | 130 (93.5) | 0.024 |
| EBA175 | Region II | 161a (79.3) | 64 (70.3) | 97 (86.6) | 0.004 | 46 (69.7) | 115 (83.9) | 0.019 |
| EBA175 | Region III–V | 184 (89.3) | 75 (82.4) | 109 (94.8) | 0.004 | 50 (74.6) | 134 (96.4) | <0.001 |
| EBA181 | Region III–V | 183 (88.8) | 73 (80.2) | 110 (95.7) | <0.001 | 56 (83.6) | 127 (91.4) | 0.097 |
| GAMA | Full ectodomain | 180 (87.4) | 74 (81.3) | 106 (92.2) | 0.020 | 51 (76.1) | 129 (92.8) | 0.001 |
| GAMA | N-terminal | 169a (83.3) | 71 (78.0) | 98 (87.5) | 0.072 | 48 (72.7) | 121 (88.3) | 0.005 |
| GAMA | C-terminal | 56a (27.6) | 26 (28.6) | 30 (26.8) | 0.777 | 11 (16.7) | 45 (32.9) | 0.016 |
| Ripr | EGF-like domain | 91a (44.8) | 35 (38.5) | 56 (50.0) | 0.100 | 26 (39.4) | 65 (47.5) | 0.280 |
| SUB2 | N-terminal | 177a (87.2) | 71 (78.02) | 106 (94.6) | <0.001 | 50 (75.8) | 127 (92.7) | 0.001 |
| Rhoptry proteins | ||||||||
| RAMA | Full ectodomain | 177 (85.9) | 72 (79.1) | 105 (91.3) | 0.013 | 48 (71.6) | 129 (92.8) | <0.001 |
| PfRh2 | PfRh2-297 | 161 (78.2) | 67 (73.6) | 94 (81.7) | 0.162 | 45 (67.2) | 116 (83.5) | 0.008 |
| PfRh2 | PfRh2-2030 | 194 (94.2) | 80 (87.9) | 114 (99.1) | 0.001 | 59 (88.1) | 135 (97.2) | 0.009 |
| PfRh2 | PfRh2a | 191 (94.1) | 82 (91.1) | 109 (96.5) | 0.108 | 58 (87.9) | 133 (97.1) | 0.009 |
| PfRh2 | PfRh2b | 175 (85.0) | 72 (79.1) | 103 (89.6) | 0.037 | 47 (70.1) | 128 (92.1) | <0.001 |
| PfRh4 | PfRh4.2 | 195 (94.7) | 82 (90.1) | 113 (98.3) | 0.010 | 60 (89.6) | 135 (97.1) | 0.024 |
| PfRh4 | PfRh4.9 | 193 (93.7) | 81 (89.0) | 112 (97.4) | 0.014 | 57 (85.1) | 136 (97.8) | <0.001 |
| PfRh5 | Full ectodomain | 108a (53.2) | 35 (38.5) | 73 (65.2) | <0.001 | 28 (42.4) | 80 (58.4) | 0.033 |
| RALP-1 | Full ectodomain | 189a (93.1) | 81 (89.0) | 108 (96.4) | 0.038 | 56 (84.9) | 133 (97.1) | 0.001 |
| RhopH1(3.1) | N-terminal | 120a (59.1) | 38 (41.8) | 82 (73.2) | <0.001 | 32 (48.5) | 88 (64.2) | 0.033 |
| RhopH1(2) | N-terminal | 154a (75.9) | 60 (65.9) | 94 (83.9) | 0.003 | 45 (68.2) | 109 (79.6) | 0.076 |
| RON2 | N-terminal | 167a (82.3) | 62 (68.1) | 105 (93.8) | <0.001 | 41 (62.1) | 126 (92.0) | <0.001 |
| RON4 | N-terminal | 191a (94.1) | 81 (89.0) | 110 (98.2) | 0.006 | 56 (84.9) | 135 (98.5) | <0.001 |
| RON6 | C-terminal | 164a (79.6) | 67 (73.6) | 97 (86.6) | 0.020 | 41 (62.1) | 123 (89.8) | <0.001 |
| Likely apical proteins | ||||||||
| Pf113 | C-terminal | 178a (87.7) | 74 (81.3) | 104 (92.9) | 0.013 | 51 (77.3) | 127 (92.7) | 0.002 |
| CSP | NANP repeat | 106 (51.5) | 46 (50.6) | 60 (52.2) | 0.817 | 31 (46.3) | 75 (54.0) | 0.301 |
The total prevalence of IgG responses to each Ag tested in a cohort of PNG children. The effects of age (≤9 or >9 y of age, n = 91 and n = 115, respectively) and concurrent parasitemia (determined by PCR, n = 67 and n = 139, respectively) on IgG prevalence are also examined. The total number of study participants was n = 206, unless indicated otherwise.
χ2 tests were used to determine statistical significance (p ≤ 0.05 shown in bold type).
a
n = 203.