Article Figures & Data
Figures
- FIG 1
Pooled ROC curves of the study participants (combined febrile and afebrile) tested with the urine malaria test and BinaxNOW Pf and BinaxNOW Pan. AUC, area under the curve. P values comparing the area under the receiver-operator characteristic (ROC) curves were computed using DeLong's test for two ROC curves.
Tables
- TABLE 1
Demographic characteristics and clinical history of the study population
Parameter No. of patients (%) Overall (n = 1,691) Febrile (n = 566) Afebrile (n = 1,125) Gender Female 970 (57) 276 (49) 694 (62) Male 721 (43) 290 (51) 431 (38) Age (yr) 2–5 416 (25) 202 (36) 214 (19) 6–11 390 (23) 175 (31) 215 (19) 12–17 195 (12) 81 (14) 114 (10) 18–20 61 (4) 20 (4) 41 (4) 21–39 427 (25) 71 (13) 356 (32) 40–54 153 (9) 13 (2) 140 (12) 55+ 49 (3) 4 (1) 45 (4) Symptoms Chills 1,135 (67) 442 (78) 693 (62) Body pain 1,159 (69) 387 (68) 772 (69) Headache 1,364 (81) 473 (84) 891 (69) Vomiting 257 (15) 129 (23) 128 (11) Stomach ache 185 (11) 128 (23) 57 (5) Weakness 68 (4) 56 (10) 12 (1) Anorexia 186 (11) 86 (15) 100 (9) Cough 189 (11) 117 (21) 72 (6) Catarrh 170 (10) 107 (19) 63 (6) Bitter taste 31 (2) 25 (4) 6 (1) Dizziness 46 (3) 35 (6) 11 (1) Other 83 (5) 25 (4) 58 (5) Study site Agura 365 (22) 75 (13) 290 (26) Bayekun 218 (13) 88 (16) 130 (12) Ijede 522 (31) 206 (36) 316 (28) Imota 439 (26) 164 (29) 275 (24) Oreta 48 (3) 6 (1) 42 (4) Shomolu 99 (6) 27 (5) 72 (6) a The mean age ± SD for each group was as follows: overall, 18.6 ± 15.9 years (range, 2.0 to 80 years); febrile, 11.6 ± 11.0 years (range, 2.0 to 70 years); afebrile, 22.1 ± 16.7 years (range, 2.0 to 80 years).
- TABLE 2
Malaria microscopy, UMT, blood-based malaria RDT (BinaxNow Pf/Pan), and urinalysis results of the study population
Parameter No. of patients (%)b Overall (n = 1,691) Febrile (n = 566) Afebrile (n = 1,125) Positive malaria diagnostic tests Microscopy 341 (20.2) 204 (36) 137 (12.2) UMT 419 (25) 231 (41) 188 (17) BinaxNOW Pf 676 (40) 315 (56) 361 (32) BinaxNOW Pan 368 (22) 224 (40) 144 (13) Parasite prevalence Detectable asexual stage parasites 338 (20) 203 (36) 155 (14) Density (no. of parasites)a 1–199 2 (1) 1 (0.5) 1 (1) 200–499 16 (5) 5 (2) 11 (7) 500–999 20 (6) 8 (4) 12 (8) 1,000–4 999 70 (21) 34 (17) 36 (23) 5,000–9 999 44 (13) 26 (13) 18 (12) 10,000–49 999 109 (32) 75 (37) 34 (22) 50,000+ 77 (23) 54 (27) 23 (15) Urinalysis Leukocytes >15/µl 189 (11) 67 (12) 182 (16) Presence of nitrites (mg/dl) 22 (1) 7 (1) 15 (1) Urobilinogen of ≥1 mg/dl 159 (9) 67 (12) 92 (8) Protein of >100 mg/dl 73 (4) 42 (7) 31 (3) Ketone of >5 mg/dl 344 (20) 176 (31) 168 (15) Bilirubin of ≥1 mg/dl 159 (9) 71 (13) 88 (8) Glucose (mg/dl) 21 (1) 5 (1) 16 (1) Blood (erythrocytes/µl) 175 (10) 77 (14) 98 (9) pH <7 1,443 (85) 493 (87) 950 (84) 7 114 (7) 45 (8) 69 (6) >7 130 (8) 27 (5) 103 (9) Specific gravity <1.010 549 (32) 158 (28) 391 (35) 1.011–1.020 725 (43) 264 (47) 461 (41) >1.021 414 (24) 144 (25) 270 (24) - TABLE 3
Performance of urine malaria test and blood-based RDTs in overall study participants and febrile and afebrile subjects at clinical presentation
Group and parametera Test performanceb P valuec UMT BinaxNOW Pf BinaxNOW Pan UMT vs BinaxNOW Pf UMT vs BinaxNOW Pan All participants (n = 1,691) Sensitivity (% [95% CI]) 79 (75, 84) 98 (96, 99) 80 (76, 84) <0.001 0.824 Specificity (% [95% CI]) 89 (87, 91) 75 (72, 77) 93 (92, 94) <0.001 <0.001 PPV (% [95% CI]) 65 (60, 69) 50 (46, 53) 74 (70, 79) 1.00 0.988 NPV (% [95% CI]) 94 (93, 96) 99 (99, 100) 95 (94, 96) 0.932 1.00 NLR 0.23 (0.23, 0.24) 0.02 (0.02, 0.03) 0.21 (0.21, 0.22) PLR 7.2 (7.2, 7.3) 3.9 (3.9, 3.9) 11.5 (11.3, 11.8) Febrile participants (n = 566) Sensitivity (% [95% CI]) 85 (79, 89) 99 (97, 100) 86 (80, 90) <0.001 0.883 Specificity (% [95% CI]) 84 (80, 88) 69 (64, 74) 86 (83, 90) <0.001 0.176 PPV (% [95% CI]) 75 (69, 80) 64 (59, 69) 78 (72, 83) 1.00 0.981 NPV (% [95% CI]) 91 (87, 94) 99 (97, 100) 92 (88, 94) 0.693 0.808 NLR 0.18 (0.17, 0.19) 0.01 (0.01, 0.04) 0.16 (0.16, 0.17) PLR 5.3 (5.1, 5.5) 3.2 (3.1, 3.2) 6.3 (6.1, 6.6) Afebrile participants (n = 1,125) Sensitivity (% [95% CI]) 72 (63, 79) 97 (93, 99) 72 (64, 80) <0.001 1.00 Specificity (% [95% CI]) 91 (89, 93) 77 (74, 80) 95 (94, 97) <0.001 <0.001 PPV (% [95% CI]) 52 (45, 59) 37 (32, 42) 69 (61, 76) 1.00 0.981 NPV (% [95% CI]) 96 (94, 97) 99 (99, 100) 96 (95, 97) 0.938 1.00 NLR 0.31 (0.30, 0.32) 0.04 (0.02, 0.06) 0.29 (0.28, 0.30) PLR 7.9 (7.7, 8.1) 4.2 (4.2, 4.2) 15.9 (15.1, 16.6) ↵a PPV, positive predictive value; NPV, negative predictive value; NLR, negative likelihood ratio; PLR, positive likelihood ratio.
↵b BinaxNOW Pf contains HRP-2, a P. falciparum-specific antigen, and BinaxNOW Pan contains aldolase, an antigen found in all species of Plasmodium. P. falciparum is the most dominant species in the trial area.
↵c P values comparing the sensitivities and specificities of the Fyodor UMT and the BinaxNOW tests were estimated using McNemar's test. P values comparing the positive and negative predictive values were calculated using the weighted generalized score statistic.
- TABLE 4
Area under the ROC curve for all tests stratified by presence of fever
Test AUC (95% CI) P valuea Febrile Afebrile UMT 0.84 (0.81, 0.88) 0.81 (0.78, 0.84) 0.212 BinaxNOW Pf 0.84 (0.81, 0.87) 0.87 (0.85, 0.89) 0.054 BinaxNOW Pan 0.86 (0.83, 0.89) 0.84 (0.81, 0.87) 0.358 ↵a P values comparing the area under the receiver-operator characteristic (ROC) curves were computed using DeLong's test for two ROC curves.
- TABLE 5
Sensitivity and specificity of UMT, BinaxNOW Pf, and BinaxNOW Pan tests by parasite density level for febrile, afebrile, and all study participants
Group and test Test performance by parasite densitya P value by density groupb Specificity (% [CI]) at 0 Sensitivity (% [CI]) 1–999 1,000–4,999 5,000+ 1–999 1,000–4,999 Total study population UMT 89 (87, 91) 58 (41, 74) 69 (56, 79) 86 (81, 90) <0.001 0.002 BinaxNOW Pf 75 (72, 77) 95 (82, 99) 96 (88, 99) 100 (98, 100) 0.055 0.042 BinaxNOW Pan 93 (92, 94) 42 (26, 59) 70 (58, 80) 90 (85, 93) <0.001 <0.001 Febrile group UMT 84 (80, 88) 71 (42, 92) 76 (59, 89) 88 (81, 92) 0.105 0.107 BinaxNOW Pf 69 (64, 74) 93 (66, 100) 97 (85, 100) NA 0.083 0.181 BinaxNOW Pan 86 (83, 90) 57 (29, 82) 79 (62, 91) NA 0.004 0.143 Afebrile group UMT 91 (89, 93) 50 (29, 71) 61 (43, 77) 82 (71, 90) <0.001 0.020 BinaxNOW Pf 77 (74, 80) 96 (79, 100) 94 (81, 99) 99 (93, 100) 0.055 0.253 BinaxNOW Pan 95 (94, 97) 33 (16, 55) 61 (43, 77) 90 (81, 96) <0.001 0.001 - TABLE 6
Urine malaria test (UMT) performance characteristics among study participants infected with Plasmodium falciparum relative to original and PCR-corrected microscopy results
Parameter and groupa UMT performance relative to: P valueb Original microscopy PCR-corrected microscopy Sensitivity (% [CI]) All participants 78 (74, 83) 77 (72, 81) 0.665 Febrile 85 (79, 89) 81 (75, 86) 0.577 Afebrile 72 (64, 79) 72 (66, 79) 1.00 Specificity (% [CI]) All participants 90 (89, 91) 92 (90, 93) 0.368 Febrile 84 (80, 88) 85 (81, 89) 0.770 Afebrile 92 (90, 93) 94 (92, 95) 0.091 PPV (% [CI]) All participants 63 (58, 67) 70 (65, 74) 1.00 Febrile 74 (68, 80) 77 (71, 82) 1.00 Afebrile 51 (44, 57) 63 (56, 69) 1.00 NPV (% [CI]) All participants 95 (94, 96) 94 (93, 95) 0.945 Febrile 90 (87, 93) 88 (84, 91) 0.891 Afebrile 97 (95, 97) 96 (95, 97) 0.941 PLR All participants 0.240 (0.237, 0.243) 0.253 (0.249, 0.256) Febrile 0.201 (0.195, 0.207) 0.228 (0.221, 0.236) Afebrile 0.304 (0.298, 0.311) 0.294 (0.287, 0.302) NLR All participants 7.87 (7.72, 8.03) 9.25 (9.11, 9.40) Febrile 5.29 (5.04, 5.55) 5.49 (5.29, 5.70) Afebrile 8.70 (8.42, 8.99) 11.2 (10.9, 11.5)
