Table 2.
Proportion of Enteropathogenic Escherichia coli, Enteroaggregative E. coli, and Shiga Toxin–Producing E. coli Pathotypes Positive by TaqMan Array Card System Quantitative Polymerase Chain Reaction With Cycle Threshold <35, Overall and Among Case and Control Children Aged <5 Years
| No. Positive for Each Pathotype, 9672 Tested (%)a | Enteroaggregative Escherichia coli n = 5908 (61.1%)a |
Typical Enteropathogenic E. coli n = 2163 (22.4%)a |
Atypical Enteropathogenic E. coli n = 2448 (25.3%)a |
Shiga Toxin–Producing E. coli n = 698 (7.2%)a |
||||
|---|---|---|---|---|---|---|---|---|
| No. of cases and controls positive by pathotype (%) | Case n = 2818/4836 (58.3%) |
Control n = 3090/4836 (63.9%)b | Case n = 1077/4836 (22.3%) | Control n = 1086/4836 (22.5%) | Case n = 1127/4836 (23.3%)b |
Control n = 1321/4836 (27.3%) | Case n = 247/4836 (5.1%)b,c |
Control n = 451/4836 (9.3%)d |
| Site | ||||||||
| ȃThe Gambia | 983 (34.9%) | 1085 (35.1%) | 427 (39.7%) | 421 (38.8%) | 365 (32.4%) | 462 (35.0%) | 79 (32.0%) | 154 (34.2%) |
| ȃMali | 956 (33.9%) | 1039 (33.6%) | 404 (37.5%) | 408 (37.6%) | 345 (30.6%) | 422 (32.0%) | 55 (22.3%) | 91 (20.2%) |
| ȃKenya | 879 (31.2%) | 966 (31.3%) | 246 (22.8%) | 257 (23.7%) | 417 (37.0%) | 437 (33.1%) | 113 (45.8%) | 206 (45.7%) |
| Age group, mo | ||||||||
| ȃ0–11 | 1122 (39.8%) | 1259 (40.7%) | 394 (36.6%) | 413 (38.0%) | 328 (29.1%) | 438 (33.2%) | 38 (15.4%) | 108 (24.0%) |
| ȃ12–23 | 952 (33.8%) | 1022 (33.1%) | 396 (36.8%) | 401 (36.9%) | 420 (37.3%) | 478 (36.2%) | 84 (34.0%) | 161 (35.7%) |
| ȃ24–59 | 744 (26.4%) | 809 (26.2%) | 287 (26.7%) | 272 (25.1%) | 379 (33.6%) | 405 (30.7%) | 125 (50.6%) | 182 (40.4%) |
| Sex | ||||||||
| ȃMale | 1534 (54.4%) | 1666 (53.9%) | 581 (54%) | 581 (53.5%) | 615 (54.6%) | 699 (52.9%) | 136 (55.1%) | 241 (53.4%) |
| ȃFemale | 1284 (45.6%) | 1424 (46.1%) | 496 (46.1%) | 505 (46.5%) | 512 (45.4%) | 622 (47.1%) | 111 (44.9%) | 210 (46.6%) |
Positive defined by TaqMan Array Card system quantitative polymerase chain reaction (cycle threshold <35).
The proportion of the E. coli pathotype was significantly higher in controls compared with cases for enteroaggregative E. coli (63.9 vs 58.3%, P = .0004), atypical enteropathogenic E. coli (27.3 vs 23.3%, P < .0001), and Shiga toxin–producing E. coli (STEC; 9.3 vs 5.1%, P < .0001).
Of the 247 moderate-to-severe diarrhea cases in whom STEC was identified, 160 tested positive for the eae gene (64.8%), or 3.3% of cases. The distribution of the Shiga toxin genotype among the 247 STEC-positive cases was as follows: 93 had stx1 alone (37.3%, or 1.9% of cases), 91 had stx2 alone (36.8%, or 1.9% of cases), and 63 had both (25.5%, or 1.3% of cases).
Of the 451 controls in whom STEC was identified, 338 tested positive for the eae gene (74.9%), or 7.0% of controls. The distribution of the Shiga toxin genotype among the 451 STEC-positive controls was as follows: 147 had stx1 alone (32.6%, or 3.0% of controls), 159 had stx2 alone (35.3%, or 3.3% of controls), and 145 had both (32.2%, or 3.0% of controls).