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Table 1 Summary of performance characteristics of PCR assay tested in this study and reported literature

From: Performance characteristics of a quantitative PCR assay on repository stool specimens and smeared filter-paper cards

TAC on stool vs. benchmark
Pathogen This study—total number of stool samples tested by TAC = 109 Reported literature
Median storage duration (IQR) and no. of samples: PPA and NPA Study design PPA and NPA
ETEC
LT (labile toxin)
ST (stable toxin)
No of samples: 59
11.5 (7.2-12.0) years
≤ 3 years: 13 samples
5–13 years: 46 samples
PPA:62.7 (49.2-75.0)
NPA:70.0 (55.4-82.1)
Stratified by duration:
≤ 3 years: PPA: 69.2 (38.6–90.9)
NPA: 66.7 (47.2–82.7)
5–13 years: PPA: 60.8 (45.4–74.9)
NPA: 75.0 (50.9–91.3)
Sample size: 109 (10 ETEC positive)
Comparator: Culture + PCR of 5 colonies
PCR platform: TAC
Storage duration: 2–4 years (10)
PPA:100.0 (69.2–100.0)
NPA (ETEC LT): 55.0 (41.6–67.9)
NPA (ETEC ST): 69.7 (57.1–80.4)
Campylobacter No of samples:21
2.6 (2.6-11.4) years
≤ 3 years: 11
5-13 years: 10
PPA:66.6 (43.0–85.4)
NPA:69.3 (58.6–78.7)
Stratified by duration:
≤ 3 years: PPA: 63.6 (30.8–89.0)
NPA: 68.8 (50.0–83.8)
5–13 years: PPA: 70.0 (34.8–93.3)
NPA: 69.6 (56.0–81.2)
Sample size: 1557 (35 Campylobacter positive)
Comparator: Culture
PCR platform: BioFire FilmArray GI panel
Storage duration: days-weeks (4)
PPA:97.1 (85.1–99.9)
NPA:98.4 (97.7–99.0)
Shigella/EIEC No of samples:10
7.6 (6.7–10) years
5–13 years: 10
PPA:100.0 (69.2-100.0)
NPA:82.8 (74.0–89.6)
Sample size: 1557 (49 Shigella/EIEC positive)
Comparator: Culture (PCR for EIEC)
PCR platform: BioFire FilmArray GI panel
Storage duration: days-weeks (4)
PPA:95.9 (86.0–99.5)
NPA:98.5 (99.5–130.0)
Norovirus No of samples:19
2.6 (2.6–2.6) years
≤ 3 years: 19
PPA:36.8 (16.2–61.6)
NPA:80.0 (70.2–87.6)
Sample size: 1557 (55 Norovirus positive)
Comparator: RT-PCR
PCR platform: BioFire FilmArray GI panel
Storage duration: days-weeks (4)
PPA:94.5 (84.9–98.9)
NPA:98.8 (98.1–99.3)
TAC on FTA card vs. standard microbiology (benchmark) This study – total number of FTA cards tested by TAC = 261
Pathogen Median storage duration (IQR) and no. of samples: PPA and NPA Stratified by duration:
ETEC No of samples:70; 10.5 (6.9–12.0) years
≤ 3 years: 14
5–13 years: 56
PPA:55.7 (43.3–67.6)
NPA:85.3 (80.0–90.0)
≤ 3 years: PPA: 57.1 (28.8–82.3)
NPA: 86.0 (75.0–93.3)
5–13 years: PPA: 55.4 (41.4–68.6)
NPA: 85.0 (77.6–90.8)
Campylobacter No of samples: 59; 10.4 (2.6–11.8) years
≤ 3 years: 28
5–13 years: 31
PPA:62.7 (49.2–75.0)
NPA:82.2 (76.2–87.2)
≤ 3 years: PPA:71.4 (51.3–86.8)
NPA: 84.0 (70.8–92.8)
5–13 years: PPA: 54.8 (36.0–72.6)
NPA: 81.6 (74.4–87.4)
Shigella No of samples: 62; 6.0 (2.5–7.6) years
≤ 3 years: 6
5–13 years: 56
PPA:88.7 (78.1–95.3)
NPA:86.4 (81.0–91.0)
≤ 3 years: PPA: 16.6 (1.0–64.1)
NPA: 94.4 (86.4–98.4)
5–13 years: PPA: 96.4 (87.6–99.6)
NPA: 81.8 (74.0–88.2)
Norovirus No. of samples: 27; 2.6 (2.6–2.6) years PPA:51.8 (32.0–71.3)
NPA:97.8 (95.0–99.3)
N/A (all samples stored ≤ 3 years)
TAC on FTA card vs. TAC on stool (benchmark)
Pathogen This study—total number of paired FTA cards and stool samples tested by TAC = 109 Reported Literature
Median storage duration (IQR) and no. of samples: PPA and NPA Study Design PPA and NPA
ETEC No. of paired samples: 52;
median duration of FTA card storage: 8.8 (2.6–11.8) years
≤ 3 years: 19
5–13 years: 33
PPA: 75.0 (63.2–86.8)
NPA: 91.2 (83.8–98.6)
Stratified by duration:
≤ 3 years: PPA: 73.6 (48.8–90.8)
NPA: 91.6 (73.0–98.9)
5–10 years: PPA: 75.8 (57.7–88.9)
NPA: 90.9 (75.6–98.0)
Total sample size: 187
ETEC positive TAC on stool: 85
Storage duration: 2 years (9)
PPA:90.6 (82.2–96.0)
NPA:97.6 (93.3–99.5)(3)
Campylobacter No. of paired samples: 41; median storage duration: 7.0 (2.6–11.8) years
≤ 3 years: 17
5–10 years: 24
PPA:58.5 (42.1–73.6)
NPA:88.2 (78.1–94.8)
Stratified by duration:
≤ 3 years: PPA: 47.0 (22.9–72.2)
NPA: 92.3 (74.8–99.0)
5-13 years: PPA: 66.6 (44.6–84.4)
NPA: 85.7 (71.4–94.6)
Total sample size: 187
Campylobacter positive TAC on stool: 11
Storage duration: 2 years (9)
PPA:90.9 (58.7–99.8)
NPA:100.0 (98.0–100.0)(3)
Shigella Shigella positive TAC on stool: 27; median storage duration: 7.7 (6.0–11.3) years
≤ 3 years: 5
5–10 years: 22
PPA: 66.6 (46.0-83.4)
NPA: 92.6 (84.8–97.2)
Stratified by duration:
≤ 3 years: PPA: 40.0 (5.2–85.3)
NPA: 94.7 (82.2–99.4)
5–13 years: PPA: 72.7 (49.8–89.2)
NPA: 90.9 (78.3–97.4)
Total sample size: 187
Shigella positive TAC on stool: 18
Storage duration: 2 years (9)
PPA:88.9 (65.2-98.6)
NPA:99.4 (96.8-99.9)(3)
Norovirus No of samples:19; median duration of FTA card storage: 2.6 (2.6–2.6) years PPA:28.0 (12.0–49.4)
NPA:92.8 (85.1–97.3)
Stratified by duration:
≤ 3 years: PPA: 36.4 (10.9–69.2)
NPA: 81.2 (636–92.8)
5–13 years: PPA: 21.4 (4.6–50.8)
NPA: 100.0 (93.2–100.0)
Total sample size: 187
Norovirus positive TAC on stool: 24
Storage duration: 2 years (9)
PPA:38.0 (18.8–60.0)
NPA:100.0 (98.9–100.0)(3)