Table 1.
Key assumptions and inputs in calculating ETEC and shigella burden
| Values | Range | Source | Reference | |
|---|---|---|---|---|
| Baseline population estimates for children younger than 5 years | Varies by country | Not included in uncertainty analysis | UN Population Division estimates for 2015 | 14 |
| Diarrhoeal mortality estimates | Differs in overall deaths and per country | 90–110%; triangular* | Midpoint estimate between 2015 MCEE and GBD | 15, 16 |
| Aetiological fraction attributed to ETEC by culture for children younger than 5 years, by WHO region | 0·043–0·074 | 75–125%; triangular* | Systematic review; updated with GEMS molecular re-analysis estimates | 17 |
| Aetiological fraction attributed to shigella by culture for children younger than 5 years, by WHO region | 0·001–0·119 | 75–125%; triangular* | Systematic review; updated with GEMS molecular re-analysis estimates | 17 |
| ETEC molecular adjustment | 1·5 | ±0·5; triangular* | GEMS re-analysis study | 18 |
| Shigella molecular adjustment | 2·0 | ±0·5; triangular* | GEMS re-analysis study | 18 |
| All-cause diarrhoeal episodes | 2·2–3·3 episodes per child-year | 80–120%; triangular* | Fischer-Walker and colleagues | 19 |
| Caretakers sought care at a health facility after the child experienced an episode of diarrhoea | 47% | 44–58%; not varied in uncertainty analysis | Demographic and Health Surveys | 20 |
| Fraction of diarrhoeal episodes that are moderate to severe | 10% | 2–15%; triangular* | GEMS Study and Demographic Health Survey | 10, 20 |
| HAZ shift with ETEC episodes | 0·068 | 80–120%; triangular* | GEMS estimate table 6 | 10 |
| HAZ shift for shigella episodes | 0·082 | 80–120%; triangular* | GEMS estimate table 6 | 10 |
| Rotavirus vaccination adjustment | Varies by country that has introduced rotavirus vaccination | With or without adjustment in sensitivity analysis | Tate and colleagues | 21 |
Ranges for estimates reflect ranges of values varied for uncertainty analysis, unless otherwise noted in the table. The rotavirus vaccination adjustment refers to accounting for the effect of the introduction of rotavirus vaccination in countries before 2014. MCEE=Maternal and Child Epidemiology Estimation Group. GBD=Global Burden of Disease Study. ETEC=enterotoxigenic Escherichia coli. HAZ=height-for-age Z score.
*
Triangular distributions are continuous with a probability function defined by minimum, maximum, and peak values.