Table 1.

Summary of global meta-analysis results for prevalence of hepatitis E virus in different water matrices divided by risk of bias

Water matrix	Prevalence (%) [95%CI]	95% Prediction interval	No of studies	No of samples	¶H [95%CI]	§I2 [95%CI]	P heterogeneity
Untreated wastewater
Overall	15.1 [9.4–21.8]	[0–64.6]	40	4412	5.1 [4.7–5.6]	96.1 [95.4–96.8]	< 0.001
Low risk of bias	9.7 [0.9–24.7]	[0–75.1]	8	1886	6.1 [5.1–7.4]	97.3 [96.2–98.2]	< 0.001
Process controlled	17.4 [7.8–29.6]	[0–75.8]	16	2414	5.8 [5.1–6.6]	97 [96.1–97.7]	< 0.001
Treated wastewater
Overall	3.8 [0–15.2]	0–63.7	11	388	3.4 [2.7–4.3]	91.5 [86.7–94.5]	< 0.001
Low risk of bias	38.3 [0–100]	NA	2	23	5.3 [3.2–8.7]	96.4 [90–98.7]	< 0.001
Process controlled	1.1 [0–9.4]	[0–48.5]	8	353	3.2 [2.4–4.2]	90 [82.8–94.2]	< 0.001
Surface water
Overall	7.5 [2.4–14.5]	[0–49]	20	1271	3.5 [3–4.1]	92 [89–94.2]	< 0.001
Low risk of bias	2 [0.6–4.1]	[0–23.9]	3	329	1 [1–3.1]	0 [0–89.6]	0.448
Process controlled	8.5 [1.4–19.7]	[0–62.9]	11	804	4.3 [3.6–5.2]	94.6 [92.1–96.3]	< 0.001
Drinking water
Overall	4.7 [0–15.9]	0–59.9	10	998	4.1 [3.3–5]	94 [90.9–96]	< 0.001
Process controlled	9.9 [0–42.9]	[0–100]	4	778	6.5 [5–8.5]	97.6 [95.9–98.6]	< 0.001
Groundwater
Overall	8.3 [0–32.4]	NA	1	12	NA	NA	1
Others
Overall	6 [0–33.2]	0–100	5	179	4.1 [3–5.6]	94.1 [89.1–96.8]	< 0.001
Low risk of bias	0 [0–7]	NA	1	24	NA	NA	1
Process controlled	0 [0–5.1]	NA	2	35	1 NA	0 NA	0.798

95% CI 95% confidence interval; NA not applicable

^¶H is a measure of the extent of heterogeneity; a value of H > 1 indicates a potential heterogeneity of the prevalence of hepatitis E virus

^§I² describes the proportion of total variation in prevalence of hepatitis E virus that is due to heterogeneity; a value > 50% indicates the presence of heterogeneity