Table 1 Summary and sensitivity analysis of prevalence across selected studies with column values of prevalence and low (LCI) and high (HCI) confidence intervals showing proportions. The value of the pooled prevalence change is depicted in the second column (‘Pooled prevalence proportion’) if the study to the left (‘Included study’) is removed from the calculation

Akinsooto 2020 [30]

0.33

0.26

0.40

1526.19

0.00

98.43

98.14

98.67

Becker 1970 [32]

0.34

0.26

0.41

1507.74

0.00

98.41

98.12

98.66

Bloch 2020 [31]

0.33

0.26

0.41

1533.65

0.00

98.44

98.15

98.68

Bopape 2008 [33]

0.33

0.26

0.40

1538.45

0.00

98.44

98.16

98.68

Donald 2019 [34]

0.33

0.26

0.41

1521.18

0.00

98.42

98.13

98.67

Govender 2018 [35]

0.33

0.26

0.41

1538.07

0.00

98.44

98.15

98.68

Hoque 2007 [36]

0.31

0.24

0.38

1284.27

0.00

98.13

97.77

98.44

Kerkhoff 2014 [37]

0.33

0.26

0.40

1528.12

0.00

98.43

98.14

98.67

Kesho Bora 2013 [47]

0.32

0.25

0.40

1471.21

0.00

98.37

98.07

98.62

Lamparelli 1988 [38]

0.34

0.27

0.41

1471.28

0.00

98.37

98.07

98.62

Lamparelli 1988b [39, 53]

0.34

0.26

0.41

1495.27

0.00

98.39

98.10

98.64

Levy 2018 [40]

0.33

0.26

0.40

1527.69

0.00

98.43

98.14

98.67

Macaulay 2018 [41]

0.34

0.26

0.42

1505.33

0.00

98.41

98.11

98.65

Mathee 2014 [42]

0.33

0.26

0.41

1490.16

0.00

98.39

98.09

98.64

Mayet 1985 [43, 54]

0.33

0.26

0.41

1492.08

0.00

98.39

98.09

98.64

Mkhize 2019 [44]

0.33

0.26

0.40

1529.13

0.00

98.43

98.14

98.67

Nandlal 2014 [51]

0.33

0.26

0.40

1380.84

0.00

98.26

97.93

98.54

Notelovitz 1972 [45]

0.33

0.26

0.41

1508.80

0.00

98.41

98.12

98.66

Ross 1981 [46]

0.33

0.25

0.41

1537.91

0.00

98.44

98.15

98.68

Symington 2019 [5]

0.33

0.26

0.41

1535.92

0.00

98.44

98.15

98.68

Tunkyi 2015 [18]

0.32

0.25

0.40

1464.87

0.00

98.36

98.06

98.62

Tunkyi 2017 [20]

0.32

0.25

0.40

1464.87

0.00

98.36

98.06

98.62

Tunkyi 2018 [19]

0.32

0.25

0.40

1464.87

0.00

98.36

98.06

98.62

van Bogaert 2006 [48]

0.35

0.28

0.42

1122.85

0.00

97.86

97.43

98.23

Weyers 2016 [49]

0.33

0.26

0.40

1538.68

0.00

98.44

98.16

98.68

Wilkinson 1997 [50]

0.33

0.27

0.41

1349.66

0.00

98.22

97.88

98.51