“…Only a few studies were reported from North America (n = 7), 37 , 43 , 49 , 52 , 63 , 81 , 82 South America (n = 4), 19 , 50 , 77 , 83 and Australia (n = 4), 14 , 68 , 84 , 85 while only one study was reported from Africa (n = 1). 86 Most of the studies were from Asia 3 , 5 – 10 , 12 , 15 – 18 , 22 , 23 , 36 , 38 , 40 , 41 , 45 , 46 , 48 , 51 , 55 – 62 , 64 – 66 , 69 – 71 , 73 – 76 , 78 , 79 , 87 – 100 and Europe 11 , 13 , 39 , 42 , 44 , 47 , 53 , 54 , 67 , 72 , 80 , 101 – 105 ( Table 2 ). Countries with more than three studies were included for the sub-group analysis.…”