“…Only two articles published prior to 2000 were included [ 91 , 92 ]. Twenty articles described research conducted in sub-Saharan Africa [ 34 , 36 – 38 , 47 – 51 , 54 , 58 , 59 , 62 , 64 , 67 , 76 , 77 , 81 , 85 , 90 ]. Another 21 were conducted in North America [ 32 , 35 , 40 , 42 , 45 , 55 , 57 , 61 , 66 , 68 , 69 , 71 , 73 , 74 , 78 , 80 , 84 , 86 , 87 , 91 , 92 ], one in South America [ 93 ], and four in the Caribbean [ 33 , 82 , 83 , 89 ].…”