Table 1.
List and characteristics of the 41 eligible studies
| Study ID | Year of study | State | Region | Study setting | Sample size | Cases | Prevalence (%) | 95% CI |
|---|---|---|---|---|---|---|---|---|
| [57] | 2011 | Rivers | SSR | School-based | 3826 | 1050 | 27.4 | 26.0–28.9 |
| [58] | 2012/2013 | Kwara | NCR | School-based | 1017 | 229 | 22.5 | 20.0–25.2 |
| [59] | 1989 | Kwara | NCR | Community-based | 907 | 797 | 87.9 | 85.6–89.9 |
| [60] | 2002 | Ogun | SWR | School-based | 1253 | 1129 | 90.1 | 88.3–91.7 |
| [61] | 2006 | Lagos | SWR | School-based | 1177 | 579 | 49.2 | 46.3–52.1 |
| [62] | 2005/2006 | Ogun | SWR | School-based | 1059 | 872 | 82.3 | 79.9–84.6 |
| [63] | 2007 | Cross River | SSR | Community-based | 350 | 174 | 49.7 | 44.4–55.1 |
| [64] | 1985 | Rivers | SSR | Community-based | 1062 | 1020 | 96.1 | 94.7–97.1 |
| [65] | 2011 | Anambra | SER | School-based | 200 | 80 | 40.0 | 33.2–47.2 |
| [66] | 2014 | Kwara | NCR | School-based | 304 | 54 | 17.8 | 13.6–22.5 |
| [67] | 1980 | Lagos | SWR | School-based | 5595 | 4241 | 75.8 | 74.7–76.9 |
| [68] | 2008 | Nasarawa | NCR | School-based | 480 | 314 | 65.4 | 61.0–69.7 |
| [69] | 2004/2005 | Ogun | SWR | School-based | 232 | 112 | 48.3 | 41.7–54.9 |
| [70] | 1993 | Anambra | SER | School-based | 1536 | 775 | 50.5 | 47.9–53.0 |
| [71] | 1987 | Oyo | SWR | School-based | 766 | 678 | 88.5 | 86.0–90.7 |
| [72] | 2012 | Kano | NWR | School-based | 570 | 95 | 16.7 | 13.7–20.0 |
| [73] | 2005 | Osun | SWR | Community-based | 369 | 48 | 13.0 | 9.8–16.9 |
| [74] | 2006/2007 | Osun | SWR | Community-based | 1228 | 684 | 55.7 | 52.9–58.5 |
| [75] | 2005/2006 | Delta | SSR | School-based | 1200 | 960 | 80.0 | 77.6–82.2 |
| [76] | 2002 | Kaduna | NWR | School-based | 800 | 86 | 10.8 | 8.7–13.1 |
| [77] | 2011 | Abuja | NCR | School-based | 220 | 90 | 40.9 | 34.4–47.7 |
| [78] | 2011 | Edo | SSR | Community-based | 140 | 29 | 20.7 | 14.3–28.4 |
| [79] | 2008/2009 | Edo | SSR | Hospital-based | 310 | 170 | 54.8 | 49.1–60.5 |
| [80] | 2012 | Delta | SSR | School-based | 200 | 117 | 58.5 | 51.3–65.4 |
| [81] | 2007 | Anambra | SER | School-based | 514 | 275 | 53.5 | 49.1–57.9 |
| [82] | 2012 | Imo | SER | School-based | 284 | 88 | 31.0 | 25.7–36.7 |
| [83] | 2000 | Osun | SWR | School-based | 749 | 245 | 32.7 | 29.4–36.2 |
| [84] | 2009 | Akwa Ibom | SSR | School-based | 405 | 286 | 70.6 | 65.9–75.0 |
| [85] | 2005 | Adamawa | NER | School-based | 250 | 114 | 45.6 | 39.3–52.0 |
| [86] | 2013 | Abia | SER | School-based | 200 | 41 | 20.5 | 15.1–26.8 |
| [87] | 2003 | Ogun | SWR | School-based | 2837 | 1376 | 48.5 | 46.7–50.4 |
| [88] | 2003–2005 | Ogun | SWR | School-based | 1519 | 435 | 28.6 | 26.4–31.0 |
| [89] | 2009 | Osun | SWR | Community-based | 352 | 121 | 34.4 | 29.4–39.6 |
| [90] | 2005 | Osun | SWR | Community-based | 300 | 18 | 6.0 | 3.6–9.3 |
| [91] | 2012 | Ebonyi | SER | School-based | 300 | 244 | 81.3 | 76.5–85.6 |
| [92] | 2004/2005 | Osun | SWR | School-based | 489 | 468 | 95.7 | 93.5–97.3 |
| [93] | 2011 | Osun | SWR | School-based | 419 | 401 | 95.7 | 93.3–97.4 |
| [94] | 2002 | Abia | SER | School-based | 300 | 277 | 92.3 | 88.7–95.1 |
| [95] | 2014 | Benue | NCR | Community-based | 228 | 23 | 10.1 | 6.5–14.8 |
| [96] | 2001/2002 | Edo | SSR | Hospital-based | 207 | 44 | 21.3 | 15.9–27.5 |
| [97] | 2013 | Rivers | SSR | School-based | 364 | 62 | 17.0 | 13.3–21.3 |
CI Confidence interval, NCR North-central region, NER North-east region, NWR North-west region, SER South-east region, SSR South-south region, SWR South-west region