Literature searches and selection
Our initial search of electronic databases such as Medline via PubMed, Scopus, Science direct, Web of Sciences and Google scholar yielded 953 articles and 3 articles manually from which 213 records remained after removing duplications. Upon screening the articles, 123 articles were further excluded; 112 were irrelevant because they were not specifically about preschool or school-age children, 6 studies were about sensitivity and specify of diagnosis of STHs, and 5 articles were not about human. Upon further assessment for eligibility, 2 studies were excluded being review articles. Finally, 88 [6, 14, 16, 19–110] published studies between 1997 and Fabrauary 2020 fulfilling the inclusion criteria were included in the final analyses [Figure 1]. The sample size of the included studies ranged from 100 [20] to 15,455 [14]. Atotal of 61,690 children with age of < 5 years (n = 5577) and ≥ 5 years ( n = 55731) or mix of both (n = 382) were recruited in the studies. Fifty two precent (52%) of the study participants were male. Majority (83) of the studies were cross sectional. Seventy three studies were about STHs in school-age children, 13 were about preschool-age and the rest were studies involved both preschool and school-age children. Thirty five and twenty four studies used Kato-katz or incombination with other tools and formalin-ether concentartion plus direct microscopic method for screening stools, respectively. Formalin-ether concentration techinques in 19 studies, direct wet mount method in 5 studies, McMaster in 4 studies and Harada Mori (Test tube culture) technique in one study utilized as screening of stools. According to our quality assessment criteria, 43 publications were of high quality with a score of 3, 11 had a score of 2 indicating moderate quality and the remaining 34 were of low quality with a score of zero or one [Table 1].
Table 1
Characteristics of the eligible studies on STH infections in Ethiopia
Name of first author and year | Study design | Population | Male | Female | Region | Laboratory method | No. sample | Cases for IPIs | Quality score |
Degarege 2013[[34] | Cross-sectional | School children | 187 | 216 | Amhara | KATO | 403 | 255 | 2 |
Abdi 2017 [73] | cross-sectional | School children | 207 | 201 | Amhara | FEC | 408 | 282 | 3 |
Abera 2014[74] | Cross-sectional | School children | 193 | 192 | Amhara | FEC | 385 | 357 | 3 |
Amare 2013[26] | Cross-sectional | School children | 218 | 187 | Amhara | KTO &FEC | 405 | 92 | 3 |
Gelaw 2013[41] | cross-sectional | School children | 170 | 134 | Amhara | DWM&FEC | 304 | 104 | 3 |
Abossie 2014[76] | Cross-sectional | School children | 191 | 209 | SNNPR | DWM&FEC | 400 | 324 | 3 |
Mathewos 2014[53] | Cross-sectional | School children | 139 | 122 | Amhara | DWM&MZN | 261 | 174 | 2 |
Gizaw 2018[108] | Cross-sectional | Preschool children | 106 | 119 | Amhara | KATO | 225 | 58 | 3 |
Yimam 2016[72] | Cross-sectional | School children | 187 | 216 | Amhara | KTO&FEC | 403 | 235 | 3 |
Hailegebriel 2017[77] | Cross-sectional | School children | 177 | 182 | Amhara | FEC | 359 | 235 | 3 |
Alemu 2018[78]] | Cross-sectional | School children | 196 | 195 | SNNPR | FCE | 391 | 182 | 2 |
Alemu 2019[80]] | Cross-sectional | School children | 180 | 171 | SNNPR | DWM&FEC | 351 | 95 | 3 |
Mekonnen 2019[109] | Cross-sectional | Preschool children | 152 | 158 | Amhara | DWM&KATO | 310 | 58 | 3 |
Jejaw 2015[36] | Cross-sectional | School children | 228 | 232 | SNNPR | DWM,FEC&KATO | 460 | 353 | 3 |
Alemu 2016[79] | Cross- sectional | Preschool children | 183 | 218 | Amhara | KATO | 401 | 141 | 3 |
Alemayehu 2017[54] | Cross-sectional | School children | 287 | 216 | SNNPR | KATO&FEC | 503 | 363 | 3 |
Gashaw 2015[57] | Cross-sectional | School children | 255 | 295 | Amhara | KATO | 550 | 365 | 3 |
Amor 2016[82] | Cross-sectional | School children | 225 | 171 | Amhara | FEC | 396 | 327 | 3 |
Nute 2018[14] | Cross-sectional | School children | 7418 | 8037 | Amhara | FEC | 15455 | 5626 | 3 |
Zemene 2018[68] | Cross-sectional | Preschool children | 118 | 118 | Amhara | DWM&FEC | 247 | 43 | 1 |
Mulatu 2015 [24] | Cross-sectional | Preschool | 81 | 77 | SNNPR | DWM,FEC&MZN | 158 | 224 | 3 |
Bekana 2019[84] | Cross-sectional | School children | 172 | 145 | Oromia | KATO&FEC | 317 | 130 | 3 |
Diro 2015[85] | prospective cohort | Both | 85 | 37 | Amhara | DWM,FEC&KATO | 122 | 371 | 1 |
Birhanu 2018[86] | cross sectional | School children | 194 | 228 | Benishangul-Gumuz | DWM | 422 | 138 | 1 |
Fentie 2013[22] | Cross-sectional | School children | 361 | 159 | Amhara | KATO&FEC | 520 | 134 | 3 |
Aiemjoy 2017[63] | Cross-sectional | Preschool children | NA | NA | Amhara | FEC | 212 | 354 | 2 |
Dessalegn 2014[21] | Cross-sectional | School children | 271 | 315 | Oromia | DWM&FEC | 586 | 91 | 3 |
Gebrehiwot 2014[110] | Cross sectional | Preschool children | 195 | 179 | Oromia | KATO | 374 | 1471 | 2 |
Leta 2018[87] | Cross sectional | School children | NA | NA | Amhara | KATO | 2,650 | 437 | 3 |
King 2013[37] | cross sectional | Both | 1130 | 1228 | Amhara | FEC | 2,338 | 267 | 3 |
Mekonnen 2013[6] | Clinical trial | School children | NA | NA | Oromia | KATO | 840 | 421 | 3 |
Mahmud 2015[44] | Clinical trial | School children | 152 | 217 | Tigray | DWM,FEC&KATO | 369 | 326 | 3 |
Mahmud 2013[43] | cross-sectional | School children | 288 | 312 | Tigray | DWM,FEC&KATO | 600 | 89 | 3 |
Tefera 2017[70] | Cross sectional | School children | 282 | 433 | Oromia | McMaster | 715 | 202 | 2 |
Tefera 2015[88] | Cross sectional | School children | 364 | 280 | Oromia | McMaster | 644 | 237 | 2 |
Nguyen 2012[31] | Cross sectional | School children | 341 | 323 | Amhara | FEC | 664 | 129 | 3 |
Hailu 2018[111] | Cross sectional | School children | 186 | 223 | Amhara | Richie’s | 409 | 263 | 2 |
Beyene 2014[28] | Cross sectional | School children | 114 | 146 | Oromia | DWM&FEC | 260 | 328 | 3 |
Alemu 2011[25] | Cross sectional | School children | 157 | 162 | Amhara | KATO&DWM | 319 | 243 | 3 |
Alemayehu 2015[90] | Cross sectional | School children | 201 | 183 | SNNPR | KATO&DWM | 384 | 131 | 1 |
Ali 1999[91] | Cross sectional | School children | 161 | 121 | Oromia | KATO&DWM | 282 | 170 | 0 |
Tulu 2016[65] | Cross sectional | School children | 251 | 241 | Oromia | DWM&FEC | 492 | 44 | 0 |
Unasho 2013[71] | Cross sectional | School children | 189 | 217 | SNNPR | DWM | 406 | 89 | 0 |
Belyhun 2010[49] | Follow up cohort | Preschool children | NA | NA | SNNPR | FEC | 905 | 292 | 3 |
Tulu 2014[38] | Cross sectional | School children | 172 | 168 | SNNPR | DWM&FEC | 340 | 113 | 1 |
Erosie 2002[40] | Cross sectional | School children | NA | NA | SNNPR | FEC | 421 | 69 | 1 |
Tadesse 2005[33] | Cross sectional | School children | 271 | 144 | Oromia | FEC | 415 | 437 | 0 |
Adamu 2005[48] | Cross sectional | Preschool children | 149 | 147 | Addis Ababa | DWM,FEC&MZN | 296 | 571 | 0 |
Jemaneh 1999[92] | Cross sectional | School children | 439 | 439 | Amhara | KATO | 878 | 165 | 0 |
Dejenie 2009[56] | Cross sectional | School children | 1012 | 998 | Tigray | DWM | 2000 | 245 | 0 |
Dejenie 2010 [66] | Cross sectional | School children | 319 | 303 | Tigray | KATO | 622 | 263 | 0 |
Nyantekyi 2010[32] | Cross sectional | Preschool children | 140 | 148 | SNNPR | KATO&FEC | 288 | 282 | 1 |
Legesse 2010[52] | Cross sectional | School children | 167 | 214 | Oromia | KATO&FEC | 381 | 166 | 0 |
Terefe 2011[61] | Cross sectional | School children | 218 | 201 | SNNPR | KATO | 419 | 285 | 1 |
Debalke 2013[93] | Cross sectional | School children | 161 | 205 | Oromia | McMaster | 366 | 66 | 1 |
Dejene 2008 [94] | Cross sectional | School children | 481 | 319 | Tigray | FEC | 800 | 530 | 0 |
Fekadu 2008 [19] | Cross sectional | School children | 63 | 37 | Oromia | Harada-Mori (Test tube culture) | 100 | 470 | 0 |
Haileamlak 2005[23] | Cross sectional | Preschool children | 487 | 437 | Oromia | DWM&FEC | 924 | 74 | 1 |
Jemaneh 2001[42] | Cross sectional | School children | 282 | 405 | Amhara | KATO | 687 | 219 | 1 |
Firdu 2014[69] | Case-control | Both | 135 | 95 | SNNPR | DWM,FEC&MZN | 230 | 199 | 1 |
Wale 2014[62] | Cross sectional | School children | 206 | 196 | Amhara | DWM&FEC | 402 | 562 | 1 |
Teklemariam 2014[67] | Cross sectional | School children | 252 | 228 | Tigray | FEC | 480 | 139 | 0 |
Ayalew 2011[27] | Cross sectional | School children | 358 | 346 | Amhara | DWM&FEC | 704 | 304 | 2 |
Merid 2001[30] | Cross sectional | School children | NA | NA | SNNPR | DWM&FEC | 150 | 465 | 0 |
Assefa 1998[112] | Cross sectional | School children | 479 | 219 | Amhara | FEC | 698 | 401 | 0 |
Roma 1997[46] | Cross sectional | School children | 352 | 168 | SNNPR | FEC | 520 | 233 | 1 |
Abera 2013[95] | cross sectional | School children | 397 | 381 | Amhara | KATO&FEC | 772 | 311 | 3 |
Kidane 2014[113] | Cross sectional | School children | 177 | 207 | Tigray | DWM | 384 | 301 | 0 |
Alamir 2013[20] | Cross sectional | School children | 192 | 207 | Amhara | DWM&FEC | 399 | 104 | 0 |
Kabeta 2017[96] | Cross sectional | Preschool children | NA | NA | SNNPR | DWM&FEC | 587 | 254 | 1 |
Shumbej 2015[97] | Cross sectional | Preschool children | 165 | 212 | SNNPR | McMaster | 377 | 245 | 3 |
Tadege 2017[98] | Cross sectional | School children | 235 | 139 | SNNPR | FEC | 374 | 127 | 3 |
Andualem 2014[99] | Cross sectional | School children | 168 | 190 | Amhara | DWM&FEC | 358 | 59 | 0 |
Reji 2011[45] | Cross sectional | School children | NA | NA | , Oromia | KATO | 358 | 52 | 1 |
Alemu 2014[64] | Cross sectional | School children | 211 | 194 | SNNPR | KATO | 405 | 110 | 0 |
Samuel 2015[114] | Cross sectional | School children | NA | NA | Oromia | FEC | 375 | 42 | 3 |
Teshale 2018[100] | Cross section | School children | 240 | 170 | Tigray | KATO | 410 | 58 | 1 |
Tekeste 2013[60] | Cross sectional | School children | 170 | 156 | Amhara | KATO | 326 | 109 | 2 |
Sitotaw 2019 [60] | Cross sectional | School children | 216 | 190 | Amhara | DWM&FEC | 406 | 235 | 3 |
Elfu 2018 [101] | Cross sectional | School children | 1129 | 1261 | Amhara | DWM&FEC | 2390 | 684 | 3 |
Molla 2018 [104] | Cross sectional | School children | 245 | 198 | SNNPR | KATO | 443 | 239 | 3 |
Weldesenbet 2019 [107] | Cross sectional | School children | 349 | 251 | SNNPR | KATO | 600 | 57 | 3 |
Eyamo 2019 [102] | Cross sectional | School children | 199 | 185 | SNNPR | DWM | 384 | 260 | 3 |
Tadesse 2020 [106] | Cross sectional | School children | 204 | 213 | Oromia | DWM&FEC | 422 | 131 | 2 |
Gadisa 2019 [16] | Cross sectional | Preschool children | 242 | 319 | Oromia | DWM&FEC | 561 | 216 | 3 |
Zenu [110] | Cross sectional | School children | 284 | 28 | Oromia | DWM&FEC | 312 | 208 | 3 |
Shumbej[109] | Cross sectional | School children | 350 | 247 | SNNPR | KATO | 597 | 141 | 3 |
Workneh[108] | Cross sectional | School children | 194 | 146 | Amhara | KATO | 340 | 51 | 3 |
DWM = direct wet mount; FEC = formal-ether: KATO = kato-katz: NNNPR = Southern nations nationalities and peoples region, IPIs = intestinal parasitic infections: STHs = soil transmitted helminths: NA = not available: |
Pooled Prevalence Estimate Of Intestinal Parasites And Heterogeneity
Eighty studies (88) studies consisting of 61,690 preschool and school-age children reported the proportion of intestinal parasitic infections. Out of these, 29,311 children were infected with one or more species of intestinal parasites giving the pooled prevalence estimate of 48% (95%CI: 43–53%) with considerable heterogeneity (χ2 = 17303.64, P < 0.001; I2 = 99.50%). The prevalence of intestinal parasitic infection was 53%(95% CI: 38–67%), 50%%(95% CI: 44–57%), 45%%(95% CI: 35–54%) and 43%%(95% CI: 29–58%) in Southern Nations Nationalities and Peoples Region (SNNPR), Amhara, Oromia, and Tigray regions, respectively (Fig. 2). We also did subgroupanalysis to see the influence of study design on prevalence. Interestingly enough, the prevalence was 48% ( 95% CI: 43–53%) for cross ectional study sdesign and therefore, the inclusion of other study designs has no influence on the overall rate of infection ( not shown).
Overall Prevalence Estimate Of Soil-transmitted Helminthes (sths) And Heterogeneity
Soil-transmitted helminths detected in the studies were Ascaris lumbricoides, Hookworms, Trichuris trichiura and Strongyloides stercoralis. A total of 19, 678 of the 61,690 children examined during the period under review were infected with one or more species of STHs yielding an overall prevalence of 33%( 95%CI: 28–38%) with substantial heterogeneity (χ2 = 30360.02, P < 0.001; I2 = 99.71%) (Fig. 3). The asymmetry of funnel plot visual inspection (Fig. 4) showed that the presence of publication bias which was statistically confirmed by Egger’s test (β = 16.7, [95% CI: 10.7–22.5], p < 0.001 and Begg’s test p < 0.001.
We did meta-regression analyses to search for the sources of heterogeneity. A univariate meta-regression between prevalence of STHs and age of children showed statistically significant correlation (P = 0.003, Fig. 5). However, year of publications, (P = 0.076), regional states (p = 0.70) and study design (p = 0.23) did not show a statistically significant correleation as shown in Table 2.
Table 2
Univariate meta-regression of factors related to the heterogeneity of soil-transmitted helminths among Ethiopian children, 2020
Variables | β-Coefficient | 95% CI | p-values |
Regional states | -0.03 | -0.18 to 0.12 | 0.70 |
Year of publication | -0.04 | -0.004 to 0.08 | 0.076 |
Age | 0.73 | 0.25 to 1.2 | 0.003 |
Study design | -0.45 | -1.2 to 0.30 | 0.23 |
CI = confidence interval |
Sub-group analysis based on geographical region and age of children
Subgroup analysis showed that the prevalence of STHs was 44% (95% CI: 31–58%) in SNNPR, 34%(95%CI : 28–41%) in Amhara region, 31% (95%CI : 19%- 43%) in Oromia region and 10% (95%CI : 7%-12%) in Tigray region as shown in Fig. 6. The age related prevalence was 51% (95% CI: 45–56%) in school-age children and 32% (95% CI: 20–44%) in preschool-age children (p = 0.003) as shown in Fig. 7. Subgroup analysis by publication year showed that the pooled prevalence of STHs between 1995–2012 years was 44% (95% CI:30–57%) while, it was 30% (95%CI: 25–34%) for studies conducted between 2013–2020 years (Fig. 8). In summary, STHs were more common in SNNPR among school-age children in studies published between 1990–2012 as shown in Table 3. We performed subgroup analysis based on study design and the result showed that the prevalence of STHs was 34% (95% CI:29–39%) for cross sectional study, 25% (95% CI:23–28%), 4% (95% CI:3–5%) for prospective study and 20% (95% CI:15–26%) for case-control study (not shown). This indicates that the overall prevalence is almost the same as the prevalence of studies with cross sectional study design and was not affected by other study designs.
Table 3
Prevalence of soil-transmitted helminths (STHs) by region, age of children and year of publication among Ethiopian Children, 2020
Variables | No. of studies | Sample | cases | Prevalence (95% CI) | Heterogeneity | P-value |
Q | I2 (%) |
Region | | | | | | | |
Addis Ababa city | 1 | 296 | 10 | 3(2–6%) | - | - | - |
Amhara region | 36 | 36809 | 12374 | 34(28–41%) | 8325.55 | 99.58 | P < 0.001 |
Benishangul-Gumuz region | 1 | 422 | 35 | 8(6–11%) | - | - | - |
Oromia region | 20 | 9119 | 2780 | 31(19–43%) | 9070.41 | 99.79 | P < 0.001 |
South Region | 22 | 9379 | 3869 | 44(31–58%) | 7621.83 | 99.72 | P < 0.001 |
Tigray region | 8 | 5665 | 610 | 10(7–12% | 66.61 | 89.49 | P < 0.001 |
Age | | | | | | | |
School | 73 | 55731 | 18225 | 36(31–42%) | 27820.22 | 99.74 | P < 0.001 |
Preschool | 13 | 5577 | 1408 | 20(11–29%) | 1764.59 | 99.32 | P < 0.001 |
Both | 2 | 382 | 45 | 6(4–9%) | - | - | - |
Year of publication | | | | | | | |
1997–2012 | 22 | 12831 | 4607 | 44(30–57%) | 14221.00 | 99.85 | P < 0.001 |
2013–2020 | 66 | 48859 | 15071 | 30(25–34%) | 15324.02 | 99.58 | P < 0.001 |
Overall | 88 | 61690 | 19678 | 33(28–38%) | 30360.02 | 99.71 | P < 0.001 |
CL = confidence interval |
Prevalence Of Sths By Species
Ascaris lumbricoides
Eighty five studies consisting of 58, 234 children have reported that the pooled prevalence of A. lumbricoides was 17% (95% CI: 15 to 19%) with substantial heterogeneity (χ2 = 8961.94, P < 0.001; I2 = 99.06%). The prevalence was 27%( 95% CI: 21 to 34%) in SNNPR, 14%( 95% CI: 11 to 17%) in Amhara region, 15%( 95% CI: 11 to 19%) in Oromia region and 6%( 95% CI: 3 to 8%) in Tigray region [supplementary file 1]. The age related prevalence of A. lumbricoides was 18% (95%CI: 15 to 20%,) in school-age children and 12% (95%CI: 8 to 17%) in preschool-age children (p = 0.06). The pooled prevalence of A. lumbricoides was 25% (95% CI: 19 to 31%) in studies published between 1997–2012 years and 14% (95% CI: 12 to 16%) beween 2013–2020 years. A univariate meta-regression between prevalence and year of publications showed statistically significant correlation (β = -0.49 (95% CI: -1.1 to -0.07, P = 0.035, Supplementary file 2). However, regional states (β: 0.046, 95% CI: -0.12 to 0. 0.22, p = 0.58) and age of children (β: 0.52, 95% CI: -0.02 to 1.1, p = 0.06) did not show a statistically significant relationship. Therefore, Ascaris lumbricoides was the most predominant species of STHs among Ethiopian children and significant decline in prevalence was observed over two decades (from late 1990s to 2020) (Table 4).
Table 4
Pooled prevalence of species specific Ascaris lumbricoides by region, age and year of publication among Ethiopian children, 2020
Variables | No. of studies | Sample | cases | Prevalence (95% CI) | Heterogeneity | P-value |
Q | I2 (%) |
Region | | | | | | | |
Addis Ababa city | 1 | 296 | 8 | 3(1–5%) | - | - | - |
Amhara region | 35 | 34419 | 5311 | 14(11–17%) | 3356.20 | 98.99 | P < 0.001 |
Oromia region | 19 | 8475 | 1271 | 15(11–19%) | 934.49 | 98.07 | P < 0.001 |
South Region | 22 | 9379 | 2374 | 27(21–34%) | 4265.90 | 99.51 | P < 0.001 |
Tigray region | 8 | 5665 | 375 | 6(3–8%) | 148.81 | 95.30 | P < 0.001 |
Age | | | | | | | |
School | 70 | 52275 | 8509 | 18(15–20%) | 7820.37 | 99.12 | P < 0.001 |
Preschool | 13 | 5577 | 822 | 12(8–17%) | 892.82 | 98.66 | P < 0.001 |
Both | 2 | 382 | 8 | 2(1–4%) | - | - | - |
Year of publication | | | | | | | |
1990–2012 | 22 | 12831 | 2841 | 25(19–31%) | 4111.93 | 99.49 | P < 0.001 |
2013–2020 | 63 | 45403 | 6498 | 14(12–16%) | 4838.10 | 98.72 | P < 0.001 |
Overall | 85 | 58234 | 9339 | 17(15–19%) | 8961.94 | 99.06 | P < 0.001 |
CL = confidence interval |
Table 5
Pooled prevalence of species specific Trichuris trichiura by region, age and year of publication among Ethiopian children, 2020
Variables | No. of studies | Sample | cases | Prevalence (95% CI) | Heterogeneity | P-value |
Q | I2 (%) |
Region | | | | | | | |
Addis Ababa city | 1 | 296 | 2 | 1(0–2%) | - | - | - |
Amhara region | 28 | 31555 | 1186 | 4(3–4%) | 528.28 | 94.89 | P < 0.001 |
Oromia region | 19 | 8738 | 1089 | 10(8–13%) | 1282.36 | 98.60 | P < 0.001 |
South Region | 22 | 9379 | 949 | 11(9–13%) | 1728.08 | 98.78 | P < 0.001 |
Tigray region | 6 | 4886 | 86 | 1(0–2%) | 61.86 | 91.92 | P < 0.001 |
Age | | | | | | | |
School | 63 | 49327 | 3093 | 7(6–8%) | 3318.18 | 98.13 | P < 0.001 |
Preschool | 12 | 5267 | 211 | 4(2–6%) | 443.50 | 97.52 | P < 0.001 |
Both | 1 | 260 | 8 | 3(2–6%) | - | - | - |
Year of publication | | | | | | | |
1990–2012 | 20 | 11786 | 1374 | 14(12–17%) | 2176.26 | 99.13 | P < 0.001 |
2013–2020 | 56 | 43068 | 1938 | 4(4–5%) | 1569.21 | 96.50 | P < 0.001 |
Overall | 76 | 58234 | 9339 | 6(6–7%) | 3766.86 | 98.01 | P < 0.001 |
CL = confidence interval |
Trichuris trichiura
Seventy six studies included of 54,854 children have reported that the pooled prevalence of Trichuris trichiura was 6% (95% CI: 6 to 7%) with considerable heterogeneity (χ2 = 3766.86, P < 0.001; I2 = 98.01%). The pooled prevalence was 11% (95%CI: 11–13%) in SNNPR, 10% (95%CI: 8–13%) in Oromia region, 4% (95%CI: 3–4%) in Amhara region and 1% (95%CI: 0–2%) in Tigray region and 1 [supplementary file 3]. The age related prevalence was also 7% (95%CI: 6% to 8%,) among school-age children and 4% (95%CI: 2–6%) among preschool-age children (p = 0.24). The pooled prevalence of T. trichura was 14% (95% CI: 12–17%) in studies conducted between 1997–2013 years and 4% (95% CI: 4–24%) between 2013–2020 years. A univariate meta-regression between prevalence and year of publications showed statistically significant correlation (Β= -0.78, 95% CI: -1.5 to -0.069, p = 0.03, Supplementary file 4). However, regional states (β: 0.003, 95% CI: -0.22 to 0. 0.23, p = 0.97) and age of children (β: 0.46, 95% CI: -0.29 to 1.2, p = 0.23) did not show a statistically significant relationship. The bottom line is that the rate of infection of Trichuris trichiura among Ethiopian children decreased significantly after starting of MDA as detailed in Fig. 5 .
Hookworms
Seventy six studies consisting of 54,854 children have also reported the pooled prevalence of Hookworms. Hence, the pooled prevalence on analysis was 12% (95% CI: 10 to 13%) with substantial heterogeneity (χ2 = 7920.16, P < 0.001; I2 = 99.05%). The pooled prevalence of hookworms was 12% (95%CI: 9–15%) in SNNPR, 16% (95%CI: 13–19%) in Amhara region, 6% (95%CI: 5–8%) in Oromia region, and 3% (95%CI: 2–4%) in Tigray region as shown in supplementary file 5. The age related prevalence of hookworms was 13% (95%CI: 11% to 15%) among school-age children and 2% (95%CI: 1–3%) among preschool-age children (p = 0.01). The pooled prevalence of hookworms was 13% (95% CI: 9–15%) in studied conducted between 1997–2012 years and 11% (95% CI: 9–13%) in studies between 2013–2020 years.
A univariate meta-regression between prevalence and age of children showed statistically significant correlation (Β = 1.03, 95% CI: 0.27 to 1.8, p = 0.01, supplementary file 6A). In Addition,meta-regression of the prevalence and regional states (β: -0.20, 95% CI: -0.40 to -0. 0.005, p = 0.045, supplementary file 6B) revealed a significant correlation. However, year of publication (β: -0.09, 95% CI: -0.79 to 0.61, p = 0.81) did not show a statistically significant relationship. In summary, Hookworms were more prevalent among children in Amhara region compared to other regions and among school-age children compared to preschool-age children ( Table 6).
Table 6
Pooled prevalence of species specific Hookworms by region, age and year of publication among Ethiopian children, 2020
Variables | No. of studies | Sample | cases | Prevalence (95% CI) | Heterogeneity | P-value |
Q | I2 (%) |
Region | | | | | | | |
Benishangul-Gumuz | 1 | 422 | 35 | 8(6–11%) | - | - | - |
Amhara region | 32 | 35678 | 6171 | 16(13–19%) | 5256.02 | 99.41 | P < 0.001 |
Oromia region | 15 | 6763 | 434 | 6(5–8%) | 392.85 | 96.44 | P < 0.001 |
South Region | 20 | 8761 | 950 | 12(9–15%) | 793.61 | 97.61 | P < 0.001 |
Tigray region | 8 | 5665 | 144 | 3(2–4%) | 96.14 | 92.72 | P < 0.001 |
Age | | | | | | | |
School | 67 | 53289 | 7648 | 13(11–15%) | 7814.96 | 99.16 | P < 0.001 |
Preschool | 8 | 3740 | 102 | 2(1–3%) | 33.50 | 79.10 | P < 0.001 |
Both | 1 | 260 | 4 | 2(1–4%) | - | - | - |
Year of publication | | | | | | | |
1990–2012 | 19 | 11253 | 1534 | 13(9–15%) | 1346.55 | 98.66 | P < 0.001 |
2013–2020 | 57 | 46036 | 6220 | 11(9–13%) | 6088.71 | 99.08 | P < 0.001 |
Overall | 76 | 57289 | 7754 | 12(10–13%) | 7920.16 | 99.05 | P < 0.001 |
CL = confidence interval |
Strongyloides stercoralis
Twenty six studies consisting of 11,748 children have reported that the pooled prevalence of Strongyloides stercoralis was 1% (95% CI: 1 to 2%). The pooled prevalence of Strongyloides stercoralis was 3% (95%CI: 1–4%) in Amhara region, 1% (95%CI: 1–2%) in SNNPR, 1% (95%CI: 0–1%) in Oromia region and 0% (95%CI: 0–1%) in Tigray region as shown in supplementary file 7. The prevalence was 1% (95%CI: 1% to 2%) in school-age children. The pooled prevalence of Strongyloides stercoralis was 1% (95% CI: 1–2%) in studies done between 1997–2012 years and 2% (95% CI: 1–2%) between 2013–2020.
A univariate meta-regression between prevalence and regional states showed statistically significant correlation (Β= -0.30, 95% CI: -0.56 to -0.03, p = 0.03, supplementary file 8). However, year of publication (β: -0.17, 95% CI: -0.70 to 1.0, p = 0.70) and age of children (β: -0.02, 95% CI: -0.96 to 0.92, p = 0.97) did not show a statistically significant relationship. Therefore, Strongyloides stercoralis is more common among children in Amhara region compared to other regions (Table 7). For further details, the summary of species specific STHs presented on Table 8.
Table 7
Pooled prevalence of species specific Strongyloides stercoralis by region, age and year of publication among Ethiopian children, 2020
Variables | No. of studies | Sample | cases | Prevalence (95% CI) | Heterogeneity | P-value |
Q | I2 (%) |
Region | | | | | | | |
Amhara region | 11 | 5131 | 163 | 3(1–4%) | 116.39 | 91.41 | P < 0.001 |
Oromia region | 5 | 1566 | 10 | 1(0–1%) | 2.13 | 00.00 | P = 0.71 |
South Region | 7 | 3149 | 54 | 1(1–2%) | 35.77 | 83.23 | P < 0.001 |
Tigray region | 3 | 1902 | 9 | 0(0–1%) | - | - | - |
Age | | | | | | | |
School | 23 | 10134 | 204 | 1(1–2%) | 150.65 | 85.40 | P < 0.001 |
Preschool | 2 | 1492 | 30 | 0(0–1%) | - | - | - |
Both | 1 | 122 | 2 | 2(0–6%) | - | - | - |
Year of publication | | | | | | | |
1990–2012 | 11 | 5653 | 79 | 1(1–2%) | 141.55 | 90.11 | P < 0.001 |
2013–2020 | 15 | 6095 | 157 | 2(1–2%) | 6088.71 | 72.96 | P < 0.001 |
Overall | 26 | 11748 | 236 | 1(1–2%) | 179.49 | 86.07 | P < 0.001 |
CL = confidence interval |
Table 8
summary of species-specific pooled prevalence estimates of STHs among Ethiopian children, 2020
Parasites | Number of studies | Sample size | positives | Prevalence (%) | 95% CI | Heterogeneity | p-value |
Q | I2 (%) |
Ascaris lumbricoides | 85 | 58234 | 9339 | 17 | 15–19% | 8961.94 | 99.06 | P < 0.001 |
Trichuris trichiura | 76 | 54854 | 3312 | 6 | 6–7% | 3766.86 | 98.01 | P < 0.001 |
Hookworms | 76 | 57289 | 7754 | 12 | 10–13% | 7920.16 | 99.05 | P < 0.001 |
Strongyloides stercoralis | 26 | 11748 | 236 | 1 | 1–2% | 179.49 | 86.07 | P < 0.001 |
CL = confidence interval |
Intesnity Of Sths Infection
Only 13 out of 88 studies included 5, 676 children reported about intensity of infection of STHs. Low intensity of infection of A. lumbricoides was observed in 16% (95% CI: 10 to 21%, supplementary file 9) children. Moderate and high intensity of infections of A. lumbricoides were observed in 13% (95% CI: 7 to 19%, supplementary file 10) and 6% (95% CI: 2 to 11%, supplementary file 11 ) of children, respectively. Low, moderate and high intensity of infections of T. trichura were observed in 16% (95% CI: 12 to 20%, supplementary 12), 3%(95% CI: 2 to 4%, supplementary file 13), 1% (95% CI: 1 to 2%, supplementary file 14) children, respectively. This reviewe also showed that low, moderate and high intensity of infections of Hookworms were recorded in 20% (95% CI: 10 to 29%, supplementary file 15), 4% (95% CI: 2 to 6%, supplementary file 16) and 5% (95% CI: 0 to 11%, supplementary file 17) children, respectively.
Regional distribution of eligible studies and risk zones (RZs) for STHs infections
The highest numbers of studies were reported from Amhara 36 (40.90%) and SNNPR 22(25%). These were followed by the Oromia region 20 (22.7%), Tigray 8 (9.1%), Benishangul-Gumuz region and Addis Ababa city each with one (1.1%) study. None of the regions is classified as High Risk Zone (HRZ) according to world health organization (WHO) risk classification. SNNPR, Amhara and Oromia regions recorded STH prevalence of 44%, 34%, 31%, respectively and are classified as moderate risk zones (MRZs) while, the rest of the regions and cities recorded prevalence estimates ranging between 1–10% and are classified as Low Risk Zones (LRZs).