In the first step of our search, 367 articles were retrieved regarding the prevalence and associated factors of intestinal parasitic infections among food handlers at PubMed, Google Scholar, Science Direct, and other sources described previously. Of these initial articles, 73 articles were excluded due to duplicates. From the remaining 294 articles, 59 articles were excluded after review of their titles and 146 abstracts being assessed as non-relevant to this review. Therefore, 89 full-text articles were accessed and assessed for eligibility based on the pre-set criteria, which resulted in the further exclusion of 71 articles primarily due to the outcome of interest not reported, inaccessibility of the full text and having data that were not extractable. As a result, 18 studies met the eligibility criteria and were included in the final meta-analysis (Figure 1).
Characteristics of original studies
Among 18 studies which were published in Ethiopia from 2000-2019, 5,049 study participants were involved to determine the pooled prevalence of IPIs among food handlers. Regarding the study design, almost all the studies are cross-sectional. The sample size of the studies ranged from 94 to 417. The lowest prevalence of IPIs among food handlers were reported in studies conducted in Wollo University student’s cafeteria(15%)(11), Awi Amhara (14.75%)(22), and Aksum town, Tigray(14%)(12), whereas the highest prevalence (61.78%) was reported in a study conducted at East and West Gojjam public prison(10). Seven of the studies were from Amhara region (10, 11, 22-26), five from SNNP region (8, 14, 27-29), three from Oromia region (9, 13), one from Addis Ababa (7) and two from Tigray region (2, 12). However, there were no studies reported from Benishangul Gumuz, Harari and Gambela regions, and Dire Dawa. Regarding quality score, the quality score of each original study ranged from a low of five to a high of eight (Table 1).
Author
|
Publication Year
|
Region
|
Study Area
|
Sample Size
|
Quality score
|
Prevalence with 95%
|
Solomon et al,.(8)
|
2018
|
SNNP
|
Wolaitasodo town
|
387
|
6
|
40 (35, 45)
|
Maram et al,.(9)
|
2018
|
Oromia
|
Haramaya University
|
417
|
6
|
25.2 (21, 29)
|
Asires et al,.(10)
|
2019
|
Amhara
|
Debre Markos Prison
|
416
|
6
|
62 (57, 66)
|
Kebede et al,.(11)
|
2019
|
Amhara
|
Wollo University
|
200
|
7
|
15(10, 20)
|
Gezehegn et al,.(12)
|
2017
|
Tigray
|
Aksum Town
|
400
|
7
|
15(11, 18)
|
Mama et al,.(30)
|
2016
|
SNNP
|
Arba Minch University
|
378
|
6
|
32(28, 37)
|
Tefera et al,.(27)
|
2014
|
Oromia
|
Yebu Town
|
118
|
5
|
44(35, 53)
|
Andargie et al,.(24)
|
2008
|
Amhara
|
Gondar Town
|
127
|
7
|
29(21, 37)
|
Girma et al,.(13)
|
2017
|
Oromia
|
JimmaUniversity
|
94
|
6
|
33(23, 42)
|
Aklilu et al,.(7)
|
2014
|
Addis Ababa
|
Addis Ababa University
|
172
|
7
|
45(37, 53)
|
Abera et al,.(23)
|
2010
|
Amhara
|
Bahir Dar Town
|
384
|
8
|
41(36, 46)
|
Gebreyesus et al,.(2)
|
2014
|
Tigray
|
Mekelle University
|
307
|
6
|
52(47, 58)
|
Dagnew et al,.(25)
|
2012
|
Amhara
|
University of Gondar
|
200
|
7
|
25(19, 31)
|
Desta et al,.(14)
|
2014
|
SNNP
|
Hawassa University
|
272
|
5
|
21(16, 25)
|
Wadilo et al,.(31)
|
2016
|
SNNP
|
Wolaitasodo town
|
288
|
5
|
34(28, 39)
|
Alemu et al(22)
|
2019
|
Amhara
|
Chagni town
|
400
|
6
|
15(11,18)
|
Kumma et al(29)
|
2019
|
SNNP
|
Wolaitasodo university
|
233
|
5
|
24(18, 29)
|
Demis et al(26)
|
2019
|
Amhara
|
Woldia university
|
256
|
7
|
17(12, 21)
|
SNNP: Southern Nations, Nationalities, and People.
Prevalence intestinal parasitic infections among food handlers working in higher public University student’s cafeterias and public food establishments in Ethiopia
The eighteen included studies revealed that prevalence intestinal parasitic infections among food handlers working in higher public University students cafeterias and public food establishments were 28.5% (95%CI: 27.4, 29.7) (Figure 2). High heterogeneity was observed across the included studies (I2 = 96.90, P<0.001). As a result, a random-effects model was employed to estimate the pooled prevalence of intestinal parasitic infection among food handlers in Ethiopia.
Heterogeneity and publication bias
The existence of heterogeneity and publication bias was determined within the included studies. Consequently, there was considerable heterogeneity across fifteen included studies in this meta-analysis (I2 = 96.9%). Publication bias was assessed using Begg’s and Egger’s tests, showing no statistically significant for estimating the prevalence of IPIs among food handlers (p=0.081) and (P=0.075) respectively.
Subgroup analysis
We performed a subgroup analysis by taking different factors. The region of the country, sample size, study area (University versus Town) was factored we considered to perform subgroup analysis. Consequently, the subgroup analysis of this study indicated that the highest prevalence of IPIs was observed in Amhara region, 27.55% (95% CI: 25.73, 29.37), SNNP, 30.39% (95% CI: 28.13, 32.64), and Oromia, 29.14% (95%Cl: 25.63, 32.65) respectively, whereas the lowest prevalence was observed in Tigray and Addis Ababa with the prevalence of 27.72 % (95%CI: 24.99, 30.45) respectively (Table 3). Furthermore, subgroup analysis was performed based on the sample size of the studies. The pooled prevalence of IPIs was higher in studies having a sample size (n) 200, 28.71% (95% CI: 27.41, 30.01) compared to those having a sample size (n) 00, 27.78% (95% CI: 24.97, 30.60). Moreover, subgroup analysis was performed based on study area/site where food handlers working in university versus public food establishments, resulting in a pooled prevalence of intestinal parasite 26.81% (95% CI: 25.14, 28.48) and 30.28% (95% CI: 28.61, 31.95), respectively (Table 2).
Table 2.Subgroup pooled prevalence of intestinal parasite among food handlers in Ethiopia, 2019(n=18)
Variables
|
Characteristics
|
Included studies
|
Sample size
|
Prevalence with (95% CI)
|
Region
|
Amhara
|
7
|
1983
|
27.55(25.73, 29.37)
|
Oromia
|
3
|
629
|
29.14(25.63, 32.65)
|
Addis Ababa and Tigray
|
3
|
879
|
27.72(24.99, 30.45)
|
SNNP
|
5
|
1558
|
30.39(28.13, 32.64)
|
Sample size
|
200
|
12
|
4138
|
28.71(27.41, 30.01)
|
200
|
6
|
911
|
27.78(24.97, 30.60)
|
Study site
|
University cafeterias
|
10
|
2,529
|
26.81 (25.14, 28.48)
|
Public town food establishments
|
8
|
2,520
|
30.28(28.61, 31.95)
|
Overall
|
|
18
|
5, 049
|
28.55(27.36, 29.73)
|
Common intestinal parasites among food handlers working in higher public University student’s cafeterias and public food establishments in Ethiopia
Furthermore, in this meta-analysis, the overall pooled prevalence of the common type of intestinal parasites among food handlers was observed from 18 studies as showed (Table S1). The pooled prevalence of E. hystolitica /E. dispar complex 6.38%(95%CI:5.73, 7.04), A. lumbricoides 4.12%(95%CI:3.56, 4.67), G. lamblia 3.12%(95%CI:2.65, 3.60), E.vermicularis 2.69%(95%CI:1.43,3.96), Hookworm 1.70%(95%CI:1.31, 2.09), Taenia species 1.07% (95%CI:0.75, 1.40), H.nana 1.03% (95%CI:0.66, 1.41), T. trichuria 0.84% (95%CI:0.42, 1.26), and S. mansoni 0.70%(95%CI:0.34, 1.07) was found from food handlers in Ethiopia (Table 3).
Table 3: pooled prevalence of some common intestinal parasites among food handlers in Ethiopia.
Types of intestinal parasites
|
pooled prevalence (95%CI)
|
I-Squared
|
A.lumbricoides
|
4.12(3.56, 4.67)
|
95.3%, p<0.001
|
E. hystolitica /E. dispar complex
|
6.38(5.73, 7.04)
|
95.0% , p<0.001
|
G. lamblia
|
3.12(2.65, 3.60)
|
76.8%, p<0.001
|
Taenia spp.
|
1.07 (0.75, 1.40)
|
73.9%, p<0.001
|
Hookworms
|
1.70(1.31, 2.09)
|
83.1%, p<0.001
|
T. trichuria
|
0.84(0.42, 1.26)
|
12.7%, p=0.33
|
H. nana
|
1.03 (0.66, 1.41)
|
90.7%, p<0.001
|
E. vermicularis
|
2.69(1.43,3.96)
|
53.0%, p=0.119
|
S. mansoni
|
0.70(0.34, 1.07)
|
51.1%, p=0.056
|
Factors associated with intestinal parasitic infections among food handlers in Ethiopia
We observed the association between fingernail trimming and intestinal parasitic infections in this meta-analysis (8-11, 13, 22, 26-29). These ten studies finding showed that the occurrence of intestinal parasitic infections was significantly associated with nail trimming habits of food handlers. Hence, the odds of intestinal parasitic infections occurrence was 3.04 times higher among food handlers who hadn’t regular nail trimming habits as compared to those who had regular nail trimming habits (OR: 3.04 95% CI: 2.19, 4.22). The finding of these test statistics revealed that there is low heterogeneity (I2=49.5% and P=0.037). As a result, a random effect model was implemented to determine the association. Possibility of publication bias was detected using Begg’s and Egger’s tests with a p-value of 0.020 and 0.002 respectively (Figure 3).
The association between handwashing after defecation with intestinal parasitic infections was evaluated by using seven studies (8, 10, 11, 13, 22, 24, 26-28). This meta-analysis result revealed that hand washing after defecation is not significantly associated with intestinal parasitic infection (11). However, the odds of having intestinal parasitic infections was 2.71 higher among food handlers who hadn’t hand washing after defecation as compared with the counterparts (OR: 2.71, 95%; CI: 1.93, 3.82) (Figure 4). This studies showed that there was the existence of high heterogeneity (I2= 85.2 % and P<0.001) therefore, random-effect meta-analysis was considered. No publication bias was detected using Begg’s and Egger’s tests with a p-value of 0.118 and 0.107 respectively.
The association between handwashing after touching any body parts with intestinal parasitic infection among food handlers was computed by using eight studies (8, 9, 12, 13, 26-29). The overall finding of this study showed that food handlers who didn’t wash their hands after touching any body parts were 2.41 higher than their counterparts (OR:2.41, 95%CI:1.64, 3.55) (Figure 6). Moderate heterogeneity (I2=67.1%; P-value=0.003) was observed among the included studies; hence, a random effect meta-analysis model was employed. Moreover, publication bias was detected using the Begg’s and Egger’s tests with a p-value of 0.266 and 0.376 respectively.
Similarly, the association between regular medical checkup and intestinal parasitic infection among food handlers in Ethiopia were computed in this meta-analysis (9, 11-13, 22, 26). The overall meta-analysis report showed that food handlers who hadn’t regular medical checkup were 2.67 more likely to have intestinal parasitic infections than those who had regular medical checkup (OR: 2.67, 95%CI: 1.51, 4.71) (Figure 6). Low heterogeneity (I2=51.2%; p-value=0.069) was detected among the included studies; for this reason, a random effect meta-analysis model was computed. Furthermore, no possible publication bias was detected using the Begg’s and Egger’s tests with a p-value of 0.133 and 0.103 respectively.
Lastly, we employed the association between food safety training and intestinal parasitic infections. We included five studies that examined the association between intestinal parasitic infections with food safety training among food handlers (8, 9, 11, 13, 26). The pooled result of this meta-analysis indicated that food handlers who didn’t receive food safety training were 2.11 more likely to have intestinal parasitic infections as compared with those who received food safety training (OR: 2.11, 95%CI: 1.18, 3.77) (Figure 5). In this meta-analysis, the included studies were characterized by low heterogeneity (I2=63.6%; P=0.027). Furthermore, low publication bias was detected using the Begg’s and Egger’s tests with a p-value of 1 and 0.248 respectively.