Ready-to-eat foods (RTF) are defined as foods being ready for consumption that could be raw or cooked, hot, or chilled and can be consumed without further treatment or any processing [
Ready-to-eat foods play a vital role in meeting the food requirements of many inhabitants and being appreciated by consumers for their affordability, accessibility, variety, and unique organoleptic properties [
Currently, the incidence of foodborne illness involving a broad range of diseases caused by pathogenic microorganisms is rising worldwide and becomes a public health concern [
The study aimed to systematically review and provide the overall current evidence on the prevalence of microorganisms of public health concerns in ready-to-eat foods in developing countries.
This systematic review and meta-analysis was conducted under the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines [
The articles that met the following inclusion criteria were included in the systematic review and meta-analysis:
The outcome of this systematic review and meta-analysis is to determine the pooled prevalence of
The articles published from 2015 to 2020 were identified through a literature search of electronic databases such as Google Scholar, PubMed, MEDLINE, CINAHL, Science Direct, Web of Science, and the Directory of Open Access Journals. From PubMed databases, articles were searched using a combination of Boolean logic operators (AND, OR, and NOT), Medical Subject Headings (MeSH), and keywords. The searches were done using the keywords and Boolean logic operators as following: (Prevalence
The identified keywords and index terms were checked by authors (Mengistu DA and Tolera ST) across the included electronic databases. Additionally, manual searching for further studies was done by authors (Mengistu DA and Tolera ST) to cover other published articles. The last search was done on April 20, 2020.
Duplicated studies were removed using the ENDNOTE software version X5 (Thomson Reuters, USA). The authors (Mengistu DA and Tolera ST) individually screened all identified articles based on their titles and abstracts by applying the eligibility criteria. Disagreements were solved by taking the mean score of the two reviewers (Mengistu DA and Tolera ST) after discussing the rationale on differences and repeating the review procedure.
All required and relevant data were extracted from the included articles using a predetermined data abstraction form by authors (Mengistu DA and Tolera ST) independently. The extracted data include the name of the authors, sample size, the primary outcome (prevalence of selected microorganisms of public health significance), countries where the article was carried out, year of publication, and study design.
For articles met inclusion criteria, abstracts were checked to establish their relevance for the study. The quality of the included articles was assessed using independent appraisal tools (JBI Critical Appraisal tools) [
The required data were extracted using a Microsoft Excel format, 2016. After the extraction, the data were imported to the Comprehensive Meta-Analysis (CMA) V3 statistical package (software). Then, the characteristics of the original articles were described using texts, tables, and forest plots. Heterogeneity among the reported prevalence was checked by using a heterogeneity
The random-effect model of meta-analysis and forest plot was used to estimate the pooled prevalence of microorganisms of public health concern in ready-to-eat foods with 95% confidence intervals. The possibility of publication bias was assessed by visual funnel plots, and a
A total of 1221 articles published from 2012 to 2020 were identified using electronic databases and hand searching. After an initial screening of articles by their titles and abstracts, 149 duplicate articles were excluded, while 1044 studies were excluded based on the predetermined inclusion and exclusion criteria. Then, the full texts of the remaining 28 articles were further assessed to determine their eligibility for the systematic review and meta-analysis. Additionally, 16 articles were excluded as they failed to report the prevalence of selected microorganisms of public health concern. Twelve original articles that meet the predetermined inclusion criteria were included in the systematic review, of which 8 articles were included in quantitative analysis (meta-analysis) (Figure
PRISMA flow diagram indicating the selection process of included articles for a systematic review and meta-analysis, 2020.
In this study, a total of 625 ready-to-eat food samples were included in eight articles published from 2015 to 2020 that were conducted in seven different developing countries: one in Ethiopia, two in Nigeria, one in India, one in Pakistan, one in Sudan, one in Namibia, and one in South Africa. All the included articles were cross-sectional studies with a sample size ranging from 15 to 205 ready-to-eat foods. In addition, based on JBI Critical Appraisal tool [
Overall characteristics of included articles in systematic review and meta-analysis, 2020.
Authors | Publication | Study design | Prevalence of selected microorganisms | Country | Risk of bias | References | |||
---|---|---|---|---|---|---|---|---|---|
Temesgen et al. | 2016 | 71 | Cross-sectional | 29.6% | 12.7% | 9.9% | Ethiopia | Low | [ |
Reddi et al. | 2015 | 150 | Cross-sectional | 42.6% | 48.6% | 73.3% | India | Low | [ |
Asghar et al. | 2018 | 40 | Cross-sectional | 30% | 2.0% | 70.0% | Pakistan | Low | [ |
Elhag et al. | 2015 | 30 | Cross-sectional | 26.7% | 13.3% | 55% | Sudan | Low | [ |
Ire and Imuh | 2016 | 15 | Cross-sectional | 100% | 73.3% | 100% | Nigeria | Low | [ |
Shiningeni et al. | 2019 | 96 | Cross-sectional | 35.0% | 11.0% | 7.0% | Namibia | Low | [ |
Okechukwu et al. | 2016 | 17 | Cross-sectional | 83.3% | 66.7% | 66.7% | Nigeria | Low | [ |
Asiegbu et al. | 2020 | 205 | Cross-sectional | 1.8% | 21.8% | 31.8% | South Africa | Low | [ |
The prevalence of
We conducted a meta-analysis using the Comprehensive Meta-Analysis (CMA) V3 statistical package to determine the pooled prevalence of microorganisms of public health concern in ready-to-eat foods.
Forest plot shows the pooled prevalence of
Based on a subgroup analysis of included articles by country, the lowest prevalence [1.8% (95% CI: 0.7%, 4.9%) with a
However, after subgroup analysis by country, the overall pooled prevalence of
Subgroup analysis of the pooled prevalence of
Regarding the publication year, the pooled prevalence of
Subgroup analysis of the pooled prevalence of
The pooled prevalence of
Among all countries, the lowest prevalence [2.0% (95% CI: 0.2%, 15.7%) with a
Subgroup analysis of the pooled prevalence of
Subgroup analysis based on publication year and prevalence of
Subgroup analysis of the pooled prevalence of
The pooled prevalence of
A subgroup analysis was performed based on the countries where the articles were conducted and the year of publication. Among the included countries, the lowest prevalence [7% (95% CI: 3.3%, 14.2%) with a
Subgroup analysis of the pooled prevalence of
Subgroup analysis based on the publication year of included articles found the lower pooled prevalence of
Subgroup analysis of the pooled prevalence of
Various studies conducted across the world are strongly agreeing with the fact that most of the pathogenic microorganisms of public health concerns are introduced to foods during handling, processing, and preparation [
Among 8 articles included in this review, Ire and Imuh 2016 reported a higher prevalence of
Show the reported prevalence of
The difference in microorganisms may be related to poor hygiene and safety practices or due to contamination of raw materials used or water supply used or the lifestyle of the community where the study was conducted.
The current review found the overall prevalence of positive ready-to-eat foods in terms of
This systematic review and meta-analysis estimated the pooled prevalence of
Comprehensive Meta-Analysis
Joanna Briggs Institute
Preferred Reporting Items for Systematic Review and Meta-Analysis
Ready to eat
World Health Organization.
All data are included in the systematic review and meta-analysis. In addition, the Supplementary materials including PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) 2015 checklist are the recommended items to address in a systematic review protocol.
The authors declare that they have no conflicts of interest.
Dechasa Adare Mengistu conceived the idea and had major roles in the data review, extraction, and analysis. Sina Temesgen Tolera had a role in data extraction too. Both authors (Mengistu DA and Tolera ST) have contributed in analysis, writing, drafting, and editing. Finally, the authors (Mengistu DA and Tolera ST) read and approved the final version to be published and agreed on all aspects of this work.
PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis) 2015 checklist is one of the recommended items to address in a systematic review.