Characterizing hepatitis C virus epidemiology in Egypt: systematic reviews, meta-analyses, and meta-regressions

Egypt is the most affected nation by hepatitis C virus (HCV) and needs a comprehensive characterization of HCV epidemiology to inform the scale-up of treatment and prevention programs. Systematic reviews, meta-analyses, and meta-regressions were conducted. A total of 25 incidence, 259 prevalence, and 47 genotype studies were identified. Incidence and prevalence levels were high across all populations. Genotype 4 accounted for 94.1% of infections with a relative Shannon Diversity Index of only 14.4%. Pooled mean HCV prevalence was estimated at 11.9% (95% CI = 11.1–12.6%) among the general population, 55.6% (95% CI = 49.4–61.7%) among populations at high risk, 14.3% (95% CI = 10.3–18.8%) among populations at intermediate risk, 56.0% (95% CI = 50.4–61.6%) among populations with liver-related conditions, and 35.0% (95% CI = 27.3–43.1%) among special clinical populations. Mean HCV viremic rate was estimated at 66.7% (95% CI = 61.7–71.5%). Meta-regression indicated 6% lower odds for HCV prevalence for each one-year increment in publication year (AOR = 0.94; 95% CI = 0.92–0.96). HCV prevalence is high with evidence for ongoing transmission mainly through healthcare. Genotype diversity is low with genotype 4 dominance. Two-thirds of antibody-positive Egyptians are chronically infected and need treatment. Clinical populations should be prioritized for screening. Despite the large-scale epidemic, prevalence appears to be declining rapidly consistent with a contracting epidemic.


Rationale
3 Describe the rationale for the review in the context of what is already known. p. [3][4] Objectives 4 Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS). p.3-4

METHODS
Protocol and registration 5 Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number. p.4 Eligibility criteria 6 Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale. p.5 Information sources 7 Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.
p.5 and Supplementary Figure S2 Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.
Supplementary Figure  S2 Study selection 9 State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis). p.5-7 Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.
p.5-6 and Supplementary Table S1 Data items 11 List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made.
p.5-6 and Supplementary Table S1 Risk of bias in individual studies 12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.
p.6 and Supplementary Figure S3 Summary measures 13 State the principal summary measures (e.g., risk ratio, difference in means). p.7-8 Synthesis of results 14 Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I 2 ) for each meta-analysis. p.5-8 Risk of bias across studies 15 Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).
p.6 and Supplementary Figure S3 Additional analyses 16 Describe methods of additional analyses (e.g., sensitivity or subgroup analyses, meta-regression), if done, indicating which were pre-specified. p.8

Study selection
17 Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.
p. [8][9]13 and Figures 1 and 2 Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations. Table 1 and  Supplementary Tables  S2-S4 Risk of bias within studies 19 Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).
Supplementary Tables  S5-S9 Results of individual studies 20 For all outcomes considered (benefits or harms), present, for each study: (a) simple summary data for each intervention group (b) effect estimates and confidence intervals, ideally with a forest plot.
p 9-11, p. 13-16, Table 2 Synthesis of results 21 Present results of each meta-analysis done, including confidence intervals and measures of consistency. p.14-16 and Table 3 Risk of bias across studies 22 Present results of any assessment of risk of bias across studies (see Item 15). p.11-12 and Supplementary Table  S5 Additional analysis 23 Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses, meta-regression [see Item 16]). p. 16-17 and Table 4 DISCUSSION Summary of evidence 24 Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers). p.17-21 Limitations 25 Discuss limitations at study and outcome level (e.g., risk of bias), and at review-level (e.g., incomplete retrieval of identified research, reporting bias). Supplementary Figure S2. Data sources and search criteria for systematically reviewing hepatitis C virus (HCV) antibody incidence and prevalence in Egypt. Same data sources and search criteria were used for systematically reviewing HCV genotypes in Egypt.

PubMed (last searched: August 3, 2015)
(  Figure S3. Description of quality assessment criteria and studies' risk of bias (ROB) appraisal.
The quality of HCV antibody incidence or prevalence measures identified through our review was determined by assessing: