For example, many articles from Japan were found to publish prevalence from hyperendemic areas. Although these studies were excluded from analysis, publications from Japan seem to be heavily populated with studies

conducted in high-prevalence settings. Conversely, lower-income Lumacaftor cell line countries known to have high seroprevalence may seem to have lower estimates because published studies mainly sample urban affluent populations. Furthermore, it must be noted that seroprevalence data are generally derived from adult and older age samples, and may not be representative samples in regions with majority younger populations. These limitations in the literature underscore the challenge of estimating global prevalence in the absence of nationally representative age-specific databases such as the NHANES U.S. Fourth, methodological limitations also apply. False positivity rates, although not a concern in enzyme immunoassay (EIA) testing for adults, is relatively high in children,

particularly in first-generation test kits, and this may be among the reasons behind the high prevalence seen in children age 1-4 years old in Central Europe Navitoclax in 1990.22, 23 Type of diagnostic test and quality of test kits were not considered, because information on the test used were at times not included in the description of methods, which makes it difficult to appropriate bias indicators in instances where this information was not present. To exclude studies without details on the testing kit would further shrink the amount of studies that could be included, and furthermore it was expected that any influence of poor testing quality would be covered by the uncertainty interval surrounding the point estimates. Finally, for regions with less data, borrowing strength from other regions may have hidden Org 27569 patterns of transmission between years and sex amid the pooled data. Although the data may be analyzed correctly using the hierarchical model, the problem with meta-analysis being used to make causal inferences has been highlighted, i.e., the studies included are observational and

“group-level correlations may be mistakenly attributed to individual-level causes.”24, 25 Three distinct epidemiological profiles of HCV transmission have been described and can be used as a basis for interpreting the age-specific seroprevalence curves in this meta-analysis. In the first transmission type, prevalence is low among younger persons, and then rises steadily or sharply through middle age. After peak prevalence is reached, the seroprevalence declines in older ages. The peak prevalence seen in type 1 transmission is commonly referred to as the “cohort effect.” In type 2 transmission, prevalence is low in younger populations but increases dramatically and is sustained in older populations as a reflection of a past high risk of infection that is no longer present.