Association between Epstein-Bar virus and colorectal cancer: A systematic review and meta-analysis.

AIM: This study aimed to investigate the prevalence and any potential association between Epstein-Barr virus (EBV) infection and colorectal cancer (CRC). METHODS: A systematic literature search was performed by finding relevant cross-sectional and case-control studies from main online databases. Heterogeneity, odds ratio (OR), and corresponding 95% confidence interval (CI) were applied to all studies through meta-analysis and forest plots. The analysis was performed using STATA Software v.14.1. RESULTS: Twenty-three articles were included in the meta-analysis, eight of them were case/control and 15 were cross-sectional. The pooled prevalence of EBV among 1954 CRC patients was 18% (95% CI: 12%-26%; I2 = 93.14%). Furthermore, in geographical regions, the highest and lowest prevalence of EBV was observed in South America 30% (95% CI: 18%-43%) and Africa 0% (95% CI: 0%-5%), respectively. An association was found between EBV infection and CRC [OR = 3.4 (95% CI (1.13-10.27); I2 = 72.3%)]. CONCLUSION: EBV infection is associated with CRC and can be considered a potential risk factor for the development of CRC. Although the exact molecular mechanism of EBV infection in the development of CRC is still unknown, it seems that latent infection by EBV, intestinal damage, and inflammation can be important factors in the induction of CRC.

Global epidemiology of HBV infection among hemodialysis patients: A systematic review and meta-analysis.

BACKGROUND & AIMS: Hemodialysis (HD) is a life-saving procedure that purifies the blood in patients with end-stage renal disease (ESRD). Among all major complications, blood-borne diseases like hepatitis B virus (HBV) may be exposed as serious side effects of hemodialysis. A comprehensive review of the global burden of HBV among HD patients has not been written so far. The aim of the current systematic review and meta-analysis was to determine the globally epidemiology of HBV infection among HD patients. METHODS: Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, articles that investigated the prevalence of HBV among HD patients were searched from the major databases such as EMBASE, PubMed, Web of Science collection, and Scopus. Pooled prevalence with 95% CI and identification of heterogeneity were obtained using the random effects model and Cochran's Q-test, respectively, and quantification was evaluated using the I2 statistics. All statistical analyses were performed by STATA 14.1 statistical software. RESULTS: among 322 datasets (795,623 cases) that included in this study, the pooled prevalence of HBV infection among HD patients was 7.32% (95% CI: 6.53-8.15%; I2 = 97.91%), including 7.57% (95% CI: 6.69-8.48%) for HBsAg and 6.09% (95% CI: 4.05-8.49%) for DNA, respectively. In addition, based on geographic area, the prevalence was 7.44% (95% CI: 6.35-8.61%) in Asia, 4.32% (95% CI: 2.21-7.04%) in North America, 7.07% (95% CI: 6.35-8.61%) in Europe, 5.52% (95% CI: 3.60-7.78%) in Africa, 8.45% (95% CI: 5.81-11.78%) in Oceania, and 9.73% (95% CI: 7.11-12.70%) in South America. CONCLUSIONS: Our analysis indicates a relatively high prevalence of HBV infection in HD patients, even in some developed countries. Considering that ESRD patients are not able to properly respond to the vaccination strategies in order to develop an acceptable immunity, vaccination of healthy individuals is highly recommended to arm their bodies for possible immunocompromise conditions in the future. Moreover, donated blood in blood transfusion centers should be checked for possible hepatitis B virus infection using sensitive molecular tests.

Association between human polyomavirus infection and brain cancer: A systematic review and meta-analysis.

AIM: The aim of this study was to investigate the prevalence and potential association between the infection with some members of the polyomaviridae family of viruses and development of the brain tumors. METHODS: A systematic literature search was performed by finding relevant cross-sectional and case-control studies from a large online database. Heterogeneity, OR, and corresponding 95% CI were applied to all studies by meta-analysis and forest plots. The analysis was performed using Stata Software v.14. RESULTS: Twenty-three articles (33 datasets) were included in the meta-analysis, four (four datasets) of which were case/control studies and the rest were cross-sectional. The pooled prevalence of polyomaviruses among brain cancer patients was 13% (95% CI: 8-20%; I2 = 96.91%). In subgroup analysis, the pooled prevalence of JCV, SV40, BKV and Merkel cell polyomavirus was 20%, 8%, 6%, and 16%, respectively. An association was found between polyomavirus infection and brain cancer [summary OR 7.22 (95% CI (2.36-22.05); I2 = 0%)]. The subgroup analysis, based on the virus type, demonstrated a strong association between JCV infection and brain cancer development [summary OR 10.34 (95% CI 1.10-97.42; I2 = 0%)]. CONCLUSION: The present study showed a significant association between polyomavirus infection and brain tumors. Moreover, these results suggest that polyomavirus infection may be a potential risk factor for the development of brain cancer.