These infections are usually asymptomatic, and patients with HEV infection are only viremic for 2 weeks. in nine (4.9%) patients and was undetectable in the remaining patients. HEV serology positive patients had more severe liver disease, characterized by liver fibrosis 3 2 (family. Four major HEV genotypes have been reported. Genotypes 1 and 2 cause acute and epidemic diseases in humans and are more frequent CHIR-99021 monohydrochloride in developing countries, where poor sanitary conditions prevail, either by fecal-oral transmission or from contaminated water or food. Genotypes 3 and 4 are typically transmitted via zoonosis, raw or undercooked pork consumption, or wild animal meat consumption (1- 5). The clinical course is usually benign with moderate and CHIR-99021 monohydrochloride self-limited symptoms in most cases, as reported by the initial series of cases among travelers to endemic regions of Asia, Africa, and the Middle East. Chronification CHIR-99021 monohydrochloride is usually more likely to occur in immunocompromised hosts (6). Previous studies have shown that patients with chronic hepatitis C virus (HCV) contamination may have liver injury aggravated by co-infection with hepatitis A virus or hepatitis B virus (HBV) (7). However, few studies have evaluated the impact of HEV contamination in HCV-infected patients. A study from Turkey exhibited that among 190 HBV-infected patients (13.7%), 174 HCV-infected patients (54%), and 178 healthy individuals (15.7%) had anti-HEV IgG antibody positivity for HEV. Therefore, the screening and development of educational programs aimed at the prevention of this contamination in Brazilians is usually justified (8). Data around the HEV role in HCV-infected patients in Brazil are scarce, whereas HEV is usually relatively uncommon, with prevalence of 1%-12.9%. In 1995, Pang et al. first reported data regarding HEV contamination in Brazil and identified HEV seroprevalence in 6% of gold mine workers in Amazonas (9). Recent studies have shown similar blood donor results, with prevalence of 4.3% and 9.8% in Rio de Janeiro and S?o Paulo, respectively (10,11). More recent data have shown prevalence of 6% in the adult population, 7% in blood donors, and 3% in the general population (12). HEV has become a public health issue, with a significant increase in morbidity and mortality worldwide. A meta-analysis study in developed countries performed on blood donors showed the seroprevalence of anti-HEV IgG antibodies using the Wantai HEV IgG ELISA kit, with 52.5%, 39.1%, 34%, and 22.4% in different regions of France, 49.6% in Poland, 49% in Italy, and 31% in the Netherlands. Three categories of risk were demonstrated: high risk (France, the Netherlands, and Poland), medium risk (Austria, Denmark, Norway, Spain, the United Kingdom, and the United States), and low risk (Canada, Scotland, Ireland, CHIR-99021 monohydrochloride Australia, and New Zealand) (10). SPP1 The main characteristics associated with high seroprevalence were advanced age; male sex; contact with animals (pig farm workers or persons with occupational exposure to pigs); raw or undercooked pork consumption; and frequent consumption of beef, CHIR-99021 monohydrochloride smoked meats, and oysters. Low prevalence is usually associated with bottled water consumption (10). Thus, we conducted this study to assess the prevalence and impact of positive markers of HEV on the severity of liver fibrosis and morbidity among Brazilian patients with chronic HCV contamination. METHODS Patients and study design This was an observational cross-sectional study of adult patients with chronic HCV contamination who were naive to antiviral treatment and followed up at the outpatient liver clinic of the Department of Gastroenterology of the University of S?o Paulo School of Medicine. This support provides tertiary health care for a broad population of 18 million people. Patients were prospectively and consecutively recruited from January 2013 to March 2016. We included those patients whose recent data suggested that interferon and ribavirin (standard HCV treatment at that moment) could also treat HEV contamination, with HCV RNA positivity for at least 6 months, and with no previous antiviral HCV treatment (5). In contrast, we excluded those with HBV or human immunodeficiency virus co-infection, other chronic liver diseases including alcoholic liver injury and non-alcoholic fatty liver disease), use of immunosuppressive therapy, or refusal to participate in the study. We evaluated a total of 727 HCV-seropositive patients for enrollment. Among them, we excluded 106 patients discharged from the clinic, 406 who received antiviral therapy, and one with HBV co-infection. Then, we also excluded the 214 patients naive for HCV treatment and 33 who underwent kidney transplantation because they were under immunosuppressive therapy. Finally, a total of 181 patients were included for analysis (Physique 1). Open in a separate window Physique 1 Flowchart of recruitment of patients. HCV, hepatitis C virus; DAA, direct-acting antiviral; HBV, hepatitis B virus. Baseline demographic, clinical, and laboratory data were obtained from all participants. They included complications of liver disease.