Updating the knowledge of hepatitis E: new variants and higher prevalence of anti-HEV in Argentina.

INTRODUCTION Hepatitis E is a disease of global distribution, with significant morbidity and mortality, whose scope and burden continue to emerge in low endemic countries. MATERIAL AND METHODS In 2012, we studied the prevalence of anti-HEV antibodies in 202 adult serum samples. We also analyzed samples from 143 patients with acute non-A-C hepatitis from January 2011 to December 2013. Acute HEV infections were diagnosed with anti-HEV IgM and/or HEV RNA. HEV RNA was also investigated in 94 swine fecal samples. HEV RNA was sequenced and characterized. RESULTS We found higher values of prevalence than those previously reported in the 1990s. The overall prevalence of anti-HEV IgG antibodies was 15.4%. The prevalence was 10.6% in the 123 adults voluntarily screened on World Hepatitis Day 2012 in Buenos Aires city and 14.8, 16.7 and 35.7% respectively in the smaller groups of healthcare workers, blood donors and HIV-positive patients from different regions of the country. Nine acute HEV infections were diagnosed in the three years analyzed. We characterized new human variants of subgenotype 3a and 3i. New subgenotype 3i variants were found in swine from two distant provinces closely related to the human ones. CONCLUSIONS These results enlarge the knowledge of HEV and contribute with new information. However, higher values of prevalence found in small groups need to be confirmed in larger studies. Many aspects of the spectrum of the disease and the reservoirs and routes of transmission are still unknown and thus deserve additional research.