noun, plural elegies. 1. a mournful, melancholy, or plaintive poem, especially a funeral song or a lament for the dead. 2. a poem written in elegiac meter. 3. a sad or mournful musical composition. Origin of elegy.
Hepatitis D virus (HDV) is an RNA virus that is structurally unrelated to hepatitis A (HAV), hepatitis B (HBV), or hepatitis C virus (HCV). It was discovered in 1977. HDV causes a unique infection that requires the assistance of viral particles from HBV to replicate and infect other hepatocytes.Its clinical course is varied and ranges from acute, self-limited infection to acute, fulminant liver failure.
It is thought that the disease originated in Africa and spread to the Americas in the 17th and 18th centuries through trading ships. The flavivirus that causes yellow fever was first identified in 1928 and the first vaccine against the disease was produced at the Rockefeller Institute in New York in 1937.