Karst is a type of landscape where the dissolving of the bedrock has created sinkholes, sinking streams, caves, springs, and other characteristic features. Karst is associated with soluble rock types such as limestone, marble, and gypsum.
A: Scientists have identified 5 unique hepatitis viruses, identified by the letters A, B, C, D, and E. While all cause liver disease, they vary in important ways. Hepatitis A virus (HAV) is present in the faeces of infected persons and is most often transmitted through consumption of contaminated water or food.exual transmission is also possible, but is much less common. There is no vaccine for HCV. Hepatitis D virus (HDV) infections occur only in those who are infected with HBV. The dual infection of HDV and HBV can result in a more serious disease and worse outcome.
Hepatitis A. By John W. Wood. Hepatitis A is referred to as one of the oldest diseases known to humankind by the World Health Organization (WHO) (1). HAV was first discovered in 1973 by Steven M. Feinstone as a nonenvoloped, spherical, positive stranded RNA virus (1).HAV was an unidentified viral disease prior to this discovery.Hepatitis A is a disease caused by infection from the hepatitis A virus (HAV) (1, 5, 8).HAV has been called epidemic hepatitis, epidemic jaundice, infectious hepatitis, catarrhal jaundice, HA and type A hepatitis in the past according to the WHO (1). The term hepatitis refers to having inflammation of the liver.AV was first discovered in 1973 by Steven M. Feinstone as a nonenvoloped, spherical, positive stranded RNA virus (1). HAV was an unidentified viral disease prior to this discovery. Hepatitis A is a disease caused by infection from the hepatitis A virus (HAV) (1, 5, 8).