Hepatitis D is caused by a defective RNA virus (delta agent) that can replicate only in the presence of hepatitis B virus. Hepatitis B infection rarely occurs as coinfection during acute hepatitis B or as superinfection during chronic hepatitis, also type B.

Working professions in mitral valve disease
It is well known that risk factors for heart disease include habits such as excessive alcohol use, such as smoking, a high-protein and high-fat diet, and also genetic factors, while less consideration is often given to factors of occupational origin.