[A group of pathogens comprising the smallest known agents of infectious disease. They are unencapsulated and are capable of replicating autonomously in susceptible cells. Positively identified viroids composed of single-stranded RNA have been isolated from higher plants, but the existence of DNA viroids pathogenic to animals is suspected. ( MSH )]
UMLS (CSP) C0042761 Relation/PAR: microorganism
Relation/CHD: prion