Passenger virus

Proving that a virus has no causative role can be difficult. Although none of the following signs is definitive, evidence that a virus found in diseased tissue might be passenger only rather than a causative agent includes: • injection of the virus into healthy animals without causing disease; • the absence of the virus at the earliest stages of the disease; • curing the viral infection using antiviral drugs or vaccination with no effect on the course of the disease. ==Examples==

A well-established example is lactate dehydrogenase virus, which is often found in mouse tumours. GB virus C and Chandipura virus are possible examples in humans. It has also been suggested that a virus related to Alcelaphine herpesvirus 1 is a passenger virus that, unlike AHV1 itself, does not cause bovine malignant catarrhal fever. The discredited Duesberg hypothesis posits that HIV is a passenger virus in the etiology of AIDS. ==References==