passenger virus passenger virus a passenger virus is a virus that is frequently found in samples from diseased tissue, such as tumours, but is not a contributing factor in causing the disease. experimental demonstration of passenger status 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.