A passenger virus is a virus that is frequently found in samples from diseased tissue, such as , 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:
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injection of the virus into healthy animals without causing disease;
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the absence of the virus at the earliest stages of the disease;
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curing the viral infection using 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.
