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.[1] GB virus C and Chandipura virus are possible examples in humans.[2][3] 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.[4] The discredited[5] Duesberg hypothesis posits that HIV is a passenger virus in the etiology of AIDS.[6]

References

1. Mongini PK, Rosenberg LT (January 1976). "Inhibition of lymphocyte trapping by a passenger virus in murine ascitic tumors: characterization of lactic dehydrogenase virus (LDV) as the inhibitory component and analysis of the mechanism of inhibition". J. Exp. Med. 143 (1): 100–13. doi:10.1084/jem.143.1.100. PMC 2190100. PMID 1244415.
2. Mphahlele MJ, Lau GK, Carman WF (June 1998). "HGV: the identification, biology and prevalence of an orphan virus". Liver. 18 (3): 143–55. doi:10.1111/j.1600-0676.1998.tb00142.x. PMID 9716223.
3. Potharaju NR, Potharaju AK (March 2006). "Is Chandipura virus an emerging human pathogen?". Arch. Dis. Child. 91 (3): 279–80. doi:10.1136/adc.2005.074708. PMC 2065945. PMID 16492900.
4. Metzler AE (January 1991). "The malignant catarrhal fever complex". Comparative Immunology, Microbiology and Infectious Diseases. 14 (2): 107–124. doi:10.1016/0147-9571(91)90125-W. PMID 1934998.
5. Cohen J (1994-12-09). "The Duesberg phenomenon". Science. 266 (5191): 1642–1644. Bibcode:1994Sci...266.1642C. doi:10.1126/science.7992043. ISSN 0036-8075. PMID 7992043.
6. Duesberg P, Rasnick D (1998). "The AIDS dilemma: drug diseases blamed on a passenger virus". Genetica. 104 (2): 85–132. doi:10.1023/A:1003405220186. PMID 10220905. S2CID 30201649.