Coinfection

In parasitology, coinfection is the term used to describe the simultaneous infection of a host by multiple pathogen species. In virology, coinfection can also refer to the simultaneous infection of a single cell by two or more virus particles. An example is the coinfection of liver cells with Hepatitis B virus and Hepatitis D virus, which can arise incrementally via initial infection followed by superinfection.

Global prevalence figures for coinfections among human hosts are not available, but coinfection is thought to be commonplace,^[1] sometimes more common than single infection.^[2] Coinfections involving helminths affect around 800 million people worldwide.^[3]

Coinfection is of particular human health importance because pathogen species can interact within the host. The net effect of coinfection on human health is thought to be negative.^[4] Interactions can be positive or negative. Under positive coinfection interactions, disease transmission and progression are enhanced and this is also known as syndemism. Negative coinfection interactions include microbial interference when one bacterial species suppresses the virulence or colonisation of other bacteria, such as Pseudomonas aeruginosa suppressing pathogenic Staphylococcus aureus colony formation.^[5] However, the general patterns of ecological interactions being parasite species are unknown, even among common coinfections such as those between sexually transmitted infections.^[6]

A globally common coinfection involves both tuberculosis and HIV. In some countries, up to 80% of tuberculosis patients are also HIV-positive.^[7] The potential for dynamics of these two infectious diseases to be interlinked has been known for decades.^[8] Other common examples of coinfections are AIDS^[9] or polymicrobial infections like Lyme Disease.^[10]

See also

• Syndemic
• Superinfection
• Infectious disease

Examples:

• Hepatitis D
• HCV-HIV coinfection
• Hookworm-malaria coinfection

References

1. ^ Cox, FE (2001). "Concomitant infections, parasites and immune responses". Parasitology. 122 Suppl: S23–38. PMID 11442193. 
2. ^ Petney, TN; Andrews, RH (1998). "Multiparasite communities in animals and humans: frequency, structure and pathogenic significance". International journal for parasitology 28 (3): 377–93. doi:10.1016/S0020-7519(97)00189-6. PMID 9559357. 
3. ^ Crompton, DW (1999). "How much human helminthiasis is there in the world?". The Journal of parasitology 85 (3): 397–403. doi:10.2307/3285768. JSTOR 3285768. PMID 10386428. 
4. ^ Griffiths, EC; Pedersen, ABP; Fenton, A; Petchey, OP (2011). "The nature and consequences of coinfection in humans". The Journal of Infection 63 (3): 200-206. doi:10.1016/j.jinf.2011.06.005. PMID 21704071. 
5. ^ Hoffman, L. R.; Deziel, E.; D'argenio, D. A.; Lepine, F.; Emerson, J.; McNamara, S.; Gibson, R. L.; Ramsey, B. W. et al. (2006). "Selection for Staphylococcus aureus small-colony variants due to growth in the presence of Pseudomonas aeruginosa". Proceedings of the National Academy of Sciences 103 (52): 19890. doi:10.1073/pnas.0606756104. PMC 1750898. PMID 17172450. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1750898. 
6. ^ Shrestha, S. (2011). "Influence of host genetic and ecological factors in complex concomitant infections – relevance to sexually transmitted infections". Journal of Reproductive Immunology. PMID 22019002. 
7. ^ "Tuberculosis and HIV". World Health Organization. http://www.who.int/hiv/topics/tb/en/index.html. 
8. ^ Di Perri, G; Cruciani, M; Danzi, MC; Luzzati, R; De Checchi, G; Malena, M; Pizzighella, S; Mazzi, R et al. (1989). "Nosocomial epidemic of active tuberculosis among HIV-infected patients". Lancet 2 (8678-8679): 1502–4. PMID 2574778. 
9. ^ Lawn, SD (2004). "AIDS in Africa: the impact of coinfections on the pathogenesis of HIV-1 infection". The Journal of infection 48 (1): 1–12. doi:10.1016/j.jinf.2003.09.001. PMID 14667787. 
10. ^ Mitchell, PD; Reed, KD; Hofkes, JM (1996). "Immunoserologic evidence of coinfection with Borrelia burgdorferi, Babesia microti, and human granulocytic Ehrlichia species in residents of Wisconsin and Minnesota". Journal of clinical microbiology 34 (3): 724–7. PMC 228878. PMID 8904446. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=228878.