Virus etiological agents

Over 20 infectious agents have been incriminated as etiologic agents for many the causal relationship has been disproved, and for others there is conflicting evidence. Human herpesvirus 6 (HHV-6) is currently the most likely causative virus. HHV-6 may initiate the autoimmune processes of MS in one of two ways. First, HHV-6 is structurally similar to myelin basic protein. When T cells become sensitive to HHV-6, the cells may attack myelin basic protein. Second, HHV-6 may directly stimulate the complement cascade, activating autoimmune processes.5 Infection with HHV-6 alone cannot fully explain MS, because HHV-6 is found in 75% of all people, but MS is much more rare. 

DNA viruses modulate the host immune response, e.g., most likely the etiologic agent of Kaposfs sarcoma, KSHV (human herpes vims —8), has captured complement-binding proteins, three cytokines (two macrophage inflammatory proteins and interleukin 6), bcl-2, interferon regulatory factors, interleukin 8 receptor. Certain retroviruses... 

Poliovirus. A virus of the genus Enterovirus that is the etiological agent of poliomyelitis, separable on the basis of specificity of neutralizing antibody into three serotypes, designated types 1, 2, and 3. 

Among biological agents and their products, the candidates for etiological agents are mycotoxins and, much more probably, toxic plants, notably Aristolochia clematitis. The possible role of viruses is very unlikely, indeed. 

Kamar N, Mansuy IM, Cointault O, Selves J, Abravanel E, Danjoux M, Otal P, Esposito L, Durand D, Izopet J, Rostaing L (2008) Hepatitis E virus-related cirrhosis in kidney- and kidney-pancreas-transplant recipients. Am J Transplant 8(8) 1744-1748 Kane MA, Bradley DW, Shrestha SM, Maynard IE, Cook EH, Mishra RP, Joshi DD (1984) Epidemic non-A, non-B hepatitis in Nepal. Recovery of a possible etiologic agent and transmission studies in marmosets. JAMA 252 3140-3145 Karron RA, Daemer R, Ticehurst J, D Hondt E, Popper H, Mihalik K, Phillips J, Eeinstone S, Purcell RH (1988) Studies of prototype live hepatitis A virus vaccines in primate models. J Infect Dis 157(2) 338-345... 

The most daunting claim to fame for a human retrovirus came in the early 1980s, when teams of researchers in France and the United States jointly identified human immunodeficiency virus (HIV-1) as the etiologic agent in the human acquired immunodeficiency syndrome called AIDS. HIV infection of human T cells eventually results in T-cell death and loss of these important cells from the immune system. AIDS patients with extremely low numbers of T cells are highly susceptible to opportunistic infectious diseases, which are often the underlying cause of death due to AIDS. 

Retroviruses are RNA-DNA viruses that require host-cell genome integration to complete their replication cycle. The retroviral enzyme reverse transcriptase is an RNA-dependent DNA polymerase that has important uses in recombinant DNA methodologies such as the synthesis of complementary DNA (cDNA). The human immunodeficiency virus (HIV) is the etiologic agent that causes acquired immunodeficiency syndrome (AIDS) in humans. HIV infects and destroys human T cells, which are required for immune system functions. 

Human rotavirus (HRV), a member of the Reoviridae, is a non-enveloped virus which is the major etiologic agent of severe dehydrating gastroenteritis in children worldwide. For the treatment of rotavirus gastroenteritis, intravenous fluid administration has been used successfully for dehydration from diarrhoea. However, in the case of... 

An unanswered question does remain regarding the extension of our findings to predict the adsorption characteristics of human hepatitis type A. This virus is the etiologic agent of infectious hepatitis, which is considered to be the most serious problem in the transmission of waterborne virus disease (i). It is similar to other enteroviruses in terms of size (27 nm in diameter), density in CsCl gradients (1.34 g cm ), stability in the presence of chemical and physical agents, and probable nucleic acid type (69). However, electrokinetic properties of this virus have yet to be characterized. This information is required before accurate predictions of electrostatic components of adsorption can be made for this virus. 

Sarin, P.S. Sun, D. Thornton, A. Muller, W.E.G. Inhibition of the Replication of Etiologic Agent of Acquired Immune Deficiency Syndrome (Human T-Lymphotropic Retrovirus /Lymphadenopathy-Associated Virus) by Avarol and Avarone. J. Natl. Cancer Inst. 1987, 78, 663-666. 

ETIOLOGIC AGENT. Eastern equine encephalitis virus, member of the family Togaviridae. genus Alphavirus Closely related to western and Venezuelan equine encephalitis viruses INCIDENCE 153 confirmed cases In the U.S. since 1964 SEQUELAE Mild to severe neurologic deficits in survivors... 

---