Question

Provide reasons why SIV is not pathogenic in its natural host. (5)

Answer 1

Simian immunodeficiency virus (SIV) is kinds of retrovirus that motive regular illnesses in at any rate 45 types of African non-human primates. in mild of research of traces located in four styles of monkeys from bioko island, which turned into detached from the terrain via growing ocean degrees round eleven,000 years lower back, it has been presumed that SIV has been to be had in monkeys and chimps for in any event 32,000 years, and in all likelihood to any extent further.

Infection strains from of these primate Species, SIV smm in grimy mangabeys and SIVcpz in chimpanzees, are accepted to have crossed the species obstruction into people, bringing about hiv-2 and hiv-1 in my view, the two human immunodeficiency infections. The maximum possibly path of transmission of hiv-1 to human beings consists of contact with the blood of chimps which are regularly pursued for bush meat in africa. 4 subtypes of hiv-1 (m, n, o, and p) likely emerged thru 4 separate transmissions of SIV to humans, and the subsequentHiv-1 accumulating m stress most regularly contaminates people worldwide. Consequently, it is speculated that SIV may additionally have these days crossed the species boundary into human has on diverse activities because forever, yet it changed into now not as of now not lengthy in the past, after the advent of cutting-edge transportation and international commuterism, that it at long remaining grabbed preserve, spreading beyond limited devastations of a couple of humans or unmarried little inborn populaces.

In no way like hiv-1 and hiv-2 diseases in people, SIV contaminations of their normal African simian non-human hosts show up regularly to be non-pathogenic because of transformative adjustment of the hosts to the infection. Wide investigations in dirty mangabeys have constructed up that SIVsmm infection does not cause any infection in those African primates, notwithstanding multiplied levels of circling infection. be that as it may, if the infection contaminates an Asian or Indian rhesus macaque, these non-African simian primates will Likewise create simian aids (saids), as they, similar to human beings (notwithstanding being an African-root simian primate species), have no longer had a drawn out records with the infection. an ongoing research of SIVcpz in wild living chimpanzees recommends that infected chimpanzees experience an aids-like illness like hiv-1 tainted people. The later stages of SIV contamination rework into saids, a good deal as HIV ailment transforms into aids.

SIV pathogenesis contains both pathogenic and non-pathogenic SIV contaminations. SIV infection of non-human primates (nhps) continuously brings approximately consistent contamination, yet seldom severe sickness. Pathogenic disorder is encapsulated through rhesus macaques infected with SIV traces got from grimy mangabeys. Contamination movement to aids occurs inner a time of months to years, contingent at the SIV pressure applied. Non-pathogenic disorder is epitomized via African nhps normally tainted with SIV. These creatures now and again progress to aids no matter preserving up viral burdens which are proportionate to SIV viral burdens in pathogenic contaminations. It's miles hypothesized that aids-like contamination in African nhps speaks to even transmission of the contamination from at least one homologous animal types in the ongoing transformative past, before harmony of co-adjustment has occurred.