Simian Immunodeficiency Virus is highly transmissible species of virus that cause multiple chronic infections on human beings, in at least 60 different species of African primates. This distressing situation has not only affected the lives of thousands of persons in Africa, but also to a great extent, affected the economical and social progress in the country. It is for this reason that vaccines against SIV have been developed. Although these are relatively safe and less damaging than other methods of prevention, still it is quite true that SIV infection can lead to a life threatening situation when the immune system is compromised by lack of exposure to adequate nutrients. As an example, AIDS is caused by retroviruses that attack the cells of the immune system causing critical overload of the cells and tissues which may lead to death.
There are numerous well known strains and subtypes of SIV, the most common being haemorrhagic fever, lymphadenitis, lymphoma, and so on. It is very difficult to track the evolution of this disease and the pathogen responsible, as the disease only shows symptoms in most of the patients after two to three years of infection. Hence, it is very difficult to assess whether the patient has SIV or not. Even in cases where the disease has been diagnosed in a person, the only reliable way of assessing whether the person is infected with SIV is by performing a serological test known as PCR, or qRT-PCR; however, even in this scenario, it is hard to differentiate between HIV and SIV.
It is interesting to note that unlike HIV, SIV does not infect any of the normal bodily cells of humans such as the white blood cells. In fact, even people who contract HIV through sexual intercourse suffer from the SIV infection. Another distinguishable characteristic of SIV is that it is directly related to the genetic material of humans (fully developed humans have no genetic material on their own), whereas HIV is transmitted via cells of other animals, such as sperm or kidney cells. Therefore, whereas HIV is incurable in its entirety, SIV can be eradicated from a person's body by undergoing treatment, which is highly successful in most patients. However, since SIV is incurable, all effort should be made to prevent the transmission of the virus to others.