A Short History of HIV/AIDS

HIV belongs to a family of viruses called the lentiviruses; it is a Retrovirus that causes acquired immunodeficiency syndrome (AIDS), a condition that causes the degeneration of the immune system. This leaves an individual more prone to opportunistic infections and some forms of cancers.

HIV/AIDS is transmitted through the contact of infected Blood, semen, vaginal fluid and through breast milk; the most common way that HIV/AIDS is spread through sexual intercourse with an infected person. This paper will look at the history of HIV/AIDS, the distribution, how the HIV/AIDS infects the host, how it targets the immune system, the clinical presentation and end on the some of the known treatments and some future treatments.

Distribution

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There are two forms of the HIV virus, HIV1 and HIV2, HIV1 is more virulent than HIV 2 this explains why HIV2 is mainly restricted to North Africa. The map above highlights the distribution of the HIV/AIDS.

Origins

There are two main theories that explain the origin of HIV/AIDs. The first one is the bushmeat practice theory of the people in Africa.  Based on the information that HIV is directly related to the simian immunodeficiency virus (SIV) that is found in chimpanzees scientists have theorised that SIV may have mutated to HIV in Africa through continuous exposure of SIV.

Secondly, HIV/AIDS is thought to have originated in Congo due to the use of poisoned vaccines that were used during the first mass immunisation against polio. This theory is supported by the fact that the first known case AIDS in central Africa is in the same area that the kaprowski’s polio vaccine was given to over a million people between 1957 – 1960. This also concedes with the reason that there were no reported cases of AIDS before 1960 even with slave trade and the European exploitation of the African resources.

The other reason is that polio vaccine was made using Chimpanzee kidneys, which could have been contaminated by simian immunodeficiency virus SIV. The mutations of SIV to HIV still remain a mystery; however, the distribution can be attributed to the urbanisation of Africa since population determines the prevalence and distribution of infection. Regardless of how HIV/AIDS stated all scientists agree on the fact that the HIV virus is related to the simian immunodeficiency virus that is found in chimpanzees, how it mutated is the next question, and more studies need to be done on it.

Discovery

The initial description of HIV/AIDS was in 1981 when unusual cases of pneumonia were reported among previously healthy homosexual males in America. This was followed by the recognition of an aggressive form of Kaposi’s sarcoma, since the first reported case thereof HIV/AIDS in 1981 there are now over 30 million people infected worldwide.

When AIDS was first discovered it seemed to be restricted to gay men, drug user and Haitians that lived in the United States and as long as AIDS was confined to these high-risk population the rest of America felt safe. This however changed when a child contracted AIDS after she was blood transfused. Later that year there were reported cases among bisexual men and women, after these cases no one was denying that AIDS was spreading to the rest of the population.

In 1982 scientists in France led by Lu Montaginer and Froncoise Barre- sinoussi isolated a new virus from an AIDS sufferer. Later in 1984 workers at the cancer institute in America also announced that they had managed to isolate the virus that causes AIDS they called it (HTLVIII) which means the human T cells virus which was later named as human immunodeficiency virus. The causes of AIDS were not identified until three years later, and soon after that the genome was sequenced and the clinical tests were developed.

The list below highlights the HIV/AIDS timeline

  • 1981 – 108 cases of AIDS reported in the US
  • June – five gay men in los angles
  • July – eight gay men reported with severe immunodeficiency
  • December – cases of AIDS in intravenous drug users
  • December – the first AIDs case reported in United Kingdom
  • By 1982 around 593 cases of AIDS were reported and with the morbidity of 243
  • June – a cluster of AIDS cases in California suggest an infectious agent
  • 1982 – Acquired immunodeficiency was given as the new name
  • December – a 20 months year old baby dies of AIDS due to multiple transfusions
  • By 1983 the mortality had gone up to 759 people
  • 1094 the mortality had gone up to 6,993
  • November CD4 molecules on the T cells identified as the receptor for the virus
  • by 1986 the mortality had gone up to about 16000, and in May of the same year the name human immunodeficiency virus was given to the virus that causes AIDS

Structure

HIV can be divided in two the HIV1 and HIV1; they can be described as an enveloped retrovirus that belongs to a family of virus called the lentivirus. The viral particle contains two strains of identical RNA and three enzymes called integrase, protease and reverse transcriptase.

These are packaged into p24 core antigen with a p7 nucleoprotein and p9. All these are surrounded by a p17 matrix protein. Antigens presenting cells like dendritic cells, macrophages as well as the CD4+T cells are potential targets for the virus because they display CD4 makers on their surface. This is because the viral envelop that is derived from the host cell display viral glycoprotein gp120 and gp41, the gp120 which is covalently bonded to gp41 is very important for infection.

References

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