Stephen J. Schueler, M.D.

AIDS Underlying Cause

Viruses are very small particles that reproduce inside cells.

A normal cell uses DNA as a code for producing proteins, which regulate the cell's function. In order to reproduce, viruses take over the mechanism for producing proteins inside the cell, interrupting cell functions and eventually causing the cell to die.

HIV weakens the immune system, which fights infection. As part of the immune system, white blood cells help kill bacteria, viruses and fungi. The viruses enter white bloods cells, take over, and destroy the cells.

After the initial infection with HIV, a person may have no signs of AIDS for months to years, because it takes time for the virus to destroy the white blood cells. When enough of the white blood cells are destroyed, then the immune system becomes deficient: it is unable to protect the body from infection. Those who develop AIDS suffer from severe infections and cancers that are rare in those who have healthy immune systems.

AIDS Origin

The exact origin of HIV is unknown, but it is suspected to have come from Africa.

Studies suggest that chimpanzees, native to West Africa, were the origin of HIV. Experts feel that chimpanzees have harbored a similar virus, called SIVcpz for a few hundred thousand years. Unlike humans, infected animals do not develop AIDS from this virus. Transmission of the virus from the animal to the human population may have been through a contaminated bites or scratches, or from eating these animals. At some point, the virus changed, or mutated, into HIV.

The oldest case of HIV infection has been authenticated from a blood sample collected in 1959 from an African man.

Continue to AIDS Transmission

Last Updated: Sep 25, 2010 References
Authors: Stephen J. Schueler, MD; John H. Beckett, MD; D. Scott Gettings, MD
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PubMed AIDS References
  1. Aberg JA, Gallant JE, Anderson J, et al: Primary care guidelines for the management of persons infected with human immunodeficiency virus: recommendations of the HIV Medicine Association of the Infectious Diseases Society of America. Clin Infect Dis 2004 Sep 1; 39(5): 609-29. [15356773]
  2. Aberg JA, Kaplan JE, Libman H, Emmanuel P, Anderson JR, Stone VE, Oleske JM, Currier JS, Gallant JE; HIV Medicine Association of the Infectious Diseases Society of America. Primary care guidelines for the management of persons infected with human immunodeficiency virus: 2009 update by the HIV medicine Association of the Infectious Diseases Society of America. Clin Infect Dis. 2009 Sep 1;49(5):651-81. [19640227]
  3. Chang R, Wong G, Gold J, et al: HIV-related emergencies: frequency, diagnoses, and outcome. J Gen Intern Med 1993 Sep; 8(9): 465-9. [8410417]
  4. Clumeck N: Choosing the best initial therapy for HIV-1 infection. N Engl J Med 1999 Dec 16; 341(25): 1925-6. [10601514]
  5. Hammer SM. Clinical practice. Management of newly diagnosed HIV infection. N Engl J Med. 2005 Oct 20;353(16):1702-10. [16236741]
  6. Knoll B, Lassmann B, Temesgen Z. Current status of HIV infection: a review for non-HIV-treating physicians. Int J Dermatol. 2007 Dec;46(12):1219-28. [18173512]
  7. McArthur JC, Brew BJ, Nath A. Neurological complications of HIV infection. Lancet Neurol. 2005 Sep;4(9):543-55. [16109361]
  8. Mylonakis E, Paliou M, Lally M, et al: Laboratory testing for infection with the human immunodeficiency virus: established and novel approaches. Am J Med 2000 Nov; 109(7): 568-76. [11063959]
  9. Paul SM, Sensakovic J, Podhurst LS, Morgan DH, Triano-Davis W. Managing HIV/AIDS patients. N J Med. 1998 May;95(5):55-60. [16013158]
  10. Treatment guidelines from the Medical Letter: Drugs for HIV Infection. Treat Guidel Med Lett 2004 Jan; 2(17): 1-8. [15529108]
  11. Varghese GK, Crane LR: Evaluation and treatment of HIV-related illnesses in the emergency department. Ann Emerg Med 1994. Sep. (3): 503-11. [8080146]
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