Living with HIV/AIDS  

The Evidence that HIV Causes AIDS

How do we know that HIV is the definitive cause of AIDS? Years of epidemiological and medical evidence support this conclusion. Eleven major arguments for this conclusion are offered here:

(1) HIV fulfills Koch’s postulates as the cause of AIDS.

Koch's postulates are criteria that a suspected pathogen (that is, a disease-causing agent) must meet in order to be accepted as the true cause of a disease. Koch's postulates are named after the pioneering German microbiologist Dr. Robert Koch, who discovered the bacterium that causes tuberculosis.

Koch’s postulates are (1):

    1. the suspected cause is found in all cases of the disease
    2. the suspected cause can be isolated and reproduced outside the host
    3. transfer of the suspected pathogen to an uninfected host produces disease in that host
    4. the suspected pathogen can be found in the newly diseased host's body

(2) The opportunistic infections and diseases now strongly associated with HIV/AIDS were extremely rare prior to the identification of HIV (1).

These include pneumocystis carini pneumonia (a bacterial infection of the lungs), Kaposi’s sarcoma (a form of cancer), Mycobacterium avium complex (a bacterial infection of the lungs).

(3) HIV infection and AIDS are strongly and consistently linked by person, place, and time.

Historically, the occurrence of AIDS in human populations around the world has closely followed the appearance of HIV in those populations (2).

(4) The only common characteristic among diverse groups of people who develop AIDS is pre-existing infection with HIV.

Infection with HIV has been the only common factor shared by people with AIDS throughout the world, including homosexual men, transfusion recipients, persons with hemophilia, sex partners of infected persons, children born to infected women, and health care workers who were infected with HIV while on the job, mainly by being stuck with a needle used on an HIV-infected patient (3).

(5) Many studies agree that only a single factor – HIV infection – predicts whether a person will develop AIDS.

Among matched groups of people with similar lifestyles (for example, sexual behaviors or illicit drug use), only those people with HIV infection develop the severe immuno-suppression conditions and AIDS-defining diseases. Studies of hemophiliacs likewise show that the death rates for people with HIV infection are much higher than for people without HIV infection (1).

(6) There is very high correlation in surveys between the percentage of people with HIV antibodies (indicating infection with HIV) and the occurrence of AIDS.

In countries with high prevalence of HIV+ people, there are high numbers of AIDS cases, while in countries with low prevalence of HIV+ people, there are very few cases of AIDS (1).

(7) Persistently low CD4+ T-cell counts, one of the diagnostic criteria for AIDS, is extremely rare in people without HIV infection or other known causes of immuno-suppression (e.g. people who have undergone cancer treatment) (1)

(8) HIV can be detected in virtually everyone with AIDS.

Essentially all people with AIDS have HIV antibodies, and HIV can be detected in their blood, semen, or vaginal secretions with sensitive testing methods (4).

(9) In twins, the HIV-infected twin develops AIDS while the uninfected twin does not.

Researchers have documented cases of HIV-infected mothers who gave birth to twins, only one of whom is infected with HIV. The HIV positive twins have gone on to develop AIDS, while the HIV negative twins do not (1).

(10) In AIDS cases traced to tainted blood transfusions, transfusion recipients are almost always infected with the same strains of HIV as are transfusion donors.

Studies of transfusion- acquired AIDS cases have repeatedly led to the discovery of similar kinds of HIV in the patient and in the blood donor (1).

(11) HIV+ people who reduce the amount of viral load by taking anti-HIV drugs do not develop AIDS or die as quickly as do HIV+ people who do not receive these drugs or do not respond positively to them (1).

If HIV did not play a central role in causing AIDS, this effect would not be seen.


1. Institutes of Allergy and Infectious Diseases (NIAID). The Evidence that HIV Causes AIDS. National Institutes of Allergy and Infectious Diseases, National Institutes of Health, U.S. Department of Health and Human Services, February 2003. Retrieved on January 20, 2004 from

2. Jaffe, H.W., Darrow, W.W., Echenberg, D.F., O'Malley, P.M., Getchell, J.P., Kalyanaraman, V.S., Byers, R.H., Drennan, D.P., Braff, E.H., Curran, J.W., & Francis, D.P. The acquired immunodeficiency syndrome in a cohort of homosexual men. A six-year follow-up study. Annals of Internal Medicine, 103(2):210-214, 1985.

3. Centers for Disease Control and Prevention (CDC). HIV Causes AIDS. Centers for Disease Control and Prevention. Retrieved on January 26, 2004 from

4. Smith, D.K., Neal, J.J., & Holmberg, S.D. Unexplained opportunistic infections and CD4+ T-lymphocytopedia without HIV infection. An investigation of cases in the United States. New England Journal of Medicine, 328(6): 373-379, 1993.

© Sociometrics Corporation, 2004