(At this point the limited research being done was almost entirely based on the premise that the conditions called AIDS must be caused by an infectious microbe. Some have stated that this premise was false and that it has therefore misdirected AIDS research for the past 18 years.)

Doctors at the Institute Pasteur in France believe they have isolated a new virus, which is the cause of AIDS. They decide to call this virus the lymphadenopathy-associated virus, or LAV.

It becomes clear that the conditions called AIDS affect different "types of people" in different parts of the USA. For example, in New Jersey, gay men represent a minority of AIDS cases, while IV drug users account for nearly half. This is very different from, for example, San Francisco, where AIDS cases are found mostly among gay men. It is also noted that different AIDS risk groups often manifest different groups of symptoms.

In May 1983 a scientific report of AIDS occurring in children suggests the possibility of casual household "transmission" of AIDS.

Three scientists, Dr. Joe Sonnabend, Dr. David Purtilo, and Dr. Steven Witkin publish an article in the Journal of the American Medical Association in May, challenging the prevailing view that a single infectious agent causes the symptoms called AIDS. They suggest that many factors, in combination with one another, can cause different symptoms in different people, eventually resulting in "immune overload."

Late in the year the number of children with AIDS increases, and it is decided that the children acquired the infection from their mothers in the womb or during birth. It is also decided that a virus must be transmitted through blood transfusions.

AIDS has been reported in 33 countries. 3,000 Americans are now said to have AIDS, of whom 1,283 have died.