In general, the term Patient Zero refers to the central or initial patient in the population sample of an epidemiological investigation.
In particular, it refers to Gaëtan Dugas (1953 - 1984), a Canadian airline steward who was Patient Zero for an early epidemiological study on HIV by the Centers for Disease Control. His sexual partners were surveyed for the disease in order to demonstrate that it was sexually transmitted. Several of them were among the first few hundred to be diagnosed with AIDS.
A misconception holds that he was the first person to introduce HIV into North America. This myth was promoted by sensationalism surrounding Randy Shilts' book And The Band Played On and the movie based upon it. He is referred to as 'Patient Zero' not because he was the first to be diagnosed with the disease but rather because at least 40 of the 248 people diagnosed with AIDS by April 1982 had either had sex with him or with someone who had.
The CDC certainly did not conclude that Dugas had introduced HIV into North America, nor was he the first to have his infection identified. In fact, many AIDS cases had been identified in North America prior to Patient Zero.
Furthermore, later research has cast doubt on the validity of the conclusions that actually were advanced. At the time, it was believed that HIV incubated for about one year. The patients that were studied due to their contact with Patient Zero had their symptoms emerge on an average of eleven months after having sex with him.
Now that the incubation time of HIV is known to be longer, it is highly unlikely that any of Patient Zero's sexual partners studied were initially infected by him.
In addition to And The Band Played On, Patient Zero was a character in the Canadian film Zero Patience, which refutes the myth along with many other misconceptions surrounding HIV and AIDS.
See also: AIDS myths and urban legends.Misconceptions
