Patient Zero

Patient Zero refers to the central or initial patient in the population
sample of an epidemiological investigation.

In particular, it refers to Ga‘tan Dugas (d. 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.

Misconceptions

A misconception holds that he was the first person to introduce HIV into
North America. This myth was promoted by sensationalism surrounding Randy
Shilts's 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.

This was not a conclusion by the CDC. 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.