Final answer:
Sandra Ford at the CDC noted an unusual increase in pentamidine orders due to a rise in cases of Pneumocystis jirovecii pneumonia, an opportunistic infection associated with the early stages of AIDS.
Step-by-step explanation:
Even before AIDS was identified, Sandra Ford at the CDC noticed an unusually high number of orders for a special drug, pentamidine, and wondered why so many people in New York were coming down with Pneumocystis jirovecii pneumonia (formerly known as Pneumocystis carinii). This type of pneumonia is a rare and deadly opportunistic infection that was later associated with AIDS, particularly in its earlier stages of discovery and public recognition in the early 1980s.
The first cases of what would later be termed Acquired Immune Deficiency Syndrome (AIDS) were reported in 1981 when young men, many of whom were gay, in large U.S. cities, were being diagnosed with rare conditions such as Kaposi's sarcoma and Pneumocystis jirovecii pneumonia. The observation of increased pentamidine orders was an early indicator of the emerging health crisis that was affecting the gay community and other groups at that time.