Parker was employed by the anatomy department of Birmingham Medical School. In August 1978, she began to feel sick and soon developed red spots on her limbs, back, and face. Doctors initially diagnosed her with chickenpox, but Parker's mother, Hilda Witcomb, who took care of her daughter through that illness during her childhood, knew that these "large blistering pustules" must be something else entirely.
The 40-year-old Parker was admitted to the Catherine-de-Barnes Isolation Hospital a little more than a week into her illness. It was soon confirmed that variola, the smallpox virus that was widely considered to be completely eradicated, was responsible for Parker's symptoms. Mass panic ensued, exacerbated by the fact that the disease has a long incubation period. The city was forced to wait for an excruciating two weeks to see if anyone else became ill.
Professor Henry Bedson, who was in charge of the smallpox laboratory at Birmingham Medical School, was "distraught" about Parker's accidental infection and the blame placed at his feet by the media and public. Though nobody but Janet's mother contracted the illness (and she, luckily, got only a minor case), the tragedy grew only worse as the days went on.
First, Janet's father, Frederick, died from a heart attack while in quarantine, possibly due to "the stress of his daughter's illness." After that, Professor Bedson died by suicide, leaving behind a note that read, "I am sorry to have misplaced the trust which so many of my friends and colleagues have placed in me and my work." Finally, Parker herself died on September 11, 1978. To this day, it's unknown how exactly she contracted the virus at the laboratory.