Those who don’t know history are doomed to repeat it.
Typhoid Mary was a cook who moved from one rich employer to another in New York and Long Island, infecting seven households with typhoid between 1900 and 1907 before doctors traced her as the common cause of the infections. The key point is that she was in good health herself throughout. When confronted, she indignantly refused to submit stool samples for analysis, until eventually imprisoned for this refusal.
After three years she was released while promising not to work as a cook. Unhappy with the low wages of a laundress, she changed her name, resumed cooking and resumed causing typhoid. After a 1915 outbreak in a hospital for women in which 25 people fell ill and two died, Mary Mallon/Brown was again arrested and kept in quarantine for the rest of her life, refusing to have her gall bladder removed. When she died in 1938, an autopsy revealed a thriving colony of typhoid bacteria in her gall bladder. For some genetic reason they had not caused any symptoms in her.
What is the current understanding of the ability to return to work and risk of reinfection/further complications for clinicians who have recovered from COVID-19?
The department will determine when a confirmed case no longer requires to be isolated in hospital or in their own home, in consultation with the treating clinician. This will be actively considered when all of the following criteria are met:
• The patient has been afebrile for the previous 72 hours, and
• At least ten days have elapsed after the onset of the acute illness, and
• There has been a noted improvement in symptoms, and
• A risk assessment has been conducted by the department and deemed no further criteria are needed.
Apparent re-infection has been reported in a small number of cases. However, most of these reports describe patients having tested positive within 7-14 days after apparent recovery. Immunological studies indicate that patients recovering from COVID-19 mount a strong antibody response. It is likely that positive tests soon after recovery represent persisting excretion of viral RNA, and it should be noted that PCR tests cannot distinguish between “live” virus and noninfective RNA.
For further information, go to the department’s website and see Advice for clinicians / epidemiology!