Utility of Ct values in differentiating COVID-19 reinfection versus prolonged viral shedding in an immunocompromised patient

We describe the case of a 26-year-old man who presented to an outside hospital with concerns of blurred vision. He subsequently tested positive for COVID-19 and his lab work suggested acute leukaemia. The patient was admitted to our hospital and completed a course of remdesivir. He eventually tested negative for COVID-19 before initiating chemotherapy. Two days after starting chemotherapy, he developed a neutropenic fever and tested positive for COVID-19. Through this case, we aim to bring attention to patients who recurrently test positive with COVID-19 PCR testing, thereby causing a dilemma of differentiating between reinfections and prolonged shedding of the virus, as well as understand and use cycle threshold values to discern these aetiologies.

Automated summary

This case highlights the challenge of distinguishing between reinfections and prolonged shedding of the virus in patients who repeatedly test positive for COVID-19 PCR testing, emphasizing the importance of understanding and using cycle threshold values to discern these etiologies.