COVID-19 Cycle Threshold/Cycle Number Testing at a Community Living Center

COVID-19 imposes a special risk to the nursing home population, including community living centers (CLCs) for veterans. Cycle threshold/cycle number (CT/CN) values obtained by serial reverse transcriptase polymerase chain reaction (RT-PCR) testing could yield valuable information about viral load and potential infectiousness. Serial testing for COVID-19 with CT/CN correlates in a nursing home population during an outbreak has not yet been reported in the literature.

A retrospective review of serial RT-PCR testing for COVID-19 during an outbreak at a CLC was performed from March 28 to April 4, 2020, with follow-up of identified patients until November 10, 2020. Testing was performed on the Abbot m2000 or Cepheid platform.

Of 80 patients tested, 25 (31%) were positive for COVID-19. CT/CN values corresponded to the infection course as expected.

Repeat testing for COVID-19 accompanied by CT/CN values could provide clinical and epidemiologic information about the likely stage of the patients' disease course, which may aid public health measures and clinical management.