COVID-19 Health Alert # 12: CDC Investigating Possible Cases of COVID-19 Re-infection

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DHS Health Alert Network

COVID-19 Health Alert # 12:

CDC Investigating Possible Cases of COVID-19 Re-infection: Request for Information

 Bureau of Communicable Diseases, May 22, 2020


  • CDC is interested in investigating possible cases of SARS-CoV-2 reinfection, defined as new clinical or laboratory evidence of COVID-19 after a documented period of recovery.
  • Clinicians who are aware of cases meeting criteria for possible re-infection are invited to submit de-identified patient information to the CDC using a survey tool developed by the Infectious Disease Society of America.

Dear Colleagues,

Clinical investigators from the CDC are investigating possible cases of re-infection among patients believed to have recovered from COVID-19.  Wisconsin clinicians are invited to notify CDC of suspected cases to assist in developing a case definition.

Several reports from China and South Korea have described cases of recurrent SARS-CoV-2 RNA detection (with or without symptoms) among patients who recovered from COVID-19; whether these cases represent re-infection versus intermittent viral RNA shedding is still being determined. The extent to which such cases are occurring in the United States is unknown.

CDC’s COVID-19 Clinical Team is working with the Emerging Infections Network (EIN, Operated by Infectious Disease Society of America) to identify clinician-suspected cases of COVID-19 reinfection in adults aged ≥18 years who meet the following criteria:

  • Laboratory-confirmed COVID-19 (SARS-CoV-2 PCR positive) disease with clinical recovery for approximately 10 days after symptom onset or diagnosis (if asymptomatic)

AND, subsequently had any one of the following:

  • Two documented negative PCR tests results followed by a positive result;
  • Recurrence of symptoms with positive PCR results; or
  • Positive PCR results for ≥30 days (without any recurrence of symptoms).

Clinicians aware of such patients are encouraged to submit de-identified patient information directly to CDC using an online reporting tool, which is available at

CDC and DHS will work with providers and local health departments to determine next best steps for cases that represent potential reinfection (e.g., additional testing, epidemiologic investigation).

Thank you for your collaboration in this effort.


Ryan Westergaard, MD, PhD, MPH
Chief Medical Officer and State Epidemiologist for Communicable Diseases
Wisconsin Department of Health Services

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