Table 2.
Characteristics of three participants with positive SARS-CoV-2 nasopharyngeal swab after positive baseline serology
| HCW 1 | HCW 2 | HCW 3 | |
|---|---|---|---|
| Sex | Female | Female | Male |
| Age range at re-infection | 50–55 | 50–55 | 40–45 |
| Blood group | Unknown | B | B |
| Comorbidities | None | Pollen allergy | Pollen allergy |
| Profession | Nurse (assistant) | Nurse (assistant) | Nurse (assistant) |
| Patient contact | Administrative | Administrative/caring | Administrative |
| First positive PCR | March 2020 | Date unknown | March 2020 |
| Date baseline serology | July 2020 | July 2020 | June 2020 |
| Anti-spike titers (units/ml), cut-off for positivity 0.8 | 25.8 | 244 | 30 |
| Second positive test (method) | January 2021 (PCR) | January 2021 (PCR) | January 2021 (PCR) |
| Days baseline to second episode | 198 | 200 | 220 |
| Days first to second episode | 297 | Unknown | 314 |
| Negative tests between first and second episode | None | None | One |
| Symptoms second test | Sore throat, coryza, headache, limb/muscle pain, eye irritation, weakness | None | Headache, dizziness, diarrhea, shivering, limb/muscle pain, eye irritation, weakness |
| Exposure | Patients | Patients | Patients, household |
| Number or household members | One | One | One |
| COVID-19 vaccine | None | None | First dose in week of positive test |
Abbreviations: HCW healthcare worker, PCR polymerase chain reaction, COVID-19 coronavirus disease 2019