Oliver Schildgen

SARS-CoV-2 is the cause of the still-ongoing COVID-19 pandemic. To date reports on re-infections after full recovery from a previous COVID-19 course remain limited due to the fact that re-infections or second infections occur at the earliest between 3 to 24 months after full recovery while the pandemic lasts only since a year. Even less data are available on re-infections associated with emerging variants. A 33-year-old previously healthy male patient was tested twice SARS-CoV-2 RNA positive with an 8 months symptom-free interval between the two COVID-19 episodes in our setting in Cologne, Germany. While the first episode was accompanied by a co-detection of human bocavirus and hardly any symptoms, the second episode was characterized by serious illness and severe flu-like symptoms, although hospitalization was not required. After the first episode no residual viral RNA was detected after the patient was released from quarantine. Follow up of the patient revealed a moderate but significant reduction of the lung volume and slightly impaired diffusion capacity. Conclusion. While it is known that re-infections with SARS-CoV-2 may occur this is the first report of a co-detection of human bocavirus (HBoV) during a primary SARS-CoV-2 infection. The first, hardly symptomatic episode showed that co-infections do not necessarily initiate severe COVID-19 courses. The second more severe episode with serious flu-like symptoms could be explained by the sustained mild damage of the airways during the primary infection.