Background A pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is on-going. Clinical characters of afebrile cases infected with SARS-CoV-2 remain poorly understood and informations are limited on the duration of SARS-CoV-2 viral positivity.
Methods We performed a single-center retrospective study of 143 patients with SARS-CoV-2 infection in Beijing Ditan Hospital, Capital Medical University from January 26 to April 15, 2020. Differences were compared among patients with/without fever. Risk factors for the duration of SARS-CoV-2 viral positivity were evaluated.
Results A total of 143 patients with positive SARS-CoV-2 test were enrolled, including 38 afebrile patients and 105 febrile patients. On admission, a total of 40 (28%) patients had leukopenia, 44 (30.8%) had lymphopenia and 8 (5.6%) had thrombocytopenia. 78 patients (54.5%) had decreased T lymphocytes and 105 patients (73.4%) had decreased CD4+T lymphocytes. Compared with febrile cases, afebrile patients had a significantly higher white blood cell count (P = 0.02), total lymphocytes (P < 0.01), platelet count (P < 0.01), T lymphocytes (P < 0.01) and CD8+ T lymphocytes (P = 0.02). The median SARS-CoV-2 viral positivity duration of these 143 patients was 14 days (IQR, 10-30 days) and for febrile and afebrile group were 13 days (IQR, 10-29 days) and 20 days (IQR, 11-31 days) respectively. Multivariate Cox regression results showed that the fever [hazard ratio (HR) = 0.49, P < 0.01]and higher count of platelet (HR = 5.47, P = 0.02) were the predominant risk factor for the SARS-CoV-2 viral positivity duration.
Conclusion The SARS-CoV-2 virial positivity duration of the afebrile group was significantly longer than that in the febrile group. Fever and a higher count of platelet were the independent protective factors for a shorter SARS-CoV-2 RNA positivity duration.