Clinical characteristics of 21 patients with COVID-19 SARS-CoV-2 nucleic acid continues to be positive for more than 30 days

Objective: To investigate the clinical features of Covid-19 patients whose nucleic acid changed from positive to negative after 30 days. Methods: The clinical data about 21 cases admitted to our ward section between February 2020 and April 2020 whose nucleic acid persistently tested positive for over 30 days was analyzed retrospectively. Results: Among the 21 cases, 17 cases were middle-aged and elderly patients (ranging 45 to 84 years old), and 15 cases had chronic preexisting diseases. All the 21 cases had different degrees of fever and cough and were diagnosed as of the common type. Some of these cases had shortness of breath after mild activity in the early stage of onset. Two cases had decreased white blood cell count, 3 cases had decreased lymphocyte count, and 4 cases had high levels of C-reactive protein. The lung CT showed that lung infiltration of these cases ranged from 1.50% to 20.00%, with an average range of 3.92%. They were given oxygen therapy, basic treatment such as control of blood pressure and adjustment of blood glucose according to their conditions, adequate treatment with abidol, thymosin, traditional Chinese medicine. Such antiviral drugs as chloroquine phosphate and favipiravir were adjusted for those whose nucleic acid did not turn negative within 7 days. Some patients received plasma transfusion in the convalescent period. There were 3 cases whose nucleic acid took 30 to 40 days to change from positive to negative, compared with 41 to 60 days in 13 cases, and more than 60 days in 4 cases. Conclusion: The commonly-used antiviral therapies and immune therapy are not effective enough, so a variety of antiviral interventions are needed. The fact that some Covid-19 patients have persistent positive nucleic acid is likely to add difficulty to prevention and control of related infections. (authors)