Transmission of the virus that causes COVID-19 from human-to-human through unknown intermediate animals began in December 2019 in Wuhan, Hubei Province, China. This infection can spread through droplets produced by coughing and sneezing in symptomatic patients before onset, or it may occur in asymptomatic individuals . The incubation period varies from 2 to 14 days. Studies have shown that the viral load in the nasal cavity is higher compared to that in the throat, but there is no difference in viral load between symptomatic and asymptomatic people . In certain populations (especially elderly patients and patients with multiple comorbidities), pneumonia, acute respiratory distress syndrome (ARDS), and multiple organ dysfunction can develop. Some patients may be asymptomatic, showing no clinical signs of infection. The overall mortality of COVID-19 is estimated to be 2–3%. However, COVID-19 shows mild clinical symptoms in most people. These patients can cause the disease to spread in the community for as long as the symptoms persist, even during clinical recovery. If patients are isolated at home, they may die accidently because the disease can suddenly worsen. If patients are active in the community, they will become the main source of widespread infection. Therefore, early and adequate treatment in the isolation department is necessary. The amount medical resources are needed to treat these non-severely infected patients and how to evaluate the cost of treatment remain uncertain. Previous studies did not answer these questions. The normal community-acquired pneumonia severity score is not suitable for these mild patients, and their CURB-65 scores are very low.
Published studies have found that the median time from symptom onset to onset of dyspnoea is 5 days, and the median hospital stay is 7 days . Our retrospective study found that the average hospital length of stay for noncritical patients was 12.26 days (median time was 14 days), which was significantly higher than that of other centres. The patients cured in our centre did not relapse. Other centres with shorter hospital stays have different proportions of relapsed patients. Adequate treatment may reduce the rate of relapse. The average cost of hospitalization in our study was $2,522.86, which is also higher than the average cost of mild community-acquired pneumonia ($1,919.98) in China . However, in 2012, the cost of hospitalization for CAP in the Netherlands was 8,301 euros; their hospitalization cost was much higher than that observed for the COVID-19 patients in this study. The high cost is mainly related to the age of the patients they included in the study (generally between 65–75 years old). There were more basic diseases in these elderly individuals, which results in higher costs for combined diseases .
The current treatment for COVID-19 is symptomatic support [10–11]. The principle is to maintain the balance of water, electrolytes and nutritional support and to control clinical symptoms such as fever, dyspnoea, and cough. In hypoxic patients, it is recommended to use nasal catheters, masks, HFNC or noninvasive ventilation. Of the 104 mild patients, only 5 patients used HFNC. There were no patients who were treated with ECMO or CRRT, and no patients died.
Traditional Chinese medicine is recommended for adjuvant treatment of COVID-19 in multiple centres in China. Our study found that the length of hospital stay was not significantly reduced after combining other treatments with traditional Chinese medicine. In contrast, these patients treated with combined therapies were hospitalized for a longer time. These patients may have had more symptoms requiring the use of more drugs.
The role of corticosteroids in the treatment of COVID-19 has not been confirmed. However, the current international consensus and the World Health Organization advocate against the use of corticosteroids. The use of low- to medium-dose corticosteroids in the treatment of ARDS is still recommended by Chinese guidelines in the short term [12–14]. Until now, there has been no clear recommendation for the use of steroids in the treatment of COVID-19. Some patients may be prescribed a certain dose of methylprednisone for a short time because of dyspnoea or rapid progression of lung injury on CT scan. In our study, 3 patients used 40 mg of methylprednisolone for 3 days, and 9 patients used methylprednisolone at a dose greater than 1 mg/kg. Patients in the high-dose treatment group had significantly longer hospital stays than those who used a small dosage or did not use it, which may suggest that these mild patients do not benefit from steroid use.
In terms of antiviral therapy, in a controlled study of SARS, patients treated with lopinavir-ritonavir combined with ribavirin had a better prognosis than those given ribavirin alone . There was a report of an anecdotal experience using remdesivir, a broad-spectrum anti-RNA drug developed for Ebola virus, in the treatment of COVID-19 . No patient used a remdesivir in the current study. Antiviral therapy or combined therapy did not affect LOS in non-severe COVID-19 patients.
Mild patients with COVID-19 achieved good clinical results after active treatment. Based on LOS and hospitalization cost, we can see the extent of medical resource utilization in these patients. These parameters may indicate that there is still a difference between the relatively severe and the relatively mild cases among these non-severe COVID-19 patients. After multiple regression analysis, the main factors affecting the condition of mild COVID-19 patients were chest imaging characteristics and LC level. After controlling for treatment, this is finding is consistent with the clinical process of treatment in COVID-19. Clinicians use the peripheral blood lymphocyte count and chest imaging characteristics to diagnose or stratify the severity of the disease. Minimizing the use of methylprednisolone in mild patients is related to reducing the medical burden of mild COVID-19.
Finally, our study was a single-centre retrospective study, and these data were limited. Multicentre research data results will be more instructive. What we need to emphasize is that the treatment of these mild patients can reduce the source of infection and has a positive significance for controlling the spread of COVID-19 pneumonia until mass immunization is possible.