In late January, 2020, the number of COVID–19 patients increased rapidly from Wuhan, Hubei Province to all over the world and had become a global health concern [4, 7]. 6 human coronaviruses including HCov-OC43, HCoV–229E, HCoV-NL–63, HCoV-HKU1, SARS-CoV, and MERS-CoV were identified, SARS-CoV and MERS-CoV could cause severe respiratory syndrome in humans. The sequence of SARS-CoV–2 was relatively different from the six other coronavirus subtypes but can be classified as beta coronavirus.The recent studies reported rapid person-to-person transmission of SARS-Cov–2 had occurred[14, 15], and another study showed that the spread of SARS-Cov–2 may be stronger than that of SARS-CoV and MERS-CoV, according to a previous study, the basic reproductive number (R0) was 2.2, which estimated that each patients could spread infection to 2.2 other people on average. The SARS-Cov–2 was spread by close contact and respiratory droplet infection and had an incubation period of 3–7 days, the longest was not more than 14 days.
Xiaoshan is one of the districts of Hangzhou, Zhejiang Province, Chinese government announced a travel quarantine of Wuhan, Hubei Province, on January 23, 2020, because of the Spring Festival that Chinese had made several billion trips throughout China to celebrate the Lunar New Year. This social phenomenon was considered a reason of COVID–19 increased spread of infection. Until now, the demographic, epidemiological, clinical and laboratory data of patients were insufficient, especially outside Hubei Province. By February 3rd, 2020, a total of 30 patients were diagnosed and enrolled in this retrospective study, to provide an insight into the control and prevention of COVID–19. The findings showed that 56.7% patients were female and the median age was 44.5 years. Based on previous studies, the age distribution of patients were mostly between 30–60 years [19, 20], which was supported by this study. Moreover, other studies suggested that male patients might be the more susceptible to SARS-CoV–2 infection [8, 19], and the sample size may be insufficient to find significant differences between genders in this study. According to epidemiological data, only 46.7% patients had exposure to Hubei Province, additionally, 53.3% patients were family clustering, that might demonstrate person-to-person transmission. This result was consistent with those of previous studies[14, 15, 20], further studies should be needed to identify SARS-Cov–2 transmission and design interventions for these settings.
In terms of clinical characteristics, this study found that the median body temperature was 37.9℃, and more than half (66.7%) of the patients had fever, a portion of them had dry cough and pharyngalgia, resembling that in previous studies[8, 20]. Moreover, 1 patient had atypical symptom (myalgia), and this study showed that 3 patients were asymptomatic infection, it may suggest that an even greater number of patients were overlooked because they may present with atypical symptoms of COVID–19. Of the 30 patients, 29 had been cured and discharged and the remaining one would be discharged soon, none of them were dead, one of the reasons was that most of them were mild and generally illness, another reason was that only a small portion of patients had chronic underlying diseases, such as hypertension, diabetes. As previously reported, patients with a history of chronic underlying diseases were at increased risk of becoming critical illness or death [8, 14]. However, nearly half of the patients received hormone therapy, and a third received oxygen therapy, no specific treatment had been identified for coronavirus infection except for supportive care at this time, all patients were treated in isolation and their close contacts were quarantined, but the present study indicated the median hospital stay and the median course of disease were still more than two weeks, which would result in a serious waste of medical resources, cause considerable economic burden to patients or government. Accordingly, prevention and early diagnosis of this disease are very important. Additionally, Laboratory data were detected and almost half of patients showed mild lymphocytopenia in the early stages of COVID–19. 40% patients had elevated concentrations of CRP. These findings were similar to the previous studies [8, 22]. One third of patients appeared to have hemoglobin decreased and all of were female, this result could be further confirmed through related studies.
There were several limitations to this study that should be noted. First, A retrospective and observational study may not fully assess the COVID–19 especially temporality, and thus the causal relationship was still indeterminate. A longitudinal follow-up study should be needed to address the limitation. Second, the sample size of raw data was insufficient and may not provide adequate statistical power to detect significant difference, especially for categorical variables with rare events, so not much emphasis was laid on presenting statistical evaluation. Third, the incubation period of COVID–19 was still not very clear in this study, and further follow-up would be needed for long-term results, so it was difficult to assess continued observations of the natural history of the disease. Moreover, some specific data from hospital was missing, such as total medical expenses, because the medical insurance system had not yet achieved the unified settlement within the medical alliance, therefore, health economics measures could not be collected for an economic evaluation.