Zhong Nanshan’s team published its latest research paper on the new coronavirus on February 9th on the professional academic website Medrxiv. The paper was completed by Zhong Nanshan in collaboration with 37 authors from the national anti-epidemic front line. The authors include Guangzhou Institute of Respiratory Health, Wuhan Jinyintan Hospital, Huanggang City Center Hospital, etc.
This paper reviews the clinical characteristics of 1099 patients diagnosed with new coronary pneumonia from 552 hospitals in 31 provinces and cities in China, and is the largest analysis of patients so far, providing many aspects such as patient clinical performance, incubation period, diagnostic accuracy, prognosis-related factors, etc.
01 Incubation period of up to 24 days does not exclude “super spreader”
Geographically, the cases in this study mainly came from Wuhan, the center of the epidemic, of which Wuhan Jinyintan Hospital accounted for 132 cases, Wuhan Concord Hospital has 55 cases, 2% of the cases are medical staff infection. There were 173 cases of severe illness, or 15.7 per cent, which is broadly in line with previous WHO data. At present, 55 patients have been cured and discharged from hospital, 15 have died, the mortality rate is 1.4%, and the majority of patients remain hospitalized. In addition, there were 55 cases of ICU in the course of treatment, accounting for 5% of the patient’s total.
(The first three columns of the data are the overall data, the data of non-severe patients and the data of patients with severe diseases, the same below)
The median age of the patient was 47. It is distributed across all age groups, with 0.9 per cent of under-15s and 41.9 per cent of women. Of these, 25.2% combined with at least one underlying disease (e.g. hypertension, chronic obstructive pulmonary disease, etc.).
In terms of epidemiological history, 43.95% (483 people) were local residents of Wuhan, and 26.0% of the patients had not recently visited Wuhan or had no history of contact with people from Wuhan. Outside Wuhan, 31.3 percent of patients have been to Wuhan and 71.8 percent have been in contact with people from Wuhan. Of the 1,099 patients, only 1.18 percent had a history of wildlife exposure. This provides further evidence for the transmission of new coronary pneumonia, but also confirms the family aggregation of the disease, asymptomatic infection transmission and other related reports, therefore, do not exclude the existence of “super-transmitters.”
As for the incubation period of the virus, the study suggests that the median incubation period of the new coronavirus is 3 days, which is shorter than previously found. However, from the sample of 1099 patients diagnosed in this multi-site, the incubation period can be up to 24 days, the minimum is 0 days.
02 Fever cough is still the main symptom CT diagnosis accuracy rate 76.4%
The paper found that fever and cough were the most common symptoms, with 87.9% of 1,099 patients showing fever and 67.7% coughing symptoms. In addition, digestive tract symptoms such as diarrhea and vomiting are also present, but are rare, at 3.7% and 5%, respectively. It is worth noting that only 43.1% of these infected people had a fever at the time of treatment, the total fever rate after hospitalization reached 87.9%, while SARS and Middle East Respiratory Syndrome (MERS), which are also co-affected by the coronavirus, have almost all fever symptoms when diagnosed, and only 1-2% do not have fever. This suggests that early diagnosis of new coronavirus infections cannot focus too much on whether fever is possible.
During hospitalization, the most common complications were pneumonia (79.1%), followed by acute respiratory distress syndrome (3.4%) and shock (1%).
The study also gives some reference to how to improve the accuracy of the detection of new coronaviruses. The study noted that 76.4 percent of patients who received CT tests showed pneumonia, mainly glass-like shadows (50 percent) and double lung plaque shadows (46.4 percent), and the vast majority of patients with severe illness were diagnosed. Some infected people show edhesological performance, only by pulmonary CT to confirm the accuracy of the new coronavirus infection is only 76.4%, if CT examination, nucleic acid kit and clinical symptoms combined, the accuracy of diagnosis can reach 97%.
03 Oxygen absorption is the main therapy timely measures is very important
Oxygen absorption is still the main treatment, with 38.0%, 6.1%, 57.5% and 35.8% of patients receiving oxygen absorption, mechanical ventilation, intravenous antibiotics, and oseltamivir. And in the study, only patients with severe illness received mechanical ventilation therapy.
Compared to two previously published studies, based on a larger sample size and cases recruited across the country, the latest study showed a significantly lower mortality rate for new coronary pneumonia, at 1.4 percent. When the pilot data in Guangdong Province were included, the fatality rate was reduced to 0.88%. This is because Guangdong has taken effective preventive measures, early isolation, early diagnosis and early treatment may have contributed to a significant reduction in the fatality rate of new coronary pneumonia in Guangdong Province.
The paper points out that strict and timely epidemiological measures are essential to curb the rapid spread of the epidemic. Effective treatments for diseases still need to be explored on an ongoing and ongoing approach.