In this new coronary pneumonia outbreak, the phenomenon of asymptomatic infection is constantly refreshing professionals and the public. On March 2, Chongqing revealed the first asymptomatic infection in Chongqing – on January 24, Chongqing confirmed three cases of new coronary pneumonia, but there was no intersection between them, and they have not been to the affected areas, becoming a “mystery”.
Original title: New coronavirus asymptomatic infection first paper report: Asymptomatic infected people look ‘healthy’
After two days and two nights of investigation, the CDC targeted a man who had contact with three people who had worked in Wuhan and returned to Chongqing to lift the isolation after 14 days of medical observation because of any symptoms. It was eventually confirmed that the person was asymptomatic. This is also an early case of asymptomatic infections found throughout the country.
On March 1, Hefei, Anhui Province, found a newly confirmed case of asymptomatic infection, resulting in 177 people concentrated isolation and sampling sent for testing, the current nucleic acid test results are negative.
On February 28th a newsletter in The Lancet pointed out that the source of a family-gathering infection involving 11 people in Nanjing was a symptomatic infection.
On March 1, a paper in the Chinese Journal of Medicine (English) revealed the details of the clinical treatment of an asymptomatic infection at Anqing Hospital, affiliated with Anhui Medical University. It is said to be the first paper on a symptomatic people diagnosed with the new coronavirus infection.
Reporters learned that the patient (patient A) with her husband (patient B) and her husband’s sister, brother-in-law in February this year was diagnosed as a family gathering of new coronary pneumonia patients. But patientS A and Patient B would be difficult to detect had it not been for detailed epidemiological inquiries and close monitoring by the health department.
The paper’s author, Professor Ong Jianping, of the Joint Public Health Laboratory of Anhui Province Health and Health Commission and China University of Science and Technology, told the China Science Daily that the patient had no clinical symptoms and imaging symptoms of viral infection for 21 days from diagnosis to hospitalization until the virus was discharged, “much like a healthy asymptomatic carrier of the virus.” “。
The paper points out that as of February 21, 83 confirmed cases of new coronary pneumonia in Anqing City, a total of 8 cases of asymptomatic infection, of which 7 in the hospital symptoms, only patient A has never shown any symptoms.
“Asymptomatic infection” has previously sparked academic discussion. Zhang Wenhong, head of the Shanghai Medical Treatment Expert Group and director of the infection department at Huashan Hospital affiliated with Fudan University, points out that light and asymptomatic illness often do not have an absolute dividing line, so asymptomatic symptoms can also be very mild, making it difficult for patients to detect.
The paper shows that fever, fatigue, pain or any gastrointestinal and respiratory symptoms, including cough, sore throat, diarrhea or vomiting, were not reported since the patient was confirmed positive for A on 6 February. Nurses and doctors also did not find her with these symptoms. On February 16th her laboratory test results were largely normal. Three chest CT scans were performed on 6, 11 and 20 February, all of which were normal.
Meanwhile, her husband, B, had no symptoms until February 7, except for a positive pharynx swab and an abnormal CT scan of the lungs. But through epidemiological information can be inferred that patient B by his sister-in-law infected, and then infected to patient A, at this time he has no symptoms.
Ong Jianping said that the patient A pharynx swab and swab virus test positive, indicating that although the patient has no clinical symptoms, but the body’s viral load is not low. Recently, researchers from Guangdong CDC, Zhongshan University and the University of Hong Kong also confirmed in an article published in the New England Journal of Medicine that there is no difference between the concentration of pharynx virus in a symptomatic infection and those with symptoms.
Therefore, the Group of Experts has also given antiviral treatments such as alpha-interferon and lopinavir/litonavir and ribavirin in accordance with the country’s provisional diagnostic norms. But until 20 days after the paper was submitted on February 26, the patient’s A-virus test did not turn negative. On 20 February, there was a slight increase in the liver enzyme. The team suggested that treatment may not be effective for the infected person, but rather cause minor liver damage.
However, the team found in follow-up after the paper was submitted that patient A continuously reviewed the virus to reverse, has been discharged from the hospital.
Does this mean that antiviral therapy is effective?
In this regard, Mr Ong said that because it was a case, it was not entirely certain that the role of antiviral drugs was at all.
As for the cause of asymptomatic infection, there is no final word. From an immunological point of view, Ong Jianping believes that the balance between autoimmune and viral, that is, the virus can not occupy and destroy the immune system, and the immune system temporarily can not remove the virus, the balance mechanism will be the next direction of research.
Fortunately, it was revealed that due to timely monitoring measures, after being diagnosed at home, patient A as a close contact was quickly isolated and monitored at home, and her general contact with the population was also timely isolation observation, at present no infected persons were found.
“From the current prevention and control effect, this category of patients did not cause a very wide spread of phenomenon, but still to maintain a high degree of vigilance. At present, the only way is to touch melons, fully investigate the epidemiological history of confirmed patients, and observe suspicious contacts in isolation. Ong Jianping said.
But the team suggests that the social cost of this method of prevention and control is higher, and that a better solution might be to develop a protective vaccine.
At present, there are warnings in the medical community that the new coronavirus may coexist with humans for a long time. Ong Jianping believes that this is also based on studies of past pandemic viruses, such as influenza virus asymptomatic carriers reached 5.2%-35.5%, a human nasal virus a study showed that asymptomatic infection is four times the symptoms of infection.
In Italy, the worst-hit in Europe, it was reported that officials were considering no longer releasing mild and asymptomatic patients to avoid panic.
In this regard, Ong Jianping reminded that from an evolutionary point of view, most infectious pathogens tend to increase the spread, toxicity to reduce this direction, but whether the new coronavirus follows this law is still uncertain. From the current case sampling in Wuhan and Wuhan outside the virus genetic analysis, the variation is very small. The global pandemic of the new coronavirus should be closely observed, and once a global pandemic is formed, it is much more difficult to control than SARS, and there is a risk of long-term coexistence.
Related papers: http://rs.yiigle.com/yufabiao/1183260.htm