New crown Fuyang personnel are safe! Chinese scientists release latest research

Patients with COVID-19 are safe in life and work after discharge from hospital and should not be discriminated against.

On July 26, a study published in the journal National Science Review showed that people with new crown infections are less likely to spread the virus after returning to the positive, which is a huge risk for the community. safe.

This research was carried out by the team of Tang Xiaoping/Li Feng from the Eighth Hospital Affiliated to Guangzhou Medical University and the team of Academician Zhong Nanshan of Guangzhou National Laboratory, in conjunction with the team of Li Yan/Ke Changwen of Guangdong CDC and Shenzhen No. The Lu Hongzhou team of the Three People’s Hospital jointly completed the analysis of the recovery and characteristics of 837 Delta hospitalized infected patients after discharge in 2021.

viral nucleic acid load reduced by 100,000 times

As early as the beginning of 2020, the phenomenon of “returning positive” after the recovery of the new crown infection has occurred from time to time. For the sake of epidemic prevention, until the latest ninth edition of the “New Coronavirus Pneumonia Prevention and Control Plan”, the discharged and recovered patients are still required to continue home health monitoring for 7 days.

According to this real-world study, at least for Delta infections, the chances of returning to positive are not low. Among the 837 confirmed cases at home and abroad, a total of 514 (61.4%) had re-positivity, which was significantly higher than that of the early strains in 2020 (7.2%).

Among the 77 native Fuyang people, 95% needed another 21 days to test negative for viral RNA, and 45% needed at least 42 days. This indicates that the persistence of viral RNA is significantly prolonged for Delta infection.

Furthermore, after a statistical analysis, researchers found that whether recovered individuals would return to positive positivity did not seem to correlate much with age, gender, underlying disease, vaccination status, and symptom severity. Some There was also no significant difference in biomarker testing, which means that there is currently no good way to determine which infected individuals are at higher risk of returning to positive.

But it is worth noting that the study found that compared with the hospitalization stage, the viral nucleic acid load in the recovery stage was reduced by 100,000-1 million times (the Ct value increased by 16-19). Among the 514 Fuyang people, 481 (93.6%) had a nucleic acid detection Ct value of ≥30.

*Note: The higher the Ct value, the lower the viral nucleic acid load. According to the “Technical Guidelines for Laboratory Detection of Novel Coronavirus Pneumonia”, a Ct value >40 is judged as “negative”.

Contact 259 people, but never caused any communication incident

According to the ninth edition of the prevention and control plan, the management of Fuyang patients is limited by the nucleic acid detection Ct value of 35. If the Ct value is greater than or equal to 35, no management is required. Once it is less than 35, it will be judged on a case-by-case basis on a case-by-case basis.

In this study, it is not uncommon for Fuyang patients to have a nucleic acid detection Ct value of less than 35. Does this mean that they still have a certain risk of spreading the virus?

In fact, most of the Fuyang personnel are ‘nucleic acid positive’, not ‘virus positive’. What remains in their bodies are some viral nucleic acid fragments, and from an epidemiological point of view, only infected persons carrying live viruses can pose a potential risk of transmission.

For Delta virus infection, a paper published in Nature Medicine in March 2022 found that in nasopharyngeal samples, the number of non-infectious viral nucleic acid fragments was There are 100,000-100 million times the infectious virus particles. But the problem is that current nucleic acid tests cannot distinguish “dead virus” from “live virus”.

Therefore, in this study, the researchers tried to cultivate live new coronaviruses from the upper respiratory tract samples of 25 Fuyang people by means of cell culture, but all failed. Among them, the Ct value of the sample with the highest viral load reached 25, but no live virus was found.

In addition, through real-world epidemiological investigations, researchers found that 23 Fuyang people had close contact with 259 people in the community, but never caused any community transmission events .

Finally, the researchers also evaluated the possible health effects of Fuyang, and found that although viral RNA remained in the body, the recovery trend was good. Among the 289 cases of Fuyang, only 16 had mild cough, throat discomfort, fatigue and other symptoms, which shows that the virus nucleic acid Fuyang did not cause the clinical symptoms to aggravate, and the Fuyang people did not need to be hospitalized.

In response to this study, the official WeChat account of the China Virology Forum “Virology Community” concluded:

The low nucleic acid load of Fuyang indicates that the discharged patients are safe in life and work. When referring to Fuyang, only the nucleic acid positive should be mentioned, but the nucleic acid Ct value should be stated to avoid causing Panic, people infected with the new crown should not be discriminated against after they are discharged from the hospital.

Source: Medicine

Editor in charge: Zheng Huaju

Proofreading: Zang Hengjia

Writing | Jun Ling

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