It's the reasons of rehabilitated patients to be positive again was be found?

A study in China has shown that patients infected with novel coronavirus may still carry the virus deep in their lungs after they are discharged from hospital after rehabilitation, and the presence of the virus cannot be detected by conventional detection methods.

The finding, published on April 28 in peer-reviewed Chinese Journal of Cell Research, may explain why more and more recovered patients are reappearing positive for novel coronavirus testing, the Hong Kong South China Morning Post website reported on April 30.

The study was led by Bian Xiuwu, professor of PLA Army Medical University.In the paper, the researchers wrote that the related research work for the first time provided pathological evidence that the residual virus in the lungs of patients who were negative for three consecutive viral tests remained.They also say there is a need to improve clinical guidelines on viral containment and disease management.

The study was based on an autopsy of a 78-year-old woman who died after infection with neocoronavirus, the report said.She was admitted to Chongqing Three Gorges Central Hospital on January 27 for treatment due to a fall.She was later found to have new coronary pneumonia and subsequently developed symptoms.

After receiving antiviral treatment, all three rounds of nasopharyngeal swab samples tested negative and were considered dischargeable on February 13.From the CT scan results, her symptoms improved greatly.One day later, however, she suddenly died of cardiac arrest.

A postmortem pathological study of the woman found no evidence of neocoronavirus in her liver, heart, intestine, skin, and bone marrow.

However, the researchers found a complete novel coronavirus in deep tissues in her lungs.They placed tissue samples under electron microscopy and confirmed that the intact novel coronavirus was encapsulated in the coronal capsid.

Hidden viruses have not brought any obvious symptoms before, and the damage shown in lung tissue is usually caused by viral infection.However, the absence of viruses in other parts of the body makes detection more difficult because commonly used detection methods do not extract samples from deep lungs.

The team led by Bian Xiuwu suggested that patients should have their lungs lavaged before they are discharged from the hospital to more accurately detect the underlying virus.

The World Health Organization is currently investigating why some recovered patients are again positive for viral testing.

As more and more infected people recover and are discharged from hospital, this phenomenon may have an impact on disease control policies and vaccine development.