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Video: COVID May Persist In Lungs Of Recovered Patients: Chinese Scientists
COVID may persist in lungs of recovered patients: Chinese scientists
Earlier WHO warned that there is no evidence that re-infection is impossible.
Photo: CC0 Public Domain
In the lungs of patients who have recovered from COVID-19, viruses that cannot be detected by standard tests can persist, according to Chinese scientists from the Military Medical University in Chongqing. According to the South China Morning Post, in their study, doctors are analyzing the case of a 78-year-old Chinese woman who was hospitalized with a coronavirus infection and underwent treatment. Tests based on the analysis of swabs from the nasal and oral cavity three times in a row showed a negative result, computed tomography also confirmed the absence of pathologies. However, a day later, the woman died of a heart attack.
An autopsy and examination did not reveal traces of the virus in the bone marrow and tissues of the liver, heart and intestines. But deep in the lungs, traces of SARS-CoV-2 particles were found. Scientists emphasize that hidden viruses did not cause any overt symptoms. It was impossible to detect them during standard testing, since modern methods for diagnosing coronavirus infection do not allow taking samples from the depths of the lungs.
Scientists suggested that patients should be given bronchoalveolar lavage before discharge. This procedure involves the introduction of a neutral solution into the bronchi and lungs, followed by its examination.
"There is an urgent need to better understand the pathogenesis of Sars-CoV-2 infection and improve clinical guidelines for localizing the virus and treating the disease," wrote the researchers, led by Dr. Bian Xuu.
Cases of repeated positive tests after recovery were recorded in several dozen patients in South Korea in early April. Also, cases of alleged re-infection have been reported in mainland China, Macau, Hong Kong, Taiwan, Vietnam and the Philippines, among others. According to media reports, some positive tests were performed 70 days after the first discharge. In Japan, a Diamond Princess cruise ship passenger over 70 years old was discharged in early March, and 10 days later he was again hospitalized with fever and other characteristic symptoms.
The World Health Organization (WHO), which is carefully investigating possible re-infection, warned that there is no evidence yet that recovered patients will not get sick again.
Some scientists speculate that re-infection is only due to testing flaws, as some test kits give false negative results when there is too little virus in the sample.
A research team in China last month found that some patients, especially young adults, had very few antibodies in their blood after recovery. This means they may be reinfected or unable to suppress the remaining viral strains in their body.
Professor Zhong Nanshan, a leading scientific advisor to the Chinese government, said in early April that the positive test results in recovered patients could be caused by the virus's fragmented genes. The scientist also emphasizes that there is still no direct evidence that a recovered patient can infect another person.