The COVID-19 pandemic continues.
In particular, in the past month, the epidemic has rapidly swept through more than 20 provinces across the country, and as of 24:00 on March 14, 31 provinces (autonomous regions and municipalities directly under the Central Government) and the Xinjiang Production and Construction Corps have reported 11,984 confirmed cases, with a cumulative report of 120504 confirmed cases and 4,636 cumulative deaths[1].
At present, the cumulative number of COVID-19 patients in the world has reached 459 million, and the number of deaths has exceeded 6 million [2].
As the number of infections and deaths continues to increase, the long-term symptoms and hidden dangers after the recovery of the new crown virus infected people have attracted increasing attention, and under the severe epidemic situation, some false information has also begun to breed and spread, and these rumors and false information have caused certain interference in the fight against the epidemic.
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What are the long-term symptoms of COVID-19? What are the common symptoms? How severe is it? Let's take a look at the authoritative evidence in top medical journals.
On 6 October 2021, the World Health Organization (WHO) first published the official clinical definition of Long-term COVID-19:
Long-term symptoms of COVID-19 are symptoms that occur within 3 months of infection, persist for at least 2 months, and cannot be explained by other diagnoses in a confirmed or suspected COVID-19 patient.
At present, the specific number of people with long-term symptoms of COVID-19 worldwide is unclear. However, about 10 to 20 percent of people with acute COVID-19 infection will have residual symptoms for weeks to months after infection [3].
In August 2021, Science Reports, a subsidiary of the journal Nature, published a study titled "The Long-Term Impact of More Than 50 TYPES of COVID-19: A Systematic Review and Meta-Analysis" [4].
(Image source: Study cover 4)
The study involved a total of 47,910 infected people, ranging in age from 17 to 87 years.
Studies have shown that 80% of infected people develop at least one long-term symptom within weeks to months of recovery.
The study identified a total of 55 long-term symptoms, of which the most common five were fatigue (58%), headache (44%), attention deficit (27%), hair loss (25%) and dyspnea (24%). In addition, there is loss of smell and taste, cough, joint pain, etc.
Lung CT abnormalities are also common in these infected patients, with 35% of infected people still showing abnormalities in lung CT 60 to 100 days after the first lung CT scan.
(The long-term effects of COVID-19.) Image credit: Lopez-Leon, S., Wegman-Ostrosky, T., Perelman, C. et al. More than 50 long-term effects of COVID-19: a systematic review and meta-analysis.）
Unfortunately, the paper doesn't mention how long these long-term symptoms last; there are no data to illustrate how likely they are to last for life.
However, there is one more thing to note: the subjects of this study were all infected people before January 1, 2021. That is, they are basically infected with the original strain of the new crown virus, rather than the Omicron strain that currently dominates the world.
It can be seen that there are large differences between the new coronavirus infection and the research object of the paper in the past 1 year, although there is still a certain reference value, but it still needs continuous research.
In July 2021, researchers from Imperial College, King's College, the University of Cambridge, the University of Southampton and the University of Chicago conducted a series of clinically validated cognitive tests, including brain tests and questionnaires, on 81,337 people, including about 13,000 people living with COVID-19.
(Image source: Study cover 5)
After controlling for factors such as age, gender, mother tongue, and education level, the researchers found that:
Compared with those who were not infected with the virus, those who had previously contracted and recovered from the new crown virus, regardless of the severity of the symptoms, experienced different degrees of cognitive deficits, and the degree of cognitive decline was directly proportional to the severity of pneumonia at the time of illness.
Unfortunately, due to the shorter tracking time, the recovery of these people is unclear: is it a temporary decline? Or a permanent descent? This discussion is not mentioned.
So, what are the reasons for the cognitive decline of people infected with the new crown virus? What happens to the brain before and after COVID-19 infection?
Research published in the journal Nature in March 2022 suggests that contracting THE CORONAVIRUS may not only lead to reduced gray matter thickness and brain tissue damage in the brain, but may also weaken the brain's ability to perform complex tasks. This study is the only longitudinal imaging study to date that compares changes in brain tissue damage before and after infection in patients with COVID-19 [6].
(Image source: Study cover 6)
The study included 785 participants aged 51 to 81 years in the UK Biobank, of whom 401 tested positive for COVID-19 (96% mild) and 384 tested negative for COVID-19. The researchers conducted two brain scans of them 141 days apart.
There are 3 obvious changes in the results of the infected person's brain scan:
The thickness of gray matter in the orbitofrontal cortex and paracynchal gyrus is reduced
Primary tissue damage in areas associated with olfactory cortical function
Reduced brain volume in COVID-19 patients (brain atrophy)
(Ratio of total brain volume to total cranial content.) Reference: Ref 6)
The gray matter of the brain, also known as the cerebral cortex, contains the cell bodies of most of the brain's neurons. The gray matter involved in the brain includes regional muscle control and sensory perception, memory, emotion, speech, decision-making, and self-control such as audio-visual.
Therefore, the reduction in gray matter thickness means that people's ability to think and act has decreased.
It should be emphasized that the study had some limitations, including the failure to strictly grade the patient's condition and the failure to identify the specific strain of the virus that the patient was infected with.
The effects of Delta and Omicron strain infection on the brain need to be confirmed by follow-up studies. For example, are these brain damage caused by the virus itself, or is there another cause? Can it be restored in the future? These issues need to be further studied.
Another study published March 8 in the journal Nature found that the thickness of gray matter in the brains of COVID-19 patients decreased by about 1% [7].
(Image source: Literature 7)
(Changes in the cerebral cortex after infection with the new coronavirus.) Image source: Literature 7)
Larisa Tereshchenko, a cardiologist and biostatistician at the Cleveland Clinic, said that "in the post-pandemic era, COVID-19 may be the highest risk factor for cardiovascular disease," even greater than the risk of factors such as smoking and obesity with solid evidence.
According to a paper published in the journal Nature Medicine in February 2022, U.S. researchers compared 153,760 infected people who tested positive for COVID-19 with two control groups involving more than 11 million people between March 1, 2020 and January 15, 2021 [8].
(Image source: Document 8)
The study found that covid-19 patients have a significantly increased risk of developing cardiovascular diseases within 30 days to 1 year of infection, including cerebrovascular disease, arrhythmias, ischemic and non-ischemic heart disease, myocarditis, heart failure and thromboembolic disease.
Infected people were 72% more likely to develop coronary atherosclerotic heart disease (coronary heart disease), 63% more likely to have a heart attack, and 52% more likely to have a stroke than the control group compared to the control group.
The risk of developing cardiovascular disease is significantly higher 1 year after infection with COVID-19, regardless of age, sex and other cardiovascular risk factors (e.g., obesity, hypertension, diabetes and chronic kidney disease), and may occur in people who have not previously had cardiovascular disease. Even in non-hospitalized patients with mild disease, the associated risks increase.
However, the study also had limitations because it did not elaborate on which strains of COVID-19 were infected and how vaccinations were given. Moreover, during this period, the COVID-19 vaccine was not widely used, and the Delta and Omicron strains did not yet appear.
Recently, the University of Hong Kong's Yuan Guoyong team conducted an experiment in hamsters. After a hamster is infected with the new coronavirus through the nose, the sperm count and testosterone level drop sharply on days 4 to 7, and the testicles shrink and the volume and weight decrease. Serum sex hormone levels decrease significantly 42 to 120 days after infection [9].
(Image source: Research Cover 9)
And intranasal infection with the Omicron and Delta variants causes similar testicular changes. However, hamsters infected with the influenza virus H1N1 through the nose or testicles did not develop testicular tissue damage.
The researchers further inactivated the hamsters with inactivated vaccines and then infected with the new crown virus, and the results showed that there was no histopathological damage to the testicles, indicating that the new crown vaccine effectively protected the testicles from the infection of the new crown virus and the complications of testicular damage that may be brought about.
Overall, COVID-19 infection can cause acute testicular injury followed by chronic asymmetric testicular atrophy and associated hormonal changes, which can be effectively avoided by covid-19 vaccination.
This also suggests that for male COVID-19 recovery patients, attention should be paid to possible hypogonadism and fertility, and the importance of COVID-19 vaccination is emphasized.
For the long-term symptoms that may be brought about by the new crown, on May 13, 2020, the National Health Commission, the Ministry of Civil Affairs, the National Medical Insurance Bureau, and the State Administration of Traditional Chinese Medicine jointly issued the "Rehabilitation Treatment Plan for Major Functional Disorders of Patients Discharged from the Hospital with New Coronary Pneumonia" (hereinafter referred to as the "Plan"), which regulates the main manifestations, assessment methods and rehabilitation training methods for respiratory function, heart function, physical function, psychological function and ability to perform activities of daily living. Focus on the rehabilitation of severely ill and critically ill patients, and take rehabilitation treatment measures for patients with different conditions and different dysfunctions.
For patients discharged from the hospital with new coronary pneumonia, it is recommended to do more breathing training, aerobic exercise, muscle strength and endurance training, flexibility training, balance function and coordination training according to the condition and tolerance. People with psychological dysfunctions such as depression, anxiety, and post-traumatic stress should receive psychological counseling and treatment in a timely manner.
That's what we know about the long-term symptoms of COVID-19 as of March 2022. For the "sequelae" of the new crown, we should neither demonize nor despise it. The COVID-19 pandemic is not over, and although our understanding of the long-term symptoms of COVID-19 needs to be deepened, no one can stay out of the epidemic.
The mainland is currently facing a critical moment in the fight against Omicron, and what we can do is to actively vaccinate, do a good job of personal protection, reduce mobility, and treat the various medical problems brought to us by the new crown pneumonia in a scientific and rational manner.
Review expert: Liu Yecheng, chief physician of Peking Union Medical College Hospital
bibliography
[1]http://www.nhc.gov.cn/xcs/yqtb/202203/8d8d2035b3884fcfb734e0ab07bede79.shtml
[2]https://news.google.com/covid19/map?hl=zh-HK&mid=%2Fm%2F02j71&gl=HK&ceid=HK%3Azh-Hant
[3]https://www.who.int/emergencies/diseases/novel-coronavirus-2019/media-resources/science-in-5/episode-68-covid-19-update-on-long-covid
[4] Lopez-Leon, S., Wegman-Ostrosky, T., Perelman, C. et al. More than 50 long-term effects of COVID-19: a systematic review and meta-analysis. Sci Rep 11, 16144 (2021). https://doi.org/10.1038/s41598-021-95565-8
[5]dam Hampshire，William Trender，Samuel R Chamberlain，et al. Cognitive deficits in people who have recovered from COVID-19. EClinicalMedicine. 2021 Sep;39:101044.DOI:https://doi.org/10.1016/j.eclinm.2021.101044
[6] Douaud G, Lee S, Alfaro-Almagro F, et al. SARS-CoV-2 is associated with changes in brain structure in UK Biobank. Nature. 2022 Mar 7. doi: 10.1038/s41586-022-04569-5. Epub ahead of print. PMID: 35255491.
[7] Gollub RL. Brain changes after COVID revealed by imaging. Nature. 2022 Mar 8. doi: 10.1038/d41586-022-00503-x. Epub ahead of print. PMID: 35260835.
[8] Xie, Y., Xu, E., Bowe, B. et al. Long-term cardiovascular outcomes of COVID-19. Nat Med (2022). https://doi.org/10.1038/s41591-022-01689-3
[9] Li C, Ye Z, Zhang AJ, et al. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections by intranasal or testicular inoculation induces testicular damage preventable by vaccination in golden Syrian hamsters. Clin Infect Dis. 2022 Feb 18:ciac142. doi: 10.1093/cid/ciac142. Epub ahead of print. PMID: 35178548; PMCID: PMC8903466.
Author: Yu Jia | Editors: Di Hao, Zhang Jie
Typesetting: Han Ningning | Operations: Li Yongmin | Coordinator: Ye Yichu
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