COVID-19 shows signs of long-term harm in some recovered patients
The disease caused by the coronavirus may do lasting harm to some people who contract it, even if they only exhibit mild symptoms.
There are growing signs that COVID-19 may have lingering effects, called sequelae in medical terminology. Early studies have found decreased lung function that might not be reversible, and damage to the heart, kidneys, gut or liver.
Experts say it is not unusual for diseases to have lasting impacts on those who contract them. Studies in the wake of an Ebola outbreak in West Africa found a significant number of survivors suffered from eye trouble or severe arthritis. Other diseases that cause pneumonia can cause permanent damage to the respiratory system. Another coronavirus, SARS, caused victims sustained lung damage even after they recovered.
“Most of the sequelae that we’re seeing are the same types of sequelae that we see with any cause of pneumonia,” said Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security. “We have a lot of information on other coronaviruses and the disease spectrum they cause.”
COVID-19 manifests itself in a frightening number of ways, causing reactions such as strokes, heart attack symptoms, rashes on the feet, and lost senses of taste and smell.
The vast majority of those who contract the coronavirus recover, and most suffer few symptoms. Some people are completely asymptomatic as the body swats the virus aside.
In the worst cases, the disease kills by shutting down the respiratory system.
Those who suffer the worst respiratory effects of the virus and have to be sedated are at risk for what doctors call post-ICU syndrome. Because they have to be sedated for long periods to go on a ventilator, those patients risk cognitive impairment that will last a lifetime.
A review of early research by scientists in the United Kingdom found more than a quarter of patients who wind up in the intensive care unit suffer cognitive impairment, psychological distress or another physical ailment. Another report found a quarter of ICU patients required advanced cardiac support, and one in five needed interventions to keep their kidneys functioning.
But most experts said that, five months after the virus first appeared in a cluster of what Chinese officials called atypical pneumonia, there is much more to learn about how the virus attacks a body and what the after-effects might be.
“While millions of people are reported to have recovered from COVID-19, we are still learning about the recovery process and long term affects that some may experience,” Maria Van Kerkhove, who heads the World Health Organization’s research into the disease, told The Hill in an email. “Experience shows us that most people who have had COVID-19 will make a full recovery, especially among those who had mild or moderate (pneumonia without needing respiratory support) disease.”
“Based on limited available evidence and the shared experience from the general critical care population around the world, however, we expect that those patients with severe or critical COVID-19 who required acute interventions during their care, including mechanical ventilation, sedation and/or prolonged bed rest, may experience a range of impairments, including, physical deconditioning, respiratory, swallow, cognitive and mental health impairments,” Van Kerkhove wrote.
The variety of symptoms caused by the coronavirus is likely a result of the way it attacks the immune system. Scientists have documented the virus’s assault on a certain immune response that, in other cases, acts to slow a pathogen’s ability to replicate inside human cells. The coronavirus hinders that response, but it does not stop another immune response that rushes virus-hunting cells to the infected part of the body.
In practice, that means the body pushes more and more of an immune response to the infected area, even as the virus itself grows, attracting a stronger and stronger response. That can create what scientists call a cytokine storm, in which an individual’s immune system makes extreme efforts to rid itself of the invading virus.
In some cases, those cytokine storms can cause lasting damage through inflammation or clotting. That has caused serious ailments in some patients, including strokes, something that has puzzled researchers.
“It is unusual to see an infectious disease causing this. It’s important to remember that it is occurring, but it is pretty rare,” Adalja said of the strokes caused by COVID-19. “It has to do with the fact that this virus and the reaction to it sets off clotting.”
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