What we know now about COVID-19: Recovery is hard, masks help, children can be carriers and more
It’s been more than seven months since China first reported a cluster of unexplained cases of pneumonia, and we’re still learning how the novel coronavirus spreads and what we can do to defeat it.
The situation with COVID-19 is both better and worse than we knew a few months ago, because many people experience mild symptoms and some report no symptoms.
The good news is that that means the odds any particular person who gets the virus will be hospitalized or die are lower than we originally thought.
The bad news is that those people can unknowingly spread the virus, putting others at risk of serious illness or death. The Centers for Disease Control and Prevention estimates as much as 40% of spread could be happening before people develop symptoms, which makes the virus particularly difficult to contain.
The Denver Post put together this guide of what we do and don’t know about COVID-19. This information will evolve as scientists keep studying the new coronavirus.
Recovery isn’t simple
While some people feel better within a week or two, others struggle with symptoms of the virus for a month or longer. A study by CDC researchers found about one-fifth of people they surveyed between ages 18 and 34 still had symptoms more than two weeks after being diagnosed with COVID-19. About one-third of middle-aged people had lingering symptoms, as did about half of adults older than 50. The most common complaints were fatigue, body aches and a lingering cough.
Even people who report they never experienced symptoms can show signs of lung damage, though that may be temporary, experts say.
It’s not entirely clear why some people have lingering symptoms and others don’t. One theory is that some people’s immune systems overreact and continue to damage tissues after the virus is gone. Another is that the virus may hide out in the body and continue to cause damage. It’s also possible that there could be some explanation, or that both the immune system and the virus could play a role.
Some treatments appear to work, others disappoint
Patients who were hospitalized with the virus in Colorado in May had a better chance of surviving than those who got sick in March. It’s possible that differences in patients’ underlying health could be a factor, but Colorado hospital leaders think that growing knowledge about the virus has also helped.
One thing we’ve learned is that patients with low oxygen levels, but who don’t feel starved for air and aren’t showing signs of cognitive trouble, sometimes do better with less-invasive supports like oxygen masks than if they’re placed on a ventilator. Ventilators can be lifesaving for some people, but they also require heavy sedation, which carries its own risks, and some people’s lungs are damaged when oxygen is forced in.
Only one medication, a steroid called dexamethasone, reduced the odds of dying for the sickest patients, according to a large British study. A review of drug research published in The British Medical Journal found it also could reduce the odds patients would progress to needing a ventilator.
Remdisivir, an antiviral drug, has been shown to reduce the time until patients have recovered enough to leave the hospital, but it’s not clear that it reduces the odds of dying from COVID-19.
Hydroxychloroquine appears to have been a bust for COVID-19, with studies finding it didn’t reduce the odds of dying for severely ill patients, or reduce the odds of needing supplemental oxygen or a ventilator for those who were moderately sick. Trials also haven’t found any evidence that it reduces the odds of developing the disease if a person has already been exposed to the virus.
Studies are ongoing to determine whether taking it before exposure reduces the odds of getting infected.
Masks aren’t perfect, but they help
An analysis of 30 studies published by the journal Lancet found mask-wearing was associated with a reduced risk of infection, though the benefit was greatest when using a medical-grade mask. Another study, in Health Affairs, found that states that adopted mask mandates saw declines in new cases faster than states that didn’t.
It’s not clear if homemade masks benefit the wearer, by blocking droplets from other people who might be infected, or if they only reduce spread in the community by keeping the wearer from exhaling droplets that infect others. Medical-grade masks can block transmission in both directions.
The virus could spread through the air, but how often does it?
The World Health Organization initially thought the virus primarily spread through the large droplets produced when people cough or sneeze, which quickly fall after expulsion. Under that scenario, the biggest risk would be being close to someone who’s spewing droplets, or touching something they touched after covering their coughs.
More recently, however, they’ve accepted that the virus may be spreading in much smaller drops, called aerosols, that we produce when speaking. Aerosols can stay in the air for almost 15 minutes indoors, raising the possibility that merely being in a shared space with a person who has the virus could lead to spread. We don’t know if the virus often spreads that way in real-world settings, though, because factors like ventilation can make a big difference in how long aerosols stick around.
Children can get infected, but how well do they spread the virus?
Some early studies suggested people under 20 are less likely to get infected and spread the virus than adults. Other studies, like one in South Korea, found kids who are 10 or older can be as contagious as adults. That raises the possibility that kids can infect others, but weren’t being identified because they had mild symptoms and were less likely to be tested.
Real-world examples have raised concerns that kids can transmit the virus more efficiently than previously believed. At a small camp in Georgia, more than half of the 600 people present tested positive for the virus, after testing negative before they arrived. Children younger than 10 were no less likely than older teens and young-adult counselors to test positive, according to The New York Times.
Some child care centers were able to operate in coronavirus hotspots without developing clusters of cases, but it’s not clear if their experiences can be scaled up. In some centers, each adult spent time with a “pod” of nine children, according to NPR — a ratio that’s not feasible in most classrooms as schools begin to reopen.
Antibodies fade, but we don’t know what that means
Antibodies to the virus can disappear within a few months, but it’s not clear how long immunity might last afterward — or if it develops at all. Antibodies are just one part of the immune system’s defense, so it’s possible people who got the virus (or a vaccine, when one becomes available) will be protected after they fade. On the other hand, it hasn’t been proven that people with COVID-19 develop immunity, so you don’t want to abandon precautions just yet, even if you already got sick.
Some people may have gotten the virus twice, but experts say that’s unlikely to be a common problem. It’s still unclear how long the virus can linger in the body, and whether people who continue to test positive weeks after infection can pass it to others.
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