After six months’ experience with Covid-19, medical researchers have learned a lot about the disease. But among the still-open questions is this big one: How many people who’ve been infected will suffer lasting symptoms and health problems?
Like many other illnesses, Covid-19 can cause enduring problems. Some victims report serious symptoms weeks and months after infection, even many who were never ill enough to be hospitalized. Nearly 100 different long-term problems, detailed in the chart below, were reported to Indiana University Medical School researcher Natalie Lambert, in a survey of more than 1,500 patients. Some of these issues go well beyond typical Covid symptoms.
In studies of Covid patients, researchers have found evidence of damage to the lungs,kidneys and heart, and one recent paper described a mechanism by which the virus may have lasting effects on the brain. Some Covid long haulers report weakness after exertion and brain fog, which are signs of chronic fatigue syndrome, a poorly understood condition that has been linked to other viral infections.
Researchers have yet to ascertain what share of people infected with Covid-19 suffer long-term symptoms. But the potential for harm is vast: At least 6.8 million people in the U.S. alone have been infected, according to Johns Hopkins data.
The actual number of cases is almost certainly much higher because limited testing, especially in the early days of the pandemic, missed many victims who had no symptoms. Youyang Gu, an M.I.T.-trained data scientist whose model of Covid infections and deaths is used by the Centers for Disease Control, estimates that in March and April the true U.S. case numbers were 10 to 15 times as high as those reported, and in June they were five times as high. Gu projects that, by November, the U.S. will reach about 60 million infections, almost double the current global case count. With numbers that large, even a low rate of long-term damage could result in significant suffering and potential disability.
Gu’s model suggests that, by November, the real global total could be more than 300 million.
To be prepared for long-term Covid-19 problems, all health systems will need to monitor “recovered” patients, assess the prevalence of lingering symptoms and look for ways to help these patients.
Note: Projection data accessed Sept. 22; Sept. 15 figures used for comparison purposes.
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