The medical impact of the new coronavirus is coming into sharper focus as it continues its spread in what is now officially recognized as a pandemic.
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Its true fatality rate isn't yet known, but it seems 10 times higher than the flu, which kills hundreds of thousands around the world each year, the United States' top infectious disease expert told lawmakers last week.
Most people have had mild to moderate illness and recovered, but the virus is more serious for those who are older or have other health problems.
That's a huge number, said Dr. Tom Frieden, a former director of the Centers for Disease Control and Prevention who now heads a global health organization. In the U.S., 60% of adults have at least one underlying health condition and 42% have two or more.
"There's still a lot that we don't know about the virus and disease it causes, COVID-19," he said.
How it spreads
Most spread is from droplets produced when an infected person coughs, which are inhaled by people nearby. Transmission from touching contaminated surfaces hasn't been shown yet, though recent tests by U.S. scientists suggest it's possible — one reason they recommend washing your hands and not touching your face.
The virus can live in the air for several hours, up to 24 hours on cardboard and up to two to three days on plastic and stainless steel. Cleaning surfaces with solutions containing diluted bleach should kill it.
“While we are still learning about the biology of this virus, it does not appear that there is a major risk of spread through sweat,” said Julie Fischer, a Georgetown University microbiologist. The biggest concern about going to the gym is infected people coughing on others, or contaminating shared surfaces or equipment, she said. Consider avoiding large classes and peak hours and don't go if you're coughing or feverish, she suggests.
The risk of virus transmission from food servers is the same risk as transmission from other infected people, but “one of the concerns is that food servers, like others facing stark choices about insurance and paychecks, may be pressured to work even if they are sick,” she said.
How fast does it spread?
Each infected person spreads to two or three others on average, researchers estimate. It spreads more easily than flu but less than measles, tuberculosis or some other respiratory diseases. It is not known if it spreads less easily among children, but fewer of them have been diagnosed with the disease. A study of 1,099 patients in China found that 0.9% of the cases were younger than 15.
What are the symptoms?
Most people get fever and cough, sometimes fatigue or shortness of breath, and recover after about two weeks. About 15% develop severe disease, including pneumonia, Chinese scientists reported from 45,000 cases there. Symptoms usually start slowly and often worsen as the illness goes on.
In a report last week on the first 12 patients in the U.S., seven were hospitalized; most had underlying health problems and got worse during the second week of illness.
In China, slightly more males have been diagnosed with COVID-19 than females, which might be because roughly half of Chinese men smoke but only 5% of females do, Frieden said.
Children seem to get less sick — a report on 10 in China found that fevers tended to be milder and they lacked clear signs of pneumonia.
What does it feel like?
Some cruise ship passengers described symptoms similar to the common cold or flu.
“Its been a 2 on a scale of 10,” said Carl Goldman, who was hospitalized in Omaha, Nebraska, after flying home.
However, a Chinese postgraduate student described going to the hospital twice after her symptoms worsened, and feeling "a heavy head while walking, unable to breathe, and nauseous."
What's the test like?
The CDC recommends at least two swabs — nose and throat. Samples are sent to labs that look for bits of viral genetic material, which takes roughly 4 to 6 hours. Altogether, it can take several days to ship a sample and get results back.
It's been taking two to three days, and "we are working really hard to see if we can shorten that time" by developing an in-house test, Dr. Aimee Moulin of the University of California, Davis said Thursday in a conference call held by the American College of Emergency Physicians.
Some areas have opened drive-thru sites for testing, which could reduce exposure to health workers and other patients or the public.
When is the virus most contagious?
The average time from exposure to developing symptoms is five to six days, but can be up to two weeks. Tests have found high amounts of virus in the throats and noses of people a couple of days before they show symptoms.
Signs of virus also have been found in stool weeks after patients recover, but that doesn't mean its capable of causing illness, scientists warn.
"The virus can be degraded," said Robert Webster, a St. Jude Children's Research Center virus expert. "It's not necessarily infectious virus at all."
How deadly is it?
That won't be known until large studies are done to test big groups of people to see how many have been infected and with or without symptoms.
Scientists have estimated the fatality rate from less than 1% Read More – Source
