When a person talks for 5 minutes, they can disperse 3,000 droplets over a range of 2m.
Only 1/900th the size of a human hair, but the strain of the virus that causes the Covid-19 epidemic is spreading anxiety around the world. Up to this point, more than 93,000 patients in 76 countries and territories have tested positive for the virus.
SARS-CoV-2 is invisible to the naked eye, and even scientists are having to figure out its mysteries. Even so, at least 540 studies have been done so far that will tell us how Covid-19 is transmitted between people.
Are the surfaces of objects at risk of carrying viruses? At what distance would contact with an infected person put you at risk of infection? Is SARS-CoV-2 sexually transmitted? In this article, we will answer all those questions in turn.
If I accidentally pass by someone with Covid-19, will I get sick?
Suppose you walk into a crowded grocery store. Among the people shopping there, there was a person infected with the new corona virus. What factors would contribute to your risk of infection from that person?
Experts agree that they still have a lot to learn, but there are four factors that could play a role in this situation: One is the distance between you and the infected person. Second, how long have you been around them? Third, is the person coughing, sneezing, or exhaling respiratory droplets? And finally, how many times will you touch your face yourself?
(Of course, your age and health are also a major factor, people with weakened immune systems and the elderly are more likely to catch the virus and get sick more easily. But let's assume you are a young and healthy person).
What is a virus droplet?
Droplets containing the virus are droplets of mucus in the respiratory tract of an infected person, which can be spread through the nose, mouth, and even eyes when they cough, sneeze, talk and… breathe. Scientists say the new corona virus cannot be suspended alone in the air by itself, but will "collect" in droplets to travel together.
Inside the respiratory tract of Covid-19 infected patients, the virus has entered the cell, attaching its RNA to the genetic material to take over the host cell machinery to replicate. When the number of viruses is enough, they will break the cell and get out. Some of the virus will continue to invade new cells, while others will be trapped in the patient's mucus.
Kin-on Kwok, a professor at the University of Hong Kong's School of Health and Public Health, said that a virus cannot "naked" alone to go out of the respiratory tract of an infected person to infect for others. It has to hitch a ride thanks to drops of their mucus or saliva.
These mucus and saliva are expelled from the mouth or nose when we cough, sneeze, laugh, sing, breathe, and talk. Research shows that when a sick person sneezes, they can release 40,000 droplets into the air. These droplets can travel up to 6 m at a speed of 50 m/s.
When a person coughs or talks for 5 minutes, they can spread 3,000 droplets. Cough droplets can travel over a range of 2 m at a speed of 10 m/s. And even when a sick person breathes, they can spread droplets over a distance of 1 m at a speed of 1 m/s.
If there is no obstacle on the way, the droplet will bring the virus to the floor or ground. Outside the host, the virus cannot live long, the droplet will quickly dry out and depending on the surfaces it lands on, the corona virus can survive for hours to days on it.
In the event that droplets from an infected person reach you, the virus must also pass through the portals of the respiratory tract to infect you. It is through the eyes, nose or mouth. Some experts believe that sneezing and coughing may be the main form of transmission.
Professor Kwok added that talking face-to-face or eating with sick people could also put you at risk of contracting Covid-19. Julian Tang, a virologist and professor at the University of Leicester in the UK, agrees
"If you can smell what the sick person ate for lunch today - like garlic, curry, etc - you are inhaling what they are exhaling, including any viruses in their breath." he said.
What distance is considered too close to a person infected with Covid-19?
Christian Lindmeier, a spokesman for the World Health Organization, said it's best to keep a distance of 3 feet (equivalent to 1 meter) from sick people.
The US Centers for Disease Control and Prevention says standing within 6 feet (equivalent to 2 meters) can put you at risk.
And what time period is considered too long for exposure?
This question still has no clear answer. Most experts agree that the longer you are in contact with an infected person, the higher your risk of infection.
Can you tell if someone is infected with Covid-19?
It seems impossible. Remember that most patients infected with Covid-19 only show mild flu-like symptoms. Some people who have contracted the virus don't even have symptoms.
This makes it impossible for us to know for sure if someone near us is infected with Covid-19, even doctors with clinical experience cannot do that.
However, WHO has so far confirmed that most patients who can infect others are showing symptoms of Covid-19, especially fever, cough, and difficulty breathing. So, if you see someone around you with these symptoms, it's best to keep your distance from them.
Can the virus survive on bus handles, touch screens or other surfaces?
Have. After many people who went to the same temple in Hong Kong fell ill, the city's Health Protection Center collected samples from the area. The faucets in the restroom and the cloth wrapped on the Buddhist scriptures tested positive for the new corona virus.
Scientifically, the SARS-CoV-2 virus is just one of many previously known similar corona strains. (They are called corona viruses (halo or crown) because of the protein spikes that protrude from the surface like a crown and glow under the electron microscope.)
A study of other coronavirus strains showed that they can survive on metal, glass and plastic surfaces for two hours to nine days.
A surface that looks clean or dirty can't tell you if there's a virus on it. If an infected person with Covid-19 sneezes nearby and a drop of them lands on a surface, a person who then touches that surface can contract the virus. The minimum number of droplets and viral load to infect a new patient are still unanswered questions.
But Gary Whittaker, a professor of virology at Cornell University College of Veterinary Medicine, said the coronavirus strains are basically all susceptible to being destroyed outside of the body. If you want to disinfect the surfaces around you, simply use disinfectant products that contain one of the following ingredients:
Sodium hypochlorite (0.1 – 0.5%), 70% ethyl alcohol, Povidone-iodine (1% iodine), Chloroxylenol (0.12%), 50% isopropanol, 0.05% benzalkonium chloride (Quaternary Ammonium Compound), 50ppm iodine in iodophor, 0.23% sodium chlorite, 1% cresol soap (sodium alkyl-benzene-zene sulfonate) and Hydrogen peroxide (0.5-7.0%).
These bactericidal compounds can easily break through the fragile envelope of the Covid-19 virus, rendering it inactivated or harmless.
Or if it's not possible to sanitize surfaces in public, as long as you'll wash your hands after touching them and before touching your face, you'll be safe because the droplets and viruses of an infected person can't get through. through the skin into the body.
That is also why you should not worry about parcels or goods being delivered from an epidemic area. If you are extra careful, you can spray disinfectant on the surface of these products and wash your hands after opening them.
Do you need to choose antibacterial soap or a specific brand of soap?
The answer is no! Both antibacterial soap and regular soap work on the principle of washing away viruses and other pathogens on the skin of your hands. Therefore, it is not necessary to choose the type of soap.
My neighbor is coughing. Should I be worried?
There is no evidence that virus particles can pass through walls or glass, said Dr. Ashish K. Jha, director of the Harvard Institute for Global Health. He shares his concerns about public spaces rather than the dangers of ventilation, as long as you keep your room well ventilated.
An infected neighbor could sneeze on the railing, and if you touch it, that would be a better route for the virus to spread, says Dr.
Is the virus sexually transmitted?
Kissing is certainly an act that can spread the virus, experts say. Although strains of corona virus are not usually sexually transmitted. But it is still too early to conclude this with Covid-19, WHO stated.
Is it safe to eat in a restaurant with someone who has coronavirus?
If the person getting sick is the chef or restaurant worker who prepares your meals, the risk cannot be ruled out. Joining a crowded buffet is also not a good choice at this time.
However, Prof Whittaker says reheating or cooking food will kill any viruses in your food. Dr. Jha concurs with this view. "With general principles, we see that food is not a transmission mechanism [Covid-19]," he said.
Should I keep my dog and cat in the same house as me?
Professor Whittaker said there is currently "no evidence" that a dog or cat can contract the corona virus and transmit it to its owner. In some cases, a pet will help you relieve stress and be more mentally stable when you have to isolate at your home.
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