Corona virus: How are those who spread the disease without symptoms and 'silence' complicating the epidemic?
As the corona virus crisis progresses, scientists have found more evidence of a strange and disturbing aspect of the corona virus. While many infected people have a cough and fever, as well as a sense of eating and smelling, there are many who have no symptoms of the disease and are unaware that they have it.
Researchers say it is important to understand how many people there are and whether they are complicating the epidemic by spreading the disease silently. When people gathered in a church in Singapore on January 19, no one expected that the gathering would be of international significance in the spread of the corona virus. The gathering included a 56-year-old couple from China that morning.
Both appeared to be in good health, but on January 22, his wife's condition began to deteriorate, and two days later, her husband became ill. Both came from Wuhan. A week later, three locals also became infected. "We were shocked," said Dr. Vernon Lee of the Singapore Ministry of Health. People who didn't know each other had infected each other, although apparently they had no symptoms.
Dr. Lee and his fellow scientists, together with police and pathologists, began the investigation and compiled maps based on who was where and when. This process is called contact tracing, which is currently practiced in the UK. Surprisingly, in just a few days, the researchers spoke to 191 members of the church and found that 142 of them were in attendance. They also found out that two Singaporeans who had been affected by the epidemic were in church when the Chinese couple also arrived.
"They may have met, talked, and welcomed each other in church routines," said Dr. Lee.
But it is not clear how the virus was transmitted from the Chinese couple to others because they had no symptoms of the disease. Another surprise was that the third person infected with the corona virus was a 52-year-old woman who had not been to church at the time. However, later that day she attended another ceremony at the same church. So how did they get the virus?
Researchers carefully examined the church's CCTV footage this Sunday and found that although the woman had gone to the church later that day, she was sitting in the same seat where the Chinese couple had been sitting for hours. It was a very unexpected discovery. Although the Chinese couple did not have symptoms of code 19 at the time, the virus was transmitted to them. The virus may have been in the hands of those who touched the seats. It is unknown at this time what he will do after leaving the post.
The only possible explanation, according to Dr. Lee, was that the virus was being transmitted from people who did not know they had it. This was a big revelation because at that time the only message about the corona virus was to keep an eye on the symptoms of the virus inside yourself and others.
Transfer before symptoms appear
The findings show that the disease can spread even before coughing, fever and other symptoms appear. This process is called 'pre-symptom migration'. This study, including other research, found that the 24 to 48 hours before symptoms appear is crucial, as people carrying the virus are more likely to pass it on to others. This is important because as soon as you find out that you are infected with the corona virus, you can warn your contacts to confine themselves to your home.
This means that they will be able to isolate or isolate themselves before symptoms appear, but how the virus is transmitted to others without coughing is still under discussion.
One way is that if the virus is growing in the upper respiratory tract, it may spread to others through inhalation, especially indoors or outdoors.
The second means of transmission can be touch, ie the virus is on someone's hand and if he touches the door or chair with the same hand, it can be transmitted to the surface and from there to any other touchier. Whatever the reason, the virus is taking advantage of people's ignorance because they will be less vigilant when they do not know they are infected.
Some people have no symptoms at all
The most mysterious thing is that scientists have not been able to find a definitive answer. It is a different matter to know that people can transmit the virus even before the symptoms appear, but it is a very different matter that people are infected with the virus and do not show any symptoms.
This condition is called 'symptomatic' or 'asymptomatic' because the disease is present in a person but does not manifest itself. The most famous of these happened in New York in the early part of the last century, when an Irish cook named Marie Mellon got a job in a house. Everyone in the house contracted typhoid and at least three people died. It turned out that Mary Melanie had typhoid but had no symptoms and had transmitted the disease against her will.
Journalists called her "Typhoid Mary" which she always resented. Authorities took no further risks and kept him under siege for 23 years until his death in 1938. Twenty-three-year-old nurse Amelia Powell came to her senses when she was diagnosed with the corona virus without symptoms. She felt safe working with code 19 patients behind protective clothing, but her saliva test was positive.
"I felt like a loved one had died," she says. I don't think that's right, I'm fine. "
He had to leave work and immediately find himself alone in his home. She says she had seen other patients' condition worsen rapidly and was worried that they might have to go through the same ordeal. But surprisingly, they showed no signs of illness. At this stage it is impossible to say how many cases there will be where the disease will be present but no one will know. Amelia was diagnosed with the condition because she was involved in an ongoing study at her hospital. The results of this study were astonishing because 3% out of 1000 patients were found to have no symptoms at the time of testing.
The biggest example of asymmetry is the Diamond Princess, a passenger ship that was sailing off the coast of Japan earlier this year. About 700 people were affected, three-quarters of whom showed no symptoms. More than half of the residents at a nursing home in Washington tested positive without symptoms. Various studies have shown that 5 to 80% of cases can be asymptomatic. This is the conclusion reached by Professor Carl Hannigan of the University of Oxford and his colleagues after reviewing 21 research studies.
According to him, the final conclusion is that "there is no single reliable study to determine the number of patients without any symptoms." He says that if only patients with symptoms were tested, as is happening in the UK, many cases would not be detected. "No research is entirely reliable."
The risk of 'quietly spreading the disease'
Nurse Amelia's biggest concern is that she may have unknowingly transmitted the virus to her co-workers or to patients who were relying on her for help. "I don't think I passed the virus on to my colleagues because their tests were negative, but the problem is how long I've been positive," she said. We do not yet know if the virus can be transmitted to others in an asymptomatic state. It's weird and there's very little knowledge about it. "
A study in China found that there were more cases without symptoms than with symptoms. Scientists have warned that attention needs to be paid to asymptomatic victims to prevent the disease. The team that studied Diamond Princess believes that people without symptoms have a lower risk of transmitting the virus to others than those with symptoms, but they still have a significant number of people infected.
The 'dark meter' of asymptomatic disease
In an effort to unravel the mystery, scientists in the British city of Norwich are urging people to be tested.
Neil Hall, a professor at the Earlham Institute, says "asymptomatic cases" could be the "dark matter" of the epidemic. It is a substance found in the universe whose existence cannot be directly observed. Professor Hall fears that asymptomatic cases may be the cause of the outbreak. "If people who don't know they're actually sick use public transportation and health care, the virus transmission will inevitably increase," he said.
According to him, treatment of patients with symptoms is half the solution to the problem.
In this regard, some members of the House of Commons in the British Parliament have written a letter to the Prime Minister Boris Johnson, in which he has stated that it is important to know about patients without symptoms. He wrote that medical and nursing staff should be tested regularly. In the Chinese city of Wuhan, where the epidemic is thought to have originated, the work has begun on a much larger scale.
In Wuhan, 6.5 million people were screened in nine days, including those with no symptoms.
Lockdown easing As a result of the easing of lockdowns, people are moving to markets and offices. In such cases, it is important to be vigilant about the unseen danger of this asymmetry.
That is why governments around the world are pushing for the persecution of those who come in contact with them, so that as soon as a person shows symptoms, all those who come in contact with him become isolated. Officials say social distance is the best defense strategy in these situations, but where this is not possible, the face should be covered, even if a homemade mask is used.
The purpose of wearing a face mask is to at least protect others if you are infected with the virus
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