What is virus exactly, why can let a person be ill?

February 26, 2020 / BIOON / -- you may sometimes feel "infected with a virus", which means that you get sick because you touch something that may be a virus In fact, you're exposed to viruses all the time Some viruses cause the common cold, others are essential for human survival New viruses will also emerge, often bringing disease to humans when they have recently moved from another species to humans When world health leaders try to determine how to deal with the new coronavirus, virus expert Marilyn J roossinck answers several questions: 1 What is a virus? Defining a virus has always been a challenge, because every time we come up with a good definition, someone will find a virus that violates the rules Viruses are entities that infect cell life They are very diverse The simplest is to wrap a pair of genes made up of RNA or DNA in a protein shell Others have hundreds of genes, more than some bacteria Photo source: https://cn.bing.com all viruses are ultimately parasites They need a host for replication because they can't generate their own energy as cells do 2 Why does the virus make people sick? When a new human viral disease appears, the most common reason is that the virus spans from a different species to humans The most serious viruses are usually those that have only recently entered the human body After crossing species, the virus will undergo a process of adaptation to the new host The real challenge, however, is the host The immune system overreacts when it tries to figure out how to adapt to an invasion from something new That's what makes the host sick Viruses don't usually make people sick; it's an accident of the host's immune system overreacting to things it doesn't know After a long time in the host, the virus is unlikely to cause disease For example, HIV is transmitted to humans from wild primates, which do not cause any disease Each virus host relationship is different In most cases, viruses do not cause any disease, and many viruses are beneficial For example, in mice, the herpes virus can prevent the infection of plague bacteria 3 Why is it so important to know the original source? If the virus comes from an animal, knowing what the corresponding animal is can help break the chain of infection Understanding the source of the virus also helps scientists to understand the possible mutations in the virus genome This is because crossing the host will affect the variation of virus genome When the virus has been in the host for a long time, its genome will fine tune the host, and mutations will not be tolerated Photo source: https://cn.bing.com 4 SARS is a terrible enemy, but it seems to have disappeared Why? The measures to control SARS began very early and were very successful The key is to stop the transmission chain by isolating infected people SARS has a short incubation period: people usually develop symptoms within two to seven days At present, there is no one on record who does not show any symptoms is the source of SARS infection When the incubation period is much longer or some people have no symptoms at all, it is much more difficult to block the transmission chain This could be a case of covid-19 caused by the virus, so it might take more time to stop it 5 What is the best way to treat virus? The virus does not respond to antibiotics, and in some cases taking antibiotics can make things worse because normal bacteria in the gut are an important part of the immune response Antiviral drugs are effective against some viruses, but the high mutation rate of most viruses means that they will soon become resistant to antiviral drugs The best treatment is to give patients the best tools to fight infection in their own bodies This usually means resting and staying hydrated Viral infection can inhibit the immune system, so secondary infection should be monitored and other treatments may be needed Prevention is very important Patients need to be isolated and healthy people need to take preventive measures Most respiratory viruses are not transmitted by the patient's breath, but by touching your hands with tiny droplets that are spread when the patient coughs or sneezes, and then touching your face So it's important to wash your hands properly! Reference: [1] what are viruses anyway, and why do they make us so sick? 【2】 Be Antibiotics Aware： Smart Use， Best Care 【3】 Viruses： Structure， Function， and Uses 【4】 When will there be a coronavirus vaccine？ 【5】 Severe Acute Respiratory Syndrome (SARS)