Viruses names and what they do

These associations are sometimes inaccurate since the location that detects a disease is rarely where it first emerged, says USA Today. According to The New York Times , the identification of COVID variants depend more on the strength of a region's genome surveillance to track mutations than on where the mutation first appeared.

WHO hopes the new system will encourage countries to report new variants without the fear of being forever associated with the variant in the public eye, reports USA Today. According to CNN, the four variants of concern and their new names include:. Two other variants first identified in the U. According to CNN, these include:. Currently, its uncertain if the new naming system will stick, says The New York Times.

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This makes them unable to reproduce independently and totally dependent on their host. After entering a host cell, a virus hijacks the cell by releasing its own genetic material and proteins into the host. Next, the virus continues to reproduce, but it produces more viral protein and genetic material instead of the usual products that the cell would produce. Viruses have different shapes and sizes. Scientists categorize viruses according to various factors, including:.

Examples of viruses with an envelope include the influenza virus and HIV. Within these categories are different types of viruses. A coronavirus, for example, has a sphere-like shape and a helical capsid containing RNA. It also has an envelope with crown-like spikes on its surface. Seven coronaviruses can affect humans, but each one can change or mutate, producing many variants.

Learn more about coronaviruses here. Just as there are friendly bacteria in the intestines that are essential to gut health , humans may also carry friendly viruses that help protect against dangerous bacteria, including Escherichia coli. Viruses do not leave fossil remains, so they are difficult to trace through time.

Scientists use molecular techniques to compare the DNA and RNA of viruses and find out more about where they come from. Three competing theories try to explain the origin of viruses.

In reality, viruses may have evolved in any of these ways. The regressive, or reduction, hypothesis suggests that viruses started as independent biological entities that became parasites. Over time, they shed genes that did not help them parasitize, and became entirely dependent on the cells they inhabit.

In this way, they gained the ability to become independent and move between cells. The virus-first hypothesis suggests that viruses evolved from complex molecules of nucleic acid and proteins either before or at the same time as the first cells on Earth appeared, billions of years ago.

When a viral disease emerges, it is not always clear where it comes from. A virus exists only to reproduce. When it reproduces, particles spread to new cells and new hosts. The features of a virus affect its ability to spread.

Some viruses can remain active on an object for some time. If a person with the virus on their hands touches an item, the next person can pick up that virus by touching the same object. The object is known as a fomite. Viruses often change over time. Some of these changes are very small and do not cause concern, but others can be more significant. Now, some viruses will also have an envelope which they obtain as they emerge from the cell. Viruses are very interesting in that they can only survive inside a living cell.

So they must have a living cell in order to survive and replicate. Antibiotics are not effective against viruses, but vaccines are, as well as some antivirals. Bettie J. Not all viral diseases are contagious. But many of them are. Common examples of contagious viral diseases include the flu, the common cold, HIV, and herpes. Other types of viral diseases spread through other means, such as the bite of an infected insect.

Respiratory viral diseases are contagious and commonly affect the upper or lower parts of your respiratory tract. Respiratory viruses are spread by droplets generated through coughing or sneezing. If someone with a viral illness coughs or sneezes nearby and you inhale these droplets, you may develop the disease.

These viruses can also be spread through contaminated objects, such as doorknobs, tabletops, and personal items. If you touch one of these objects and then touch your nose or eyes, you could develop a disease. Respiratory viral diseases usually heal on their own. But over-the-counter OTC medications, including nasal decongestants, cough suppressants, and pain relievers, can help to reduce symptoms. In addition, Tamiflu, an antiviral drug, is sometimes prescribed if someone is in the very early stages of developing the flu.

The best way to avoid respiratory viral diseases is to practice good personal hygiene. Wash your hands often, cover your mouth when you cough or sneeze, and limit your interactions with people who show symptoms of a respiratory condition. Gastrointestinal viral diseases affect your digestive tract. The viruses that cause them are contagious and usually lead to a condition called gastroenteritis , also called the stomach flu.

Gastrointestinal viruses are shed in the stool during bowel movements. You can also get the virus from sharing utensils or personal objects with someone who has a virus. In many cases, they resolve on their own within a day or two. In the meantime, drink plenty of fluids to replace those lost from diarrhea or vomiting. You can prevent gastrointestinal viral diseases by washing your hands often, especially after using the bathroom.

Wiping down contaminated surfaces and not sharing personal items or eating utensils can also help. Many exanthematous viruses are spread through respiratory droplets from the cough or sneeze of someone with the virus. Other exanthematous viral diseases, such as chickenpox and smallpox, can be transmitted by coming into contact with fluid in broken skin lesions. Chikungunya virus is spread through a mosquito bite and cannot be transmitted from person to person.

Treating exanthematous viral diseases focuses on managing symptoms.