With our society knee-deep in the consequences of COVID-19, which has affected our mental and physical health, it is appropriate to offer some depth to this topic through the lens of sports medicine, with the hope that this knowledge will help us navigate our current events, as well as those that will unfold during the next few months.
Viruses are the most abundant life form on earth, with an estimated 1031 viruses on the planet, and recently we have as a society been markedly affected by the new Coronavirus. Before the current pandemic, nearly 40 percent of the referrals to sports medicine clinics were due to upper respiratory tract infections (URI) – one of the most common diseases in humans.
Besides URIs, participation in sports exposes the athlete to a variety of viruses from other participants as well as from contact with athletic surfaces, including mats and contact with equipment. Table 1 summarizes the viruses commonly encountered in sports medicine.
A virus is a very efficient package capable of penetrating a cell membrane to reach the cells own machinery, using the machinery to replicate itself, and then escape, killing the cell in the process.
The structure of the virus helps us to understand infections and prevention. All viruses have two basic components: a protective, protein coat, and inside this a strand, or two, of DNA or RNA (the genome) – the basic building blocks of life. Many viruses also have an outermost layer made up of a fatty membrane, called the envelope. The envelope serves as a shield, cloaking the virus against a host-cells immune system, making it easier to infect the host undetected.
The main purpose of a virus is to multiply. To do this, the virus binds to the surface of a host cell, introduces the protein coat and genome into the cell, and eventually, the DNA or RNA multiplies and new viruses are synthesized and assembled, and then they are released, killing the host cell in the process.
How does our body fight viruses?
The conversation surrounding immunity to COVID-19 has produced questions about our body’s response to a virus. Viral immunity is accomplished by three very complicated mechanisms.
Vaccines are an important way to prevent infections and are created in a variety of ways. The two most common are:
Live vaccines: These are used to fight both viruses and bacteria. This involves injecting a very small amount of a living virus or bacteria into the body to stimulate a response. Because only a very small dose is given, it does not cause a full-blown infection in people with a normal immune system but allows the body to create antibodies and T cells, allowing the body to be primed in case it ever encounters the real virus.
Examples of live vaccines include MMR (measles, mumps and rubella) and Varicella (chickenpox). The nasal flu vaccine also delivers a live, although weakened, virus as part of the vaccine.
Inactivated vaccines: These are also used to fight both viruses and bacteria. Here, pieces of the protein coat are injected. In the case of viruses, by only giving a piece, it is impossible for the virus to replicate, but the body can still learn to create a defense system.
The injected flu vaccine, the pneumonia vaccine, the HPV vaccine and the vaccine against meningitis are examples of inactive vaccines.
Another important concept is the way viruses spread between people, i.e. the mode of transmission, as this gives us an idea how to prevent spread and protect athletes.
Fomite: Fomites are inanimate objects that can become contaminated. Infectious agents deposited by one person can potentially be transmitted to a subsequent person. To be successful, not only does the virus have to live on the surface, it has to be transferred to another person and maintain the ability to infect them. Recent studies show there is no fomite transfer of the virus that causes COVID-19.
The idea of viral particles on inanimate objects brings up the proper way to clean surfaces and objects. According to the Environmental Protection Agency, there are different levels of “clean.”
Fecal-oral: The virus is excreted from one person and then enters the gut of another person – often due to poor sanitary conditions and poor hygiene.
Airborne: The virus is breathed, coughed or sneezed and enters the respiratory tract of other people.
Aerosol: The virus is suspended in the air and can be spread great distances. A classic example is Tuberculosis.
The importance of hand washing
Hand washing is an easy but very effective way to stop viral spread. All soap works by breaking down the protein coat, drying out the virus and killing it. Washing with soap for 20 seconds allows enough time for the soap to react with the viral coat and break it down. Soap is more effective than hand sanitizer at killing viruses, and all soaps are anti-bacterial and anti-viral.
A few comments about COVID-19
The novel virus, SARS-CoV-2, is a new strain of the coronavirus and diseases caused by it are called COVID-19, because the virus was discovered in 2019. There are a few characteristics that make the SARS-CoV-2 virus successful. Like any other virus, the infected cells trigger the body’s immune system, which tries to destroy the virus; however, uniquely, the COVID-19 virus can intercept the immune system, replicating before a person shows symptoms. Furthermore, when the immune system does finally attack the virus, it goes into overdrive, suffocating and/or negatively affecting the organs it is trying to save.
The COVID-19 virus binds to a specific receptor, which has been found in numerous organs and explains the symptoms that it produces. These receptors are found in the lung, heart, esophagus, kidneys, bladder and intestine. The symptoms of COVID-19 can take up to 14 days to appear. The six most sensitive symptoms are: cough, sore throat, fever, muscle or joint aches, fatigue, and headache.
Treatment and Prevention
Most viral infections resolve on their own. Treatment is aimed toward making the patient more comfortable and supporting the immune system with rest and hydration. Unlike bacterial infections, viral diseases don’t respond to antibiotics, so prevention is important. Wearing a mask helps reduce the spread of airborne infections, while keeping surfaces clean helps kill fomites and frequent handwashing helps reduce spread.
Vaccines have nearly eliminated many deadly viral diseases in developed countries, but this takes years to perfect. As our society deals with the current viral pandemic, staying abreast of the rapidly evolving science can help our athletes get back to sport in a way that protects the health and safety of all of those involved in athletics.
Neha P. Raukar, MD, MS, CAQSM, is an emergency medicine and sports medicine specialist at the Mayo Clinic in Rochester, Minnesota, and a member of the NFHS Sports Medicine Advisory Committee.