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Posted by Dr. Monica Wonnacott | January 23, 2016

What Is A Virus?

Kids with viruses constitute a large portion of my “sick visits” in a given day. Naturally, I field a lot of questions about viruses. I’ve included below some good, basic information about viruses.

What is a virus?

(Here is the science lesson for today). A virus is a microscopic (too small to see) infectious agent. Each viral particle is made up of DNA or RNA genes and has a protein coat surrounding the genes. Some viruses have a fat envelope around the protein coating. There are millions of different viruses that affect essentially every ecosystem on the earth.

How are viruses spread?

Viruses are spread in every method possible.

  1. Respiratory viruses, the cough and runny nose type, are spread by respiratory droplets. For example, an infected person coughs and millions of infectious particles get spread in the air. An unsuspecting person then breathes in the air and is now infected. Another way to spread a virus is from all the infected particles in the snot of a runny nose. For example, a sick person doesn’t wash his or her hands after blowing his or her nose (or worse after wiping with one’s hands) and then touches an object. Soon after, an unsuspecting person touches the same (now infected) object and then touches his or her face and the virus enters the body.
  2. G.I. viruses, the vomit and diarrhea type, are spread by the fecal/oral route. Again, if infected people don’t wash their hands after using the bathroom and then touch something, that something now has a virus on it. If an unsuspecting person then touches the infected object (e.g., a door handle) and then touches his or her mouth, he or she is then infected.
  3. Other methods of transmission include sexual contact or exposure to infected blood. HIV is the most noteworthy virus transmitted in this way.

What treatment is there?

There is no medicine, or antibiotic, that can cure a virus. This is why your doctor usually doesn’t give you any medicine after diagnosing a virus. There are a few special viruses or cases in which medications can be used to modify or slow viral replication. For example, an antiviral medication like oseltamivir (Tamiflu) can be used for the Influenza virus if caught early (while the virus is still replicating) to decrease the severity of symptoms and shorten the duration of illness. HIV medications are another example of antiviral medications created to stop the replicating virus and thereby increasing an infected person’s lifespan. For most viruses, there are no modifying antiviral medications. Your body’s own immune system usually works better than anything medicine can offer at overcoming viruses.

Why won’t my doctor give me an antibiotic? What’s the harm, just in case?

If your doctor thinks that your illness is causes by a virus, an antibiotic will not treat the virus. Antibiotics are used to treat bacteria only. In fact, giving an antibiotic when the cause is a virus only contributes to antibiotic resistance.

How long do viruses last?

The average virus lasts 7-10 days. This is why your doctor says things like, “Come back if things aren’t better after a couple of weeks,” or “Let me know if your symptoms get worse, not better.” After the initial few days, most people tend to recover and get better as their body conquers the virus. Of course, there are always exceptions to the rule. Epstein Barr Virus (EBV, which causes Mononucleosis) symptoms can last for weeks. Other viruses, like Herpes, stay in your system permanently, waiting to be reactivated. Some viruses, like HIV, will ultimately kill you.

What are the symptoms?

Just about any symptom can be caused by a virus. The most common symptoms are cough, runny nose, sore throat, vomiting, diarrhea, rash, and fever. However, some bacterial infections can cause the same symptoms. For example, strep throat is a bacterial infection which should be treated with an antibiotic. It usually causes sore throat, headache, fever, and abdominal pain (in younger children).

Should I see my doctor?

You should see your doctor if you have isolated symptoms, sharp or localized pains, or unusual symptoms. If your symptoms have persisted for a long time (keep in mind the average virus lasts 7-10 days) or are getting worse, you should also see a doctor. Finally, if you are concerned, uncertain, or have questions, it is probably a good idea to see your doctor.