Viral infection

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at March 29, 2016
StartDiseasesViral infection

Those who have a viral infection may mistake it for a bacterial infection, and they may end up seeking the wrong treatment for it. Viral infections require a different set of treatments from bacterial infections, so it is important to know what a virus is, what the symptoms and causes of viral infections are, and how viral infections should be treated.


Definition & Facts

A virus is a microscopic organism that invades a cell by attaching itself to the cell wall and injecting the cell with its DNA or RNA. This genetic material takes over the cell and makes it reproduce the virus which causes the cell to die. Once the cell dies, it releases the reproduced viruses where they can infect other cells. There are many different kinds of viral infections with a range of symptoms.

Symptoms & Complaints

People can come down with a number of symptoms when they develop a viral infection which depend entirely on the kind and severity of the viral infection. There is a wide gulf between the common cold and Ebola virus disease, for example. However, typical complaints of viral infections such as the common cold and influenza include:

If a person has a viral upper respiratory tract infection and one or more of these complaints lasts for more than 5-7 days, then that person should contact a doctor. If any of these symptoms gets worse like having a high grade fever or red spots appear on the skin, then the person should see a doctor immediately for treatment.

Some viral hemorrhagic fevers cause a high fever, severe joint pain and muscle pain, headaches, rashes, and bleeding from the orifices. Zika virus may cause birth defects in children such as microcephaly.


Viruses can be spread in a variety of ways based on the composition of the virus. Some viruses are spread from person to person through coughing, sneezing, hand shaking and sex. Viruses can be transmitted to people who eat or drink food or water that has been contaminated with fecal matter and then ingested; this type of transmission is called the fecal-oral route. Other viruses are arboviruses which means that they are carried by arthropods including insects like mosquitoes, flies and ticks who infect people when the insect bites them.

Many people feel climate change is causing the spread of viruses that were once almost exclusive to places with warm tropical climates. Some of these viruses that are now starting to be seen in places like the US and southern Europe are the Zika virus, the West Nile virus, the Crimean-Congo hemorrhagic fever virus and the Rift Valley Fever virus to name a few.

Diagnosis & Tests

Because people often confuse viral infections with bacterial infections, it is important for them to get an accurate diagnosis so that they can get the proper treatments and medication. There are three diagnostic methods physicians will use when dealing with a possible viral infection.

First, they will look at the physical symptoms because some viruses, like the ones that cause measles and chickenpox, are easily noticeable. Second, physicians will check to see if there are any other similar cases or epidemics in the area. Third, they may need to order blood tests and culture samples for a more specific diagnosis.

Physicians will use a variety of blood and culture tests to determine the type of virus a person may have. These include antibody tests, antigen detection tests, viral cultures and viral DNA and RNA detection tests. For these tests, blood samples, urine samples, stool samples, organ tissue samples, cerebrospinal fluid samples collected during a spinal tap, and saliva testing may be used depending on the type of virus a person is suspected to have.

These tests are also used in a variety of ways to assess risk and screen out possible contaminants such as during organ transplants, blood donations, checking a health professional’s exposure to a virus and checking on the risk of a pregnant woman passing a virus onto her unborn child.

Treatment & Therapy

The body puts up natural defenses against viral infections starting with the skin, but if a virus gets inside the body, then the body’s immune system tries to defend against the virus. The immune system’s defense response is to produce white blood cells which attacks the virus and tries to destroy it and the infected cell. When the body’s natural defenses are unable to destroy the virus, then other treatments will be needed.

In the cases of gastroenteritis and common cold, there is no effective over-the-counter antiviral medication that can provide a cure, and treatment only temporarily relieves the bothersome symptoms. This treatment may involve drinking plenty of fluids, using nasal decongestants, taking a topical anesthetic that numbs the throat via lozenges or sprays, using moisturizing creams or taking over-the-counter anti-inflammatory medication.

There are some antiviral drugs that do not provide a cure against viral infections, but they help to interfere with the ability of the virus to replicate itself and to help strengthen the body’s immune system. These antiviral drugs are used to fight against or treat influenza, herpes, hepatitis C and HIV.

Prevention & Prophylaxis

People are exposed to viruses every day and can come down with a viral infection in a variety of ways. It is easy to develop a viral infection, but there are ways in which people can reduce their chances of getting sick depending on how the underlying virus is transmitted. One of the easiest ways people can stop the spread of viruses is to frequently wash their hands and cover their coughing and sneezing.

Practicing food safety helps stop the spread of viruses that cause foodborne illness. Using protection when having sex is instrumental in preventing viruses that cause STD's like herpes, HIV, and HPV.

Thankfully there are vaccines available for many viral infections including the MMR vaccine for measles, mumps, and rubella, chickenpox vaccine, HPV vaccines, yellow fever, and influenza vaccines.