COVID-19 vs. Flu vs. RSV: How to tell the difference between respiratory infections

A respiratory tract infection is an infection of the lungs, airways, sinuses, or throat. While respiratory infections occur year-round, there is a significant increase in these infections during the fall and winter months (cold and flu season) when people tend to spend more time inside,

During cold and flu season, it helps to know the common symptoms and how to avoid spreading illness to those around you. With the increasing cases of COVID-19, understanding the difference between common respiratory infections and your treatment options is even more important. In this blog, we provide information to help you prepare for the upcoming respiratory virus season.

What is the difference between the flu, COVID-19, and RSV?

The flu, COVID-19, and respiratory syncytial virus (RSV) are all highly contagious respiratory infections caused by viruses: The flu by influenza virus, COVID-19 by SARS-CoV-2 virus, and RSV by respiratory syncytial virus. It is possible for a person to be infected with multiple viruses at the same time.

What causes the flu?

The flu is caused by the influenza virus and spreads easily during the winter months when people spend time together indoors. There are many strains of influenza virus, and the virus can change from year to year, which is why you should get a flu vaccine each year.

What causes COVID-19?

COVID-19 is caused by SARS-CoV-2, a new coronavirus. Coronaviruses are a family of viruses named for their corona-like shape. Sometimes, the general term “coronavirus” is used with COVID-19, but this is technically incorrect because there are many types of coronaviruses in this family, including SARS-CoV-1 which emerged in 2002 and other coronaviruses that commonly infect humans. While a vaccine against SARS-CoV-2 is not yet available, several candidate vaccines are in development.

What causes RSV?

RSV is caused by the respiratory syncytial virus, a highly contagious virus that can infect children and adults. In adults and older children, RSV is typically a mild illness very similar to the common cold. In infants and the elderly, the symptoms can be more severe.

What are the symptoms of the flu, COVID-19, and RSV?

According to the CDC, the flu and COVID-19 share very similar symptoms, and it might be hard to tell which of the two you have. It can take longer for people infected with SARS-CoV-2 to show symptoms and people stay infectious longer than with the flu. A symptom that seems to be unique to COVID-19 is loss of taste or smell. Both viruses can cause:

• Fevers
• Chills
• Headaches
• Cough
• Muscle soreness
• Fatigue
• Vomiting
• Diarrhea
• Shortness of breath
• Runny nose
• Sore throat

RSV can infect anyone, but is most dangerous in infants and the elderly. Its symptoms are similar to those of the common cold. They tend to run their course with only mild intensity in adults and older children. In infants and elderly, symptoms tend to be more severe, and can include fevers and wheezing. Some cases may require hospitalization, but most infections run their course within 1 to 2 weeks. A baby contracting RSV may require a lot of attention until recovery. However, be on the lookout for serious symptoms that can indicate a need for emergency treatment. If your baby is unusually tired, breathing rapidly or has bluish fingernails, call 911 or go to the ER immediately.

How do I determine if I have COVID-19 or the flu?

Since the symptoms are so similar, the best way to accurately determine whether you have COVID-19 or the flu is to get tested.

COVID-19, Flu, RSV Combined Test

The COVID-19, Flu, RSV combined test is an option if you would like to determine what type of infection you have. The test determines if you are currently infected with SARS-CoV-2, influenza A/B, and/or respiratory syncytial virus (RSV) and is available through doctors, hospitals, and other authorized healthcare providers nationwide. We recommend reaching out to your doctor or a healthcare provider for more information.

At-home collection kit

If you are experiencing symptoms and would like an easy way to determine if you are infected with SARS-CoV-2 (the virus that causes COVID-19), an at-home kit may be an option for you. 

Labcorp OnDemand offers a COVID-19, Flu and RSV at-home collection kit for individuals ages 2 and up. To collect your sample, you will use one nasal swab that is short and only entered into the lower nostril making it quick, easy, and pain-free. 

How do I treat the flu, COVID-19, and RSV?

Viruses are significantly different from bacteria, and treatments such as antibiotics won’t work on viral infections. Your body responds to infections, including infection with SARS-CoV-2, by producing antibodies, either on its own or with the help of a vaccine. Antibodies are proteins that your immune system designs to target specific infections. Antibodies are very specialized and are tailor-made for a particular strain or type of a virus or bacteria. For this reason, vaccines against influenza and other viruses won’t protect you against SARS-CoV-2 and vice versa.

There are currently multiple FDA-authorized vaccines for SARS-CoV-2, but some drugs and treatments can help combat disease once they occur. If you think you might be infected, ask your provider about treatment options. Additionally, a COVID-19 test can help determine if your symptoms are caused by SARS-CoV-2.

How do I prevent the flu, COVID-19, and RSV?

You can drastically decrease your odds of contracting the flu by getting a flu shot. There are many locations to get the vaccine including from your local provider, pharmacies, and grocery stores. The flu shot you get each year is designed to protect against that year’s anticipated most common strains of flu.

Engaging in proper hygiene practices with your baby can reduce the risk of infections including RSV. Avoid placing your baby in contact with anyone who exhibits symptoms of the common cold, wash your hands regularly, and don’t let anyone smoke around your baby.

You can reduce the risk of contracting COVID-19 by getting vaccinated and following CDC guidelines. It’s always important to wash or sanitize your hands regularly.