RSV: A-to-Z Guide from Diagnosis to Treatment to Prevention

Cute baby looking right into the camera. RSV can be serious in babies.

Introduction to RSV:

Very few things are more frightening than watching a small baby struggle to breathe. What is just a common cold to an adult can be a major threat for some small babies.

What is it?

RSV, or respiratory syncytial virus, is the most important respiratory infection of early childhood. The virus lives inside the cells lining the respiratory system, causing swelling of this lining coupled with the production of large amounts of excess mucus.
In adults, this shows up as a bad, lingering cold with thick nasal congestion and a deep, productive cough. In infants, however, the excess mucus can be enough to plug their small airways or bronchioles, resulting in a severe illness that requires hospitalization. RSV is the most significant cause of bronchiolitis and pneumonia in babies and young children.

Who gets it?

Almost all children have had RSV by the time they are two years old. Children who first get it under 6 months of age (or who have serious underlying illnesses) are at the highest risk for severe disease. Thankfully, severe RSV infection is very uncommon in the first 6 weeks of life, because these babies still have antibodies from their mothers.

RSV occurs throughout the world, and in each location, it tends to occur in yearly winter outbreaks. In the northern hemisphere, the peak of the epidemic is usually in January, February, or March, although in some years it may begin earlier and/or end later. Although most babies have mild illness, almost 125,000 infants are sick enough to be hospitalized with RSV each year in the United States.

What are the symptoms?

Typically, a parent, or more likely an older sibling, comes down with a bad cold first. He or she exposes the baby to the virus. The time from exposure to illness is usually about 4 days, give or take a few.

Then the infant typically develops a runny nose and a red throat. Over the next 3 days or so, the infant gets sicker. Symptoms might include cough, wheezing, and sometimes a fever or an ear infection. In most infants, this is as severe as RSV gets.

Some, though, will get progressively sicker with fast respirations (>60 per minute), difficulty breathing, and listlessness. About 3 percent of infected infants get sick enough to require hospitalization.

The specific symptoms will depend on the specific child and on the parts of the respiratory tract infected (croup, bronchitis, bronchiolitis, pneumonia, etc.). In very young babies, less than a month old, the only symptoms might be poor feeding, irritability, or perhaps lethargy.

Is it contagious?

RSV is very contagious. The disease spreads when infected droplets in the air or on the hands encounter someone else’s mouth or nose. It has never been shown to be passed from someone standing as far as 6 feet away. It can remain on the hands for half an hour, and on fomites for hours.

How long does it last?

The disease usually lasts 5 to 12 days. Most who are hospitalized are well enough to go home within a few days.

Children who are sick enough to come to medical attention and be diagnosed with RSV have an increased chance of having recurrent wheezing later in life. This is even more likely if the child has eczema or if there is asthma in the family. The older a child is (over the age of 1) with severe RSV, the higher the likelihood that the child eventually will be diagnosed with asthma.

A simple blood test may predict which children are most likely to go on and develop asthma. Several studies have shown that children with RSV bronchiolitis who had a high eosinophil count at the time of the illness had a higher chance of persistent wheezing and of developing asthma. (Pediatrics 2000; 105 (1): 79 -83).

While RSV and asthma certainly go together, even with severe RSV and a high eosinophil count, there is a good chance of avoiding asthma altogether. It is not known whether the virus damages the respiratory system thereby causing the asthma, or if people’s susceptibility to asthma predisposes them to severe RSV. I suspect that it is a little of both.

How is it diagnosed?

Rapid RSV tests are available, and are done using nasal swabs.

How is it treated?

There are no specific medicines for treating RSV at home. It is important to give plenty of fluids to prevent dehydration. Also, a humidifier or saline nose drops might be recommended to thin the mucus.

Some children need supplemental oxygen or even mechanical help to breathe. A powerful aerosol treatment specifically against RSV is sometimes used for hospitalized children.

Steroids and antibiotics are not usually helpful.

How can it be prevented?

If possible, protect your baby from exposure to sick individuals during the peak RSV season. In addition, good hand washing, particularly just before anyone handles susceptible infants, can decrease spread. Use a tissue when you cough or sneeze!

Two products are now available to prevent RSV infection in children at high risk for serious disease (e.g., infants with a history of prematurity, cardiac defects, and lung disease). RSV-IGIV (RespiGam) and palivizumab (Synagis) have been approved for high-risk children.

Related concepts:

Rhus dermatitis, Contact dermatitis

Dr. Alan Greene

As a father of four himself, Dr. Greene has devoted himself to freely giving real answers to parents' real questions -- from questions about those all too common childhood conditions to those that address the most recent and rare pediatric illnesses. His answers combine cutting edge science, practical wisdom, warm empathy, and a deep respect for parents, children, and the environment. He is also an electrifying public speaker, and has personally touched many during his talks in North America, Europe, Asia, and the Middle East.

Dr. Greene is a graduate of Princeton University and the University of California at San Francisco. Upon completion of his pediatric residency program at Children's Hospital Medical Center of Northern California he served as Chief Resident. He entered primary care pediatrics in January 1993.

Dr. Greene is the Past President of The Organic Center and on the Board of Directors of Healthy Child Healthy World. He is a founding partner of the Collaborative on Health and the Environment. He also consults for the Environmental Working Group.

In 1995, he launched, cited by the AMA as “the pioneer physician Web site” on the Internet. His award-winning site has received over 80 million Unique Users from parents, concerned family members, students, and healthcare professionals. In addition to being the founder of, he is the Medical Director for HealthTap.

In 2010 Dr. Greene founded the WhiteOut Movement to change how babies in the United States are fed. In 2012 he founded TICC TOCC - Transitioning Immediate Cord Clamping To Optimal Cord Clamping. He is also the founder of KidGlyphs, a free iPhone app that provides a tool for young children to express themselves beyond their verbal skills while teaching them important language skills.

Dr. Greene is the Founding President of the Society for Participatory Medicine and has served as both President and Board Chair of Hi-Ethics (Health Internet Ethics. He is on the Board of Directors for Healthy Child Healthy World, The Lunchbox Project, and The Society for Participatory Medicine. He has also served as an advisor to URAC for both their inaugural and their updated health web site accreditation program. He is a founding member of the e-Patient Scholars Working Group, and a founding board member of the Center for Information Therapy.

Dr. Greene is a regular columnist for Parenting Magazine. He is also the Pediatric Expert for The People’s Pharmacy (as heard on NPR) and Healing Quest (seen on PBS stations). He was the original Pediatric Expert for both Yahoo! and iVillage.

Dr. Greene is the author of Feeding Baby Green (Wiley, 2009), Raising Baby Green (Wiley, 2007), From First Kicks to First Steps (McGraw-Hill, 2004), The Parent's Complete Guide to Ear Infections (People's Medical Society, 1997), and a co-author of The A.D.A.M. Illustrated Family Health Guide (A.D.A.M., Inc., 2004). He is the medical expert for three additional books, The Parent's Soup A-to-Z Guide to Your New Baby, (Contemporary Books, 1998) The Parent's Soup A-to-Z Guide to Your Toddler, (Contemporary Books, 1999), and The Mother of All Baby Books, (Hungry Minds, Inc., 2002).

Dr. Greene is a frequent keynote speaker at important events such as Health 2.0 2011 held in San Diego, CA, IFOAM 2008 (International Federation of Organic Agriculture Movements), held in Modena Italy, the first European Internet health conference, held in Maastricht, the first International eHealth Association Conference, held in Jeddah, and the largest e-Healthcare World Conference, held in Las Vegas, and the first Green Power Baby Shower, held in Hollywood. Dr. Greene also appears frequently on TV, radio, websites, and in newspapers and magazines around the world, including such venues as the TODAY Show, Good Morning America, Fox and Friends, The Dr. Oz Show, CNN, ABC, CBS, and NBC network news, NPR, The New York Times, The Wall Street Journal, USA Today, Time Magazine, Parade, Parenting, Child, Baby Talk, Working Mother, Better Home's & Gardens, and the Reader's Digest.

Dr. Greene loves to think about challenging ideas, he enjoys being where nothing manmade can be seen, and he wears green socks.

Get Dr. Greene's Wellness Recommendations

Sign up now for a delightful weekly email with insights for the whole family. Plus Dr. Greene's FREE Top 5 Wellness Tips For 2017.