Symptoms of Respiratory Syncytial Virus in Infants

The respiratory syncytial virus infection (RSV) is only dangerous for some infants. It shouldn't be a cause for concern in most cases. Currently, there's a lot of research going on to develop a vaccine against it.
Symptoms of Respiratory Syncytial Virus in Infants

Last update: 01 October, 2021

The respiratory syncytial virus (RSV) is an infection that could leave bad sequelae in infants under two years of age. However, this is rare, since most children get over it and have no further problems.

This type of infection is most common in the winter and spring months. It causes respiratory symptoms similar to those of a cold. Nevertheless, the respiratory syncytial virus precedes bronchitis and pneumonia in some infants so it’s important to be alert.

Symptoms of respiratory syncytial virus usually disappear within five to seven days. Most children get it before the age of three. Note that they only develop short-term immunity and so the disease can recur.

Reasons why the respiratory syncytial virus serious in infants

A child crying.
The respiratory syncytial virus tends to affect children under 3 years of age.

There are some cases in which a severe respiratory syncytial virus infection can occur. Indeed, this disease can occur at any age although it tends to be more severe in infants.

This is because babies don’t have well-developed airways and cannot cough up mucus as a more mature organism would. Thus, it can lead to a more serious problem like bronchiolitis or even pneumonia.

Infants most susceptible to the respiratory syncytial virus are those who meet the following criteria:

  • Infants below the age of 6 months
  • Premature or low birth weight infants
  • Children under 2 years of age with chronic lung disease
  • Those under 2 years of age with heart problems
  • Infants with a weakened immune system due to another illness or treatment
  • Children with neuromuscular disorders, especially if they limit swallowing or coughing
  • Maternal smoking during pregnancy or exposure to secondhand smoke at home
  • A history of allergy or eczema
  • Living in crowded conditions

Main symptoms of a respiratory syncytial virus

The symptoms of respiratory syncytial virus disease are similar to those of the common cold. However, it’s important to closely monitor the course of the infection for any signs of worsening.

Common symptoms

The usual symptoms of RSV are:

  • Fever
  • Dry cough or with phlegm
  • Runny nose
  • Nasal congestion
  • Sneezing
  • Irritability
  • Lack of appetite
  • Low energy
  • Wheezing

Severe symptoms

The appearance of other more severe symptoms is usually an indicator that the infection worsened. The following manifestations are good indicators of it:

  • Fast or labored breathing
  • Fluttering in the nostrils
  • Rhythmic grunting when breathing
  • The stomach moves and there’s pulling in the lower part of the neck or between the ribs when breathing
  • Noticeable wheezing
  • The rib cage sinks and forms a “V” when breathing
  • Lethargy or slow movements
  • Sleepier than normal
  • The baby might stop breathing

Possible complications

The main complication occurs when respiratory syncytial virus disease progresses to bronchiolitis. This is an inflammation of the small airways of the lung. Also, the bronchi can become inflamed and lead to bronchitis.

Pneumonia, an infection in the lungs, occurs in the most severe cases and can be life-threatening. Estimates indicate that two out of every 100 children with respiratory syncytial virus infection will require hospitalization. In addition, they may require oxygen, intubation, or assisted breathing.

The infant is also at risk of becoming dehydrated if not drinking enough fluids. This is why it’s important to keep up with their intake of breast milk or formula, water, and other fluids — if tolerated.

When to see a doctor

Symptoms of worsening usually occur between days three and five after the onset of illness. Call your doctor if the child has one or more of the following symptoms:

  • Unusually high fever that doesn’t go away
  • Thick nasal discharge
  • A cough that worsens and coughing up a yellow, gray, or green discharge
  • Wetting one diaper only every eight hours is a sign of dehydration

Other manifestations indicate a need to go to the ER:

  • Difficulty breathing or pauses in breathing
  • Bluish, purple, or grayish color of the tongue, lips, or skin
  • Visible lethargy or noticeable decrease in the baby’s activity
  • Restless or poor sleep
  • Fever higher than 104 degrees Fahrenheit
  • Symptoms that don’t improve after seven days

Diagnosis and treatment of the respiratory syncytial virus

A baby at the doctor's office.
It’s important to see a physician in the presence of respiratory syncytial virus symptoms.

Most commonly, the pediatrician will diagnose respiratory syncytial virus infection based on a baby’s symptoms. Then, they’ll also perform a detailed physical examination. They may order a nasal swab test to verify RSV when in doubt.

An oxygen saturation test or chest x-ray may also be necessary in some cases. Treatment will begin right after confirming the diagnosis as the goal is to relieve symptoms and prevent complications.

The most common measures are:

  • Drugs. Medications may be used to help open the airways if the case warrants it and sometimes also antivirals.
  • Oxygen. This is mainly for babies with difficulty breathing as additional oxygen can prevent further complications.
  • Intravenous hydration. This is for a baby that shows signs of dehydration or trouble eating or drinking.

Home care and recovery

In the absence of severe symptoms, one can efficiently treat respiratory syncytial virus infection at home. It requires taking some simple measures to relieve symptoms and help the baby recover.

Some of the measures one can take are:

  • First, promote fluid intake by breastfeeding them and giving them water (if they tolerate it).
  • Also, use a rubber bulb to remove mucus from the mouth and nose and allows the baby to breathe and eat more easily. You can also apply saline solutions to these areas for the same purpose.
  • In addition, create steam in the bathroom by turning on the hot water faucet in the shower and letting the room fill with steam. This helps reduce the inflammation of the respiratory tract and dilutes the mucus.
  • Make sure the child is as comfortable as possible.
  • A humidifier can moisten the air, this helps thin the baby’s secretions.
  • Lastly, a doctor may prescribe over-the-counter medications such as acetaminophen and such.

RSV usually resolves without complications

In most cases, respiratory syncytial virus infection resolves without problems. Thus, pay close attention to an infant with any of the risk factors.

RSV is highly contagious and, therefore, the best way to prevent it is not to expose the baby to crowds or sick people. Finally, keep in mind that breastfeeding is an excellent antidote against all types of infections.

It might interest you...
Respiratory Diseases in Newborns
Step To Health
Read it in Step To Health
Respiratory Diseases in Newborns

Respiratory diseases in newborns can be life threatening. Thus, an early diagnosis is the key. Read on to learn more about this!



  • Naclerio, R. M., Bachert, C., & Baraniuk, J. N. (2010). Pathophysiology of nasal congestion. International Journal of General Medicine, 3, 47.
  • González Barredo, M. (2016). Presencia de aleteo nasal y frecuencia respiratoria alta en pacientes con disnea. Valoración enfermera en triage.
  • Benitez, J. A., Brac, E. S., Frías, L., & Aguirre, O. (2007). Virus sincitial respiratorio aspectos generales y básicos sobre la evolución clínica, factores de riesgo y tratamiento. Rev Posgrado Med, 171, 8-12.