Respiratory Syncytial Virus (RSV) is a highly contagious virus that infects the lungs and breathing passages. It is so prevalent that almost all children contract the virus at least once by the age of two, though it infects people of all ages. RSV typically follows a seasonal pattern, with outbreaks occurring from the fall into the late spring months. While often causing a mild illness resembling a cold, this virus can lead to serious complications in specific populations.
How RSV Spreads
RSV is primarily transmitted through respiratory droplets expelled when an infected person coughs or sneezes. These droplets can travel a short distance and enter another person’s body through the eyes, nose, or mouth. Transmission also occurs through direct physical contact, such as kissing a child with the virus.
The virus is capable of surviving on surfaces and objects for several hours, contributing significantly to its spread. An individual can contract the virus by touching a contaminated surface, like a doorknob or crib rail, and then touching their face. The incubation period, the time between exposure and the onset of symptoms, typically ranges from two to eight days.
Common Respiratory Signs
Initial RSV symptoms often mimic those of a common cold, beginning with signs of an upper respiratory tract infection. These usually include a congested or runny nose, sneezing, and a mild, dry cough. A low-grade fever is also frequent in the early stages of the illness.
As the infection progresses, symptoms can worsen, indicating the virus has moved into the lower respiratory tract. This progression can lead to a more severe cough or wheezing. Wheezing occurs as the small airways in the lungs become inflamed and narrowed. These respiratory symptoms generally develop slowly over several days.
Gastrointestinal Symptoms and Vomiting
The question of whether RSV causes vomiting is relevant, especially in infants, where gastrointestinal symptoms can occur. While RSV is primarily a respiratory virus, non-respiratory symptoms, including vomiting and diarrhea, are sometimes present, particularly in young children. Vomiting is not a universal symptom, but it can be caused by a few different mechanisms related to the infection.
One common reason for vomiting is the significant increase in mucus production due to the respiratory infection. Infants may swallow large amounts of this mucus from postnasal drip, which can irritate the stomach lining and trigger a vomit reflex. Furthermore, the fever and systemic inflammatory response the body mounts to fight the virus can disrupt normal digestive processes.
Decreased appetite and feeding difficulties associated with severe nasal congestion also contribute to vomiting in babies. When an infant is struggling to breathe through a congested nose, feeding becomes difficult, and any swallowed milk or formula may be quickly rejected. This helps explain why vomiting, when it occurs, is often more related to the mechanical effects of the illness rather than a direct gastrointestinal infection.
Identifying High-Risk Groups and Urgent Warning Signs
While most healthy individuals experience only mild, cold-like symptoms, certain groups face a higher risk of developing severe RSV disease requiring hospitalization. Infants under six months of age are particularly vulnerable because of their small airways and developing immune systems. Premature babies and young children with underlying conditions, such as congenital heart disease or chronic lung issues, are also at an elevated risk.
Older adults, especially those aged 65 and above, and individuals with weakened immune systems or chronic diseases like asthma or heart failure, are prone to severe complications. Monitoring for signs of severe illness is important for these high-risk groups.
Urgent warning signs indicate a lack of oxygen or dehydration and require immediate medical attention. These signs include rapid, shallow breathing or struggling to breathe, which may manifest as retractions, where the chest or belly skin visibly pulls inward with each breath. A bluish discoloration of the lips, tongue, or skin, known as cyanosis, signals low oxygen levels. Other severe indicators are extreme lethargy, difficulty waking up, and signs of dehydration, such as decreased wet diapers or a lack of tears when crying.