Responsible for more than 100,000 pediatric hospitalizations in the United States every year, respiratory syncytial virus (RSV) is considered to be the major cause of respiratory infections in infants and young children [1] [2]. In fact, it is estimated that virtually all children up to age 3 will become infected with RSV, almost universally in a symptomatic fashion [3]. However, several reports have emphasized its role as a respiratory pathogen across all age groups, including adults and the elderly, and approximately 11,000-17,000 deaths in the United States are attributed to RSV every year [4] [5]. In milder cases, the clinical presentation is comprised of a cough, wheezing, fever, croup, and nasal congestion, with bronchiolitis being the most common type of infection [2] [6]. In some patients, otitis media may be the initial manifestation of RSV infection [3]. More severe forms, however, such as pneumonia, have been encountered more commonly in patients who exhibit any of the following risk factors: immunosuppression (B or T-cell inherited immunodeficiencies, human immunodeficiency virus infection, immunosuppressive therapy after marrow transplantation), premature birth, cyanotic congenital heart disease, chronic obstructive pulmonary disease (COPD), and older age [1] [3] [6] [7]. Severe pneumonia can be life-threatening, both in infants and in adults, suggesting that an early diagnosis is pivotal.

Having in mind the rather common occurrence of RSV infection in clinical practice, particularly in young children, the physician must include this viral pathogen in the differential diagnosis of respiratory infections. The first step during workup is a thorough patient (or parent) interview that will assess the presence and course of symptoms, as well as the existence of any of the mentioned risk factors that could predispose to a more severe form of infection. The physical examination, particularly lung auscultation, is equally important, after which laboratory studies should be conducted. Microbiological testing is the cornerstone for the diagnosis of RSV infection, as the clinical presentation is nonspecific [7], and several methods have been described in the literature. Initially, viral cell cultivation was considered as the optimal procedure for isolation of RSV but the introduction of more rapid and also more reliable tests has removed it from regular use [5] [6] [8]. Direct antigen detection through immunofluorescent or enzyme immunoassays (IFA and EIA) has shown to be an efficient test to recognize RSV, but even better results are obtained through molecular studies that evaluate the presence of viral genetic material, such as polymerase chain reaction (PCR) and reverse-transcriptase PCR (RT-PCR) [4] [6] [8]. Unfortunately, their cost still is a major limiting factor [5].

There is no specific antiviral treatment for RSV infection. Management primarily focuses on relieving symptoms. This can include ensuring adequate hydration, using over-the-counter pain relievers to reduce fever, and employing humidifiers to ease breathing. In severe cases, particularly in infants, hospitalization may be necessary to provide oxygen therapy or mechanical ventilation.

The prognosis for RSV infection is generally good, especially in healthy children and adults. Most people recover within one to two weeks. However, infants, elderly individuals, and those with underlying health conditions may experience more severe illness and complications. In these cases, close monitoring and supportive care are crucial.

RSV is caused by the respiratory syncytial virus, a member of the Paramyxoviridae family. It is an RNA virus that primarily infects the epithelial cells of the respiratory tract. The virus is highly contagious and spreads through direct contact with respiratory secretions or contaminated surfaces.

RSV is a global health concern, with annual outbreaks occurring during the fall, winter, and early spring months in temperate climates. It is the most common cause of bronchiolitis and pneumonia in children under one year of age. Nearly all children are infected with RSV by the age of two, and reinfections can occur throughout life.

RSV infects the epithelial cells lining the respiratory tract, leading to inflammation and increased mucus production. This can cause airway obstruction, particularly in infants with smaller airways. The immune response to the virus can also contribute to airway inflammation and damage, exacerbating respiratory symptoms.

Preventing RSV infection involves good hygiene practices, such as frequent handwashing, avoiding close contact with infected individuals, and cleaning contaminated surfaces. In high-risk infants, a medication called palivizumab may be administered to help prevent severe RSV disease. There is currently no vaccine available for RSV, but research is ongoing.

Respiratory Syncytial Virus infection is a common and contagious respiratory illness that primarily affects young children but can also impact adults. While most cases are mild and self-limiting, severe infections can occur, particularly in vulnerable populations. Diagnosis is based on clinical evaluation and, if necessary, laboratory tests. Treatment focuses on symptom relief, and prevention relies on good hygiene practices.

If you or your child experience symptoms such as a runny nose, cough, or difficulty breathing, it may be due to RSV infection. Most cases are mild and resolve on their own, but it's important to monitor symptoms, especially in young children and the elderly. Practicing good hygiene can help prevent the spread of RSV. If symptoms worsen or you have concerns, consult a healthcare professional for further guidance.

1. Walsh EE. Respiratory syncytial virus infection in adults. Semin Respir Crit Care Med. 2011;32(4):423-432.
2. Lanari M, Giovannini M, Giuffré L, et al. Prevalence of respiratory syncytial virus infection in Italian infants hospitalized for acute lower respiratory tract infections, and association between respiratory syncytial virus infection risk factors and disease severity. Pediatr Pulmonol. 2002;33(6):458-465.
3. Ogra PL. Respiratory syncytial virus: the virus, the disease and the immune response. Paediatr Respir Rev. 2004;5 Suppl A: S119-126.
4. Walsh EE, Falsey AR. Respiratory syncytial virus infection in adult populations. Infect Disord Drug Targets. 2012;12(2):98-102.
5. Popow-Kraupp T, Aberle JH. Diagnosis of Respiratory Syncytial Virus Infection. Open Microbiol J. 2011;5:128-134.
6. Falsey AR, Walsh EE. Respiratory Syncytial Virus Infection in Adults. Clin Microbiol Rev. 2000;13(3):371-384.
7. Falsey AR. Respiratory syncytial virus infection in adults. Semin Respir Crit Care Med. 2007;28(2):171-181.
8. Falsey AR, Formica MA, Walsh EE. Diagnosis of Respiratory Syncytial Virus Infection: Comparison of Reverse Transcription-PCR to Viral Culture and Serology in Adults with Respiratory Illness. J Clin Microbiol. 2002;40(3):817-820.