RSV is short for respiratory syncytial virus. The name of the virus derives from the syncytia. This is a tricky term, as it refers to clusters of cells visualized on electron micrographs, where the nuclei of infected patient cells have fused with nearby cells to form one big multinucleated cell. Hence the name.
A virus like that is found only in parts of the globe, giving rise to such diseases. It is a single-stranded RNA virus and a cause of seasonal lower respiratory tract disease.
Children are more likely to get RSV, but adults do get sick as well, especially seniors and the immunocompromised. RSV is the main cause of disease – acute respiratory infection in children. Not only is acute illness caused by RSV, but long-term sequelae develop in some patients with very severe infections. Sometimes, this progresses into chronic inflammation of the respiratory tract.
Decades of study have prepared us to know more about how to diagnose and treat such a virus. At the same time, there is no treatment (mostly supportive) yet. With effective treatments hard to find, new antiviral drugs are being tested with growing optimism over their potential. There is also a vaccine for RSV out there—researchers are working on this right now—for which we may also get good protection. Learn more about this organism that causes an infection.
Different immunodeficiency states in children and adults can also increase the risk of contracting RSV infection and disease. One example is HIV infection, which can greatly increase the severity of this disease process. Curiously, the season and the climate also aid in the emergence of this viral infection. Worldwide, RSV infections are seasonal. Temperate regions prevent the active disease from being expressed as infection late in autumn, winter, and spring. Still, the tropical and Arctic climates have conditions where the disease is possible all year. Although seasonality is usually associated with low temperatures and high precipitation, epidemics can also occur in warm, rainy seasons under a more tropical climate.
RSV is an enveloped virus of the Pneumovirus genus that can undergo antigenic variations, resulting in large pandemics. The pathogen was first isolated from a colony of chimpanzees in 1956. It was subsequently found to be isolated from several infants and identified as a human virus. After RSV penetrates the body via mucous membranes in the nostrils or mouth, it focuses on and contaminates airway epithelial cells within the higher respiratory tract. Halfway down, the lower respiratory tract is involved, and the virus proceeds to the bronchioles, where viral replication may be preferentially more efficient.
Respiratory syncytial virus (RSV) is a major global microbe responsible for substantial morbidity and mortality. It is also the most common cause of diseases like pneumonia and bronchiolitis in infants. Pneumonia mainly impacts the under-5 age group. Around the first 6 months of life, children have the highest probability of dying. Most children who have RSV infections have no comorbidities. Who is more prone to be treated in hospital: Low birth weight and prematurity, congenital or acquired immunodeficiency, cardiovascular diseases, chronic lung disease, and neurodevelopmental disorders.
RSV is also known to take a toll on many adult populations at high risk. The significant ecological impact on older people needs to be better quantified, with the consensus being that the virus is also relatively dangerous (inherently high risk) to this group. Hospitalization for RSV infection is rare in otherwise healthy, immunocompetent adults. However, the situation of RSV infection is so high that it is estimated to be at least of the same order of magnitude as an influenza burden of disease in the old age population. Adult mortality associated with RSV is an emerging public health concern, given the population aging seen in the Western world.
If a patient replicates the virus particles, they can infect other people, which is considered contagious. Infected people carry the virus until it is shed. Virus shedding is highly variable and dependent on several factors. Adults typically shed the virus for between three and seven days post-infection. The virus can be shed (spread) for up to 14 days to 3 weeks in infants. The immunosuppressed, however, can continue to excrete the virus for months after infection.
Many respiratory viruses are known to be moved by multiple modes of transmission, as the scientists tell us. The droplet routemainly transits RSV. But also by viruses that give disease from dirty surfaces. These droplets may land on various surfaces as they disperse and travel through the air. Surfaces: At least a few hours (may survive longer on surfaces). Thus, there is a need for protective measures such as disinfection.
Besides minimizing contact with patients with the virus, to reduce RSV transmission from person to person, frequent disinfection of surfaces contaminated with the virus and washing hands with soap and water is also recommended. Otherwise — sneezing and coughing into your elbow will do the virus transmission prevention trick, but we know it's hard to stop a sneeze.
The virus is a highly contagious microbe with epidemic potential. That is something to be mindful of in hospitals and outside in the wild during the season of disease, too. The disease shows in a spectrum from mild to severe and is characterized by disseminated inflammation due to the infection. It is suspected that exposure to cigarette smoke is associated with more severe disease. As RSV infection corresponds to symptom-free infection, virus transmission is possible from patients to others. The RSV can cause respiratory infections in children, but the disease differs from adults. Below, find the precise RSV signs and symptoms you can identify.
Children infected with RSV present with a spectrum of clinical illnesses. The range can be mild to life-threatening in the very young. In newly born children, virus is more contagious than in older children, with an increased risk for a severe course.
This viral infection typically begins with typical infectious symptoms, such as a high body temperature and cough. In contrast, conjunctival symptoms are associated with rhinitis and pharyngitis in children. In children, nasal congestion and generalized malaise may culminate in feeding problems and dehydration. The tympanic membrane can be erythematous and progresses to otitis media less often. Children with the right care experience a viral disease that goes away without any significant repercussions if the disease does not progress further.
One-third of infants with viral respiratory infection develop lower respiratory tract involvement, most often as bronchiolitis, although pneumonia and laryngotracheitis (croup disease) also occur. A lower respiratory leap may be engendered at the terminal phase of RSV contagion. In that case, they might need some mechanical ventilation if hospitalized. Thus, clinicians should determine whether respiratory failure symptoms indicate a patient merits hospital admission. Bronchiolitis, as manifested by wheezing audible to parents, is characterized by progressive loss of respiratory function.
Other clinical signs include nasal discharge, rib congestion, and cyanosis. There are also flu-like symptoms: fever, fatigue, etc. Moreover, some infants vomit, which makes children particularly vulnerable to dehydration. Sometimes, apnea—a temporary halt in breathing—can be one of the first signs of the disease in very young infants. Some extrapulmonary symptoms are rare, and they may include seizures, arrhythmia, heart failure, and hepatitis.
The disease is itself prolonged and results in long-lasting sequelae. So chronic infection doesn't only amplify the health burden of acute infection. It also leads to lung function impairment due to chronic airway disease. Many people do not see the consequences. Infections with respiratory syncytial virus (RSV) during infancy have been linked to childhood and adult allergies and asthma, particularly those that are severe. Still, the reasons for this susceptibility have not been fully understood. Those infected extremely soon in life experienced a greater rate of wheezing later in life and long-term lung injury. The same is true for children with a more serious disease.
RSV infection will be mild for adults with a working immune system and no concomitant diseases. But for those at risk, particularly older people, the sick, and patients with weakened immune systems, the risk of a severe course is even higher than for children. Thus, older persons die more from this viral infection.
Healthy adults also experience a RSV infection. They deal with the virus far better than kids do. The symptom range is limited in most adults with RSV infection. Fever and malaise with a sore throat contribute to upper respiratory symptoms. Coughing and other lower respiratory tract symptoms are also reported. The disease resolves independently after some time, and the patient heals without significant problems and difficulties.
The more serious course of the disease is found in those with weakened immunity, in patients with cardiovascular disease, and in the elderly. This type of population tends to present with lower respiratory tract involvement. The disease begins with nasal mucosa congestion, followed by cough (90% of cases) in adults and elders. Unlike with influenza, systemic symptoms (e.g., fever, myalgias, and gastrointestinal complaints) are less common. Unlike other respiratory viral illnesses, wheezing is also frequently observed.
In addition to these hallmark pulmonary symptoms, otalgia or sinusitis is seen in the immunocompromised. In severe illness, the degree of immune impairment is closely related to the severity level of infection. For example, they are at the highest risk for recipients of bone marrow transplants. In patients who had a lung transplant, RSV infection can cause acute pneumonia. And it can also exacerbate existing cardiopulmonary illness.
Similarly to children, adults may have long-term complications after recovering from an acute infection. In the most severely affected adults, there may be permanent pulmonary dysfunction after a long illness course. It is relevant that RSV infection in lung transplant recipients may trigger chronic graft dysfunction associated with bronchiolitis, remodeling, and air trapping in the small airways. It also plays an important role in asthma morbidity in adults from respiratory tract diseases in the form of viral infections.
But what about the diagnosis? How simple is it to diagnose this vicious virus? You can feel like doctors get a little lax. The diagnosis of RSV infection is based on the child's symptoms, physical examination, and a discussion with the child and parents. Even though laboratory tests are not always desirable, they can provide valuable information. The elusive laboratory marker is required to identify a deadly germ and possibly direct the application of appropriate treatments. This is because other viral and bacterial indices of the respiratory tract have similar clinical symptoms.
Nasal swabs from the nose can be uncomfortable for the patient. However, they are the only basis for making a diagnosis. Although nasopharyngeal aspirates are normally used, it must also be considered that swabs present the disadvantage of lower yield results due to the lower sample collection volume. Lastly, nasal swabs in immunosuppressed patients have a low sensitivity for RSV, possibly due to lower viral load. But there is nothing we can do about it. Imaging tests can also be performed on patients. In more serious conditions, such tests are useful to examine whether bad changes have occurred.
The culture-based method for diagnosis of RSV infection has been in use for a long time. This fast and thorough classical technique enables strain typing, genomic characterization, and susceptibility testing against antiviral medication. Nonetheless, it is mainly limited to research laboratories and large hospitals because of the laborious and intricate process. Antigenic methods are also used. It would need to involve looking through a microscope at labeled proteins. Due to its simplicity and low turnaround time (<1 hour), it is widely utilized to facilitate the timely delivery of appropriate therapy.
Current guidelines do not routinely recommend chest radiographs in children with an uncomplicated course. However, if those studies happen, they give interesting signals. Findings include hyperinflation with diaphragmatic flattening, bilateral abnormal infiltrates (airspace opacities), and atelectasis. Chest X-ray can show pneumonia as well. These results suggest the lesions are caused by viral and subsequent bacterial infection.
We also do these exams in some of the older patients. Seniors are worth looking at, as they're the ones who take much of the hit throughout the condition. These are usually associated with fusible crackles on chest examination and infiltrates on chest X-ray. These exceptional assessments can also help differentiate other viral, common infectious causes, such as cytomegalovirus blackout, for which affirmation is vital.
While numerous studies have addressed other therapeutic approaches, supportive treatment is still the primary treatment modality for the infection. The good news is that most children and adults with the disease resolve spontaneously. Basic care is enough in patients with a mild course. Patients with worse symptoms might need intensive supportive care in the hospital.
What does supportive treatment mean in RSV infection? Updated guidelines issued by specialty health organizations emphasize decently supplying supplemental oxygen and hydration. Noninvasive and positive pressure ventilation strategies are used to supply oxygen. If oral hydration is insufficient, hydration may be with intravenous or nasogastric fluids.
Moreover, upper airway suctioning should also be considered for the child's respiratory distress, apnea, and feeding difficulties. This has led to some controversy, with saline also being used as an optional treatment in children. No recent guidelines recommend using antipyretics or antitussives, even though they are commonly used to treat viral infections. Chest physical therapy has also been discouraged, though it may be employed in children with comorbidities.
Treatment for bronchiolitis with pharmacologic agents. Patients receive systemic and inhaled drugs that, among other things, expand the air passages. Antibiotics are permitted if bacterial co-infection occurs, but antibiotics are not used in other cases. Improved outcomes with less progression to lower respiratory tract involvement and less mortality were seen after antiviral use in immunocompromised patients with trends towards significance. However, these drugs are not very frequently used; supportive treatment continues to be the usual way. Many new therapeutic agents are presently being studied and will be used in the future.
This absence of relevant, disease-targeted inhibitors leads researchers to do additional research. Given the global burden of infection, they are seeking methods to control infections. Sadly, it is challenging to create vaccines for RSV. Even in adults, infection does not confer long-lasting immunity, and re-infection with the same strain of virus is common. While there are some successful immunization strategies for newly born children, many vaccines need further exploration.
A certain vaccine was released in the 1960s for babies and kids, but it was not effective enough. Regardless of these challenges, numerous potential vaccines are advancing, and we have a fair level of confidence that in the next several years, at least one or more perhaps effective vaccines will make it to market. Hope is, therefore, not lost. All of this deeper understanding of RSV will aid in managing this virus.
On a more optimistic note, vaccinating against the worst is possible. There is just one vaccine, but still. Its drawbacks are that this vaccine works well but is given only to high-income countries and is expensive for all high-risk infants. But don't worry; research is still ongoing.
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