Respiratory syncytial virus affects the upper and lower airways. It is the most common cause of respiratory infections, especially in premature babies, infants and small children. Since their immune system is not yet fully developed, severe courses occur again and again, in very rare cases even death. People with immunodeficiency or suppressed immune systems are also at risk. In healthy adolescents and adults, on the other hand, an RSV infection is usually harmless. Because RSV also occurs more frequently in the cold season and has almost identical symptoms, the two infections are similar in terms of the clinical picture.
The symptoms of an RSV infection can vary in severity – the infection can range from a simple respiratory disease with a cough, runny nose and some fever to severe pneumonia that requires ventilation. However, the infection can also run its course without any symptoms (asymptomatic). Especially in infants in the first months of life, an infection with RSV can lead to dangerous bronchitis, pneumonia or simultaneous inflammation of the trachea and bronchi (tracheobronchitis). At the beginning of the infection there is a runny nose, a dry cough and sometimes a sore throat. After one to three days, the lower respiratory tract (bronchi, lungs) can also be affected – with a stronger, productive cough, shortness of breath and even shortness of breath. The general condition can deteriorate significantly: affected children do not want to drink or eat, have to throw up, are weakened – and suffer from shortness of breath to the point of shortness of breath. In severe cases, the bronchioles can become narrowed and congested, which makes it difficult to breathe out (“silent obstruction”) – there is also accelerated breathing and poor oxygen saturation with a bluish discoloration of the skin. Since the symptoms of those affected vary greatly and can deteriorate quickly, those affected may have to be repeatedly presented to a doctor or observed in the hospital as an inpatient.
RS viruses are mostly transmitted by droplet infection. The viruses enter the body via the conjunctiva of the eyes or the nasal mucosa. It is assumed that infection can also occur via contaminated objects, surfaces and hands. For example, the virus can survive in cough or runny nose secretions for 20 minutes on hands, 45 minutes on paper towels and up to several hours on plastic surfaces. And people with no or only a few symptoms can also transmit the virus unnoticed – and also children who have already received a so-called passive vaccination. In principle, one can become infected with RS viruses at any age. There is no long-term immunity. Adults in particular who are in regular contact with small children often become infected more than once.
The incubation period is between two and eight days. Infected people can pass on RSV as early as a day after infection – before they even develop symptoms.
Infected people with a healthy immune system are usually contagious for up to eight days. However, premature and newborn babies and those with weakened or suppressed immune systems can be infectious for several weeks.
RSV is particularly dangerous for premature babies and children with previous lung diseases or certain heart defects. Boys are about twice as likely as girls to be hospitalized for RSV. However, high-risk patients with chronic heart or lung diseases and immunocompromised or immunosuppressed sufferers of all ages also have a particularly high risk of developing severe pneumonia when infected with RSV. A common complication of RSV infection is acute otitis media. As a long-term complication after an RSV infection, hyperexcitability of the airways (bronchial hyperreactivity) can lead to paroxysmal constriction of the bronchi with wheezing, shortness of breath, chest tightness and coughing.
Within their first year of life at least half and by the end of the second year almost all children have experienced at least one RSV infection. But then you are not immune to the virus. Reinfections are common – in particular, adults who have regular contact with small children are repeatedly infected. In children, RSV reinfection can affect the lower respiratory tract again – but usually less severely than with the initial infection. The illness lasts about three to twelve days – but the cough can last up to four weeks or longer. In adults, RSV infections are often asymptomatic or as a respiratory disease with flu-like symptoms such as fatigue, runny nose, non-productive cough, possibly bronchitis or fever.
Children under the age of one who have a febrile cold infection and children who have had a high fever for more than three days should be seen by a doctor. Alarm signals for which you should go to the doctor immediately are shortness of breath, rapid and heavy breathing or crackling breathing noises. The same applies if the children stop drinking or cough so hard that they throw up. Very young children up to three months old can already be seriously ill if they do not yet have a fever but appear listless overall and refuse to drink.
Sick people should drink enough and try to keep their airways as free as possible, for example by using nasal rinses and nose drops. In the case of severe courses, oxygen administration in the hospital or even ventilation with machines are necessary. So far there is neither a vaccination nor effective medication against RS viruses. According to the RKI, however, there is preventive antibody therapy for children who are particularly at risk.
So far, no vaccine has been approved for active immunization. An antibody (palivizumab), which is administered once a month during the RSV season, is available for the passive immunization of only small risk patients. However, the maximum protective effect is only achieved after the second dose. Adhering to hygiene rules such as regular hand washing, hygienic coughing and sneezing and cleaning children’s toys and other objects that may be contaminated can minimize the risk of infection. Infected children should not visit community facilities such as day care centers and toddler groups while they are contagious in order to protect other children.