Respiratory syncytial infection (RSI) is a disease caused by respiratory syncytial virus (RSV). Respiratory syncytial virus (RSV) is a virus in the family Pneumoviridae and genus Orthopneumovirus that affects the respiratory system in people of all ages and usually causes mild "cold" symptoms such as cough and runny nose. Most patients recover in 1-2 weeks. However, in patients from medical risk groups, the disease can be severe and lead to hospitalization and even death: in particular, in infants under 6 months and people over 60 years old with concomitant diseases.
The circulation of RSV is seasonal: usually the incidence of respiratory syncytial infection increases in autumn and reaches peak values in winter; in general, the disease season lasts from November to April-May in countries with a temperate climate. According to WHO data , RSV is the world's most common cause of lower respiratory tract diseases in all age groups.
Symptoms of the disease usually appear 4-6 days after infection. The following symptoms are most often observed:
Symptoms usually occur in stages rather than all at once. In infants, only irritability, reduced activity and difficulty breathing can be observed.
Almost all children encounter the virus and develop RSI by the age of 2 years.
Be sure to seek medical help if the child has difficulty breathing, does not drink enough fluids, or his condition worsens.
Although the course of the disease is mild in most cases, in some cases - particularly in infants and the elderly - the disease can be complicated by bronchiolitis (inflammation of the small airways in the lungs) and pneumonia ("inflammation of the lungs"). RSI is the most common cause of bronchiolitis and pneumonia in children under 1 year of age, which can sometimes be fatal. Also, according to WHO data, there is an increase in the number of hospitalizations among patients over 65 years of age, as well as deaths among elderly patients with concomitant diseases or a weakened immune system (this number approaches the number of deaths due to influenza in this group of patients). The risk of a severe course in adults of any age increases in the presence of concomitant chronic lung diseases, cardiovascular diseases, and functional disorders . The risk of hospitalization for RSI is also increased in infants and immunocompromised patients. A high mortality rate is observed in RSV-infected patients after bone marrow or lung transplantation.
Who belongs to the risk group of severe RSI?
In some cases, RSI can worsen the course of chronic diseases, such as:
In case of a severe course of the disease, elderly people with RSI may be hospitalized. Fatal cases are also possible. The risk of serious complications is higher in the elderly because their immune system works less efficiently due to advanced age.
Antiviral agents are not recommended for the treatment of RSI. In most cases, symptomatic and supportive therapy is used. Most patients recover without specific treatment within 1-2 weeks. However, in some patients, the disease can be severe.
How to relieve symptoms?
Usually, healthy adults and children with RSI do not require hospitalization. However, some patients - in particular, people over 60 and babies under 6 months - may need it if they have breathing difficulties or are severely dehydrated. In the most difficult cases, the patient may need additional oxygen (oxygen therapy), connection to a ventilator, or drips to prevent dehydration. In most cases, hospitalization lasts only a few days.
The virus is transmitted by aerosol or contact:
Almost all children encounter the virus before the age of 2 years. However, in the future, it is possible to re-infect at any age.
People infected with RSV are usually contagious for 3-8 days (although they can start infecting others a day or two before symptoms appear). However, some babies, as well as adults with weakened immune systems, can spread the virus even after the symptoms stop - up to 4 weeks.
Children often become infected with RSV outside the home - for example, in schools or kindergartens - and infect family members.
Currently, the FDA ( American Drug Safety Agency) has approved for use two vaccines against RSV:
The Arexvy vaccine manufactured by GSK is recommended for adults over 60 years old , (in particular, for those of them who have chronic diseases, a weakened immune system, live in homes for the elderly or are constantly in a medical institution; the decision on the need to vaccinate a specific patient from this age group is taken by a doctor). Currently, this group is recommended to receive a single dose of the vaccine.
Abrysvo vaccine manufactured by Pfizer is recommended for adults over 60 years of age , (in particular, for those of them who have chronic diseases, a weakened immune system, live in nursing homes or are permanently in a medical facility; the decision on the need to vaccinate a specific patient from this age group is taken by a doctor) and pregnant women . The purpose of vaccinating a pregnant woman is to protect the baby during the first months of his life. The recommended timing of vaccination is from 32 to 36 weeks of pregnancy. Currently, one dose of the vaccine is recommended for these groups. (However, since the primary purpose of vaccinating a pregnant woman is to protect the baby, vaccination should be carried out during each pregnancy).
Note : On May 31, 2024, the FDA approved a third RSV vaccine for adults 60 years of age and older, the mRESVIA mRNA vaccine, so the CDC guidelines will be updated soon to reflect this information.
As for infants and young children, there are currently no vaccines recommended for use in this age group. However, the FDA approved a drug to protect against RSI by the so-called of passive immunization - nirsevimab (trade name - Beyfortus). Nirsevimab is a monoclonal antibody that provides the patient with "ready-made" antibodies to fight the virus (in contrast to the vaccine, which stimulates the independent production of antibodies by the body of the vaccinated person). The drug is usually administered to infants whose mothers did not receive the RSV vaccine during pregnancy.
For babies from certain risk groups (in particular, premature newborns and babies with bronchopulmonary dysplasia), another monoclonal antibody - pavilizumab - is still used . This drug requires monthly administration throughout the disease season - (from November to April-May in countries with a temperate climate)
It is also important to note that since RSI is usually transmitted by contact with infected secretions through the hands or with aerosol droplets, isolation of the sick, use of protective masks and hand hygiene are important to prevent the spread of infection.