RSV, the “tripledemia” virus that puts babies at risk in America

Several countries in Latin America and the Caribbean continue to report a high number of cases of respiratory syncytial virus (RSV), the main cause of severe respiratory infections in children under one year of age, while in the United States the situation is beginning to stabilize after the saturation of its pediatric units, regional health sources explained to Efe.

RSV is part of the current wave of respiratory viruses called “tripledemia”, a simultaneous upsurge in cases of COVID-19, influenza and respiratory syncytial virus that has led health authorities in America and Europe to strengthen prevention and treatment measures. , especially in the child population.

RSV produced an increase in hospitalizations in countries such as Canada, Mexico, Brazil, Uruguay and the United States, mainly affecting premature babies and children under one year of age.

Syncytial virus and its rebound in America

RSV is a causevery common infection of the lower respiratory tract (bronchial tubes, bronchioles, and air sacs) that can affect people of any age, but can be serious, especially in infants and the elderly”, Dr. Andrea Vicari, head of the Infectious Threat Management Unit of the Pan American Health Organization (PAHO), warns Efe.

“Pneumonia and bronchiolitis are the leading causes of mortality among infants with RSV and the common cause of acute respiratory infection in young children.”, adds the PAHO expert.

In fact, a study published in May of last year in The Lancet confirmed that the respiratory syncytial virus was responsible in 2019 for more than 100,000 deaths worldwide in children under five years of age and 97% of deaths occurred in countries low and middle income.

And it is premature babies, with chronic lung disease (chronic lung disease or bronchopulmonary dysplasia, cystic fibrosis), with congenital heart disease or with immunodeficiencies who have a higher risk of suffering complications and hospitalization due to RSV.

North America and the Southern Cone, the most affected

RSV activity normally peaks in the winter months, with a variable pattern in the tropics. However, this winter season the number of hospitalizations of minors has been higher.

Vicari mentioned the most recent data from PAHO, corresponding to the epidemiological week of December 27, 2022, which indicate that syncytial virus activity remains high in North America, but with a downward trend.

In the Caribbean, the islands of Martinique and Guadeloupe reported increases in RSV; in Central America cases rose in Guatemala, while in Panama they fell; and in Brazil and Chile increased virus activity continued.

This rise has been linked to a post-pandemic phenomenon known as “immune debt”, since due to COVID-19 the children stayed at home and limited their social interaction, which also led to their not being exposed to other viruses and not developing their respective defenses.

In this regard, Dr. Rubén Ruiz Santa Cruz, from the Latin American Association of Pediatrics (Alape) and former president of the Pediatric Association of Guatemala, explained to Efe that the alarm was triggered in the region due to the high occupancy in hospitals, due to a rise in cases in the United States and South America that had not been seen during the pandemic.

“Theories point to an immune gap because if a child hasn’t been exposed to the virus, their immune system obviously won’t respond to something they haven’t come into contact with.”, adds this intensive care pediatrician.

Actions before the VSR

Symptom care, which includes continuous coughing or wheezing, rapid breathing, and fever, remains the cornerstone of RSV, as there is no vaccine approved by regulatory authorities.

Vicari explained that most infections by this virus are “self-limit“in one to two weeks, although young infants are at higher risk of serious complications and hospitalization for infection.”

In that case, “passive immunization with monoclonal antibodies -palivizumab- is an appropriate intervention to reduce severe acute respiratory infection by RSV in infants at risk”, underlines the PAHO expert.

Palivizumab corresponds precisely to a monoclonal antibody, an artificial protein that acts on the immune system, and is a technology approved by the United States Food and Drug Administration and the European Medicines Agency.

Palivizumab reduces hospitalization rates by preventing “severe RSV disease in certain infants and children who are at high risk”, such as those born prematurely, with congenital heart disease or bronchopulmonary dysplasia, according to the US Centers for Disease Control and Prevention.