RSV virus: a very deadly “nasty cold” in infants

In 7-9% of infant deaths under 6 months, babies carried respiratory syncytial virus (RSV), according to a study published in the journal The Lancet Global Health. According to the authors, the most affected babies, and therefore the most vulnerable to RSV, were those under three months of age. Finally, during their work, the scientists also discovered that two thirds of these deaths did not take place in hospital, which means that the children had not been medically monitored and therefore had no received adequate care.

RSV is dangerous for fragile children and infants

RSV is a virus that affects the respiratory tract, i.e. the nose, the trachea, the respiratory ducts in the lungs and the lungs themselves. This is very common and benign in children, with cold-like symptoms. But for those who are fragile or for infants – whose respiratory system is developing – RSV can be more dangerous because they are therefore at greater risk of developing severe forms. A worrying phenomenon, especially since there are currently no effective drugs or vaccines to stop it.

Infant mortality due to RSV is underestimated

Until now, studies have estimated that around 120,000 infants die of RSV each year. But this figure was underestimated, because it only counted deaths that took place in hospitals. Thus, the authors of this new study wanted to better quantify infant mortality due to RSV. “The fact that there are more deaths in young infants under 3 months can be explained by two main reasonsexplains Christopher Gill, lead author of this study. The first is that very young infants have very small airways and are more susceptible to RSV infections. Then, the two new solutions proposed to prevent RSV infections – vaccination of mothers and infant monoclonal antibodies (that is to say manufactured specifically to treat this disease) – are very effective when given but protection decreases over time“.

72% of RSV deaths were in infants under 3 months old

To reach this conclusion, the authors analyzed data from a study of infant mortality from pertussis virus in Zambia over a three-year period. The scientists took nasal swabs and PCR tests from the infants who died. They were aged from four days to six months. In detail, they observed that 9% of these deaths did not take place in hospital, compared to 4% to 5% in a hospital environment. On the other hand, about 72% of deaths occurred in infants under 3 months.

A problem of access to care

The researchers were thus able to determine that RSV was the direct cause of the death of 2.8% of infants. A percentage that rose to 4.7% among babies who were not in a hospital environment. “Our previous work has shown that there are delays in finding and accessing appropriate care in most poor countries, says Rachel Pieciak, one of the study’s authors. The management of RSV infections tends to rely heavily on certain care such as oxygen (…) but we assume that the majority of infants in our study (conducted in Zambia) died before they even had access to this basic care”.