Most adults who get RSV end up with a mild cold for just a few days, but the virus can be much more dangerous in infants. RSV infection is the leading cause of hospitalization for all infants, often leading to life-threatening conditions such as pneumonia and bronchitis. To understand why babies are so vulnerable to RSV, scientists had to take a closer look inside their noses.
In a new study published in the journal Infection logResearchers have observed how RSV affects children and adults differently through “mini-noses”—tiny, lab-grown models of nasal tissue that contain the same types of cells as a real nose. In infant nasal models, cells have been shown to have much greater difficulty with RSV infection; Understanding the mechanisms underlying this cellular fight may be the key to improving RSV treatments for the youngest patients.
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Symptoms of RSV in infants
RSV (respiratory syncytial virus) is a common viral infection in both adults and children. In fact, almost all children will be infected with RSV by the time they are 2 years old. However, infants are at greatest risk of developing severe symptoms. According to the Centers for Disease Control and Prevention (CDC), two to three out of every 100 children under 6 months of age are hospitalized with RSV each year.
Minor RSV Symptoms in infants include irritability, fatigue and mild breathing problems that may go away on their own within a few days. However, in some cases, the infection worsens and spreads to the lower respiratory tract; According to the American Lung Association, one of the first signs during this stage is a barking or wheezing cough.
If this is followed by more serious symptoms, such as a flared nose, bluish lips or nails, or difficulty breathing, your child needs emergency care.
According to the CDC, severe complications of RSV in infants can be prevented either by maternal vaccination during pregnancy or by immunizing infants with injections of monoclonal antibodies against RSV.
Cells inside a mini nose
In a new study, scientists created models of the nose (also known as organoids) following a naresal swab in both infants and adults. The material from these swabs was then grown into three-dimensional “mini-tissues” that the researchers could study to find several types of cells, including ciliated cells with hair-like structures that sweep out mucus, basal cells that regenerate tissue, and goblet cells that produce mucus.
Comparing the infant and adult models, the researchers found that the infant model contained more mucus-producing cells. This explains why one of the main dangers of infants contracting RSV is excessive mucus clogging the nasal passages.
The study confirmed that RSV primarily infects ciliated cells, but also showed that the virus infects additional cell types in infants.
“In infants, RSV did not stop at ciliated cells. It also infected basal cells and ionocytes, rare cells involved in airway fluid regulation. These infections were not observed in adults,” said co-author Pedro Piedra, professor of molecular virology and microbiology at Baylor College of Medicine, in his paper. statement. “This broader 'tropism,' or range of target cells in infants, may be associated with RSV causing more severe disease in young children.”
Protecting infants from RSV
In addition to the loss of ciliated cells, infant nasal patterns were affected by a number of other cellular changes; An increase in goblet cells promotes mucus accumulation, and a decrease in the number of club cells, which help maintain healthy airways, leads to a higher risk of inflammation and tissue damage.
Infant cells also had a less coordinated response to infection compared to adult cells, allowing RSV to spread more efficiently through the respiratory tract.
Now that researchers have the first detailed atlas of nasal cells in adults and infants, they say identifying age-related differences could help them develop more effective treatments for RSV infections in infants.
This article does not contain medical advice and should be used for informational purposes only.
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