RSV severity increases with genetic variant and environmental factors

RSV severity increases with genetic variant and environmental factors | Courtesy of
An international team of scientific investigators has discovered that combining a specific gene mutation with an urban environment increases the chance that children will contract severe infections of respiratory syncytial virus (RSV).

Experts estimate half the infants around the world are infected with RSV. Between 1 and 2 percent of these infants must receive hospitalization because of the severity of their infections.

The study pinpointed a specific sub-population of children who have increased risks for severe RSV. The researchers analyzed two independent populations of infants to determine how much genetic variants in TLR4 -- a receptor that signals the need for an immune response -- and environmental factors influence the severity of RSV infections.

The results showed that a specific genetic mutation in TLR4 increases the severity of RSV infections in infants living with urban middle-class families. In contrast, this same mutation correlates with mild RSV infections in infants from rural areas. These TLR4 mutations are protective measures that the human body takes when it is exposed to bacteria in the environment. This is why the mutation behaves differently in urban and rural environments.

The study results have furthered the understanding of these children’s RSV infections, making it possible for researchers to develop treatments that will decrease the risk of severe RSV infections in infants.