Young children growing up in towns and cities suffer more chest infections than those who grow up in the countryside, according to research presented at the European Respiratory Society International Congress in Milan, Italy.

Two studies, presented at the Congress and published in Pediatric Pulmonology, shows that factors such as attending day care, living in a damp home or near dense traffic increase the risk of chest infections in young children, while breastfeeding reduces the risk.

Researchers say that some children, who are otherwise healthy, can suffer with repeated chest infections, so it is important to understand why this is and look for ways to help.

The first study was presented by Dr Nicklas Brustad, a researcher on the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) based at the University of Copenhagen, Denmark. It included 663 children and their mothers who took part in the research from pregnancy until the children were three years old. Researchers recorded whether the children were growing up in urban or rural areas and how many respiratory infections they developed. This revealed that children living in urban areas had an average of 17 respiratory infections compared to an average of 15 infections in children living in rural areas.

The researchers also carried out detailed blood tests on the mothers during pregnancy and on their new-born babies, and analysed the children’s immune systems when they were four weeks old. They found that children living in urban areas had different immune systems compared to those living in rural areas.

Dr Brustad said: “We don’t know why babies and young children living in towns and cities suffer more infections than those growing up in the countryside, but we did take account of factors like air pollution and attending day care. Our results suggest that the environment children live in can have an effect on their developing immune system before they are exposed to coughs and colds. We want to do more research to understand how and why this happens.”

The second study was presented by Dr Tom Ruffles from BSMS and University Hospitals Sussex NHS Foundation Trust, Brighton, UK. It included data on 1,344 mothers and their children living in Scotland and England. The mothers completed detailed questionnaires when their children were one year old and again when their children where two years old. These included questions on chest infections, symptoms such as coughing and wheezing, respiratory medication, and exposure to potential environmental risk factors.

Analysis of the questionnaires revealed that breastfeeding for longer than six months helped protect babies and children from infections, while attending day care increased the risk. Young children living in homes with visible damp were twice as likely to need treatment with an inhaler to relieve respiratory symptoms and twice as likely to need treatment with a steroid inhaler. Living in an area with dense traffic increased the risk of chest infections and exposure to tobacco smoke increased the risk of cough and wheezing.

Dr Ruffles said: “This research provides some important evidence about how we can help reduce chest infections in babies and toddlers. The benefits of breastfeeding are well-established, and we should continue to support mothers who want to breastfeed their babies. We should also be making every effort to reduce exposure to infections at day care, keep homes free of damp and mould, reduce tobacco smoking and cut air pollution.”

Co-researcher Professor Somnath Mukhopadhyay, Chair of Paediatrics at BSMS and University Hospitals Sussex NHS Foundation Trust, added: “The link between damp mouldy housing and the need for these very young children to take asthma treatments emphasises how urgently we need legislation to tackle mould and damp in social housing. For example, here in the UK we want to see rapid implementation of Awaab’s Law, which will force social landlords to fix damp and mould within strict time limits.” Awaab’s Law was proposed following the death of two-year-old Awaab Ishak, caused by the damp and mould in his local-authority home.

European Respiratory Society spokesperson says: “We know that some young children suffer with recurrent coughs and colds, and this can lead on to conditions such as asthma as they grow older. It’s important that we understand any factors that might be contributing to this, such as the conditions where children live and where they are cared for. The more we understand about these factors, the more we can do to protect the developing lungs of these young children.”

Dr Katy Fidler, Consultant in Paediatric Infectious Diseases at BSMS, said: "This research really highlights the importance of a variety of modifiable environmental factors on infant respiratory infections and symptoms and needs to be addressed urgently. This could help reduce not only infant morbidity, but potentially also reduce both NHS costs and parental loss of earning costs, by reducing infant illness."

Read the full paper here >