Spanish scientists have identified risks for contracting pneumonia caught outside hospital.
They found that regular contact with children, abrupt temperature fluctuations in the workplace, smoking, excessive alcohol consumption and certain treatments involving inhalers increased risk of the condition.
Jordi Almirall, lead researcher and an intensive care specialist at the Hospital de Mataró in Barcelona and colleagues, carried out a case–control study of patients aged 14 upwards from 64 primary care centres in eastern Spain in the study in this month’s European Respiratory Journal.
They recorded all suspected cases of pneumonia acquired outside hospital over 13 months. Patients were also given a chest X-ray to confirm diagnosis, which was repeated until recovery.
1,336 patients with confirmed community-acquired pneumonia were compared with 1,326 control subjects. 53% were men with an average age of 59.
Some medical treatments appeared to increase susceptibility to infection. For example, amiodarone, oxygen therapy and corticosteroid treatment. Inhalers also increased risk of infection 1.5 times. This was particularly the case when spacers were used.
Heavy drinking (over 40g of alcohol daily) increased the risk of pneumonia in men. This went up 2.64 fold where there were large fluctuations in workplace temperature.
“Basic research on humans and animals has shown that breathing in cold air cools the nasal epithelium, and this drop in temperature within the nose weakens the airways’ defence against infections” said Dr Almirall.
Living with more than ten people, living with children and contact with pets were also risk factors. However, being single, widowed or divorced was also independently associated with a higher risk for pneumonia than being married or living with a partner – although the authors say they don’t know why.
In contrast, those who had visited the dentist within the previous month had a 30% lower risk of pneumonia. Influenza vaccination cut the risk by 20% and pneumococcus vaccination by 46%.
“Timely medical care and preventive strategies directed towards the general population or those patients at risk are relevant measures for reducing the incidence of community-acquired pneumonia,” the authors concluded.
Eur Respir J 2008; 31: 1274–84