Risk factors for lower respiratory complications of rhinovirus infections in elderly people living in the community: prospective cohort study

Abstract

Objective: To assess the role of rhinoviruses in elderly people living in the community. Design: Prospective community based surveillance of elderly people, without intervention. Subjects were telephoned weekly to identify symptomatic upper respiratory tract infections. Symptoms and impact of illnesses were monitored, and specimens were collected for diagnostic serology and human rhinovirus polymerase chain reaction. Setting: Leicestershire, England. Subjects: 533 subjects aged 60 to 90. Main outcome measures: Symptoms, restriction of activity, medical consultations, and antibiotic use during 96 rhinovirus infections. Adjusted odds ratios for lower respiratory syndromes with respect to smoking and health status. Results: A viral cause was established in 211 (43%) of 497 respiratory illnesses; rhinoviruses were identified in 121 (24%) and as single pathogens in 107. The median duration of the first or only rhinovirus infection in the 96 people with 107 rhinovirus infections was 16 days; 18 of the 96 patients were confined to bed and 25 were unable to cope with routine household activities. Overall, 60 patients with rhinovirus infections had lower respiratory tract syndromes; 41 patients consulted their doctor, 31 of them (76%) receiving antibiotics. One patient died. Logistic regression analysis showed that chronic medical conditions increased the estimated probability of lower respiratory rhinovirus illness by 40% (95% confidence interval 17% to 68%) and smoking by 47% (14% to 90%). There were almost six times as many symptomatic rhinovirus infections as influenza A and B infections. Conclusions: Rhinoviruses are an important cause of debility and lower respiratory illness among elderly people in the community. Chronic ill health and smoking increase the likelihood of lower respiratory complications from such infections. The overall burden of rhinovirus infections in elderly people may approach that of influenza. Rhinoviruses are responsible for more colds in elderly people living in the community than are other respiratory pathogens combined Almost two thirds of elderly people with rhino- virus infections can be expected to develop lower respiratory illness More than 40% of rhinovirus infections in elderly people are seen by medical practitioners, and three quarters of those consulting are prescribed antibiotics Risk factors for lower respiratory rhinovirus illness include chronic medical conditions and cur- rent smoking; past smoking is not an independent risk factor and stopping smoking is the only factor identified thus far that could reduce the severity of rhinovirus illness in elderly people