INTRODUCTION: According to hospital-based studies, increased susceptibility to certain infections is associated with genotypes that cause low serum levels of the protein mannose-binding lectin (MBL). However, the contribution of MBL insufficiency to the incidence of common childhood infections on a population basis is unknown. To investigate the effect of MBL insufficiency on the risk of acute respiratory infections (ARI) in unselected children, we performed a prospective population-based study of ARI in young children in Sisimiut, Greenland. MATERIAL AND METHODS: An open cohort of children aged 0-2 years was formed in 1996, and followed up with weekly morbidity surveillance visits for a two-year period. Episodes of ARI were diagnosed on medical history and clinical examinations. MBL genotypes were determined from blood samples according to the presence of structural alleles and promoter alleles. RESULTS: Altogether 294 children participated and 44 refused. Blood samples were taken from 252 participants. A 2.1-fold (95% confidence interval 1.4-3.1) increased risk of ARI was found in MBL-insufficient children compared with MBL-sufficient children (p
Acute respiratory infections cause considerable morbidity among Inuit children, but there is very little information on the risk factors for these infections in this population. To identify such factors, the authors performed a prospective community-based study of acute respiratory infections in an open cohort of 288 children aged 0-2 years in the town of Sisimiut, Greenland. Between July 1996 and August 1998, children were monitored weekly, and episodes of upper and lower respiratory tract infections were registered. Risk factor analyses were carried out using a multivariate Poisson regression model adjusted for age. Risk factors for upper respiratory tract infections included attending a child-care center (relative risk = 1.7 compared with home care) and sharing a bedroom with adults (relative risk = 2.5 for one adult and 3.1 for two adults). Risk factors for lower respiratory tract infections included being a boy (relative risk = 1.5), attending a child-care center (relative risk = 3.3), exposure to passive smoking (relative risk = 2.1), and sharing a bedroom with children aged 0-5 years (relative risk = 2.0 for two other children). Breastfeeding tended to be protective for lower respiratory tract infections. The population-attributable risk of lower respiratory tract infections associated with passive smoking and child-care centers was 47% and 48%, respectively. The incidence of acute respiratory infections among Inuit children may be reduced substantially through public health measures.