[Forms of care and children's infections. 1. Occurrence and causal factors].

On an average, preschool children have 6-8 acute infections annually. This corresponds to approximately 80 sick-days including mild colds. If days in which the general health is affected only are included, approximately 25 days per child per annum are concerned. The amount of sickness in children attending day care centres is between 2-7 times as great as that of children cared for in their own homes. In particular, an increased risk has been demonstrated for children attending day care centres to develop conditions such as secretory otitis media, pneumonia, gastroenteritis, hepatitis A and meningitis. A close dose-response connection can be demonstrated between ill health and the number of children with whom the child is cared for. The increased possibilities of exposure to infection in day institutions must, therefore, be assumed to be the central factor for the excess morbidity demonstrated. The significances of a series of modifying factors in the pathogenesis, including age, genetically determined immunity, psychosocial stress, atmospheric contamination, quality of atmosphere and low temperatures, are reviewed. Despite the term "colds", there is no evidence that upper respiratory infections have any connection with cooling. With the object of establishing rational measures against spread of infection, the occurrence and routes of infection of the relevant microorganisms are reviewed. About 80% of the infections must be presumed to be viral. In children attending day care centres, viruses have been demonstrated in 10% of the children without symptoms. Air-borne infection appears to be responsible for a very limited proportion of infections. The routes of infection are mainly by direct or indirect contact infection e.g. via tables and toys.(ABSTRACT TRUNCATED AT 250 WORDS)