Effect of cleaning and disinfection of toys on infectious diseases and micro-organisms in daycare nurseries.

Ibfelt, T.
Engelund, E.H.
Schultz, A.C.
Andersen, L.P.
Journal of Hospital Infection 89(2), 109-115.


The purpose of this study is to explore whether systematic cleaning and disinfection of toys can reduce the bacterial load and respiratory viruses in daycare nurseries and thereby reduce sickness absence among children in Danish daycare nurseries.


The study shows that respiratory virus DNA/RNA was widespread in the nurseries, but that very few pathogenic bacteria were found. The intervention reduced the presence of viruses that cause different types of disease (adenovirus, which affects the mucous membrane in the upper respiratory tract, the external eye or the intestinal tract, rhinovirus, which is a respiratory virus/cold, and respiratory syncytial virus, which is a respiratory virus) compared with the control group, but the intervention had no effect on sickness absence or disease patterns in the nurseries. The authors conclude that although cleaning and disinfecting toys every two weeks can decrease the microbial load in nurseries, it does not appear to reduce sickness absence among nursery children.


The study is based on samples of bacteria and viruses collected at 12 nurseries in the City of Copenhagen. The study includes data on sickness absence and disease patterns for a total of 587 children between the ages of six months and three years. The nurseries were randomised to intervention and control groups (six nurseries in each group). The intervention, which was carried out by a commercial cleaning company, consisted of washing and disinfecting toys and linen every two weeks for three months.

Data on sickness absence and disease patterns was recorded every day for all the children in the study from December to March. The number of children who were absent and the cause of absence was recorded by the nursery staff within the following categories: respiratory infections, gastrointestinal infections, other types of sickness absence and days off. Moreover, ten sampling points in each nursery were examined for bacteria and respiratory viruses before and after introduction of the intervention. The samples were taken from ten pre-defined areas in the nursery environment; seven from the play area and three from the toilet area. The samples were subsequently analysed as to whether bacteria and viruses were present.



Ibfelt, T., Engelund, E.H., Schultz, A.C. & Andersen, L.P. (2015). Effect of cleaning and disinfection of toys on infectious diseases and micro-organisms in daycare nurseries. Journal of Hospital Infection 89(2), 109-115.

Financed by

This work received funding from the Danish Council for Technology and Innovation under the Ministry of Science, Innovation and Higher Education as part of the Sundhed i Børneinstitutioner (health in ECEC centres) innovation consortium.