An individual-based network model to evaluate interventions for controlling pneumococcal transmission.
BACKGROUND
Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide, but also a common colonizer of the upper respiratory tract. The emergence and spread of antibiotic resistant pneumococcal strains has threatened effective therapy. The long-term effects of measures aiming to limit pneumococcal spread are poorly understood. Computational modeling makes it possible to conduct virtual experiments that are impractical to perform in real life and thereby allows a more full understanding of pneumococcal epidemiology and control efforts.


METHODS
We have developed a contact network model to evaluate the efficacy of interventions aiming to control pneumococcal transmission. Demographic data from Sweden during the mid-2000s were employed. Analyses of the model's parameters were conducted to elucidate key determinants of pneumococcal spread. Also, scenario simulations were performed to assess candidate control measures.


RESULTS
The model made good predictions of previous findings where a correlation has been found between age and pneumococcal carriage. Of the parameters tested, group size in day-care centers was shown to be one of the most important factors for pneumococcal transmission. Consistent results were generated from the scenario simulations.


CONCLUSIONS
We recommend, based on the model predictions, that strategies to control pneumococcal disease and organism transmission should include reducing the group size in day-care centers.
Karlsson
Diana
D
Molecular Biology, School of Life Sciences, University of Skövde, SE-541 28 Skövde, Sweden. diana.karlsson@his.se
Jansson
Andreas
A
Normark
Birgitta Henriques
BH
Nilsson
Patric
P
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D003140:Communicable Disease Control / Q000379:methods; D003198:Computer Simulation; D004812:Epidemiologic Methods; D006801:Humans; D007223:Infant; D008875:Middle Aged; D008954:Models, Biological; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D012307:Risk Factors; D013296:Streptococcus pneumoniae; D013548:Sweden / Q000453:epidemiology