Interpersonal relationships and group A streptococcus spread in a Mexican day-care center

Résumé 0

"Objective. To study the effect of different degrees ofcentrality on the carrying of identical group A streptococcus(GAS) clones in the nasopharynx of children from aMexican public day-care center. Material and Methods.Nasopharyngeal cultures were performed in children fromrooms B (RB) (n = 35) and C (RC) (n = 37). The RestrictionFragment Length Polymorphism (RFLP) patterns were comparedamong GAS isolates. A social networks questionnairewas filled out for each child and 10 classmates. Structurecoefficients were compared among children with and withoutGAS. Results. Four GAS clones were identified; clone I infive children from RC; clone II in two from RC and one fromRB; clone III in one from RB and one from RC; and clone IVin one from RC. Social network structure: Density of RB andRC = 0.40 (± 0.87) and 0.35 (± 0.80), respectively. In RB, thehomophily pattern of interaction was different in carriers(0.00), non-carriers (0.47) and both (0.47) p = 0.35. In RC,the homophily pattern was also different in carriers (0.46),non-carriers (0.68) and mixed (0.19), p = .001. In 4/5 withclone I, the values of degree, closeness and betweennesswere above the group mean. In 3/3 with clone II, the valuesof degree and betweenness were also above the mean. Incontrast, in those with clone III and IV, the values of degree,closeness and betweenness were below the group mean.Conclusions. The spread of specific GAS clones was associatedwith groups of children having a high proportion ofties and a high centrality level. This is evidence that spreadof GAS strains among children attending day-care centers isnot random but dependent on the degree of communicationand physical contact between pairs."