Objective To analyze the characteristics of methicillin-resistant Staphylococcus aureus (MRSA) colonization near nasal vestibule and factors influencing the colonization in healthy infants.
Methods A total of 530 infants meeting the conditions were included. General data of the subjects were collected using selfdesigned questionnaire. Specimens from nasal vestibule were sampled and cultured at 1, 2, 3, 4, 5 and 6 months of the selected infants. Colonization of Staphylococcus aureus (SA), MRSA, and Streptococcus pneumoniae (SP) were observed. Logistic regression analysis was used to analyze the risk factors of MRSA colonization at 6 months of age.
Results SA colonization rate was highest at 1 month of age (n=128, 24.2%), and declined gradually with age increasing (χ2=47.128, P<0.001); SP colonization rate was lowest at 1 month of age (n=20, 3.8%), and increased gradually with age increasing (χ2=52.486, P<0.001); MRSA colonization rate was highest at 1-2 months of age (n=24, 4.5%; n=15, 2.8%), and decreased to a valley (χ2=6.293, P=0.042). The results of multivariate logistic regression analysis showed that birth weight <2 500 gOR (95%CI):1.267 (1.036-3.754), P=0.042, environmental tobacco smoke exposureOR (95%CI):1.244 (1.084-4.766), P=0.045, history of hospitalizationOR (95%CI):1.539 (1.369-6.847), P=0.033, and using antibioticsOR (95%CI):1.832 (1.645-4.021), P=0.019 were independent risk factors for MRSA colonization.
Conclusion Healthy infants have a high rate of MRSA colonization at the early period than the late period in the first 6 months of life. Low birth weight, history of hospitalization, Environmental tobacco smoke exposure, and using antibiotics are independent risk factors for MRSA colonization. Strengthening hand hygiene of medical workers and hospital disinfection as well as strictly prohibiting smoking indoors would help reduce MRSA colonization.
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