Staphylococcus aureus in the Community: Colonization Versus Infection

Abstract

BackgroundAntibiotic-resistant Staphylococcus aureus infections have increased dramatically in the community, yet S. aureus nasal colonization has remained stable. The objectives of this study were to determine if S. aureus colonization is a useful proxy measure to study disease transmission and infection in community settings, and to identify potential community reservoirs.Methodology/Principal FindingsRandomly selected households in Northern Manhattan, completed a structured social network questionnaire and provided nasal swabs that were typed by pulsed field gel electrophoresis to identify S. aureus colonizing strains. The main outcome measures were: 1) colonization with S. aureus; and 2) recent serious skin infection. Risk factor analyses were conducted at both the individual and the household levels; logistic regression models identified independent risks for household colonization and infection.Results321 surveyed households contained 914 members. The S. aureus prevalence was 25% and MRSA was 0.4%. More than 40% of households were colonized. Recent antibiotic use was the only significant correlate for household colonization (p = .002). Seventy-eight (24%) households reported serious skin infection. In contrast with colonization, five of the six risk factors that increased the risk of skin infection in the household at the univariate level remained independently significant in multivariable analysis: international travel, sports participation, surgery, antibiotic use and towel sharing. S. aureus colonization was not significantly associated with serious skin infection in any analysis. Among multiperson households with more than one person colonized, 50% carried the same strain.Conclusions/SignificanceThe lack of association between S. aureus nasal colonization and serious skin infection underscores the need to explore alternative venues or body sites that may be crucial to transmission. Moreover, the magnitude of colonization and infection within the household suggests that households are an underappreciated and substantial community reservoir.

Prevalence of Community-Acquired Methicillin-Resistant Staphylococcus aureus Nasal Colonization Among Children

“…This might be due to poor hygiene and overcrowding. Recent studies have demonstrated the importance of close contacts within households and with parents in spread of S. aureus carriage among children residing in the same household [23,24]. In our study, history of hospitalization prior to one year, visits to hospitals or clinics and contact with the health care workers were not statistically significant factors associated with nasal carriage of S. aureus, as in contrast to other studies [5,6,[25][26][27].…”

Trends in Methicillin-Resistant Staphylococcus aureus Anovaginal Colonization in Pregnant Women in 2005 versus 2009

“…While the rate of anovaginal colonization has been shown to be lower than colonization of the anterior nares when assessed in the same subjects (0.3 to 1% versus 2 to 4%) (19,28,30), a recent study of S. aureus nasal colonization in northern Manhattan, New York City, NY, the catchment area for our institution, demonstrated that the prevalence of MRSA colonization of the anterior nares was 0.4% (24). Thus, MRSA anovaginal colonization may be lower in our population due to a lower overall prevalence of MRSA in our community.…”

Frequency of Colonization and Sensitivity of Staphylococcus aureus in a group of health children in Asunción

“…Todavía existen datos escasos sobre la portación nasal de SA en Paraguay en niños en edad escolar. La mayoría de los estudios publicados se basan en la búsqueda de la colonización en fosas nasales, sin embargo, algunos autores consideran que es necesaria la obtención de más de un tipo de exudado cuando se realizan estudios para la localización de portadores, como (13,17) por ejemplo, exudado axilar o de región inguinal .…”

“…Con una población humana en crecimiento, el medio microbiano en nuestro país debe ser estrechamente monitorizado, especialmente con los recientes informes de propagación mundial de (4,(10)(11)(12)(13) resistencia a los antibióticos .…”

“…Se sugieren como factores de riesgo que seleccionan y condicionan la colonización por este tipo de cepas: las hospitalizaciones prolongadas, las intervenciones quirúrgicas, pacientes admitidos en una unidad de cuidados intensivos, el uso irracional de antibióticos, contacto con animales, presencia de comorbilidades, antecedentes de infecciones en la piel, el nivel socioeconó-mico, hacinamiento, número de hermanos, la asistencia a hogares infantiles. Los grupos humanos que pueden tener mayor susceptibilidad: niños, militares, deportistas, trabajadores del área de la salud, personas hospitalizadas, veterinarios, o la proximidad al personal médico u otros pacientes coloniza- (13,14) dos o infectados por SA .…”