Prevalence of Nasal Colonization by Methicillin-Resistant Staphylococcus aureus in Persons Using a Homeless Shelter in Kansas City

Abstract

Nasal colonization of methicillin-resistant Staphylococcus aureus (MRSA) plays an important role in the epidemiology and pathogenesis of disease. Situations of close-quarter contact in groups are generally regarded as a risk factor for community-acquired MRSA strains due to transmission via fomites and person-to-person contact. With these criteria for risk, homeless individuals using shelter facilities, including showers and toilets, should be considered high risk for colonization and infection. The aim of this study was to determine the prevalence of nasal colonization of MRSA in a homeless population compared to established rates of colonization within the public and a control group of subjects from a neighboring medical school campus, and to analyze phylogenetic diversity among the MRSA strains. Nasal samples were taken from the study population of 332 adult participants and analyzed. In addition, participants were surveyed about various lifestyle factors in order to elucidate potential patterns of behavior associated with MRSA colonization. Homeless and control groups both had higher prevalence of MRSA (9.8 and 10.6%, respectively), when compared to the general population reported by previous studies (1.8%). However, the control group had a similar MRSA rate compared to health-care workers (4.6%), while the homeless population had an increased prevalence. Risk factors identified in this study included male gender, age over 50 years, and use of antibiotics within the past 3 months. Phylogenetic relationships between nine of the positive samples from the homeless population were analyzed, showing eight of the nine samples had a high degree of relatedness between the spaA genes of the MRSA strains. This indicates that the same MRSA strain might be transmitted from person-to-person among homeless population. These findings increase our understanding of key differences in MRSA characteristics within homeless populations, as well as risks for MRSA associated with being homeless, such as age and gender, which may then be a useful tool in guiding more effective prevention, treatment, and health care for homeless individuals.

Methicillin Resistant Staphylococcus aureus and public fomites: a review

“…In agreement with this, a study conducted between July 2012-June 2014 on a homeless shelter in Kansas City showed that individuals in this homeless shelter are at high risk of obtaining an MRSA infection. In addition, the risk of infections within such individuals was significantly higher than the general population with a prevalence of 9.8% in homeless groups compared to 1.8% in the general population [97]. Another study conducted in April, 2006 in Canada revealed a 4.5% prevalence of MRSA colonization among residents of three homeless shelters in Ottawa, Ontario [98].…”

“…Closed community settings are considered areas of high-risk for CA-MRSA transmission, colonization, and infection due to increased person-to-person contact [97]. Homeless shelters are a very good example of such high-risk community settings.…”

Identification of Nasal Carriage of Staphylococcus aureus among Nursing Students during Curricular Clinical Internships: An Observational Study

“…In healthy subjects, over time, three patterns of carriage can be distinguished: about 20% of people are persistent carriers, 60% are intermittent carriers, and approximately 20% almost never carry S. aureus. Methicillin-resistant Staphylococcus aureus (MRSA) is a strain of S. aureus identified for the first time in the United Kingdom in 1961, which is resistant to β-lactam antibiotics [4,5]. Initially, these bacteria were considered a concern for hospitalized patients until in the last two decades strains of MRSA have emerged in the community.…”

<p>Low prevalence of resistance genes in sheltered homeless population in Marseille, France, 2014–2018</p>

“…Several studies are available regarding the prevalence of antimicrobial resistance in homeless populations. An 8–10% prevalence of methicillin-resistant Staphylococcus aureus was evidenced in nasal sample from homeless people in Kansas City and in Boston, USA with resistance to erythromycin, levofloxacin and clindamycin 3,4. A study conducted in New Orleans, USA evidenced that housing in homeless shelter was an independent risk factor for high level of penicillin-non-susceptible Streptococcus pneumoniae carriage 5…”