Point-of-care molecular diagnostics for the detection of group A Streptococcus in non-invasive skin and soft tissue infections: a validation study.

BACKGROUND: Skin and soft tissue infections (SSTIs) are commonly caused by group A Streptococcus (GAS). Rapid molecular assays for detecting GAS in wounds would help with clinical management. This study assessed a point-of-care system for the detection of GAS in non-severe SSTIs in a Native American community in the Southwest. METHODS: Patients presenting with a new non-severe SSTI were eligible if a swab was collected. The swab was tested by traditional culture methods and using the cobas® Liat® point-of-care (POC) system and results were compared. RESULTS: 399 samples were included. The final result from the POC assay was positive for 52.0% of samples. Compared to culture, the POC assay had a sensitivity of 100% and specificity of 99.5%. CONCLUSIONS: The cobas® Liat® system accurately and efficiently identified GAS in non-severe SSTIs. Having a POC test available to rapidly identify or rule out GAS could help to minimize overuse of antibiotics.

High Burden of Staphylococcus aureus Among Native American Individuals on the White Mountain Apache Tribal Lands.

BACKGROUND: This study was done to determine the burden of invasive Staphylococcus aureus on the White Mountain Apache Tribal lands. METHODS: Active population and laboratory-based surveillance for invasive S aureus infections was conducted from May 2016 to April 2018. A case was defined as a Native American individual living on or around the White Mountain Apache Tribal lands with S aureus isolated from a normally sterile body site. RESULTS: Fifty-three cases were identified. Most cases were adults (90.6%) and had ≥1 underlying medical condition (86.8%), the most common of which were diabetes (49.1%) and obesity (41.5%). A total of 26.4% cases were categorized as community acquired. Most infections were methicillin-resistant (75.5%). A total of 7.5% of cases required amputation, and 7.7% of cases died within 30 days of initial culture. The incidence of invasive S aureus was 156.3 per 100 000 persons. The age-adjusted incidence of invasive methicillin-resistant S aureus was 138.2 per 100 000 persons. CONCLUSIONS: This community has a disproportionately high burden of invasive methicillin-resistant S aureus compared with the general US population. Interventions are urgently needed to reduce the morbidity and mortality associated with these infections.

The burden of Staphylococcus aureus among Native Americans on the Navajo Nation.

INTRODUCTION: Native Americans in the southwestern United States have a higher risk for many infectious diseases and may be at higher risk for Staphylococcus aureus due to the high prevalence of risk factors for S. aureus. Recent data on invasive S. aureus infections among Native Americans are limited. METHODS: Active population- and laboratory-based surveillance was conducted in 2016-2017 on the Navajo Nation to document the rate of invasive S. aureus. A case of invasive S.aureus infection was defined as a Native American individual with S. aureus isolated from a normally sterile body site whose reported community of residence was on or around the Navajo Nation. RESULTS: One hundred and fifty-nine cases of invasive S. aureus from 152 individuals were identified. The median age of cases was 56.3 years and 35% were female. Thirty-five percent of cases had community-acquired infections. Ninety-three percent of cases had underlying medical conditions, including diabetes (60%) and obesity (42%), 28% of cases had a documented prior S. aureus infection, and 33% were infected with methicillin-resistant S. aureus. The annual incidence of invasive S. aureus and of invasive methicillin-resistant S. aureus was 64.9/100,000 persons and 21.2/100,000 persons, respectively. CONCLUSIONS: This community has a high burden of invasive S. aureus infections. Further research is needed to identify prevention strategies and opportunities for intervention.