Environmental Methicillin-resistant Staphylococcus aureus Contamination, Persistent Colonization, and Subsequent Skin and Soft Tissue Infection.

Importance: The longitudinal association among persistent Staphylococcus aureus colonization, household environmental contamination, and recurrent skin and soft tissue infection (SSTI) is largely unexplored to date. Objectives: To identify factors associated with persistent S aureus colonization and recurrent SSTI in households with children with community-associated methicillin-resistant S aureus (MRSA) SSTI. Design, Setting, and Participants: This 12-month prospective cohort study included 150 children with community-associated MRSA SSTI, 542 household contacts, and 154 pets enrolled from January 3, 2012, through October 20, 2015. A total of 5 quarterly home visits were made to 150 households in the St Louis, Missouri, region. Statistical analysis was performed from September 18, 2018, to January 7, 2020. Exposures: Covariates used in S aureus strain persistence and interval SSTI models included S aureus colonization and contamination measures, personal hygiene and sharing habits, health history, activities external to the home, and household characteristics (eg, cleanliness, crowding, home ownership, and pets). Serial samples to detect S aureus were collected from household members at 3 anatomic sites, from pets at 2 anatomic sites, and from environmental surfaces at 21 sites. Main Outcomes and Measures: Molecular epidemiologic findings of S aureus isolates were assessed via repetitive-sequence polymerase chain reaction. Individual persistent colonization was defined as colonization by an identical strain for 2 consecutive samplings. Longitudinal, multivariable generalized mixed-effects logistic regression models were used to assess factors associated with persistent S aureus personal colonization, environmental contamination, and interval SSTI. Results: Among 692 household members in 150 households, 326 (47%) were male and 366 (53%) were female, with a median age of 14.82 years (range, 0.05-82.25 years). Of 540 participants completing all 5 samplings, 213 (39%) were persistently colonized with S aureus, most often in the nares and with the strain infecting the index patient at enrollment. Nine pets (8%) were persistently colonized with S aureus. Participants reporting interval intranasal mupirocin application were less likely to experience persistent colonization (odds ratio [OR], 0.44; 95% credible interval [CrI], 0.30-0.66), whereas increasing strain-specific environmental contamination pressure was associated with increased individual persistent colonization (OR, 1.17; 95% CrI, 1.06-1.30). Strains with higher colonization pressure (OR, 1.47; 95% CrI, 1.25-1.71) and MRSA strains (OR, 1.57; 95% CrI, 1.16-2.19) were more likely to persist. Seventy-six index patients (53%) and 101 household contacts (19%) reported interval SSTIs. Individuals persistently colonized with MRSA (OR, 1.56; 95% CrI, 1.17-2.11), those with a history of SSTI (OR, 2.55; 95% CrI, 1.88-3.47), and index patients (OR, 1.54; 95% CrI, 1.07-2.23) were more likely to report an interval SSTI. Conclusions and Relevance: The study findings suggest that recurrent SSTI is associated with persistent MRSA colonization of household members and contamination of environmental surfaces. Future studies may elucidate the effectiveness of specific combinations of personal decolonization and environmental decontamination efforts in eradicating persistent strains and mitigating recurrent SSTIs.

The clinical impact of a multiplex real-time PCR system for microbiological diagnosis of sepsis: a mortality study.

To evaluate the impact of the use of a multiplex-real time PCR-based assay (SeptiFast M-Grade®) on in-hospital mortality in ICU sepsis patients. Demographic, clinical and microbiological data from ICU patients with suspected sepsis and available SeptiFast (SF) test results were gathered. The intervention group comprised patients in which SF indicated a clinical intervention; the non-intervention group included patients in whom SF result did not lead to any clinical intervention. The study looked at expected and observed in-hospital mortality rates in both intervention and non-intervention groups. Two-hundred and fifty-five patients (121 patients in the intervention group and 134 patients in the non-intervention group) were included in the study. When comparing both groups, we found no significant differences in severity scores, either in estimated or observed mortalities. Older age, high APACHE II scores, and infections caused by Gram-negative pathogens and carbapenem-resistant enterobacteria were all associated with a higher risk of death in both groups. Overall, blood cultures and SF agreed in 75.3% of cases. Positivity rates were 22.0% for blood culture, 29.4% for SF, and 38.0% combined. Though we did not find a correlation between SeptiFast-based intervention and changes in in-hospital mortality, SeptiFast improved positivity rates. The above improvement in microbiological diagnosis might be associated with fewer complications, lower hospitalization costs and presumably better long-term survival rates in sepsis patients.