Prolonged and large outbreak of invasive group A Streptococcus disease within a nursing home: repeated intrafacility transmission of a single strain.

OBJECTIVES: Multiple invasive group A Streptococcus (GAS) infections were reported to public health by a skilled nursing facility (facility A) in Illinois between May 2014 and August 2016. Cases continued despite interventions including antibiotic prophylaxis for all residents and staff. Two other geographically close facilities reported contemporaneous outbreaks of GAS. We investigated potential reasons for ongoing transmission. METHODS: We obtained epidemiologic data from chart review of cases and review of facility and public health records from previous investigations into the outbreak. Infection control practices at facility A were observed and evaluated. Whole genome sequencing followed by phylogenetic analysis was performed on available isolates from the three facilities. RESULTS: From 2014 to 2016, 19 invasive and 60 noninvasive GAS infections were identified at facility A occurring in three clusters. Infection control evaluations during clusters 2 and 3 identified hand hygiene compliance rates of 14% to 25%, appropriate personal protective equipment use in only 33% of observed instances, and deficient wound-care practices. GAS isolates from residents and staff of all three facilities were subtype emm89.0; on phylogenetic analysis, facility A isolates were monophyletic and distinct. CONCLUSIONS: Inadequate infection control and improper wound-care practices likely led to this 28-month-long outbreak of severe infections in a skilled nursing facility. Whole genome sequencing and phylogenetic analysis suggested that intrafacility transmission of a single highly transmissible GAS strain was responsible for the outbreak in facility A. Integration of genomic epidemiology tools with traditional epidemiology and infection control assessments was helpful in investigation of a facility-wide outbreak.

[Usefulness of nuclear medicine in Erdheim-Chester disease: A Lille experience]. / Intérêt de la médecine nucléaire dans la maladie d'Erdheim-Chester : une expérience lilloise.

INTRODUCTION: Erdheim-Chester disease is a rare form of non-langerhans histiocytosis and its etiology is still not well established. The aims of the study were to assess the value of the bone scintigraphy and the 18F-FDG PET/CT for the diagnostic and for the latter in the therapeutic evaluation. METHODS: We retrospectively reviewed 49 patients suspected of Erdheim-Chester disease between 2004 and 2016. Bone scintigraphy was compared with histopathology and PET-CT to conventional morphological examinations and bone scintigraphy. For therapeutic evaluation, thresholds similar to PERCIST 1.0 were used. RESULTS: Forty-nine bone scintigraphy were evaluated with a sensitivity of 100%, a specificity 97%, a positive predictive value 90% and a negative predictive value of 100%. Eight patients had at least an initial PET-CT. The sensitivity compared to conventional morphological examinations differed from the location but was excellent for orbital, bone and vascular involvements. Specificity was comparable between the different examinations. Six patients treated with interferon® and three with vemurafenib® were followed by PET-CT. PET-CT, in agreement to clinicobiological data, identified 4 partial responses and one complete response with interferon® et two partial responses and one complete response with vemurafenib®. CONCLUSION: Our retrospective study suggests that bone scintigraphy and 18F-FDG PET/CT could be useful in the initial assessment of Erdheim-Chester disease but also for the latter in the therapeutic evaluation.