Changing incidence and characteristics of non-tuberculous mycobacterial infections in Scotland and comparison with Mycobacterium tuberculosis complex incidence (2011 to 2019)

BACKGROUND: An increase in infections with nontuberculous mycobacteria (NTM) has been noted globally, and their incidence has overtaken that of Mycobacterium tuberculosis complex (MTBc) in many countries. Using data from a national reference laboratory, we aimed to determine if this trend could be observed in Scotland. METHODS: We undertook a retrospective review of all NTM isolates received by the Scottish Mycobacteria Reference Laboratory (SMRL) over 9 years from 2011 to 2019 inclusive. Clinical episodes were defined as per 2017 British Thoracic Society and 2020 American Thoracic Society/European Respiratory Society/European Society of Clinical Microbiology and Infectious Diseases/Infectious Diseases Society of America NTM guidelines. These rates were compared with Scottish tuberculosis rates over the same period. RESULTS: Of 8552 NTM isolates from 4586 patients in 2011 to 2019, 7739 (90.5%) were considered clinically relevant. These represented 2409 episodes of NTM infection, with M. avium, M. intracellulare, and M. abscessus complex being most common. A total of 1953 (81.1%) were pulmonary NTM infection episodes from 1470 patients and 456 extrapulmonary episodes from 370 patients. We estimated a rise in incidence from 3.4 to 6.5 per 100 000 person-years (2011–2019 inclusive), with an increase in NTM incidence over MTBc incidence in Scotland by 2017. CONCLUSIONS: The incidence of NTM infection in Scotland has overtaken MTBc incidence. NTM infection leads to a costly health care burden, possibly as much as UK£1.47 million (US$ and €1.73 million) annually. We recommend standardization of isolate referral with clinical surveillance and implementation of agreed standards of care delivered through multidisciplinary teams. This would improve diagnosis and patient management as well as assessment of diagnostics and novel treatments through clinical trials

Three Year Evaluation of Xpert MTB/RIF in a Low Prevalence Tuberculosis Setting

Objectives Xpert MTB/RIF (Cepheid) is a rapid molecular assay shown to be sensitive and specific for pulmonary tuberculosis (TB) diagnosis in highly endemic countries. We evaluated its diagnostic performance in a low TB prevalence setting, examined rifampicin resistance detection and quantitative capabilities predicting graded auramine microscopy and time to positivity (TTP) of culture. Methods Xpert MTB/RIF was used to test respiratory samples over a 3 year period. Samples underwent graded auramine microscopy, solid/ liquid culture, in-house IS6110 real-time PCR, and GenoType MTBDRplus (HAIN Lifescience) to determine rifampicin and/or isoniazid resistance. Results A total of 2103 Xpert MTB/RIF tests were performed. Compared to culture sensitivity was 95.8%, specificity 99.5%, positive predictive value (PPV) 82.1%, and negative predictive value (NPV) 99.9%. A positive correlation was found between auramine microscopy grade and Xpert MTB/RIF assay load. We found a clear reduction in the median TTP as Xpert MTB/RIF assay load increased. Rifampicin resistance was detected. Conclusions Xpert MTB/RIF was rapid and accurate in diagnosing pulmonary TB in a low prevalence area. Rapid results will influence infection prevention and control and treatment measures. The excellent NPV obtained suggests further work should be carried out to assess its role in replacing microscopy

Three Year Evaluation of Xpert MTB/RIF in a Low Prevalence Tuberculosis Setting

Objectives Xpert MTB/RIF (Cepheid) is a rapid molecular assay shown to be sensitive and specific for pulmonary tuberculosis (TB) diagnosis in highly endemic countries. We evaluated its diagnostic performance in a low TB prevalence setting, examined rifampicin resistance detection and quantitative capabilities predicting graded auramine microscopy and time to positivity (TTP) of culture. Methods Xpert MTB/RIF was used to test respiratory samples over a 3 year period. Samples underwent graded auramine microscopy, solid/ liquid culture, in-house IS6110 real-time PCR, and GenoType MTBDRplus (HAIN Lifescience) to determine rifampicin and/or isoniazid resistance. Results A total of 2103 Xpert MTB/RIF tests were performed. Compared to culture sensitivity was 95.8%, specificity 99.5%, positive predictive value (PPV) 82.1%, and negative predictive value (NPV) 99.9%. A positive correlation was found between auramine microscopy grade and Xpert MTB/RIF assay load. We found a clear reduction in the median TTP as Xpert MTB/RIF assay load increased. Rifampicin resistance was detected. Conclusions Xpert MTB/RIF was rapid and accurate in diagnosing pulmonary TB in a low prevalence area. Rapid results will influence infection prevention and control and treatment measures. The excellent NPV obtained suggests further work should be carried out to assess its role in replacing microscopy

MRSA:treating people with infection

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) has a gene that makes it resistant to methicillin, as well as to other beta-lactam antibiotics, including flucloxacillin, beta-lactam/beta-lactamase inhibitor combinations, cephalosporins, and carbapenems. MRSA can be part of the normal body flora (colonisation), especially in the nose, but it can cause infection, particularly in people with prolonged hospital admissions, with underlying disease, or after antibiotic use. About 8% of S aureus in blood cultures in England, Wales, and Northern Ireland is resistant to methicillin. METHODS AND OUTCOMES: We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of selected treatments for MRSA infections at any body site? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2014 (BMJ Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview). RESULTS: At this update, searching of electronic databases retrieved 312 studies. After deduplication and removal of conference abstracts, 133 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 55 studies and the further review of 78 full publications. Of the 78 full articles evaluated, 15 systematic reviews and one subsequent RCT were added at this update. In addition, six studies were added to the Comment sections. We performed a GRADE evaluation for 12 PICO combinations. CONCLUSIONS: In this systematic overview we categorised the efficacy for five interventions, based on information about the effectiveness and safety of cephalosporins (ceftobiprole, ceftaroline), daptomycin, linezolid, quinupristin-dalfopristin, pristinamycin (streptogramins), and tigecycline

First report of an astrovirus type 5 gastroenteritis outbreak in a residential elderly care home identified by sequencing

Background: This is the report of an outbreak of human astrovirus type 5 gastroenteritis that occurred in a residential care home for older people in June 2013 in Tayside, Scotland, and which involved seven staff members and thirteen residents. This type of astrovirus has not been found in Scotland before and is rarely described in the literature. Objectives: Using molecular methods such as PCR and sequencing to detect the cause of this gastroenteritis outbreak and to contain the outbreak using Public Health measures. Study design: Following an epidemiological investigation, stool samples were sent for routine virology and microbiology testing at the local microbiology and virology laboratory and were found to be negative. Further testing with real-time PCR and gene sequencing at the West of Scotland Specialist Virology Centre was performed. Data on the epidemiology and the response to the outbreak was collected. Results: All samples had a 99% match to human astrovirus type 5. The use of standard infection control precautions with the addition of transmission-based precautions most likely contained the spread of the virus in this situation. Conclusions: This report illustrates the importance of using PCR and sequencing to identify pathogens such as astrovirus in outbreaks of vomiting and diarrhoea in older people particularly if routine virology and microbiology tests are negative