A comparison of persistence of SARS-CoV-2 variants on stainless steel.

The survival of newer variants of SARS-CoV-2 on a representative surface has been compared to the established UK circulating isolate to determine whether enhanced environmental stability could play a part in their increased transmissibility. Stainless steel coupons were inoculated with liquid cultures of the three variants, with coupons recovered over seven days and processed for recoverable viable virus using plaque assay. After drying, there was no significant difference in inactivation rates between variants, indicating that there is no increased environmental persistence from the new variants.

Invasive group A streptococcal infections in North West England: epidemiology, risk factors and fatal infection.

OBJECTIVES: In England, notifications of invasive group A streptococcal (iGAS) infections have increased since 2015. We describe time trends, risk factors, as well as clinical and infection characteristics amongst iGAS cases in North West England, focussing on people who inject drugs (PWIDs), prisoners and homeless populations (referred to as risk groups), and analyse factors for fatal infection. STUDY DESIGN: The study design used was a cross-sectional study. METHODS: Data for all iGAS cases notified to Public Health England North West between January 2016 and May 2019 were used. Analysis consisted of time trend analysis, descriptive statistics, hypothesis testing to investigate differences in clinical and infection characteristics between risk and non-risk groups and binary logistic regression to identify factors associated with fatal infection. RESULTS: There were 1353 cases. Two hundred and two were amongst risk groups, who were predominantly PWIDs in Greater Manchester. Soft tissue risk factors were widespread. There were differences in strain-type between risk and non-risk groups. Female gender, cancer, emm1.0 and emm5.23 were associated with increased odds of death, whilst cellulitis was associated with reduced odds. The relationship between age and death was U-shaped. CONCLUSIONS: iGAS has increased in North West England since 2016, including amongst PWIDs. This may be due to emm-type replacement, barriers to good hygiene and increasing colonisation.

Mycobacterium chimaera infection following cardiac surgery in the United Kingdom: clinical features and outcome of the first 30 cases.

OBJECTIVES: Mycobacterium chimaera infection following cardiac surgery, due to contaminated cardiopulmonary bypass heater-cooler units, has been reported worldwide. However, the spectrum of clinical disease remains poorly understood. To address this, we report the clinical and laboratory features, treatment and outcome of the first 30 UK cases. METHODS: Case note review was performed for cases identified retrospectively through outbreak investigations and prospectively through ongoing surveillance. Case definition was Mycobacterium chimaera detected in any clinical specimen, history of cardiothoracic surgery with cardiopulmonary bypass, and compatible clinical presentation. RESULTS: Thirty patients were identified (28 with prosthetic material) exhibiting a spectrum of disease including prosthetic valve endocarditis (14/30), sternal wound infection (2/30), aortic graft infection (4/30) and disseminated (non-cardiac) disease (10/30). Patients presented a median of 14 months post surgery (maximum 5 years) most commonly complaining of fever and weight loss. Investigations frequently revealed lymphopenia, thrombocytopenia, liver cholestasis and non-necrotizing granulomatous inflammation. Diagnostic sensitivity for a single mycobacterial blood culture was 68% but increased if multiple samples were sent. In all, 27 patients started macrolide-based combination treatment and 14 had further surgery. To date, 18 patients have died (60%) a median of 30 months (interquartile range 20-39 months) after initial surgery. Survival analysis identified younger age, mitral valve surgery, mechanical valve replacement, higher serum sodium concentration and lower C-reactive protein as factors associated with better survival. CONCLUSIONS: Mycobacterium chimaera infection following cardiac surgery is associated with a wide spectrum of disease. The diagnosis should be considered in all patients who develop an unexplained illness following cardiac surgery.

Surveillance of giardiasis in Northwest England 1996-2006: impact of an enzyme immunoassay test.

The incidence of giardiasis in Central Lancashire increased following the introduction of a sensitive enzyme immunoassay diagnostic test in November 2002. We compared the epidemiological trends for 1996-2006 in Central Lancashire with a control area which used a standard wet preparation diagnostic method throughout. Poisson regression modelling was used to investigate trends in giardiasis before and after the introduction of the test. In the control area, incidence of giardiasis was four per 100,000 in 2005. In contrast, in Central Lancashire, the rates increased in temporal association with the introduction of the enzyme immunoassay test from 10.1 per 100,000 population in 2002 to 33.6 per 100,000 in 2006. The increase in giardiasis was unexplained by local factors including travel, outbreaks or sampling trends. The increase in giardiasis occurred in all age groups except for males aged 0-14 years and was most marked in males aged 25-44 years. The relative risk for trend post-test introduction in Central Lancashire was 1.11 (95% CI, 1.01-1.23). This suggests that the increase in giardiasis following the introduction of the sensitive enzyme immunoassay test was at least in part due to improved detection. There appears to be considerable under-diagnosis of giardiasis, particularly in adults. Additional research is required to evaluate the enzyme immunoassay test more widely. The test may assist in standardisation of diagnostic methods for giardiasis and enable more accurate estimation of disease burden and transmission routes.