Epidemiology of community-acquired meticillin-resistant Staphylococcus aureus obtained from the UK West Midlands region

Between January 2005 and December 2005, 199 meticillin-resistant Staphylococcus aureus (MRSA) isolates were obtained from nonhospitalised patients presenting skin and soft tissue infections to local general practitioners. The study area incorporated 57 surgeries from three Primary Care Trusts in the Lichfield, Tamworth, Burntwood, North and East Birmingham regions of Central England, UK. Following antibiotic susceptibility testing, pulsed-field gel electrophoresis, Panton-Valentine leukocidin gene detection and SCCmec element assignment, 95% of the isolates were shown to be related to hospital epidemic strains EMRSA-15 and EMRSA-16. In total 87% of the isolate population harboured SCCmec IV, 9% had SCCmec II and 4% were identified as carrying novel SCCmec IIIa-mecI. When mapped to patient home postcode, a diverse distribution of isolates harbouring SCCmec II and SCCmec IV was observed; however, the majority of isolates harbouring SCCmec IIIa-mecI were from patients residing in the north-west of the study region, highlighting a possible localised clonal group. Transmission of MRSA from the hospital setting into the surrounding community population, as demonstrated by this study, warrants the need for targeted patient screening and decolonisation in both the clinical and community environments

Spatial aspects of MRSA epidemiology:A case study using stochastic simulation, kernel estimation and SaTScan

The identification of disease clusters in space or space-time is of vital importance for public health policy and action. In the case of methicillin-resistant Staphylococcus aureus (MRSA), it is particularly important to distinguish between community and health care-associated infections, and to identify reservoirs of infection. 832 cases of MRSA in the West Midlands (UK) were tested for clustering and evidence of community transmission, after being geo-located to the centroids of UK unit postcodes (postal areas roughly equivalent to Zip+4 zip code areas). An age-stratified analysis was also carried out at the coarser spatial resolution of UK Census Output Areas. Stochastic simulation and kernel density estimation were combined to identify significant local clusters of MRSA (p<0.025), which were supported by SaTScan spatial and spatio-temporal scan. In order to investigate local sampling effort, a spatial 'random labelling' approach was used, with MRSA as cases and MSSA (methicillin-sensitive S. aureus) as controls. Heavy sampling in general was a response to MRSA outbreaks, which in turn appeared to be associated with medical care environments. The significance of clusters identified by kernel estimation was independently supported by information on the locations and client groups of nursing homes, and by preliminary molecular typing of isolates. In the absence of occupational/ lifestyle data on patients, the assumption was made that an individual's location and consequent risk is adequately represented by their residential postcode. The problems of this assumption are discussed, with recommendations for future data collection

Optimum timing of blood tests for monitoring patients with Clostridium difficile-associated diarrhea.

OBJECTIVE This study aimed to identify optimum timing of blood tests and suitable cutoff values when managing patients with Clostridium difficile-associated diarrhea (CDAD), in relation to early mortality. METHODS Review of 204 patients treated as inpatients for a first episode of CDAD from January to December 2008. Differences in values during the first 7 days of CDAD for white cell count (WCC), albumin, C-reactive protein, and creatinine between those who died and survivors to 30 days were compared using Mann-Whitney U tests. Cutoff values were assessed using receiver operating characteristic curves. RESULTS Overall 30-day mortality was 27% (n = 56/204). White cell counts were significantly higher in those who died on the first 3 days (P < 0.001, P = 0.015, and P = 0.001, respectively). Median WCC in those who died was 20 x 10(9)/L or greater on both days 1 and 2. Albumin was significantly different on day 1 only (P = 0.003); C-reactive protein, and creatinine did not differ significantly on any day. The highest WCC in the first 3 days produced an area under the curve of 0.718 (P < 0.001). A WCC cutoff at 20 x 10(9)/L or greater when compared with 15 x 10(9) or greater had a higher positive predictive value (0.46 vs 0.34) and specificity (0.82 vs 0.60) but a lower sensitivity (0.49 vs 0.65). Mortality rates in the 2 groups were 46% and 34%, respectively. CONCLUSIONS White cell count in the first 3 days is the strongest serum predictor of mortality and should be routinely monitored. A WCC of 20 x 10(9)/L or greater may be the best cutoff value to objectively identify cases at higher risk of death

Cisplatin-associated ototoxicity amongst cervical cancer patients: A prospective cohort study in south Africa.

BackgroundConcurrent chemoradiotherapy using weekly cisplatin remains standard of care for locally advanced cervical cancer in Sub-Saharan Africa. While cisplatin remains a popular cancer chemotherapeutic, it has an irreversible ototoxic effect on patients' auditory system. However, there is a paucity of epidemiological information on its extent and severity during cervical cancer treatment. In a region with a high burden of cervical cancer, this has serious consequences for aural intervention and rehabilitation.Methods and findingsUsing a prospective cohort study design, 82 patients with incident cervical cancer, receiving weekly cisplatin chemotherapy (50 mg/m2 body surface) at a tertiary level hospital in KwaZulu-Natal Province of South Africa, underwent audiological assessments at various intervals. We describe the temporal impact of cisplatin exposure on hearing loss, its combined effect with HIV-infection, and estimate ototoxicity incidence in this cohort. The median age was 52 years with Stages IIB (45%) and IIIB (35.4%) cancers being most common. Complaints of reduced hearing sensitivity increased significantly (pConclusionThe findings of this epidemiologic study highlight the temporal course and severity of ototoxicity experienced by cervical cancer patients treated with cisplatin, with greater impact in HIV-positive subgroup, thus underscores the need for audiological monitoring and timely interventions in this cohort

Gram-negative bacteraemia; a multi-centre prospective evaluation of empiric antibiotic therapy and outcome in English acute hospitals.

Increasing antibiotic resistance makes choosing antibiotics for suspected Gram-negative infection challenging. This study set out to identify key determinants of mortality among patients with Gram-negative bacteraemia, focusing particularly on the importance of appropriate empiric antibiotic treatment. We conducted a prospective observational study of 679 unselected adults with Gram-negative bacteraemia at ten acute English hospitals between October 2013 and March 2014. Appropriate empiric antibiotic treatment was defined as intravenous treatment, on the day of blood culture collection, with an antibiotic to which the cultured organism was sensitive in vitro. Mortality analyses were adjusted for patient demographics, co-morbidities and illness severity. The majority of bacteraemias were community onset (70%); most were caused by Escherichia coli (65%), Klebsiella spp (15%) or Pseudomonas spp (7%). Main foci of infection were urinary tract (51%), abdomen/biliary tract (20%) and lower respiratory tract (14%). The main antibiotics used were co-amoxiclav (32%) and piperacillin-tazobactam (30%) with 34% receiving combination therapy (predominantly aminoglycosides). Empiric treatment was inappropriate in 34%. All-cause mortality was 8% at 7-days and 15% at 30-days. Independent predictors of mortality (p<0.05) included older age, greater burden of co-morbid disease, severity of illness at presentation and inflammatory response. Inappropriate empiric antibiotic therapy was not associated with mortality at either time point (adjusted OR=0.82 (95% CI 0.35-1.94) and 0.92 (0.50-1.66) respectively). Although our study does not exclude an impact of empiric antibiotic choice on survival in Gram-negative bacteraemia, outcome is determined primarily by patient and disease factors