E. coli O157 on Scottish cattle farms: evidence of local spread and persistence using repeat cross-sectional data.

BACKGROUND: Escherichia coli (E. coli) O157 is a virulent zoonotic strain of enterohaemorrhagic E. coli. In Scotland (1998-2008) the annual reported rate of human infection is 4.4 per 100,000 population which is consistently higher than other regions of the UK and abroad. Cattle are the primary reservoir. Thus understanding infection dynamics in cattle is paramount to reducing human infections.A large database was created for farms sampled in two cross-sectional surveys carried out in Scotland (1998-2004). A statistical model was generated to identify risk factors for the presence of E. coli O157 on farms. Specific hypotheses were tested regarding the presence of E. coli O157 on local farms and the farms previous status. Pulsed-field gel electrophoresis (PFGE) profiles were further examined to ascertain whether local spread or persistence of strains could be inferred. RESULTS: The presence of an E. coli O157 positive local farm (average distance: 5.96 km) in the Highlands, North East and South West, farm size and the number of cattle moved onto the farm 8 weeks prior to sampling were significant risk factors for the presence of E. coli O157 on farms. Previous status of a farm was not a significant predictor of current status (p = 0.398). Farms within the same sampling cluster were significantly more likely to be the same PFGE type (p < 0.001), implicating spread of strains between local farms. Isolates with identical PFGE types were observed to persist across the two surveys, including 3 that were identified on the same farm, suggesting an environmental reservoir. PFGE types that were persistent were more likely to have been observed in human clinical infections in Scotland (p < 0.001) from the same time frame. CONCLUSIONS: The results of this study demonstrate the spread of E. coli O157 between local farms and highlight the potential link between persistent cattle strains and human clinical infections in Scotland. This novel insight into the epidemiology of Scottish E. coli O157 paves the way for future research into the mechanisms of transmission which should help with the design of control measures to reduce E. coli O157 from livestock-related sources.

An estimate of syphilis incidence in Eastern Europe.

AIM: Eastern Europe experienced epidemic levels of syphilis after the collapse of the Soviet Union. Presently data are less comprehensive outside the European Union (EU) and European Free Trade Association (EFTA). This review aims to identify published papers with suitable data to estimate a regional burden of disease for syphilis in the 19 member countries of Eastern Europe. METHODS: A systematic literature review was conducted to identify published data relating to syphilis incidence in Eastern Europe through Web of Knowledge, PubMed and Google Scholar databases in addition to the latest surveillance report from the European Center for Disease Prevention and Control. A total of 381 papers fitted our search criteria; 30 papers were subjected to full text analysis. RESULTS: Seven papers were included in this study and provided useable data for 13 out of 19 member countries. There was a high level of heterogeneity observed in the incidence rates from the member countries. Gross, population weighted and geographically subdivided incidence rate estimates were carried out but the comprehensiveness of some of the included data is doubtful. CONCLUSIONS: Despite the limits of the data, the incidence of syphilis in Eastern Europe is still substantially larger than that observed in the EU15 countries. This indicates that efforts to control syphilis in Eastern Europe can be enhanced; however, such goals would require significant investment in infrastructure, technology and surveillance mechanisms.