Outbreak In Norway Research Articles

Development and implementation of a core genome multilocus sequence typing scheme for Yersinia enterocolitica: a tool for surveillance and outbreak detection.

Yersinia enterocolitica (Y. enterocolitica) is the most frequent etiological agent of yersiniosis and has been responsible for several national outbreaks in Norway and elsewhere. A standardized high-resolution method, such as core genome Multilocus Sequence Typing (cgMLST), is needed for pathogen traceability at the national and international levels. In this study, we developed and implemented a cgMLST scheme for Y. enterocolitica. We designed a cgMLST scheme in SeqSphere + using high-quality genomes from different Y. enterocolitica biotype sublineages. The scheme was validated if more than 95% of targets were found across all tested Y. enterocolitica: 563 Norwegian genomes collected between 2012 and 2022 and 327 genomes from public data sets. We applied the scheme to known outbreaks to establish a threshold for identifying major complex types (CTs) based on the number of allelic differences. The final cgMLST scheme included 2,582 genes with a median of 97.9% (interquartile range 97.6%-98.8%) targets found across all tested genomes. Analysis of outbreaks identified all outbreak strains using single linkage clustering at four allelic differences. This threshold identified 311 unique CTs in Norway, of which CT18, CT12, and CT5 were identified as the most frequently associated with outbreaks. The cgMLST scheme showed a very good performance in typing Y. enterocolitica using diverse data sources and was able to identify outbreak clusters. We recommend the implementation of this scheme nationally and internationally to facilitate Y. enterocolitica surveillance and improve outbreak response in national and cross-border outbreaks.

Investigation, management and control of a maedi outbreak in Norway in 2019-2020

BackgroundVisna-maedi is a notifiable disease in Norway, and eliminating the disease is a national goal. The import of sheep into Norway is very limited, and strict regulations apply to the movement of small ruminants between flocks and within defined geographical regions. Several outbreaks have occurred in the last 50 years, and the most recent before 2019 occurred in Trøndelag county in Central Norway in 2002. A national surveillance programme for small ruminant lentivirus infection exists since 2003.ResultsIn 2019, the national surveillance programme detected seropositive animals for small ruminant lentivirus in a sheep flock in Trøndelag. Based on the result of polymerase chain reaction analysis and histopathological findings, the Norwegian Food Safety Authority concluded the diagnosis of maedi. Further investigations detected maedi in eight additional sheep flocks in the same county. The flocks were placed under restrictions, and the authorities also imposed restrictions on 82 contact flocks. Sequencing of partial gag genes indicated that the virus in the current outbreak was related to the small ruminant lentivirus detected in the same area between 2002 and 2005.ConclusionsThe outbreak investigation shows the need for sensitive and specific diagnostic methods, and an improved and more targeted surveillance strategy. It also demonstrates the risk of disease spreading between flocks through animal movements, and highlights the importance of biosecurity and structured livestock trade. In addition to allowing livestock trade only from flocks documented free from maedi, it may be necessary to monitor sheep flocks over many years, when aiming to eliminate maedi from the Norwegian sheep population.

Development of a Bead-Based Multiplex Fluorescent Immunoassay to Detect Antibodies against Maedi-Visna Virus in Sheep.

The Maedi-visna virus (MVV) causes a persistent infection in small ruminants, and its high genetic heterogeneity affects the performance of diagnostic tests when used in different populations. Therefore, the aim of this study was to develop a bead-based multiplex immunoassay tailored to detect antibodies against a Norwegian MVV strain. We used tissue samples from 14 PCR-positive sheep from a recent MVV outbreak in Norway to sequence the viral strain and produced recombinant antigens based on sequences from one animal. The assay included commercial TM-A and recombinant Norwegian p25, p16-25 and SU5 antigens. Cut-off values for each antigen were determined using receiver operating characteristic curves on 40 ELISA-negative and 67 ELISA-positive samples from the outbreak. The intraplate and interplate repeatability were investigated by testing a quadruplicate of five samples over three days, while the analytical sensitivity (aSe) and specificity (aSp) were measured in comparison to a commercial ELISA. The repeatability showed a coefficient of variation below 15% for most positive samples. The aSe was equal or higher for the multiplex assay than the ELISA, and the aSp of each antigen was 91.7, 93.3, 95.0 and 93.3% for p25, p16-25, SU5 and TM-A, respectively. The assay shows promising results; however, further evaluations of diagnostic characteristics are necessary before implementation in the Norwegian surveillance programme.

The impact on primary care of a large waterborne campylobacter outbreak in Norway: a controlled observational study

Objective Document the impact of an outbreak of gastroenteritis on local primary health care services, compared to a control period. Design Controlled observational study with data from the outbreak and a control period. Data obtained from electronic medical records (EMR) of general practitioners (GPs) and the out-of-hours (OOH) service. Telephone data from the OOH service’s telephone records. Setting Campylobacteriosis outbreak in Askøy municipality, Norway in 2019. Over 2000 individuals were infected. Subjects Patients in contact with GPs and the OOH service during the outbreak and a control period. Main outcome measures Patient contacts with GPs and the OOH service during the outbreak and a control period. Results There was a 36% increase in contacts during the outbreak compared to the control period (4798 vs. 3528), with the OOH service handling 78% of outbreak-related contacts. Telephone advice was the dominant method for managing the increase in contacts to primary care, both in OOH services and daytime general practice (OR 3.73 CI: [3.24–4.28]). Children aged 0–4 years had increased use of primary care during the outbreak (OR 1.51 CI: [1.28–1.78]). GPs referred 25% and OOH services referred 75% of 70 hospitalized cases. Conclusion The OOH service handled most of the patients during the outbreak, with support from daytime general practice. The outbreak caused a shift towards telephone advice as a means of providing care. Young children significantly increased their use of primary care during the outbreak.

Innovative Approaches for Ecological Monitoring Disease Outbreaks Carried by Horseflies (Diptera, Tabanidae): A Systematic Review

Background: The spread and adaptation of horseflies to new habitats, driven by global climate change, threatens not only animal health but also human well-being. Objective: This article addresses the significant health risks posed by horseflies, which are known carriers of multiple pathogens causing up to 25 different infectious, parasitic, and viral diseases, including anthrax, tularemia, leptospirosis, and anaplasmosis. Methodology: The study provided an overview based on an extensive literature review from 1929 to 2022, analyzing both Russian and English publications. Results: The 2011 tularemia outbreak in Norway, linked to lemming population surges, and the higher susceptibility among men in Slovakia's annual tularemia cases highlight the role of animal reservoirs and gender in disease transmission. Leptospirosis, prevalent globally except in cold regions, is influenced by climate events, with significant public health impacts observed in various regions, including Russia and the Philippines following natural disasters. Anaplasmosis, transmitted by insects and ticks and more prevalent in warmer months, remains under-researched, with its rising threat exemplified by the growing ixodes tick population in Belarus. Conclusion: In conclusion, understanding the epidemiology and sources of these diseases, along with recognizing the environmental and anthropogenic factors that influence their transmission, is vital. The study underscores the importance of ongoing surveillance, research, and preventive measures to mitigate the impact of these infectious diseases on public health. Bangladesh Journal of Infectious Diseases, December 2023;10(2):77-84

One year of COVID-19 in dental health services in Norway: psychological impact, risk perceptions and vaccination status

BackgroundIncreased psychological pressure on oral healthcare professionals (OHP) due to COVID-19 has been shown, yet little is known about the long-term psychological impacts. We aimed to study the psychological impact of COVID-19 and associated factors including perceived risk and preparedness and vaccination status among OHP in the first year after the lockdown period in Norway.MethodsA structured questionnaire sent electronically to dentists, dental hygienists and dental assistants inquired experiences and perceptions during the second year following the outbreak in Norway. The questionnaire comprised a COVID-19 fear scale and questions about risk perception, preparedness and vaccination status. Exploratory factor analysis (EFA) and Structural Equation Modeling (SEM) were used to assess psychological impact, perception of risk and preparedness according to vaccination status of the respondents.ResultsThe majority of the 708 respondents were female (92.8%), had ten or more years of work experience (67.1%), and worked in public dental clinics (95.9%). Fears and concerns related to COVID-19 were common, 72.6% feared getting infected and 85.4% feared infecting others. Of the 642 respondents who agreed that their workplaces handled the situation well, 55.6% were fully vaccinated. Three factors were retrieved from EFA: Insecurity, Instability and Infection. SEM showed that females were more concerned with Infection, and respondents with long clinical experience were less likely to express fear about Instability. Fully vaccinated individuals felt more insecure about becoming infected, and those agreeing that their workplaces handled the current situation well were concerned with Insecurity.ConclusionsDespite widespread perception of adequate preparedness and high vaccine coverage, a considerable psychological impact and high levels of fear of COVID-19 were observed among the majority of OHP. Fully vaccinated individuals had a larger psychological burden than not fully vaccinated and those with unknown vaccination status. These findings can inform means and interventions to reduce negative impacts of fear in populations with a high psychological burden.

Development of a PCR assay for the specific identification of the fish pathogen Tenacibaculum piscium.

Tenacibaculosis is an emerging disease that severely affects salmonid farming in Chile, producing high mortalities and causing great economic losses. This work describes a novel PCR assay for the specific detection of Tenacibaculum piscium, a species recently described and identified in tenacibaculosis outbreaks in Norway and Chile. The designed primers amplified a 678-bp fragment of the peptidase gene (peptidase M23 family) from T.piscium. This method is specific for T.piscium; no other chromosomal DNA amplification products were obtained for other Tenacibaculum species. In pure cultures, the PCR assay detected up to 500 pg of DNA, or the equivalent of 2.44 ± 0.06 × 104 CFU/ml. For seeded fish samples (i.e., gills, liver, kidney, and mucus), the sensitivity limit was 4.88 ± 0.11 × 106 CFU/g, sufficient to detect T.piscium in acute infections in fish. Notably, this sensitivity level was 100-fold lower for DNA extracted from mucus samples. As compared to other existing methodologies (e.g., gene sequencing), the PCR approach described in this work allowed for the easiest detection of T.piscium in mucus samples obtained from challenged fish, an important outcome considering that the identification of this bacterium is difficult. Our results indicate that the designed specific primers and PCR method provide a rapid and specific diagnosis of T.piscium.

Triploid Atlantic salmon (Salmo salar) may have increased risk of primary field outbreaks of infectious salmon anaemia.

The impact that escaped farmed fish may have on wild populations is of major concern for Atlantic salmon (Salmo salar) farming. Triploid fish, being infertile, were originally introduced to mitigate the genetic impact of escaped fish. In the recent years, an increase in the number of infectious salmon anaemia (ISA) outbreaks in Norway has been observed, mainly in the northern parts, which is also where farming of triploid fish has been licensed. The present study investigated the susceptibility of triploid Atlantic salmon to ISA both by field observations and experimental infections. Based on field observations, we found an increased susceptibility, with 9.4 increased odds to primary ISA outbreaks in triploid fish versus diploid fish at production-site level, and a tendency of increased odds (3.4) of ISA in triploid fish at individual cage level at sited with primary outbreaks. At some sites, ISA outbreaks were only diagnosed in cages with triploid fish and not in cages with diploid fish. Primary ISA outbreaks are the source for further spread of the disease, and it is noteworthy that in an experimental trial we found significantly more viral RNA in non-ISA-vaccinated triploid than in non-ISA-vaccinated diploid fish at the peak of the infection. Interestingly, the notable differences of susceptibility to ISA for non-ISA vaccinated diploid and triploid fish observed in field were not repeated experimentally. The possible increased risk of ISA should be considered when evaluating the costs and benefits of triploid salmon in farming. It is recommended to keep triploid and diploid fish in biosecure separated sites, or that triploid fish are not farmed at all.

Risk factors, immune response and whole‐genome sequencing of SARS‐CoV‐2 in a cruise ship outbreak in Norway

ObjectiveTo improve understanding of SARS-CoV-2-transmission and prevention measures on cruise ships, we investigated a Norwegian cruise ship outbreak from July to August 2020 using a multidisciplinary approach after a rapid outbreak response launched by local and national health authorities. MethodsWe conducted a cross-sectional study among crew members using epidemiologic data and results from SARS-CoV-2 polymerase chain reaction (PCR) of nasopharynx-oropharynx samples, antibody analyses of blood samples, and whole-genome sequencing. ResultsWe included 114 multinational crew members (71% participation), median age 36 years, and 69% male. The attack rate was 33%; 32 of 37 outbreak cases were seropositive 5-10 days after PCR. One PCR-negative participant was seropositive, suggesting a previous infection. Network-analysis showed clusters based on common exposures, including embarkation date, nationality, sharing a cabin with an infected cabin-mate (adjusted odds ratio [AOR] 3.27; 95% confidence interval [CI] 0.97-11.07, p = 0.057), and specific workplaces (mechanical operations: 9.17 [1.82-45.78], catering: 6.11 [1.83-20.38]). Breaches in testing, quarantine, and isolation practices before/during expeditions were reported. Whole-genome sequencing revealed lineage B.1.36, previously identified in Asia. Despite extensive sequencing, the continued transmission of B.1.36 in Norway was not detected. ConclusionsOur findings confirm the high risk of SARS-CoV-2-transmission on cruise ships related to workplace and cabin type and show that continued community transmission after the outbreak could be stopped by implementing immediate infection control measures at the final destination.

Mental health symptoms during the first months of the COVID-19 outbreak in Norway: A cross-sectional survey study.

The COVID-19 pandemic has led to major social and economic changes that could impact public mental health. The main aim of the current study was to investigate mental health in Norway during the COVID-19 outbreak (since the first confirmed case on 26 February 2020). The results are from the first wave of the data collection (1 April-2 June 2020), which took place during the outbreak along with its initial restrictions. A total of 19,372 (11,883 students) people participated in a cross-sectional web-based survey. A total of 21.8% scored above the cut-off for depression and 23.7% for anxiety. Severity of symptoms was associated with the accumulation of risk factors, such as possible/confirmed infection for oneself or one's family, female/other sex, students, having mental health problems, increased use of tobacco, increased use of alcohol, less exercise, losing one's job, suffering economic impact and lower education. COVID-19 could have a negative association with public mental health, especially for certain risk groups. Future data-collection waves will provide further insight into the development of symptoms following the pandemic.

A tale of two STs: molecular and clinical epidemiology of MRSA t304 in Norway 2008\u20132016

The purpose of this study was to investigate the epidemiological, molecular, and clinical characteristics of MRSA t304/ST8 and t304/ST6 in Norway from 2008 to 2016. Clinical and epidemiological data were collected for each case included in the study. Strains were characterized by PCR, spa typing, antimicrobial susceptibility testing, and whole genome sequencing. The overall number of cases of MRSA t304 increased from 27 in 2008 to 203 in 2016. Most MRSA t304/ST8 cases were defined as HA-MRSA (89.9%) and diagnosed in persons with Norwegian background, many of them living in nursing homes (62.3%). The number of t304/ST8 cases declined throughout the study period and it has not been reported in Norway since 2014. The increasing MRSA t304/ST6 genotype has mainly been introduced to Norway by immigration from the Middle East, but also from other parts of the world. The t304/ST6 clone is mostly classified as CA-MRSA (75.1%), does not seem to cause serious infections, is not multi-resistant, and has not yet caused outbreaks in Norway. This study provides an example of two MRSA clones with the same spa type found in different epidemiological settings. This is very unusual, but still a reminder that spa typing in some cases may have insufficient discriminatory power for surveillance of MRSA. Our results highlight the importance of active surveillance and characterization of emerging MRSA clones with high potential for spread in the community, which may potentially cause outbreaks in healthcare facilities.

Changes in the fecal microbiota in dogs with acute hemorrhagic diarrhea during an outbreak in Norway.

BackgroundA severe form of acute hemorrhagic diarrhea syndrome (AHDS) occurred in dogs in the Oslo region of Norway during autumn 2019.ObjectivesTo characterize the fecal microbiota of dogs with AHDS during the outbreak and compare it to that of healthy dogs from the same period and before the outbreak.AnimalsDogs with AHDS (n = 50), dogs with nonhemorrhagic diarrhea (n = 3), and healthy dogs (n = 11) were sampled during the outbreak. In addition, 78 healthy dogs from the same region were sampled before the outbreak between 2017 and 2018.MethodsRetrospective case‐control study. The fecal microbiotas were characterized using 16S rRNA gene amplicon sequencing.ResultsDogs with AHDS had significantly different microbiota composition (R 2 = .07, P < .001) and decreased intestinal diversity relative to healthy dogs from the outbreak period (median, 2.7; range, 0.9‐3.5 vs median, 3.2; range, 2.6‐4.0; P < .001). The microbiota in dogs with AHDS was characterized by a decrease of Firmicutes and an outgrowth of Proteobacteria, with increased numbers of Clostridium perfringens and Providencia spp. Among the Providencia spp., 1 showed 100% sequence identity with a Providencia alcalifaciens strain that was cultivated and isolated from the same outbreak. No Providencia spp. was found in healthy dogs sampled before the outbreak.Conclusions and Clinical ImportanceDogs with AHDS had marked changes in fecal microbiota including increased numbers of Providencia spp. and C. perfringens, which may have contributed to the severity of this illness.

Use of Alcohol and Addictive Drugs During the COVID-19 Outbreak in Norway: Associations With Mental Health and Pandemic-Related Problems.

Background: The outbreak of COVID-19 has had a major impact on people's daily life. This study aimed to examine use of alcohol and addictive drugs during the COVID-19 outbreak in Norway and examine their association with mental health problems and problems related to the pandemic.Methods: A sample of 4,527 persons responded to the survey. Use of alcohol and addictive drugs were cross-tabulated with sociodemographic variables, mental health problems, and problems related to COVID-19. Logistic regression analyses were used to examine the strength of the associations.Results: Daily use of alcohol was associated with depression and expecting financial loss in relation to the COVID-19 outbreak. Use of cannabis was associated with expecting financial loss in relation to COVID-19. Use of sedatives was associated with anxiety, depression, and insomnia. Use of painkillers was associated with insomnia and self-reported risk of complications if contracting the coronavirus.Conclusion: The occurrence of mental health problems is more important for an understanding of the use of alcohol and addictive drugs during the COVID-19 outbreak in Norway, compared to specific pandemic-related worries.

Sykdomspulsen One Health - A real time surveillance system in an infrastructure coping with half a million analysis a day

Sykdomspulsen is a real time surveillance system developed by the Norwegian Institute of Public Health (NIPH) for One Health surveillance and the surveillance of other infectious diseases in humans like respiratory diseases and lately covid-19. The One Health surveillance comprise of Campylobacter data from humans and chicken farms and also includes diagnosis codes from doctor appointments and weather data with analysis forecasting outbreaks in Norway. It is a joint project between the Norwegian Institute of Public Health (NIPH) and the Norwegian Veterinary Institute (NVI), under the framework of the OHEJP NOVA (Novel approaches for design and evaluation of cost-effective surveillance across the food chain) and MATRIX (Connecting dimensions in One-Health surveillance) projects. The system relies on two pillars, the first being an analytics infrastructure which in real time retrieves data from tens of sources, cleans and harmonizes it, then runs over half a million analyses each day and produces over 20 000 000 rows of results to be used every day. The analytics infrastructure is based on R. Results are notably being used by NIPH for the monitoring of covid-19 development and the surveillance of other transmittable diseases such as influenza and gastro-intestinal illness. The analytics framework also generates hundreds of reports every day, directed at dissemination to municipal health authorities. This framework is not currently publicly available, but an open-source release is expected by the end of 2021. The second pilar is an interactive R Shiny dashboard platform, which is used for communicating the data and the model results to partner organisations. It allows for the easy creation of a website where public and animal health researchers and food safety experts can view real time analyses. This dashboard combines the powerful data visualisation and analysis strength of R with the accessibility, flexibility, structure and interactivity of web-based platforms. The result is a real time interactive surveillance system, that is supported by a solid infrastructure and streamlined data flow, and shared with actors through a beautiful and user-friendly website, based entirely on R.

Genomic and Phenotypic Characterisation of Campylobacter jejuni Isolates From a Waterborne Outbreak.

Campylobacter infections are the leading cause of bacterial gastroenteritis. In Europe, over 246,000 cases are confirmed annually. Infections are often transmitted via contaminated food, such as poultry products, but water may be the source of infection as well. The aim of this study was to characterise a selection of Campylobacter jejuni human isolates, together with a water isolate, from a waterborne outbreak in Norway in 2019, including human isolates from early, mid-, and late epidemic. The isolates were characterised with whole-genome sequencing, analysing the expression of putative virulence genes and demonstrating the pathogenic potential in an in vitro adhesion model using HT-29 cells. All isolates belonged to the multilocus sequence type 1701 and ST45 clonal complex. In the genomic analysis, the water isolate clustered somewhat separately from the human isolates. There was some variation between the human isolates, but the water isolate seemed to display the greatest pathogenic potential, demonstrated by the highest levels of virulence gene expression, adhesion to epithelial cells and IL-8 induction. These results suggest that the water isolate of the study has potential to cause human infections, and that some bacterial changes due to host or environmental adaptation, may occur during a waterborne Campylobacter epidemic. This is, to the best of our knowledge, the first study on C. jejuni isolates from a waterborne outbreak, including both human isolates and a water isolate, characterised with genomic and phenotypic approaches.

Correlates of Health-Protective Behavior During the Initial Days of the COVID-19 Outbreak in Norway.

The coronavirus outbreak manifested in Norway in March 2020. It was met with a combination of mandatory changes (closing of public institutions) and recommended changes (hygiene behavior, physical distancing). It has been emphasized that health-protective behavior such as increased hygiene or physical distancing are able to slow the spread of infections and flatten the curve. Drawing on previous health-psychological studies during the outbreak of various pandemics, we investigated psychological and demographic factors predicting the adoption and engagement in health-protective behavior and changes in such behavior, attitudes, and emotions over time. We recruited a non-representative sample of Norwegians (n = 8676) during a 15-day period (March 12–26 2020) at the beginning of the COVID-19 outbreak in Norway. Employing both traditional methods and exploratory machine learning, we replicated earlier findings that engagement in health-protective behavior is associated with specific demographic characteristics. Further, we observed that increased media exposure, perceiving measures as effective, and perceiving the outbreak as serious was positively related to engagement in health-protective behavior. We also found indications that hygiene and physical distancing behaviors were related to somewhat different psychological and demographic factors. Over the sampling period, reported engagement in physical distancing increased, while experienced concern or fear declined. Contrary to previous studies, we found no or only small positive predictions by confidence in authorities, knowledge about the outbreak, and perceived individual risk, while all of those variables were rather high. These findings provide guidance for health communications or interventions targeting the adoption of health-protective behaviors in order to diminish the spread of COVID-19.

COVID-19 cases reported to the Norwegian Institute of Public Health in the first six weeks of the epidemic.

The first case of SARS-CoV-2 infection in Norway was confirmed on 26 February 2020. Following sharpened advice on general infection control measures at the beginning of the outbreak, extensive national control measures were implemented on 12 March, and testing was focused on those with severe illness. We describe the first six weeks of the outbreak in Norway, viewed in light of testing criteria and control measures. We described all laboratory-confirmed cases of COVID-19 reported to three different surveillance systems under the Norwegian Institute of Public Health up to 5 April 2020, and compared cases reported up to 12 March with those reported from 13 March. By 12 March, 1 128 cases had been reported. Their median age was 47 years, 64% were male, 66% had travelled abroad, 6% were hospitalised at the time of reporting, and < 1% had died. The median age of the 4 742 cases reported from 13 March was 48 years, 47% were male, 18% had travelled abroad, 15% were hospitalised, and 3% died. The distribution of COVID-19 cases before and after 12 March reflects different phases of the outbreak. However, findings must be interpreted in the light of criteria for testing, testing activity, control measures and characteristics of surveillance systems.

DNA-based faecal source tracking of contaminated drinking water causing a large Campylobacter outbreak in Norway 2019

During June 2019, an outbreak of campylobacteriosis occurred in Askøy, an island northwest of Bergen, Norway. According to the publicly available records, over 2000 residents fell ill and 76 were hospitalised, and two deaths were suspected to be associated with Campylobacter infection. By investigating the epidemic pattern and scope, an old caved drinking water holding pool was identified that had been faecally contaminated as indicated by the presence of Escherichia coli (E. coli). Furthermore, Campylobacter bacteria were found at several points in the water distribution system. In the escalated water health crisis, tracking down the infectious source became pivotal for the local municipality in order to take prompt and appropriate action to control the epidemic. A major task was to identify the primary faecal pollution source, which could further assist in tracking down the epidemic origin. Water from the affected pool was analysed using quantitative microbial source tracking (QMST) applying host-specific Bacteroidales 16S rRNA genetic markers. In addition, Campylobacter jejuni, Enterococcus faecalis, Clostridium perfringens and Shiga toxin-producing E. coli were detected. The QMST outcomes revealed that non-human (zoogenic) sources accounted predominantly for faecal pollution. More precisely, 69% of the faecal water contamination originated from horses.

The Hypothesis of Circulus Hypoxicus and Its Clinical Relevance in Patients With Methanol Poisoning - An Observational Study of 35 Patients.

Methanol mass poisoning is a global problem with high fatality rates and often severe sequelae in survivors. Patients typically present late to the hospital with severe metabolic acidosis followed by a rapid deterioration in their clinical status. The hypothesis 'Circulus hypoxicus' describes the metabolic acidosis following methanol poisoning as a self-enhancing hypoxic circle responsible for methanol toxicity. We wanted to test the validity of this hypothesis by an observational study based on 35 patients from the methanol outbreaks in Norway (2004) and the Czech Republic (2012). Comprehensive laboratory values, including S(serum)-methanol, S-formate, S-lactate, arterial blood gases, anion and osmolal gaps, were used in the calculations. Laboratory values and calculated gaps were compared to each other using linear regression. S-lactate and S-formate correlated better with the increased base deficit and anion gap than did S-formate alone. Base deficit rose to about 20 mmol/L and S-formate rose to 12 mmol/L prior to a significant rise in S-lactate - most likely caused by formate inhibition of mitochondrial respiration (type B lactacidosis). The further rise in S-lactate was not linear to S-formate most likely due to the self-enhancing pathophysiology, but may also be associated with hypotension in critically ill patients and variable ethanol drinking habits. Our study suggests that the primary metabolic acidosis leads to a secondary lactic acidosis mainly due to the toxic effects of formate. The following decline in pH will further increase this toxicity. As such, a vicious and self-enhancing acidotic circle may explain the pathophysiology in methanol poisoning, namely the 'Circulus hypoxicus'.

Expression of Shiga toxin 2 (Stx2) in highly virulent Stx-producing Escherichia coli (STEC) carrying different anti-terminator (q) genes

Shiga toxins (Stx) are key virulence factors of Shiga toxin-producing Escherichia coli (STEC) during development of haemolytic uremic syndrome (HUS). It has been suggested that not only specific stx2 subtypes, but also the amount of Stx2 expressed might be essential for STEC pathogenicity. We aimed to investigate if various anti-terminator (q) genes might influence the expression level of Stx2 in highly virulent STEC.A multiplex PCR detecting q933, q21, and qO111 was run on 20 stx2a-positive STEC strains, of which 18 were HUS associated serotypes (HAS) and two non-HAS. Relative expression of Stx2 mRNA was assessed for all strains, both in non-induced and induced (mitomycin C) state.The HAS STEC carried either q933 (n = 8), qO111 (n = 8), or both (n = 2). In basal state, no STEC strains showed higher expression of Stx2 mRNA than the calibrator EDL933 (non-sorbitol fermenting (NSF) O157:H7carrying q933). Variations among strains were not associated with different q genes present, but rather related to specific serogroups. In induced state, O104:H4 strains (q933) showed higher Stx2 mRNA level than EDL933, whereas sorbitol fermenting (SF) O157:H- (qO111) and O121:H? (q933) STEC showed levels comparable with EDL933. An association between the presence of q933 and higher Stx2 level was seen within some HAS, but not all. Interestingly, the O103:H25 STEC strains, responsible for a HUS outbreak in Norway, carried both q933 and qO111. However, the Stx2 mRNA level in these strains was significantly lower than EDL933 in both states, indicating that other factors than the level of Stx2 might explain the aggressiveness of these bacteria. The two non-HAS STEC did not carry any of the examined q genes. In induced state, these bacteria showed the lowest Stx2 mRNA level compared to EDL933. One of the non-HAS STEC was not induced by mitomycin C, suggesting that stx2a might be located on a defect bacteriophage.No association between specific q genes and Stx2 mRNA expression level was revealed in stx2a-positive HAS STEC. Our results suggest that other factor(s) than specific q genes might influence the level of Stx2 produced in highly virulent STEC.