A verocytotoxin-producing E. coli outbreak with a surprisingly high risk of haemolytic uraemic syndrome, Denmark, September-October 2012.

Denmark faced an outbreak of verocytotoxin-producing E. coli (VTEC) O157:H7 infections in autumn 2012. Thirteen cases were diagnosed of which eight had haemolytic uraemic syndrome (HUS). Epidemiological investigations suggested ground beef as the vehicle of the outbreak. The outbreak strain had a rare toxin gene subtype profile: eae, vtx1a and vtx2a, and a high proportion of HUS (62%) among cases, a finding previously linked with the outbreak subtype profile. Toxin subtyping can be useful to identify high risk VTEC strains.

Clonality and virulence traits of Escherichia coli associated with haemorrhagic septicaemia in turkeys.

Fifty-five clinical isolates of avian pathogenic Escherichia coli (APEC) from seven outbreaks of acute haemorrhagic septicaemia in turkeys were characterized by serotyping, plasmid profiling including restriction analysis with HindIII, ribotyping with EcoRI and HindIII, multilocus sequence typing (MLST) and virulence profiling. A clonal relationship was demonstrated for each outbreak according to serotype, plasmid profiling, ribotyping, and MLST. In addition, isolates demonstrated highly similar virulence profiles, as all isolates were positive for F11 pili and possessed genes encoding aerobactin (iucD), increased serum survival (iss), temperature-sensitive haemagglutinin (tsh) and colicin V plasmid operon genes (cva/cvi). However, only 20% of the isolates produced colicin V and 42% exhibited serum resistance. All strains with O group O111 and a single O18ac strain (demonstrating non-clonal DNA profiles) were positive for enteroaggregative heat-stabile toxin (EAST1), while isolates of a single outbreak all possessed the enteroaggregative toxin gene (astA). All isolates were negative for genes encoding verocytotoxins (vtx/stx), iron-repressible protein (irp2), P-fimbria (papC), invasion plasmid antigen (ipaH), attaching and effacing gene (eae), enterohaemolysin (ehxA), and enterotoxins LT, STIa (ST(p)) and STIb (ST(h)). In conclusion, highly similar virulence profiles were demonstrated for isolates of E. coli associated with a single well-defined lesion type of colibacillosis in turkeys; acute haemorrhagic septicaemia. The isolates obtained, however, demonstrated a different phylogenetic background, underlining the importance of using well-defined strain collections for characterization of APEC pathotypes.

Characteristics of the enteroaggregative Shiga toxin/verotoxin-producing Escherichia coli O104:H4 strain causing the outbreak of haemolytic uraemic syndrome in Germany, May to June 2011.

The Escherichia coli strain causing a large outbreak of haemolytic uraemic syndrome and bloody diarrhoea in Germany in May and June 2011 possesses an unusual combination of pathogenic features typical of enteroaggregative E. coli together with the capacity to produce Shiga toxin. Through rapid national and international exchange of information and strains the known occurrence in humans was quickly assessed.We describe simple diagnostic screening tools to detect the outbreak strain in clinical specimens and a novel real-time PCR for its detection in foods.

Outbreaks of gastroenteritis linked to lettuce, Denmark, January 2010.

At least 11 linked outbreaks of gastroenteritis with a total of 260 cases have occurred in Denmark in mid January 2010. Investigations showed that the outbreaks were caused by norovirus of several genotypes and by enterotoxigenic Escherichia coli. Lettuce of the lollo bionda type grown in France was found to be the vehicle.

Oral health status of handicapped primary school pupils in Dar es Salaam, Tanzania.

BACKGROUND: There is hardly any information regarding oral health status of handicapped primary school pupils in Tanzania. Determination of their oral health status could help in planning sustainable intervention programmes for this disadvantaged group. OBJECTIVES: To determine caries and periodontal status and treatment needs of handicapped primary school pupils in Dar es Salaam, Tanzania. DESIGN: A descriptive cross-sectional study. SETTING: Uhuru Mchanganyiko and Buguruni special schools, Dar es Salaam. RESULTS: The sample consisted of 179 (55.8%) males and 142 (44.2%) females aged between 7 and 22 years. Majority (71%) were deaf followed by blind (17.8%) and mentally retarded (8.7%). Six (1.9%) pupils were both deaf and blind, while one (0.3%) pupil was blind and mentally retarded. Forty one (12.8%) pupils had at least one decayed deciduous tooth, with the mean (dmfs) ranging from 0.25 to 3.24. The deaf had the highest mean decayed surfaces, followed by the mentally retarded and the blind. There was only one (0.3%) pupil who had a filled deciduous tooth. Thirty three (10.3%) pupils had decayed permanent teeth and 31 (9.7%) had missing permanent teeth. None of the decayed permanent teeth were restored. The blind had the lowest mean deciduous surfaces (DS) scores of between 0 and 1.0. In the mentally retarded group the mean DS ranged from 0.25 to 1.75. About 73.5% of the studied group had bleeding of the gums, with the blind having the highest mean bleeding index scores (p < 0.001) and about 82.8% of the pupils had calculus, with highest mean scores mainly among the blind (p = 0.008). CONCLUSION: The caries prevalence among handicapped primary school pupils was quite low. However, there was relatively high level of gingival bleeding and calculus. Regarding treatment needs, 23% required dental fillings mainly of one and two surface restorations and 82% required scaling and polishing. Despite these treatment needs these pupils had not received any dental attention.

Shiga toxin-producing Escherichia coli: incidence and clinical features in a setting with complete screening of patients with suspected infective diarrhoea.

OBJECTIVES: Shiga toxin-producing Escherichia coli (STEC) causes diarrhoeal disease, bloody diarrhoea, and haemolytic uraemic syndrome. The aim of this study was to describe the incidence of STEC and the clinical features of STEC patients from a well-defined Danish population in which all fecal samples of patients with suspected infective gastroenteritis were analysed for STEC. METHODS: In this population-based cohort study, all stool samples referred to two clinical microbiology laboratories were screened for STEC by culture and/or PCR. Epidemiological (n=170) and clinical (n=209) characteristics were analysed using data from local and national registries. RESULTS: Overall, 75,132 samples from 30,073 patients were screened resulting in 217 unique STEC-isolates. The epidemiological analysis showed an incidence of 10.1 cases per 100,000 person-years, which was more than twofold higher than the incidence in the rest of Denmark (3.4 cases per 100,000 person-years, p <0.001). Three groups were associated with a higher incidence: age <5 years (n=28, p <0.001), age ≥65 years (n=38, p 0.045), and foreign ethnicity (n=27, p 0.003). In the clinical analysis, patients with STEC harbouring only the Shiga toxin 1 gene (stx1-only isolates) showed a lower frequency of acute (n=11, p <0.05) and bloody diarrhoea (n=5, p <0.05) and a higher frequency of gastrointestinal symptoms for ≥3 months (n=8, p <0.05) than the other STEC patients. CONCLUSIONS: We report a more than twofold higher incidence in the project area compared with the rest of Denmark, indicating that patients remain undiagnosed when selective STEC screening is used. We found an association between patients with stx1-only isolates and long-term gastrointestinal symptoms.

A method for fast and simple detection of major diarrhoeagenic Escherichia coli in the routine diagnostic laboratory.

A multiplex PCR was developed for the detection of the following genes characteristic of diarrhoeagenic Escherichia coli (DEC): verocytotoxins 1 (vtx1) and 2 (vtx2), characteristic of verocytotoxin-producing E. coli (VTEC); intimin (eae), found in enteropathogenic E. coli (EPEC), attaching and effacing E. coli and VTEC; heat-stable enterotoxin (estA) and heat-labile enterotoxin (eltA), characteristic of enterotoxigenic E. coli (ETEC); and invasive plasmid antigen (ipaH), characteristic of enteroinvasive E. coli (EIEC) and Shigella spp. The method allowed the simultaneous identification of all six genes in one reaction, and included a 16S rDNA internal PCR control. When applied to pure cultures from a reference strain collection, all virulence genes in 124 different DEC strains and 15 Shigella spp. were identified correctly, and there were no cross-reactions with 13 non-E. coli species. The detection limit of the method was 10(2)-10(3) DEC CFU/PCR in the presence of 10(6) non-target cells. When the multiplex PCR was tested with colonies from plate cultures of clinical stool samples, it was a faster, more sensitive, less expensive and less laborious diagnostic procedure than DNA hybridisation. When used with DNA purified from spiked stool samples (by two different commercial kits), the method had a detection limit of 10(6) CFU/mL stool sample.

Attaching and effacing Escherichia coli isolates from Danish children: clinical significance and microbiological characteristics.

This study describes the prevalence, clinical manifestations and microbiological characteristics of attaching and effacing Escherichia coli isolates, i.e., enteropathogenic E. coli (EPEC) belonging to the classical EPEC serotypes, non-EPEC attaching and effacing E. coli (A/EEC) and verocytotoxin-producing E. coli (VTEC), isolated in a case-control study of Danish children aged <5 years. Among 424 children with diarrhoea and 866 healthy controls, EPEC and VTEC were more prevalent in cases (2.4% and 2.6%, respectively) than in controls (0.7% and 0.7%, respectively). There was a high frequency of A/EEC isolates (n = 121), but these were equally prevalent in cases (11.3%) and controls (12.5%), and comprised a heterogeneous distribution of O:H serotypes. The intimin (eae) subtypes in A/EEC isolates showed an even distribution; the eae-gamma subtype predominated in classical EPEC cases. The virulence genes encoding the bundle-forming pilus (bfpA) and enteroaggregative heat-stable enterotoxin (astA) were rare among all isolates, and seemed to be of limited pathogenic importance in this population. Virulence characterisation of A/EEC isolates did not reveal any significant differences between cases and controls. Colonisation of children with A/EEC was associated with contact with sheep or goats (OR 2.2). The role of A/EEC, not being VTEC or belonging to the classical EPEC serotypes, requires further clarification, but serotyping is useful in discriminating between EPEC and A/EEC strains.

Patients' satisfaction with dental care provided by public dental clinics in Dar es Salaam, Tanzania.

BACKGROUND: In Tanzania, patient satisfaction with dental services has received only minor attention. OBJECTIVE: To assess patients' satisfaction with public dental health services in Dar es Salaam. DESIGN: A cross-sectional study. SETTING: Five public dental clinics randomly selected from a list of all the nine public dental clinics in Dar es Salaam. SUBJECTS: Five hundred and sixteen consecutive patients, 193 males and 323 females aged between 12 and 77 years who, during the study period between July and November, 2002 were attending five dental clinics were randomly selected. RESULTS: No significant differences in patients' satisfaction level (overall or for the specific studied items) were found in all the five public dental clinics. The answers to the specific sub-items, apart from time spent with doctor, were around the average with very few responses with a high ranking. CONCLUSIONS: Findings indicate a moderate level of patient satisfaction with dental care offered in public dental clinics in Dar es Salaam. Areas identified as needing improvement included; technical quality of care, interpersonal aspects and communication.

Biotypes of oral Candida albicans isolates in a Tanzanian child population.

Although biotypes of Candida albicans from adult populations, especially in the West, have been described, there are no data either from a child population, or from the African continent. Hence a total of 200 oral C. albicans isolates from Tanzanian children aged 6-24 months were biotyped using two commercially available API micromethod kit systems and a boric acid resistance test. The predominant biotypes, which comprised two thirds of the organisms isolated, were J1S (19.5%), A1S (16.0%), J1R (14.5%), A1R (9.5%) and P1R (7.5%). In total, 16 new biotypes comprising 44 (22%) isolates which have not hitherto been described were found in this Tanzanian population and, of these, the P1R biotype predominated with 15 (7.5%) isolates. There was no significant association between predominant biotypes (with clusters > or = 15 isolates) and age, gender, breast feeding and malnutrition. These data indicate that the biotype profile of C. albicans isolates may differ in paediatric and adult populations, and/or global distribution of various subtypes of this common opportunistic pathogen.

The use of an IpaC-specific ELISA to identify enteroinvasive Escherichia coli strains of unusual serogroups.

Twenty five Escherichia coli isolates expressing O antigens different from the conventionally recognized enteroinvasive E. coli were tested in the Sereny test, with an invasion plasmid-specific DNA probe, and by an enzyme-linked immunosorbent assay recognizing the secreted IpaC antigen. These results indicate that the IpaC enzyme-linked immunosorbent assay is a sensitive method to recognize enteroinvasive E. coli, irrespective of their serogroups.

Dental care of HIV-infected patients: attitudes and behavior among Danish dentists.

The aims of the study were to study Danish dentists' attitudes and behavior with regard to providing dental care to HIV-infected persons and to look for explanatory variables for the dentists' attitudes and behavior. Two hundred and twenty-eight Danish dentists responded to a questionnaire on dental treatment of HIV-infected patients and related problems (response rate: 91.2%). The dentists' attitudes differed a great deal from the current national policy as to where HIV-infected patients should be treated and with regard to the possibility of being tested for HIV anonymously. 64% of the dentists favored the idea of referral of HIV-infected patients to special dental clinics for routine dental treatment, and 93% disapproved of the idea that infected individuals themselves should decide whether they wish to inform their dentist or doctor of seropositivity. Older dentists were more reluctant to treat HIV-infected individuals than younger. Other differences with regard to a number of demographic variables were not found. No difference in attitude towards HIV-infected persons was found when compared to that towards HBV-infected individuals. The reluctance towards treatment of HIV-infected persons was present irrespective of any subsidy for an extra cost for treatment of HIV-infected patients.

Dental health in a group of drug addicts attending an addiction-clinic.

The present study was undertaken to investigate the dental health of a group of parenteral drug addicts. The study population comprised 134 persons with a mean age of 25 yr (min. 18, max. 37) examined in 1977-81. Mean DMFT was 18.3 and mean DMFS was 50.2, approximately twice as much as found in comparable age groups in Denmark. Even free smooth surfaces were often involved. The oral hygiene was measured by the use of the Visible Plaque Index (VPI) and the Bleeding Index (BI). Both indices were high, mean VPI = 77.4 and mean BI = 71.3. 12-40% of the teeth selected had a loss of periodontal attachment of more than 4 mm. It is suggested that not only drug abuse, but also factors like low social status, low education and different barriers towards receiving dental treatment should be considered in a multifactorial cause-effect relationship. The effect of offering a free dental care system for this high-risk group will be dealt with in another paper.

Five-year evaluation of a dental care delivery system for drug addicts in Denmark.

The present study describes the experiences and results of the first 5-year period of a municipal dental clinic offering free dental care to drug addicts. One of the many problems was the instability of this socially deprived group whose erratic life style made it impossible to maintain regular dental care. The DMFS level of the drug addicts was 50.2 and mean caries increment per yr was 2.5 (1.3 new surfaces and 1.2 surfaces with recurrent decay). The caries increments among the present drug abusers and the individuals on methadone maintenance were higher than among the previous drug addicts, 3.1 and 1.3 surfaces per yr respectively, but this difference was not statistically significant. Only slight improvement in oral hygiene (VPI) could be demonstrated whereas gingivitis (BI) remained unaltered. Traumatic injuries of the orofacial region were frequent. The mean time expenditure concerning dental treatment was 5 hr per individual in the initial treatment phase but decreased to 1-2 h per individual per yr. Broken appointments and last minute cancellations were as a rule related to drug/alcohol abuse. The mean number of fillings was 8.2 per individual in the initial treatment phase and 1.7 per yr for individuals in a maintenance phase. The poor dental health of the drug addicts seems closely related to their life style habits and the clue to an improvement would probably follow the cure of the drug abuse and a concurrent resocialization.

Dental care of infectious patients in Denmark, 1986-1993: theoretical considerations and empirical findings.

Changes in infection control and behavior and attitudes towards HIV-infected patients from 1986 to 1992/93 were studied among a random sample of 335 Danish dentists; previous studies among random samples of Danish dentists served as references. 249 (74.3%) returned a mailed questionnaire together with a time, steam, temperature (TST) control indicator strip processed in their steam autoclaves, 3.4% of the autoclaves had not sterilized properly, which was an insignificant decrease compared to 1986. Overall, infection control had improved since 1986. In 1992/93 17.3% of dentists surveyed reported use of gloves always: in 1986 0.8% did so. Many (60.2%) reported at least one needlestick or cut accident within the last year. The number of dentists who were willing to treat HIV-infected patients and the number of clinics that found they could treat infectious patients safely had increased from 56.1% to 78.7% and from 43.0% to 66.8%, respectively. Other attitudinal dimensions, for example views on secrecy of HIV test results and HIV screening policy, had not changed. A conceptual model based on the theory of reasoned action formed the framework for multiple logistic regression analysis with two different outcomes: Willingness to treat HIV-infected individuals and Treatment of HIV-infected patients. In particular, expected staff problems turned out to have a high explanatory value (odds ratio = 18.2) if HIV-infected patients were received. In both models Certainty about hygienic precautions had some explanatory value. The findings may give some clues about how to plan and implement future continuing education on infection control and attitudinal and behavioral aspects of caring for infectious patients.

Determining causation in epidemiology.

Epidemiology uses many methods to identify the causes of disease, although it remains impossible to provide proof that any specific factor is a cause. We are only able to present supporting evidence. We subscribe to the pragmatic view that a factor is indeed a cause if its elimination improves health. We describe a deterministic causal model, where disease develops when the necessary component causes exist in one of several possible constellations of causes, each of which constitutes a sufficient set of component causes. If we accept this concept of disease causation, the notion of multifactorial disease becomes meaningless. We should rather turn our attention to component causes that we can eliminate in order to improve public health. The complex nature of diseases and the fact that it is only possible to present supporting evidence for a causal relationship are some of our reasons for basing the identification of causes on a theoretic model or framework. The purpose is to construct and present a model that is complex enough to formalize basic intuitions concerning cause and effect. Finally, conceptual frameworks provide guidance for the use of multivariable statistical techniques and may assist in the interpretation of the results.

Perceived need and use of oral health services among adolescents and adults in Tanzania.

The perceived need and use of oral health services among adolescents and adults in Tanzania were studied. One region from each of the country's five zones was chosen at random. Final sample selection (n = 1061) was done in the main towns of the selected regions. Participants were interviewed using a structured questionnaire which dealt with perceived need for dental treatment and use of oral health services and several demographic variables. Frequency tables were computed and analyzed. Odds ratios were calculated based on 2 x 2 tables and logistic regression models. The majority, 82% (95% CI: 79-85%) had sought treatment due to pain or for tooth extraction. Perceived need, dissatisfaction with own oral health status and use of oral health services were slightly more frequent among women. Bleeding gums had no explanatory value on the dependent variables. The strongest explanatory variable in a logistic regression model for perceived need and dissatisfaction with own oral health status was previous dental treatment with an estimated odds ratio of 6.4 (95% CI: 4.7-8.7) and 7.2 (95% CI: 5.3-9.9), respectively. People living nearest a treatment facility tended to use the services more [odds ratio 1.3 (95% CI: 0.8-2.1)]. A very strong relation between previous dental problems and use of oral health services was found, namely an odds ratio of 68.8 (95% CI: 39.0-121.4). The findings in the study may be useful in the attempts to implement Tanzania's National Plan for Oral Health.

Dental health of Vietnamese Boat People on Pulau Bidong, Malaysia.

The influx of refugees from Vietnam to the industrialized countries has attracted a certain interest to studies describing the oral health status of these population groups. The present study comprises 361 refugees arriving in Malaysia from Vietnam and collected immediately at the refugee camp on Pulau Bidong. Dental caries, calculus, gingival bleeding and loss of periodontal attachment were recorded. Mean dmft increased from 1.3 for 0-2-yr-olds to 7.4 for 3-5-yr-olds. For 6-9-yr-olds mean DMFT was 2.4 while it ranged between 8.5 and 10.10 for the older age groups. The frequency of secondary lesions was high for all age groups. Calculus increased consistently with age, while gingival bleeding was common even in the youngest age group. Loss of periodontal attachment greater than or equal to 6 mm was rare in all age groups except the oldest (45 yr or older). A strategy for oral health care for these population groups is discussed.

Patient satisfaction with emergency oral health care in rural Tanzania.

Emergency oral health care, as conceived in Tanzania, is an on-demand service provided at a rural health center or dispensary by a Rural Medical Aide. The service includes: simple tooth extraction under local anesthesia, draining of abscesses, control of acute oral infection with appropriate drug therapy, first aid for maxillo-facial trauma, and recognition of oral conditions requiring patient referral for further care at the district or regional hospital dental clinic. The objective of the present study was to describe patient satisfaction with emergency oral health care services in rural Tanzania and determine the relative importance of factors influencing patient satisfaction. The study was carried out as a cross-sectional interview survey between April 1993 and May 1994 using a patient satisfaction questionnaire in rural villages in the Rungwe district of Tanzania. It included 206 patients aged 18 years or more who had received emergency oral health care between April 1993 and March 1994. Overall, 92.7% of the respondents reported that they were satisfied with the service. Patients who were married, had no formal education and lived more than 3 km from the dispensary were more likely to be satisfied with treatment. In a logistic regression model, a good working atmosphere at the dispensary, a good relationship between care provider and patients (art of care) and absence of post-treatment complications significantly influenced patient satisfaction with odds ratios of 10.3, 17.4 and 6.2, respectively.