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Non-typhic Salmonella is one of the major bacterial pathogens that cause foodborne infections as well as economic losses for the food production industry. There is therefore a need to improve early detection to prevent the emergence and spread of Salmonella within the agro-food chain. The passive laboratory-based surveillance system of the Salmonella network has been integrated into the French Food Safety Agency's working plan. The objective of this study was to evaluate the ability of this network to detect unusual Salmonella contamination as early as possible in the agro-food chain. Three statistical methods were used to detect unusual events from the time-series of counts. After an experimental period of more than 1 year, this approach detected several unusual events linked to contamination in the agro-food chain that were confirmed in a timely manner at national or regional levels. This evaluation also reinforced the position of the Salmonella network as an integral part of the national public health surveillance system.
EuroRotaNet, a laboratory network, was established in order to determine the diversity of co-circulating rotavirus strains in Europe over three or more rotavirus seasons from 2006/2007 and currently includes 16 countries. This report highlights the tremendous diversity of rotavirus strains co-circulating in the European population during three years of surveillance since 2006/2007 and points to the possible origins of these strains including genetic reassortment and interspecies transmission. Furthermore, the ability of the network to identify strains circulating with an incidence of ⩾1% allowed the identification of possible emerging strains such as G8 and G12 since the beginning of the study; analysis of recent data indicates their increased incidence. The introduction of universal rotavirus vaccination in at least two of the participating countries, and partial vaccine coverage in some others may provide data on diversity driven by vaccine introduction and possible strain replacement in Europe.
Bovine tuberculosis (TB) is primarily a disease of cattle. In both Ireland and the UK, badgers (Meles meles) are an important wildlife reservoir of infection. This paper examined the hypothesis that TB is spatially correlated in cattle herds, established the range of correlation and the effect, if any, of proactive badger removal on this. We also re-analysed data from the Four Area Project in Ireland, a large-scale intervention study aimed at assessing the effect of proactive badger culling on bovine TB incidence in cattle herds, taking possible spatial correlation into account. We established that infected herds are spatially correlated (the scale of spatial correlation is presented), but at a scale that varies with time and in different areas. Spatial correlation persists following proactive badger removal.
We examined 20 300 raw shell chicken eggs sold at retail stores in Japan for Salmonella outside and inside eggs. The eggs were purchased at 220 retail stores throughout Japan between August 2007 and January 2008. Of 2030 pooled egg samples (10 eggs/sample), Salmonella was isolated from five shell samples (0·25%), but not from any of egg-content samples. The serovars of the isolates were Salmonella Enteritidis (2), S. Derby, S. Livingstone and S. Cerro. The samples positive for Salmonella originated from five different egg grading and packaging (GP) centres. All the GP centres washed their egg shells according to government guidelines for hygienic practice in GP centres. Thus, practical control measures at GP centres need to be reviewed and implemented to diminish Salmonella prevalence of egg shells because Salmonella contamination on eggs is a potential hazard for foodborne salmonellosis in Japan.
Early detection of highly pathogenic avian influenza (HPAI) in its natural reservoirs is a prerequisite for preventing disease spread to humans. The risk of introduction of H5N1 HPAI was assessed in order to design a risk-based surveillance system in Spain. Areas at highest risk for H5N1 HPAI followed a northeast–southwest direction, with two significant clusters located in the north and the southwest of the country. Most (83%) of the veterinary units (VUs) obtained fewer samples than would have been expected if samples had been collected using a risk-based design. In October 2009, a HPAI outbreak was reported for the first time in a Spanish layer farm located in a VU at high risk for HPAI, but no samples were collected. This risk-based surveillance approach will increase the cost-effectiveness of HPAI surveillance in Spain and can be easily extended to and adopted by other countries and regions throughout the world.
This study assessed risk factors for 30-day mortality in 66 patients with carbapenem-resistant Acinetobacter baumannii (CRAB) infection or colonization during an outbreak in an intensive-care unit. Clinical and demographic characteristics were evaluated. The overall 30-day mortality was 47·0%. In the multivariate Cox regression model, septic shock [adjusted hazard ratio (aHR) 5·01, 95% confidence interval (CI) 2·32–10·01] and APACHE II score at onset of infection (aHR 1·11, 95% CI 1·04–1·18) were significantly associated with 30-day mortality. Administration of appropriate therapy was a protective factor, but it was not statistically significant (aHR 0·48, 95% CI 0·21–1·12). A sample of isolates tested (n=27) carried the blaOXA-23 gene. Severity of baseline condition and severity of infection presentation were major risk factors for mortality during the outbreak. Patients who received appropriate therapy tended to have lower mortality rates, although therapy was started late and dosage was suboptimal in most cases.
Two distinct measles outbreaks, unrelated from the epidemiological point of view but caused by genetically related strains, occurred in the Friuli Venezia Giulia region of northeastern Italy. Forty-two cases were reported during the period April–May 2008. In the first outbreak the index case was a teacher who introduced the virus into the Pordenone area, involving eight adolescents and young adults. The other concomitant outbreak occurred in the city of Trieste with 33 cases. The containment of the epidemics can be explained by the high MMR vaccine coverage in an area where the first dose was delivered to 93·4% and the second dose to 88·3% of the target children. Phylogenetic analysis of 14 measles virus strains showed that they belonged to a unique D4 genotype indistinguishable from the MVs/Enfield.GBR/14.07 strain, probably introduced from areas (i.e. Piedmont and Germany) where this genotype was present or had recently caused a large epidemic.
We determined the extent by which mandatory reporting on isolates of Shigella and Salmonella underestimates the burden of diarrhoeal diseases in individuals aged <17 years in Israel and examined paediatricians' knowledge, attitudes and practices related to patient visits with diarrhoeal diseases. Sources of data were a nationwide population-based telephone survey for presence of diarrhoeal diseases, Maccabi Healthcare Services databases and a mail survey among its paediatricians. Monte Carlo simulation and rate estimates for all stages, from visit to physician to reporting on a culture-confirmed case of shigellosis or salmonellosis, were used to determine the underestimation factor. Of 1492 children, 5·7% reported a diarrhoeal episode during the 2 weeks prior to interview. The rate of visiting a physician with and without fever was 86% and 16%, respectively. A stool culture was performed for around 20% of patients and the isolation rates were 7·1% for Shigella and 2·1% for Salmonella. Paediatricians (n=214) ranked very young age of patient and the complaint ‘bloody diarrhoea’ as the most important determinants. We estimated that one reported isolate of Shigella or Salmonella represented 152 diarrhoeal episodes of all aetiologies. This estimate is important for further assessments of the true burden of diarrhoeal diseases.
This research compared public opinions about Escherichia coli O157 (an increasing environmental hazard associated with livestock) in two farming areas with contrasting incidence of E. coli O157 disease. A questionnaire was administered in rural Grampian (10·8 cases/100 000 population per year) and North Wales (2·5 cases/100 000 population per year). Awareness was highest among farmers in Grampian (91%) and lowest among visitors to both areas (28%). Respondents were more likely to indicate vomiting (76%) than bloody diarrhoea (48%) as a common symptom. Undercooked meat and contact with farm animal faeces were identified by 60% of all respondents as risk factors who described ‘basic hygiene’ for risk reduction indoors. Visitors view E. coli O157 as a food hazard, not an environmental hazard that produces vomiting not dysentery. Efforts to reduce human infections in livestock farming areas could be improved with proximate reminders for visitors of the environmental pathway of E. coli O157 infection.
Most studies describing high rates of acute respiratory illness in aboriginals have focused on rural or remote communities. Hypothesized causes include socioeconomic deprivation, limited access to healthcare, and a high prevalence of chronic disease. To assess influenza rates in an aboriginal community while accounting for healthcare access, deprivation and chronic disease prevalence, we compared rates of influenza-related outpatient and emergency-department visits in an urban Mohawk reserve (Kahnawá:ke) to rates in neighbouring regions with comparable living conditions and then restricted the analysis to a sub-population with a low chronic disease prevalence, i.e. those aged <20 years. Using medical billing claims from 1996 to 2006 we estimated age-sex standardized rate ratios. The rate in Kahnawá:ke was 58% greater than neighbouring regions and 98% greater in the analysis of those aged <20 years. Despite relatively favourable socioeconomic conditions and healthcare access, rates of influenza-related visits in Kahnawá:ke were elevated, particularly in the younger age groups.
The prevalence of Helicobacter pylori infection is decreasing in developed countries. In this study we included 22 612 patients in whom a first culture of gastric biopsy (routinely performed in our medical centres) yielded an interpretable result over a 20-year period (1988–2007) in Brussels. The effects of patients' age, gender and ethnic background were analysed. The overall proportion of H. pylori-infected patients was 37·7%, with a progressive decline over time (P<10−5). A gender effect was observed in adults. The lowest infection rate was observed in Western European patients (n=11 238) with respectively 36·2% and 15·2% infected subjects in 1988 and 2007, compared to 71·7% and 40% in North African patients (n=3200) (P<10−5). However, no trend of decline was observed over time in North African children aged ⩽9 years. These data show the effects of time, age and ethnicity on the prevalence of H. pylori infection, and its complex heterogeneity in the same cosmopolitan urban area.
The documented vaccine coverage rate of measles-mumps-rubella (MMR) vaccination is almost 99% in Korea, but measles cases are constantly being reported. This study evaluated the vaccine coverage, timeliness, and barriers to immunization of measles vaccination in preschool children in Korea. We assessed 452 children aged 15–23 months and 300 children aged 4–6 years in September 2007. Questionnaires were administered in order to estimate measles vaccination rate, its timeliness and barriers to vaccine uptake. Being unaware of the necessity for vaccination and its schedule, child being sick during the recommended vaccination period, and recommended vaccination period not being over were significant preventive factors to timely vaccination (P<0·05). Children with working mothers, single parents, those not being cared for by their parents, and those younger among siblings were at a higher risk of not being vaccinated on time. In order to increase timely vaccination, accurate information should be delivered and a systematic approach should be targeted to high-risk groups.
This is the first study comparing societal costs of acute illness with Salmonella Typhimurium (ST) and Salmonella Enteritidis (SE) in the UK. It included the cost and severity of the illness and explored the impact of each Salmonella serovar on the patients, their families, the NHS, and the wider economy. The study ascertained confirmed cases of ST and SE between July and November 2008. The mean costs per case were £1282 (ST) and £993 (SE). The indirect costs associated with the work-time lost by the case, parents, or carers were £409 (ST) and £228 (SE); this difference was statistically significant. The aggregate cost of ST and SE identified using laboratory test results for the UK as a whole was estimated as £6.5 million. Work-time lost and caring activities are cost categories that are not frequently investigated within the infectious intestinal disease literature, although they represent an important societal cost.
Rodents are a potential source of pathogenic Yersinia enterocolitica and Y. pseudotuberculosis. In order to study this, 190 rodents were captured and sampled on seven pig farms (n=110), five chicken farms (n=55) and six other locations (n=25) in Sweden. Pigs from three of the pig farms were also sampled (n=60). Pathogenic Y. enterocolitica was detected by TaqMan PCR in about 5% of rodent samples and 18% of pig samples. Only rodents caught on pig farms tested positive for the pathogen. Y. enterocolitica bioserotype 4/O:3 strains isolated from the rodent and pig samples were compared by pulsed-field gel electrophoresis and revealed a high degree of similarity, which was confirmed by random amplified polymorphic DNA. Y. pseudotuberculosis was only detected in one rodent sample. Thus, rodents may be vectors for the transmission of pathogenic Y. enterocolitica to pigs, acting as carriers rather than a reservoir, and should therefore remain an important issue in hygiene control measures on farms.
The purpose of this study was to estimate the prevalence of healthcare-associated infections (HAIs) in the region of Western Greece and its relationship with possible predisposing factors. Two 1-day prevalence studies were performed in all hospitals of the region. The average HAI prevalence was 2·9% (range 0–6·8%) in the hospitals and 0–22·7% between different medical wards. Overall, 90% of HAI patients had predisposing factors. The most frequently isolated microorganism was Escherichia coli (14·3%). The study revealed a relatively low overall point prevalence of HAI, but remarkable discrepancies between the hospitals and wards. This may be due to the presence of confounding medical conditions and/or underreporting of HAIs from certain hospital wards. Local point-prevalence surveys may increase the awareness of HAIs in hospital staff and contribute to the establishment of effective infection control.
Since 1998, the French Health Insurance (NHI) system had established a national database in order to reimburse drug prescriptions. These electronical data are a considerable potential source for syndromic surveillance because of their exhaustive and regular updates. The aim of this study was to develop a method to identify acute gastroenteritis (AG) cases from drug reimbursements of the NHI database. The algorithm aimed at discriminating AG from other pathologies was determined from a sample of 206 AG prescriptions and 351 non-AG prescriptions collected in five pharmacies. The AG case identification was mainly based on the lag time between the prescription and delivery day, the occurrence of non-AG case-specific drugs, AG case-specific drug associations and treatment duration. The discriminant algorithm led to a sensitive and specific indicator of medically treated cases of AG with a time–spatial resolution power which met the need for waterborne AG surveillance.
Highly pathogenic avian influenza (HPAI) has devastating consequences for the poultry industry of affected countries. Control of HPAI has been impaired by the role of wildlife species that act as disease reservoirs and as a potential source of infection for domestic populations. The reproductive ratio (R0) of HPAI was quantified in nine clusters of outbreaks detected in wild birds in Europe (2005–2008) for which population data were not available. The median value of R0 was similar (1·1–3·4) for the nine clusters and it was about tenfold smaller than the value estimated for poultry in The Netherlands in 2003. Results presented here will be useful to parameterize models for spread of HPAI in wild birds and to design effective prevention programmes for the European poultry sector. The method is suitable to estimate R0 in the absence of population data, which is a condition typically observed for many wildlife and certain domestic species and systems.
Measles is regarded as a disease that can be eliminated by vaccination; however, disease epidemics still occur in Wuhan, China. This study explored the effect of measles control programmes on the periodic structure of disease epidemics in Wuhan. The monthly reported measles incidence from 1953 to 2008 was divided into pre-vaccine range (1953–1965) and post-vaccine range (1966–2008). For the incidence in each range, spectral analysis was conducted and power spectral density (PSD) was obtained. In PSD for the pre-vaccine range, the most dominant spectral line was observed at a 2·0-year period, as in the case of Japan. It was confirmed that spectral lines of periodic modes longer than a 1-year cycle of the incidence rates behave in response to the introduction of measles control programmes. The investigation of periodic structures of measles epidemics will contribute to effective measles control programmes in Wuhan.
Infections involving Salmonella enterica subsp. enterica serovars have serious animal and human health implications; causing gastroenteritis in humans and clinical symptoms, such as diarrhoea and abortion, in livestock. In this study an optical genetic mapping technique was used to screen 20 field isolate strains from four serovars implicated in disease outbreaks. The technique was able to distinguish between the serovars and the available sequenced strains and group them in agreement with similar data from microarrays and PFGE. The optical maps revealed variation in genome maps associated with antimicrobial resistance and prophage content in S. Typhimurium, and separated the S. Newport strains into two clear geographical lineages defined by the presence of prophage sequences. The technique was also able to detect novel insertions that may have had effects on the central metabolism of some strains. Overall optical mapping allowed a greater level of differentiation of genomic content and spatial information than more traditional typing methods.
Triple therapy is commonly used for the treatment of Helicobacter pylori infection. We determined risk factors associated with its failure in compliant patients focusing on H. pylori density, virulence marker and 23S ribosomal RNA (rRNA) point mutations associated with clarithromycin resistance. H. pylori infection was diagnosed by 14C urea breath test (14C UBT) and rapid urease test or histology. Triple therapy with esomeprazole 20 mg b.i.d., amoxicillin 1 g b.i.d. and clarithromycin 500 mg b.i.d. was prescribed for 10 days. 14C UBT was repeated 4 weeks after treatment. In total, 111 patients [69 (62%) males] with a mean age of 46±16 years were enrolled. The mean age of treatment failure was 39±14 years compared to 48±16 years with eradication (P=0·002). Treatment failure was associated with younger mean age, point mutations in the 23S rRNA gene of H. pylori and vacA s1a and m1 when associated with cagA negativity.