Consumption of poultry meat is considered as one of the main sources of human campylobacteriosis, and there is clearly a need for new surveillance and control measures based on quantitative data on Campylobacter spp. colonization dynamics in broiler chickens. We conducted four experimental infection trials, using four isolators during each infection trial to evaluate colonization of individual broiler chickens by Campylobacter jejuni over time. Individual and pooled faecal samples were obtained at days 4, 7 and 12 post-inoculation (p.i.) and caecal samples at day 12 p.i. There were large differences between broiler chickens in the number of C. jejuni in caecal and faecal material. Faecal samples of C. jejuni ranged from 4·0 to 9·4 log c.f.u./g and from 4·8 to 9·3 log c.f.u./g in the caeca. Faecal c.f.u./g decreased with time p.i. Most variation in c.f.u. for faecal and caecal samples was attributed to broiler chickens and a minor part to isolators, whereas infection trials did not affect the total variance. The results showed that pooled samples within isolators had lower c.f.u./g compared to the arithmetic mean of the individual samples. There was a significant correlation between faecal c.f.u./g at days 4 and 7 p.i., days 7 and 12 p.i. and for caecal and faecal c.f.u./g at day 12 p.i.

A large measles outbreak occurred in South Wales in 2012/2013. The outbreak has been attributed to low take-up of measles-mumps-rubella (MMR) immunization in the early 2000s. To understand better the factors that led to this outbreak we present the findings of a case-control study carried out in the outbreak area in 2001 to investigate parents' decision on whether to accept MMR. Parents who decided not to take-up MMR at the time were more likely to be older and better educated, more likely to report being influenced by newspapers [adjusted odds ratio (aOR) 3·07, 95% confidence interval (CI) 1·62–5·80], television (aOR 3·30, 95% CI 1·70–6·43), the internet (aOR 7·23, 3·26–16·06) and vaccine pressure groups (aOR 5·20, 95% CI 2·22–12·16), and less likely to be influenced by a health visitor (aOR 0·30, 95% CI 0·16–0·57). In this area of Wales, daily English-language regional newspapers, UK news programmes and the internet appeared to have a powerful negative influence. We consider the relevance of these findings to the epidemiology of the outbreak and the subsequent public health response.

Cryptosporidium infects millions of people worldwide causing acute gastroenteritis, but despite its remarkable epidemiological and economic impact, information on the epidemiological trends of human cryptosporidiosis is still scarce in most countries. Here we investigate a panel of 486 cases collected in Galicia (NW Iberian Peninsula) between 2000 and 2008, which sheds new light on the epidemiology in this region of the South Atlantic European façade. Incidence rates in Galicia are one order of magnitude higher than those reported in other regions of Spain, suggesting that this parasite remains largely underdiagnosed in this country, and are also larger than those typical of other European countries with available data. Two species dominate our dataset, Cryptosporidium hominis (65%) and C. parvum (34%). The sex ratio of patients infected by either species was 0·5, but C. hominis was significantly more common in younger males. C. parvum infections were more acute and required more specialized medical attention, which suggests a differential adaptation of each species to human hosts. The parasites display strong seasonal and geographical variation. C. parvum incidence peaked during summer and was mainly detected in rural areas while C. hominis infections were more frequent in autumn and exhibited a more even geographical distribution. Such differences probably reflect their distinct sources of infection – C. parvum is mainly zoonotic and C. hominis anthroponotic – and the effects of climatic variables, like temperature and rainfall.

The US Center for Medicare and Medicaid Services (CMS) requires nursing homes and long-term-care facilities to document residents' vaccination status on the Resident Assessment Instrument (RAI). Vaccinating residents can prevent costly hospital admissions and deaths. CMS and public health officials use RAI data to measure vaccination rates in long-term-care residents and assess the quality of care in nursing homes. We assessed the accuracy of RAI data against medical records in 39 nursing homes in Florida, Georgia, and Wisconsin. We randomly sampled residents in each home during the 2010–2011 and 2011–2012 influenza seasons. We collected data on receipt of influenza vaccination from charts and RAI data. Our final sample included 840 medical charts with matched RAI records. The agreement rate was 0·86. Using the chart as a gold standard, the sensitivity of the RAI with respect to influenza vaccination was 85% and the specificity was 77%. Agreement rates varied within facilities from 55% to 100%. Monitoring vaccination rates in the population is important for gauging the impact of programmes and policies to promote adherence to vaccination recommendations. Use of data from RAIs is a reasonable approach for gauging influenza vaccination rates in nursing-home residents.

Between 1 January 2009 and 31 December 2012 in England, a total of 3717 cases were reported with evidence of Shiga toxin-producing E. coli (STEC) infection, and the crude incidence of STEC infection was 1·80/100 000 person-years. Incidence was highest in children aged 1–4 years (7·63/100 000 person-years). Females had a higher incidence of STEC than males [rate ratio (RR) 1·24, P < 0·001], and white ethnic groups had a higher incidence than non-white ethnic groups (RR 1·43, P < 0·001). Progression to haemolytic uraemic syndrome (HUS) was more frequent in females and children. Non-O157 STEC strains were associated with higher hospitalization and HUS rates than O157 STEC strains. In STEC O157 cases, phage type (PT) 21/28, predominantly indigenously acquired, was also associated with more severe disease than other PTs, as were strains encoding stx2 genes. Incidence of STEC was over four times higher in people residing in rural areas than urban areas (RR 4·39, P < 0·001). Exposure to livestock and/or their faeces was reported twice as often in cases living in rural areas than urban areas (P < 0·001). Environmental/animal contact remains an important risk factor for STEC transmission and is a significant driver in the burden of sporadic STEC infection. The most commonly detected STEC serogroup in England was O157. However, a bias in testing methods results in an unquantifiable under-ascertainment of non-O157 STEC infections. Implementation of PCR-based diagnostic methods designed to detect all STEC, to address this diagnostic deficit, is therefore important.

The study characterizes a collection of 67 neonatal septicaemic Escherichia coli isolates on the basis of phylogroup, serotype, virulence, antibiotic resistance and also the association of CTX-M-producing E. coli and the ST131 clone in a developing country. Phylogroups B2 and D were predominant (33% and 19%, respectively). The most prevalent virulence factors (VFs) were traT (69%) and iucC (68%) and most VFs were concentrated in the B2 isolates. High levels of resistance (⩾70%) to cefotaxime, ciprofloxacin and trimethoprim/sulfamethoxazole was recorded but meropenem remained the most active antimicrobial. Six (9%) of the study isolates belonged to the ST131 clone, five of which were from the same hospital, and were either indistinguishable or closely related by pulsed-field gel electrophoresis. Although the prevalence of CTX-M-15-producing isolates was high (81%), the ST131 clone was relatively infrequent (11%) in extended spectrum β-lactamase (ESBL)-producers. The ST131 clone was characterized by the presence of blaCTX-M-15, qnrS, aac(6′)-Ib-cr, IncF plasmids and virulence determinants such as iucC, papC, traT, usp, hlyA, iroNE.coli, cnf, and sat. We conclude that clonal spread of ST131 did not contribute directly to the high prevalence of CTX-M-15 in our settings.

The purpose of this study was to identify the clinical outcomes of ambulatory-treated Clostridium difficile infection (CDI) and risk factors associated with community-associated CDI (CA-CDI). Adult patients diagnosed with CDI in the institutional or ambulatory-care setting between 1 April 2005 and 30 April 2011, with no other CDI diagnosis in the previous 180 days, and who purchased an ambulatory, anti-CDI agent within 7 days of CDI diagnosis were included. A total of 1201 patients were included with 914 (76%) and 287 (24%) identified with CA-CDI and nosocomial CDI (N-CDI), respectively. Patients with N-CDI were more likely to have had a recurrent CDI (P = 0·043) and died from any cause (P < 0·001). Patients with CA-CDI were younger, healthier, and had fewer traditional risk factors compared to patients with N-CDI. To prevent CA-CDI, clinicians should be aware that patients at risk for CA-CDI are unique from those at risk for N-CDI.

A peptide library was used to screen for regions containing potential linear B-cell epitope sites in the glycoproteins and nucleoprotein of Crimean-Congo haemorrhagic fever virus (CCHFV) in an enzyme-linked immunosorbent assay (ELISA). The library consisted of 156 peptides, spanning the nucleoprotein and mature GN and GC proteins in a 19-mer with 9-mer overlap format. Using pooled serum samples from convalescent patients to screen the library, six peptides were identified as potential epitope sites. Further testing of these six peptides with individual patient sera identified two of these peptides as probable epitope sites, with peptide G1451–1469 reacting to 13/15 and peptide G1613–1631 to 14/15 human sera. These peptides are situated on the GC protein at amino acid positions 1451–1469 (relative to CCHFV isolate SPU103/97) (TCTGCYACSSGISCKVRIH) and 1613–1631 (FMFGWRILFCFKCCRRTRG). Identified peptides may have application in ELISA for diagnostic or serosurveillance purposes.

Giardia spp. is a common gastrointestinal (GI) parasite of multiple host species, including dogs and humans, with the potential for zoonotic transmission. The risk of GI parasitism in dogs (including Giardia spp.) may increase with park use in urban areas. This study aimed to (1) determine whether park attendance is a risk factor for Giardia spp. infection in dogs and (2) characterize the behavioural and demographic risk factors for Giardia spp. infection in park-attending and non-park-attending dogs. From August to September 2012, a total of 1293 dog owners completed a survey and 860 corresponding dog faecal samples were collected. Dog faeces were screened for Giardia spp. using a direct immunofluorescence assay and associations assessed among behaviours, demographics, and Giardia spp. infection. Main results included off-leash and swimming frequencies within parks as significantly positively associated with Giardia spp. infection in dogs. Dog-owner age was negatively associated with off-leash and swimming frequencies in parks. The results suggest some recreational behaviours in parks and certain demographics are risk factors for parasitism in pet dogs.

About 20–90% of the world's population has had contact with Toxoplasma gondii parasites. The aim of this study was to determine the seroprevalence and risk factors associated with T. gondii infection in the Central Region, Ghana. A community-based cross-sectional study was conducted in three selected communities. Serum samples were tested for the presence of anti-T. gondii IgG and IgM antibodies by ELISA. A serological criterion for seropositivity was a positive test result for any of the two anti-Toxoplasma IgG or IgM antibodies or a combination of both. In all, 390 participants of mean age 47·0 years consisting of 118 (30·3%) males and 272 (69·7%) females were tested. The overall seroprevalence of T. gondii was 85% (333/390) where fishermen, farmers and fishmongers, respectively, had the highest seropositivity. IgG and IgM antibodies were detected in 329 (84%) and 25 (6%), respectively, while both IgG and IgM antibodies were detected in 21 (5%) of the participants. Respectively, 1% (4/390) and 79% (308/390) of participants tested positive for IgM-only and IgG-only antibodies. There was a significant relationship between Toxoplasma seropositivity and contact with soil, presence of a cat in the surrounding area, age, sources of drinking water, level of formal education, and socioeconomic status. The results suggest that the seashore may serve as a good ground for sporulation and survival of Toxoplasma oocysts.

This study examined the temporal and spatial patterns of diarrhoea in relation to hydro-meteorological factors in the Mekong Delta area in Vietnam. A time-series design was applied to examine the temporal pattern of the climate–diarrhoea relationship using Poisson regression models. Spatial analysis was applied to examine the spatial clusters of diarrhoea using Global Moran's I and local indicators of spatial autocorrelation (LISA). The temporal pattern showed that the highest peak of diarrhoea was from weeks 30–42 corresponding to August–October annually. A 1 cm increase in river water level at a lag of 1 week was associated with a small [0·07%, 95% confidence interval (CI) 0·01–0·1] increase in the diarrhoeal rate. A 1 °C increase in temperature at lag of 2 and 4 weeks was associated with a 1·5% (95% CI 0·3−2·7) and 1·1% (95% CI 0·1−2·3) increase in diarrhoeal risk, respectively. Relative humidity and diarrhoeal risk were in nonlinear relationship. The spatial analysis showed significant clustering of diarrhoea, and the LISA map shows three multi-centred diarrhoeal clusters and three single-centred clusters in the research location. The findings suggest that climatic conditions projected to be associated with climate change have important implication for human health impact in the Mekong Delta region.

Diarrhoeal diseases are major causes of morbidity and mortality in developing countries. This longitudinal study aimed to identify controllable environmental drivers of intestinal infections amidst a highly contaminated drinking water supply in urban slums and villages of Vellore, Tamil Nadu in southern India. Three hundred households with children (<5 years) residing in two semi-urban slums and three villages were visited weekly for 12–18 months to monitor gastrointestinal morbidity. Households were surveyed at baseline to obtain information on environmental and behavioural factors relevant to diarrhoea. There were 258 diarrhoeal episodes during the follow-up period, resulting in an overall incidence rate of 0·12 episodes/person-year. Incidence and longitudinal prevalence rates of diarrhoea were twofold higher in the slums compared to rural communities (P < 0·0002). Regardless of study site, diarrhoeal incidence was highest in infants (<1 year) at 1·07 episodes/person-year, and decreased gradually with increasing age. Increasing diarrhoeal rates were associated with presence of children (<5 years), domesticated animals and low socioeconomic status. In rural communities, open-field defecation was associated with diarrhoea in young children. This study demonstrates the contribution of site-specific environmental and behavioural factors in influencing endemic rates of urban and rural diarrhoea in a region with highly contaminated drinking water.

This study investigated clinical implications of human leukocyte antigen (HLA) I and II haplotypes, in combination with HBV sub-genotype C2, in hepatitis B virus (HBV) infections in northeastern China. Here, HLA haplotypes of 230 HBV-infected patients were compared to 210 healthy, unrelated Han individuals. Of the 230 HBV-infected patients, 54 had acute self-limited hepatitis (ASH) with sub-genotype C2 (ASH-C2), 144 had chronic hepatitis (CH) with sub-genotypes C2 and B2 (CH-C2 and CH-B2), and 32 spontaneously recovered without sub-genotype results. All groups underwent HLA typing and haplotype analysis. The results revealed that A*02-DRB1*12 and A*02-B*15-DRB1*09 carriers were susceptible to HBV infection. A*02-B*15-DRB1*09 is probably associated with acute onset and viral clearance and A*02-DRB1*12, with viral persistence. In HBV infections, B*40-DRB1*12 was associated with HBV persistence, whereas B*46-DRB1*09, A*24-DRB1*14, and B*15-DRB1*04 carriers easily recovered from the disease. By contrast, when infected with the HBV-C2 sub-genotype, A*24-DRB1*14, B*15-DRB1*04, A*02-B*15, A*02-DRB1*15, and A*02-B*15-DRB1*09 carriers displayed an acute clinical course before recovery. This study reveals a relationship between HLA haplotypes and HBV pathogenesis, thereby providing potential therapeutic targets to treat HBV infection.

In Canada, vaccination policies against the 2009 influenza H1N1 pandemic (H1N1pdm09) were modified at different times during the autumn wave. We hypothesized that ethnicity and place of residence influenced the odds of vaccination. To test this hypothesis, we used vaccination databases for the entire province of Manitoba, and obtained the age distribution of vaccination for First Nations (FN) and non-First Nations (non-FN) populations. We used regression analysis to determine the effect of ethnicity and location of residence on odds of vaccination. We found that individuals with FN identity were over 2.8 times [95% confidence interval (CI) 2.79–2.87] more likely to receive vaccination compared to non-FN individuals. For the FN populations, on-reserve residency was associated with 5.15-fold (95% CI 5.00–5.30) higher odds of vaccination compared to off-reserve residency. Our study highlights the importance of demographic and geographical variables in developing strategies for vaccine prioritization.

This series of serologically confirmed Lyme disease is the largest reported in the UK and represents 508 patients who presented to one hospital in the South of England between 1992 and 2012. The mean rate of borreliosis throughout this period was 9·8/100 000 population, much higher than the reported national rate of 1·7/100 000. The actual rate increased each year until 2009 when it levelled off. Patients clinically presented with rash (71%), neurological symptoms (16%, of whom half had VII cranial nerve palsies), arthropathy (8%), pyrexia (5%), cardiac abnormalities (1%) or other manifestations (<1%). Twenty percent of patients had additional non-specific symptoms of fatigue, myalgia, and cognitive changes. Serological diagnosis was with a two-tiered system of ELISA and immunoblot. There was a marked seasonal presentation in the summer months and in the first and sixth decades of life. A third of patients gave a clear history of a tick bite. The median interval between tick bite and clinical symptoms was 15 days [interquartile range (IQR) 9–28 days], with a further interval of 14 days to clinical diagnosis/treatment (IQR 2–31 days). Most cases were acquired locally and only 5% abroad. Patients responded to standard antibiotic therapy and recurrence or persistence was extremely rare. A second group of patients, not included in the clinical case series, were those who believed they had Lyme disease based on a probable tick bite but were seronegative by currently available validated tests and presented with subjective symptoms. This condition is often labelled chronic Lyme disease. These patients have a different disease from Lyme disease and therefore an alternative name, chronic arthropod-borne neuropathy (CAN), and case definition for this condition is proposed. We suggest that this chronic condition needs to be distinguished from Lyme disease, as calling the chronic illness ‘Lyme disease’ causes confusion to patients and physicians. We recommend research initiatives to investigate the aetiology, diagnosis and therapy of CAN.

This is a retrospective study using the test-negative case-control method to estimate seasonal 2010–2011 influenza vaccine effectiveness (VE) in Croatia. Of patients consulting a physician for influenza-like illness (ILI) and for whom a swab was taken, we compared RT–PCR influenza-positive and RT–PCR influenza-negative patients. We used a structured questionnaire and physicians' records to obtain information on vaccination status and potential confounders. We conducted a complete case analysis using logistic regression to measure adjusted VE overall, against A(H1N1)pdm09 and in age groups. Out of 785 interviewed patients, 495 eligible patients were included in the study, after applying exclusion criteria [217 cases, of which 92·6% were A(H1N1)pdm09 positive, 278 controls]. Crude VE was 31·9% [95% confidence interval (CI) −40·9 to 67·1] and adjusted VE was 20·7% (95% CI −71·4 to 63·3), with higher VE in youngest and oldest age groups. Results from this first VE study in Croatia suggest a low to moderate VE for the 2010–2011 season. Studies year on year are needed with a greater sample size to provide more precise estimates, and also by age group and risk groups for vaccination.

People who inject drugs are vulnerable to infections and injuries at injection sites, but these have rarely been studied in those injecting image- and performance-enhancing drugs (IPEDs). This study examined the factors associated with reported symptoms of injection site infections and injuries in IPED injectors. Of the 366 male IPED injectors surveyed, 42% reported ever having redness, swelling and tenderness (36% in the preceding year), and 6·8% had ever had an abscess or open wound at an injection site. Having these symptoms was associated with a range of factors related to drug use and healthcare utilization. One sixth (17%) of those reporting redness, tenderness and swelling had ever sought treatment, as had the majority (76%) of those reporting an abscess, sore or open wound. Most common sources of advice were emergency clinics and General Practitioners. Interventions are needed to support access to appropriate injecting equipment and provide targeted harm reduction advice.

Measles vaccination is estimated to have averted 13·8 million deaths between 2000 and 2012. Persisting heterogeneity in coverage is a major contributor to continued measles mortality, and a barrier to measles elimination and introduction of rubella-containing vaccine. Our objective is to identify determinants of inequities in coverage, and how vaccine delivery must change to achieve elimination goals, which is a focus of the WHO Decade of Vaccines. We combined estimates of travel time to the nearest urban centre (⩾50 000 people) with vaccination data from Demographic Health Surveys to assess how remoteness affects coverage in 26 African countries. Building on a statistical mapping of coverage against age and geographical isolation, we quantified how modifying the rate and age range of vaccine delivery affects national coverage. Our scenario analysis considers increasing the rate of delivery of routine vaccination, increasing the target age range of routine vaccination, and enhanced delivery to remote areas. Geographical isolation plays a key role in defining vaccine inequity, with greater inequity in countries with lower measles vaccine coverage. Eliminating geographical inequities alone will not achieve thresholds for herd immunity, indicating that changes in delivery rate or age range of routine vaccination will be required. Measles vaccine coverage remains far below targets for herd immunity in many countries on the African continent and is likely to be inadequate for achieving rubella elimination. The impact of strategies such as increasing the upper age range eligible for routine vaccination should be considered.

We performed a study to determine rates of reinfection in three groups followed for 2 years after successful treatment: American Indian/Alaska Native (AI/AN) persons living in urban (group 1) and rural (group 2) communities, and urban Alaska non-Native persons (group 3). We enrolled adults diagnosed with H. pylori infection based on a positive urea breath test (13C-UBT). After successful treatment was documented at 2 months, we tested each patient by 13C-UBT at 4, 6, 12 and 24 months. At each visit, participants were asked about medication use, illnesses and risk factors for reinfection. We followed 229 persons for 2 years or until they became reinfected. H. pylori reinfection occurred in 36 persons; cumulative reinfection rates were 14·5%, 22·1%, and 12·0% for groups 1, 2, and 3, respectively. Study participants who became reinfected were more likely to have peptic ulcer disease (P = 0·02), low education level (P = 0·04), or have a higher proportion of household members infected with H. pylori compared to participants who did not become reinfected (P = 0·03). Among all three groups, reinfection occurred at rates higher than those reported for other US populations (<5% at 2 years); rural AI/AN individuals appear to be at highest risk for reinfection.

We undertook a longitudinal study within a cohort of 52 dairy heifers maintained under constant management systems and sampled weekly to investigate a comprehensive range of risk factors which may influence shedding or super-shedding of E. coli O157 (detected by direct faecal culture and immunomagnetic separation). E. coli O157 was detected from 416/933 (44·6%) samples (faeces and recto-anal mucosal swabs) and 32 (3·4%) samples enumerated at >10000 c.f.u./g. Weekly point prevalence ranged from 9·4% to 94·3%. Higher temperature (P < 0·001), rainfall (P = 0·02), relative humidity (P < 0·001), pasture growth (P = 0·013) and body score (P = 0·029) were positively associated with increased shedding. Higher rainfall (P < 0·001), hide contamination (P = 0·002) and increased faecal consistency (P = 0·023) were positively associated with super-shedding. Increased solar exposure had a negative effect on both shedding and super-shedding within bivariate analyses but in the final multivariate model for shedding demonstrated a positive effect (P = 0·017). Results suggest that environmental factors are important in E. coli O157 shedding in cattle.