Disease surveillance programmes ought to be evaluated regularly to ensure they provide valuable information in an efficient manner. Evaluation of human and animal health surveillance programmes around the world is currently not standardized and therefore inconsistent. The aim of this systematic review was to review surveillance system attributes and the methods used for their assessment, together with the strengths and weaknesses of existing frameworks for evaluating surveillance in animal health, public health and allied disciplines. Information from 99 articles describing the evaluation of 101 surveillance systems was examined. A wide range of approaches for assessing 23 different system attributes was identified although most evaluations addressed only one or two attributes and comprehensive evaluations were uncommon. Surveillance objectives were often not stated in the articles reviewed and so the reasons for choosing certain attributes for assessment were not always apparent. This has the potential to introduce misleading results in surveillance evaluation. Due to the wide range of system attributes that may be assessed, methods should be explored which collapse these down into a small number of grouped characteristics by focusing on the relationships between attributes and their links to the objectives of the surveillance system and the evaluation. A generic and comprehensive evaluation framework could then be developed consisting of a limited number of common attributes together with several sets of secondary attributes which could be selected depending on the disease or range of diseases under surveillance and the purpose of the surveillance. Economic evaluation should be an integral part of the surveillance evaluation process. This would provide a significant benefit to decision-makers who often need to make choices based on limited or diminishing resources.

Following a resurgence of fox rabies in northeastern Italy in 2008–2009, two emergency oral rabies vaccination (ORV) campaigns were performed in the Alpine mountain ranges in 2009 and 2010 using aerial distribution to prevent the disease from spreading further inland. Vaccine baits were distributed only below the freezing point altitude, 1000 m above sea level (a.s.l.) in December 2009–January 2010 and 1500 m a.s.l. in April–May 2010, to avoid repeated freeze–thaw cycles. Spatial analysis unexpectedly identified fox rabies hotspots above the threshold altitudes, probably representing local residual rabies foci which may have contributed to maintaining the infectious cycle in areas not vaccinated at higher altitudes. Based on the results obtained, in May 2010, the second ORV campaign was extended to include threshold altitudes of up to 2300 m a.s.l. to eliminate residual foci. The observations made may help in the formulation of ORV strategies in countries sharing similar topographical features.

Respiratory syncytial virus (RSV) is the most common cause of documented viral respiratory infections, and the leading cause of hospitalization, in young children. We performed a retrospective time-series analysis of all patients aged <18 years with laboratory-confirmed RSV within a network of multiple affiliated academic medical institutions. Forecasting models of weekly RSV incidence for the local community, inpatient paediatric hospital and paediatric intensive-care unit (PICU) were created. Ninety-five percent confidence intervals calculated around our models' 2-week forecasts were accurate to ±9·3, ±7·5 and ±1·5 cases/week for the local community, inpatient hospital and PICU, respectively. Our results suggest that time-series models may be useful tools in forecasting the burden of RSV infection at the local and institutional levels, helping communities and institutions to optimize distribution of resources based on the changing burden and severity of illness in their respective communities.

The purpose of this study was to describe the characteristics of patients with bronchiolitis admitted to a paediatric intensive care unit (PICU), and to evaluate a national registry of hospitalizations (Programme de Médicalisation des Systèmes d'Information; PMSI) as a potential source of epidemiological data. Of the 49 French PICUs invited to take part in a retrospective survey of children aged <2 years who were hospitalized during the 2005–2006 epidemic season, 24 agreed to participate. Overall, 467 children were enrolled: 75% were aged <2 months, 76% had positive respiratory syncytial virus (RSV) tests, 34·9% required non-invasive ventilation, 36·6% were mechanically ventilated, and six infants died. The main neonatal characteristics were: prematurity (31·9%), respiratory disease (16·5%), congenital heart disease (6·4%), receiving mechanical ventilation (11·6%), and bronchopulmonary dysplasia at day 28 (3·8%). For bronchiolitis episode, the kappa coefficient between the survey and PMSI data was good only for mechanical ventilation (0·63) and the death rate (0·86).

Invasive infections caused by Corynebacterium diphtheriae in vaccinated and non-vaccinated individuals have been reported increasingly. In this study we used multilocus sequence typing (MLST) to study genetic relationships between six invasive strains of this bacterium isolated solely in the urban area of Rio de Janeiro, Brazil, during a 10-year period. Of note, all the strains rendered negative results in PCR reactions for the tox gene, and four strains presented an atypical sucrose-fermenting ability. Five strains represented new sequence types. MLST results did not support the hypothesis that invasive (sucrose-positive) strains of C. diphtheriae are part of a single clonal complex. Instead, one of the main findings of the study was that such strains can be normally found in clonal complexes with strains related to non-invasive disease. Comparative analyses with C. diphtheriae isolated in different countries provided further information on the geographical circulation of some sequence types.

We report an outbreak associated with a dinner cruise on Lake Michigan. This took place on the same day as heavy rainfall, which resulted in 42·4 billion liters of rainwater and storm runoff containing highly diluted sewage being released into the lake. Of 72 cruise participants, 41 (57%) reported gastroenteritis. Stool specimens were positive for Shigella sonnei (n=3), Giardia (n=3), and Cryptosporidium (n=2). Ice consumption was associated with illness (risk ratio 2·2, P=0·011). S. sonnei was isolated from a swab obtained from the one of the boat's ice bins. Environmental inspection revealed conditions and equipment that could have contributed to lake water contaminating the hose used to load potable water onto the boat. Knowledge of water holding and distribution systems on boats, and of potential risks associated with flooding and the release of diluted sewage into large bodies of water, is crucial for public health guidance regarding recreational cruises.

Cyclospora cayetanensis is an emerging infectious agent. The aim of this study was to describe an outbreak that occurred in 250 adults exposed to contaminated food, focusing on the duration and relapses of symptoms, complications and evidence of local transmission. This outbreak affected workers who ate in a restaurant in June 2005. Cyclospora sp. was observed in the stools of 20 cases and 122 probable cases were identified. The attack rate was estimated at 89%. Main symptoms were diarrhoea (96%), nausea (88%), fatigue (87%), abdominal cramps (85%), fever (52%) and headaches (45%). Contaminated fresh basil originating from a Mexican farm, used to prepare an uncooked appetizer, was identified as the source. In this non-endemic population of immunocompetent adults, Cyclospora infection presents with watery diarrhoea lasting from 4 to 18 days and fatigue lasting from 11 to 42 days. For a small proportion of affected persons, recovery can be delayed.

To determine whether drinking water contaminated with antimicrobial-resistant E. coli is associated with the carriage of resistant E. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005–2006 were asked to participate in a cross-sectional study. Household members aged ⩾12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain of E. coli and 28% carried a multidrug-resistant strain. The risk of carriage of resistant E. coli was 1·26 times higher for users of water contaminated with resistant E. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance in E. coli.

Few hard data are available on emergent diseases. However, the need to mitigate and manage emergent diseases has prompted the use of various expert consultation and opinion elicitation methods. We adapted best-worst scaling (BWS) to elicit experts' assessment of the relative practicality and effectiveness of measures to reduce human exposure to E. coli O157. Cattle vaccination was considered the most effective and hand-washing was considered the most practical measure. BWS proved a powerful tool for expert elicitation as it breaks down a cognitively burdensome process into simple, repeated, tasks. In addition, statistical analysis of the resulting data provides a scaled set of scores for the measures, rather than just a ranking. The use of two criteria (practicality and effectiveness) within the BWS process allows the identification of subsets of measures judged as potentially performing well on both criteria, and conversely those judged to be neither effective nor practical.

Recent epidemiological data suggest a link between the consumption of bovine offal products and Shiga toxin-producing Escherichia coli (STEC) infection in Japan. This study thus examined the prevalence of STEC in various types of these foods. PCR screened 229 bovine offal products for the presence of Shiga toxin (stx) gene. Thirty-eight (16·6%) samples were stx positive, of which eight were positive for rfbEO157 and three were positive for wzyO26. Four O157 and one O26 STEC isolates were finally obtained from small-intestine and omasum products. Notably, homogenates of bovine intestinal products significantly reduced the extent of growth of O157 in the enrichment process compared to homogenates of beef carcass. As co-incubation of O157 with background microbiota complex from bovine intestinal products in buffered peptone water, in the absence of meat samples, tended to reduce the extent of growth of O157, we reasoned that certain microbiota present in offal products played a role. In support of this, inoculation of generic E. coli from bovine intestinal products into the homogenates significantly reduced the extent of growth of O157 in the homogenates of bovine intestinal and loin-beef products, and this effect was markedly increased when these homogenates were heat-treated prior to inoculation. Together, this report provides first evidence of the prevalence of STEC in a variety of bovine offal products in Japan. The prevalence data herein may be useful for risk assessment of those products as a potential source of human STEC infection beyond the epidemiological background. The growth characteristic of STEC O157 in offal products also indicates the importance of being aware when to test these food products.

We analysed the data from the control group in a typhoid vaccine trial in Karachi to assess the differences in individual-, household- and cluster-level characteristics for developing typhoid fever. The annual incidence of typhoid in children aged 2–16 years in the control arm of the vaccine trial was 151/100 000 population. After adjustment, the risk of typhoid was lower with increasing age [risk ratio (RR) 0·89, 95% confidence interval (CI) 0·83–0·95], was higher with an increase in population density (RR 1·13, 95% CI 1·05–1·21) and was lower in the households using a safe drinking-water source (RR 0·63, 95% CI 0·41–0·99). Typhoid fever affects younger children living in areas of high population density and lack of access to safe water in Pakistan. A combination of environmental and biological interventions is required to prevent the continued epidemiological and economic impact of typhoid fever in high-risk areas of Pakistan.

Routine typing of 14 469 isolates from human cryptosporidiosis cases between 2000 and 2008 revealed that 7439 (51·4%) were Cryptosporidium (C.) hominis, 6372 (44·0%) C. parvum, 51 (0·4%) both C. hominis and C. parvum, 443 (3·1%) were not typable and 164 (1·1%) were other Cryptosporidium species or genotypes. Of the latter, 109 were C. meleagridis, 38 C. felis, 11 C. ubiquitum, one C. canis, two horse, two novel and one skunk genotype. C. hominis monkey genotype and C. cuniculus were identified in a separate study. Patients with unusual infections were older than those with C. hominis (P<0·01) or C. parvum (P<0·01) and were more likely to be immunocompromised (Fisher's exact P<0·01). Forty-one percent of unusual cases had travelled abroad, mainly to the Indian subcontinent. Significant risk factors in those with unusual species were travel abroad (C. meleagridis, P<0·01), being immunocompromised (C. felis, Fisher's exact P=0·02), and contact with cats (C. felis, Fisher's exact P=0·02).

From January 2009 to May 2010, 436 faecal samples from patients with diarrhoeal illnessin Southern Ireland were identified as Campylobacter genus-positive by an automated multiplex PCR; however, 204 (46·8%) of these samples were culture-negative for campylobacters. A combination of Campylobacter-specific uniplex PCR and 16S rRNA sequencing confirmed the presence of Campylobacter DNA in 191 (93·6%) of the culture-negative samples. Species-specific PCR identified C. jejuni (50·7%) C. ureolyticus (41%) and C. coli (5·7%) as the most prevalent species while C. fetus, C. upsaliensis, C. hyointestinalis and C. lari accounted for 10% of culture-negative samples; mixed Campylobacter spp. were detected in 11% of samples. We conclude that non-culturable Campylobacter spp. are responsible for a considerable proportion of human enteritis and the true incidence of infection is likely to be significantly underestimated where conventional Campylobacter culture methods are used in isolation.

This study investigated individual and contextual factors associated with the duration of diarrhoeal episodes in 693 young children living in a large Brazilian city who were followed-up for at least 3 months. The outcome is analysed as a continuous variable, by means of a hierarchical conceptual model organizing the factors in meaningful blocks. A total of 2397 episodes were recorded (median duration 2 days, interquartile range 1–3 days). Low percentage of households connected to the sewerage system in the neighbourhood, low family purchasing power, high agglomeration, mother aged <19 years, low zinc content in child's diet, and episode severity were significantly associated with longer duration (0·26–0·69 days more). Purchasing power effect was largely mediated by environmental conditions, characteristics of the child, and hygienic behaviour. Environmental conditions acted as a possible effect modifier, enhancing the effect on duration of diarrhoea of the child not having being vaccinated against measles or breastfed for >6 months.

In France surveillance underestimates the true burden of acute gastroenteritis (AG). We conducted a population-based, retrospective cross-sectional telephone survey between May 2009 and April 2010 in order to obtain more accurate estimates of the incidence and the burden of AG and to describe healthcare-seeking behaviour for AG. Of the 10 080 persons included in the survey, 260 respondents reported 263 episodes of AG. The incidence rate of AG was estimated at 0·33 cases/person-year (95% CI 0·28–0·37). It was highest in children aged <5 years and declined with age. Thirty-three percent (95% CI 27–40) of the AG cases consulted a physician and 76% (95% CI 70–82) used medication. Our results indicate that there are more than 21 million episodes of AG each year in France. These results allow a more accurate interpretation of the data derived from existing AG surveillance systems.

We examined non-pregnancy-related listeriosis cases in England and Wales reported to the Health Protection Agency between 1990 and 2009 (n=1864) using unconditional multivariate logistic regression analysis to identify factors independently associated with mortality. A subset analysis of cases between 2005 and 2009 (n=694) investigated the additional effect of antibiotic therapy on survival. In these cases particular malignancies, alcoholism, cardiovascular disease, increasing age, and treatment to reduce gastric acid secretion were positively associated with mortality. The absence of a concurrent condition and presence of autoimmune disease had a protective effect. The subset analysis identified illness in winter or spring as a risk factor and antibiotic therapy as a protective factor for mortality. The impact of antibiotic therapy, seasonality and reduced gastric acid status on survival should be further investigated. Policy-makers and clinicians need to more broadly advise those at risk of contracting this disease and dying as a consequence.

We studied a cross-sectional sample of the population of Kech, a small rural town in Pakistan to determine the prevalence and risk factors for hepatitis C infection. The prevalence of hepatitis C was 110 out of 2000 persons (5·5%, 95% confidence interval 4·5–6·5). Higher rates were identified in males. Independent risk factors identified were age ⩾75 years, being a healthcare worker, and injecting drug use. There was a high prevalence of many potential routes of transmission of bloodborne viruses and most people reported at least one potential risk factor.

Despite the increased prevalence of hepatitis B and C in most migrant groups in The Netherlands, a national screening policy for these infections is not available. In order to estimate the prevalence of hepatitis B and C in the largest group of first-generation migrants (FGM) in The Netherlands, we conducted a screening project in the Turkish community of Arnhem. In a separate project we identified patients from the target population with chronic hepatitis B and C from hospital records (1990–2008). Educational meetings concerning hepatitis were organized, with all participants being offered a blood screening test. Participants were tested for hepatitis B surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc) and antibodies to hepatitis C virus (anti-HCV). In total 709 persons were tested, a complete dataset was available for 647 patients. We found that 3·0% and 0·4% of Turkish FGM aged >24 years in Arnhem had active hepatitis B, defined as HBsAg positive, and tested positive for anti-HCV, respectively. The hospital records revealed another 32 patients, 28 with hepatitis B and four with hepatitis C representing 0·7% for hepatitis B and 0·1% for hepatitis C in relation to the total number of Turkish FGM in Arnhem. We believe that active hepatitis screening of FGM from Turkey should be part of the national health policy as it will benefit the individual and public health.

Leptospirosis is one of the most widespread zoonoses in the world. A large outbreak of suspected human leptospirosis began in Sri Lanka during 2008. This study investigated spatial variables associated with suspected leptospirosis risk during endemic and outbreak periods. Data were obtained for monthly numbers of reported cases of suspected clinical leptospirosis for 2005–2009 for all of Sri Lanka. Space–time scan statistics were combined with regression modelling to test associations during endemic and outbreak periods. The cross-correlation function was used to test association between rainfall and leptospirosis at four locations. During the endemic period (2005–2007), leptospirosis risk was positively associated with shorter average distance to rivers and with higher percentage of agriculture made up of farms <0·20 hectares. Temporal correlation analysis of suspected leptospirosis cases and rainfall revealed a 2-month lag in rainfall-case association during the baseline period. Outbreak locations in 2008 were characterized by shorter distance to rivers and higher population density. The analysis suggests the possibility of household transmission in densely populated semi-urban villages as a defining characteristic of the outbreak. The role of rainfall in the outbreak remains to be investigated, although analysis here suggests a more complex relationship than simple correlation.