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.

On 26 November 2010, an outbreak of scombroid fish poisoning occurred in the French Armed Forces in Dakar, Senegal. This chemical intoxication, due to high histamine concentration in fish, is often mistaken for an allergic reaction. A case-control study was undertaken including the 71 cases and 78 randomly selected controls among lunch attendees. The usual symptoms for scombroid fish poisoning were observed in cases, i.e. flushing (85·9%), headache (83·1%), rapid/weak pulse (59·1%) and diarrhoea (47·9%). Symptoms occurred from within a few minutes to up to 3 h following the meal. Most patients quickly recovered with antihistamine and/or symptomatic treatment. Tuna was the only food item positively associated with illness (odds ratio 36·3, 95% confidence interval 6·3–210·0), with the risk of illness increasing with the quantity of fish consumed. No bacterial contamination was found in leftover food, but histamine concentration in tuna was found to be 4900 mg/kg, almost 50-fold higher than the concentration allowed by European regulations. This report is unique because of the large size of the case series – to our knowledge, the largest event of scombroid fish poisoning ever reported – and the chemical and bacteriological analyses results obtained on leftover food.

We investigated a measles outbreak in the Jerusalem district in 2007–2008 (992 cases). Most cases (72·6%) were aged <15 years, 42·9% aged <5 years, and 12·8% were infants aged <1 year. The peak incidence rate was in infants aged 6–12 months (916·2/100 000). This represents a significant shift from former outbreaks in 2003–2004, where the peak incidence was in the 1–4 years age group. Of children aged <5 years the proportion aged 6–12 months tripled (7·7% vs. 25·6%). In a case-control study (74 cases, 148 controls) children who developed measles were less likely to be registered in a well-baby clinic and had lower overall immunization coverage. The differences in proportions for registration, DTaP3 and MMR1 coverage were 35·1%, 48·6% and 80·8%, respectively (all P<0·001). Rising birth order of cases and their siblings was associated with non-registration and non-compliance with MMR immunization. The vulnerability of young infants and the risk markers noted above should be taken into account in planning intervention programmes.

Infectious gastroenteritis causes a considerable burden of disease worldwide. Effective control should be targeted at diseases with the highest burden and costs. Therefore, an accurate understanding of the relative importance of the different microorganisms is needed. The objective of this study was to determine the incidence and aetiology of gastroenteritis in adults requiring hospital admission in The Netherlands. Five hospitals enrolled patients admitted with gastroenteritis for about 1 year during the period May 2008 to November 2009. Participants completed questionnaires and provided a faecal sample. The hospital completed a clinical questionnaire. In total, 44 adults hospitalized for gastroenteritis were included in the study. The cases had serious symptoms, with 31% subsequently developing kidney failure. One or more pathogens were found in 59% of cases. Overall, rotavirus (22%) was the most common infection. Co-infections were observed relatively often (22%). This study emphasizes that rotavirus can also cause serious illness in adults.

A meta-analysis was performed using all published and one unpublished long-term infection-challenge experiments to quantify the age- and dose-dependence of early and late shedding of Mycobacterium avium subsp. paratuberculosis (MAP) in cattle. There were 194 animals from 17 studies that fulfilled the inclusion criteria, of which 173 received a known dose of MAP and 21 were exposed naturally. Results from parametric time-to-event models indicated that challenging older calves or using multiple-exposure experimental systems resulted in a smaller proportion and shorter duration of early shedding as well as slower transition to late shedding from latent compartments. Calves exposed naturally showed variable infection progression rates, not dissimilar to other infection routes. The log-normal distribution was most appropriate for modelling infection-progression events. The infection pattern revealed by the modelling allowed better understanding of low-grade endemicity of MAP in cattle, and the parameter estimates are the basis for future transmission dynamics modelling.

Phylogenetic analyses suggest lyssaviruses, including Rabies virus, originated from bats. However, the role of bats in the maintenance, transmission and evolution of lyssaviruses is poorly understood. A number of genetically diverse lyssaviruses are present in Africa, including Lagos bat virus (LBV). A high seroprevalence of antibodies against LBV was detected in Eidolon helvum bats. Longitudinal seroprevalence and age-specific seroprevalence data were analysed and capture–mark–recapture (CMR) analysis used to follow 98 bats over 18 months. These data demonstrate endemic infection, with evidence of horizontal transmission, and force of infection was estimated for differing age categories. The CMR analysis found survival probabilities of seronegative and seropositive bats were not significantly different. The lack of increased mortality in seropositive animals suggests infection is not causing disease after extended incubation. These key findings point towards acute transmission of bat lyssaviruses in adapted bat hosts that occurs at a far higher rate than the occurrence of disease.

Human adenoviruses (HAdV) cause a broad spectrum of diseases including acute respiratory infection (ARI), and are responsible for 5% of cases requiring hospitalization in children aged <5 years in Colombia; however, little is known about the circulating types, partly due to the lack of reliable typing tests. In order to evaluate a VA gene PCR-sequencing approach for identification of HAdV circulating types in a Colombian population, 52 nasopharyngeal aspirates/swabs from children with ARI were processed. After a BLAST analysis, matches with species B (41/48, 85·42%), C (6/48, 12·5%), and D (1/48, 2·08%) were found; and at the type level, type 3 (22/48, 45·83%) was the most frequent. This initial effort to expand our knowledge about the molecular epidemiology of HAdV circulating in Bogota, Colombia, showed that HAdV-B was the predominant circulating species in the study period and reports, for the first time in Colombia, the presence of HAdV-D in a respiratory sample.

We describe the largest outbreak of hepatitis B virus infection reported to date in the UK. Between July 2001 and December 2005, 237 cases were identified in Avon, South West England. The likely route of transmission was injecting drug use in 44% (104/237) and heterosexual intercourse in 30% (71/237) of cases. A case-control study in injectors showed that injecting crack cocaine [adjusted odds ratio (aOR) 23·8, 95% confidence interval (CI) 3·04–186, P<0·001] and sharing injecting paraphernalia in the year before diagnosis (aOR 16·67, 95% CI 1·78–100, P=0·010) were strongly associated with acute hepatitis B. In non-IDUs number of sexual partners and lack of consistent condom use were high compared to a national sample. We describe the control measures implemented in response to the outbreak. This outbreak has highlighted the problems associated with the low uptake from the national hepatitis B vaccination policy which targets high-risk groups, the difficulties of identifying those at risk of acquiring hepatitis B infection through heterosexual sex, and injecting crack cocaine as a risk factor for hepatitis B.

We examined the prevalence, correlates and trends of H. pylori infection in Israel using residual sera obtained in 2007–2008 from 1466 Jewish subjects aged 0–77 years and 897 Arabs aged 0–19 years, and in 2000–2001 from 627 Jewish and 575 Arab subjects aged 0–19 years. H. pylori IgG antibodies were measured by ELISA. The age-adjusted H. pylori seroprevalence was 45·2% in Jewish participants. Seropositivity increased with age, reaching 60% at age ⩾50 years and ranged from 24·3% in subjects originating from North America/Western Europe/Australia, to 63·2% in those from Asia/Africa/South America. Among Arabs, H. pylori seroprevalence was 42·1% and reached 65% in adolescents. There was no significant change in seroprevalence between 2000–2001 and 2007–2008. High prevalence of H. pylori was found in Arabs, and in Jews originating from countries of high H. pylori endemicity. These findings are characteristic of countries of diverse ethnic structure and recent immigration.

Rabies is a major public health problem in Bangladesh, where most of the population live in rural areas. However, there is little epidemiological information on rabies in rural Bangladesh. This study was conducted in 30 upazilas (subdistricts) covering all six divisions of the country, to determine the levels of rabies and animal bites in Bangladesh. The total population of these upazilas was 6 992 302. A pretested questionnaire was used and data were collected by interviewing the adult members of families. We estimated that in Bangladesh, 166 590 [95% confidence interval (CI) 163 350–170 550] people per year are bitten by an animal. The annual incidence of rabies deaths in Bangladesh was estimated to be 1·40 (95% CI 1·05–1·78)/100 000 population. By extrapolating this, we estimated that 2100 (95% CI 1575–2670) people die annually from rabies in Bangladesh. More than three-quarters of rabies patients died at home. This community-based study provides new information on rabies epidemiology in Bangladesh.

To assess the measles seroepidemiology of healthcare workers (HCWs), from 2004 to 2009 all newly recruited staff at a university hospital in Taiwan, were tested for specific immunoglobulin G antibodies for measles virus using enzyme-linked immunosorbent assays. A total of 1584 HCWs were included. The positivity rate of measles antibody for physicians and nurses was about 90%. The positivity of measles antibody in different age groups was 78·1%, 93·9% and 94·2% for 20–29, 30–39 and ⩾40 years age groups, respectively. Equivocal results were more frequent in the 20–29 (17·1%) years age group. A lack of antibody against measles was reported for 66 (4·2%) of those tested. Medical student (8·3%) and housekeeping personnel (5·3%) had the greatest lack of antibodies. This study demonstrates the waning measles immunity in younger HCWs in Taiwan, which poses the potential risk of nosocomial transmission of measles. Periodic surveillance and revaccination of susceptible HCWs is recommended.

Rabbit haemorrhagic disease is a major tool for the management of introduced, wild rabbits in Australia. However, new evidence suggests that rabbits may be developing resistance to the disease. Rabbits sourced from wild populations in central and southeastern Australia, and domestic rabbits for comparison, were experimentally challenged with a low 60 ID50 oral dose of commercially available Czech CAPM 351 virus – the original strain released in Australia. Levels of resistance to infection were generally higher than for unselected domestic rabbits and also differed (0–73% infection rates) between wild populations. Resistance was lower in populations from cooler, wetter regions and also low in arid regions with the highest resistance seen within zones of moderate rainfall. These findings suggest the external influences of non-pathogenic calicivirus in cooler, wetter areas and poor recruitment in arid populations may influence the development rate of resistance in Australia.

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.

The WHO recommends hepatitis A virus (HAV) immunization according to level of transmission and disease burden. We aimed to identify susceptible age groups by standardized serosurveys to inform HAV vaccination policy in participating countries: Belgium, Czech Republic, England, Finland, Germany, Italy, Lithuania, Malta, Romania, and Slovakia. Each country tested national serum banks (n = 1854–6748), collected during 1996–2004, for anti-HAV antibodies. Local laboratory results were standardized to common units. Forty-one per cent of those aged <30 years and 6% of those aged ⩾30 years were susceptible to HAV in Romania; compared to 70–94% and 26–71%, respectively, elsewhere. Romania reported high HAV incidence in children and young adults. Other countries reported HAV disease primarily in older risk groups. The results suggest low level of HAV transmission in most of Europe. Romania, however, appeared as an area with intermediate transmission. Vaccination of risk groups in countries with high susceptibility of young and middle-aged adults needs to be continued.

Community and hospital-acquired cases of human rotavirus are responsible for millions of gastroenteritis cases in children worldwide, chiefly in developing countries, and vaccines are now available. During surveillance activity for human rotavirus infections in Ireland, between 2006 and 2009, a total of 420 rotavirus strains were collected and analysed. Upon either PCR genotyping and sequence analysis, a variety of VP7 (G1–G4 and G9) and VP4 (P[4], P[6], P[8] and P[9]) genotypes were detected. Strains G1P[8] were found to be predominant throughout the period 2006–2008, with slight fluctuations seen in the very limited samples available in 2008–2009. Upon either PCR genotyping and sequence analysis of selected strains, the G1, G3 and G9 viruses were found to contain E1 (Wa-like) NSP4 and I1 VP6 genotypes, while the analysed G2 strains possessed E2 NSP4 and I2 VP6 genotypes, a genetic make-up which is highly conserved in the major human rotavirus genogroups Wa- and Kun-like, respectively. Upon sequence analysis of the most common VP4 genotype, P[8], at least two distinct lineages were identified, both unrelated to P[8] Irish rotaviruses circulating in previous years, and more closely related to recent European humans rotaviruses. Moreover, sequence analysis of the VP7 of G1 rotaviruses revealed the onset of a G1 variant, previously unseen in the Irish population.

The burden of respiratory infections is mainly seen in primary healthcare. To evaluate the potential impact of new preventive strategies against respiratory infections, such as the implementation of pneumococcal conjugate vaccines for infants in 2006 in The Netherlands, we conducted a baseline retrospective cohort study of electronic primary-care patient records to assess consultation rates, comorbidities and antibiotic prescription rates for respiratory infections in primary care. We found that between 1995 and 2005, overall registered consultation rates for lower respiratory tract infections had increased by 42·4%, upper respiratory infections declined by 4·9%, and otitis media remained unchanged. Concomitantly, there was a steady rise in overall comorbidity (75·7%) and antibiotic prescription rates (67·7%). Since Dutch primary-care rates for respiratory infections changed considerably between 1995 and 2005, these changes must be taken into account to properly evaluate the effect of population-based preventive strategies on primary-care utilization.

On account of the serious complications of hepatitis C virus (HCV) infection and the improved treatment possibilities, the need to improve HCV awareness and case-finding is increasingly recognized. To optimize a future national campaign with this objective, three pilot campaigns were executed in three regions in The Netherlands. One campaign was aimed at the general population, a second (similar) campaign was extended with a support programme for primary care and a third campaign was specifically aimed at hard-drug users. Data from the pilot campaigns were used to build a mathematical model to estimate the incremental cost-effectiveness ratio of the different campaigns. The campaign aimed at the general public without support for primary care did not improve case-finding and was therefore not cost-effective. The similar campaign accompanied by additional support for primary care and the campaign aimed at hard-drug users emerged as cost-effective interventions for identification of HCV carriers.

Between 2000 and 2009, the total number of patients with Clostridium difficile infections increased considerably in Southeastern Germany. A clear seasonality was observed with a higher number of affected patients occurring in the winter months (January–March). Moxifloxacin and erythromycin-resistant C. difficile PCR ribotypes 001 (72%) and 027 (4·6%) were the most commonly isolated strains.

The kernel of modelling transmission dynamics of infectious diseases lies in constructing the force of infection (FOI). Traditionally, it was based on mass-action law. In this paper, we show, based on survey data of Escherichia coli O157 infection on Scottish cattle farms, that the actual form of FOI deviates greatly from mass-action law. Further, control effectiveness deviates qualitatively: the epidemic of mass-action FOI can be controlled with a control effort larger than the so-called herd immunity, while the epidemic inferred from the survey data of E. coli O157 infection was shown to be difficult to control. This indicates that, at least for E. coli O157 infection on cattle farms, it is risky to rely on models of transmission dynamics that were based on mass-action law to design the optimal intervention programme for infectious diseases. This suggests the importance of collecting epidemic data and model selection from data-driven models to infer the most likely model of transmission dynamics.