Diphtheria is an uncommon disease in the UK due to an effective immunization programme; consequently when cases do arise, there can be delays in diagnosis and case-fatality rates remain high. We reviewed 102 patients with infections caused by toxigenic corynebacteria (an average of four per year) reported in the UK between 1986 and 2008: 42 Corynebacterium diphtheriae, 59 C. ulcerans and one C. pseudotuberculosis, as well as 23 asymptomatic carriers. Five fatalities were reported, all in unvaccinated patients. The major risk factor for C. diphtheriae infection continued to be travel to an endemic country. C. ulcerans infections became more common than C. diphtheriae infections in the UK; they were associated with contact with companion animals. The occurrence of indigenous severe C. ulcerans infections and imported C. diphtheriae cases highlights the need to maintain UK routine vaccination coverage at the 95% level in the UK, as recommended by the World Health Organization.

The UK was one of few European countries to document a substantial wave of pandemic (H1N1) 2009 influenza in summer 2009. The First Few Hundred (FF100) project ran from April–June 2009 gathering information on early laboratory-confirmed cases across the UK. In total, 392 confirmed cases were followed up. Children were predominantly affected (median age 15 years, IQR 10–27). Symptoms were mild and similar to seasonal influenza, with the exception of diarrhoea, which was reported by 27%. Eleven per cent of all cases had an underlying medical condition, similar to the general population. The majority (92%) were treated with antiviral drugs with 12% reporting adverse effects, mainly nausea and other gastrointestinal complaints. Duration of illness was significantly shorter when antivirals were given within 48 h of onset (median 5 vs. 9 days, P=0·01). No patients died, although 14 were hospitalized, of whom three required mechanical ventilation. The FF100 identified key clinical and epidemiological characteristics of infection with this novel virus in near real-time.

The world is currently confronting the first influenza pandemic of the 21st century [caused by a novel pandemic influenza A (H1N1) virus]. Earlier pandemics have been characterized by age distributions that are distinct from those observed with seasonal influenza epidemics, with higher attack rates (and correspondingly increased proportionate or relative mortality) in younger individuals. While the genesis of protection against infection in older individuals during a pandemic is uncertain, differential vulnerability to infection by age has important implications for disease dynamics and control, and for choice of optimal vaccination strategies. Age-related vulnerability to infection may explain differences between school- and community-derived estimates of the reproductive number (R) for a newly emerged pandemic strain, and may also help explain the failure of a newly emerged influenza A (H1N1) virus strain to cause a pandemic in 1977. Age-related factors may also help explain variability in attack rates, and the size and impact of influenza epidemics across jurisdictions and between populations. In Canada, such effects have been observed in the apparently increased severity of outbreaks on Indigenous peoples' reserves. The implications of these patterns for vaccine allocation necessitate targeted research to understand age-related vulnerabilities early in an influenza pandemic.

The apparent family clustering of avian influenza A/H5N1 has led several groups to postulate the existence of a host genetic influence on susceptibility to A/H5N1, yet the role of host factors on the risk of A/H5N1 disease has received remarkably little attention compared to the efforts focused on viral factors. We examined the epidemiological patterns of human A/H5N1 cases, their possible explanations, and the plausibility of a host genetic effect on susceptibility to A/H5N1 infection. The preponderance of familial clustering of cases and the relative lack of non-familial clusters, the occurrence of related cases separated by time and place, and the paucity of cases in some highly exposed groups such as poultry cullers, are consistent with a host genetic effect. Animal models support the biological plausibility of genetic susceptibility to A/H5N1. Although the evidence is circumstantial, host genetic factors are a parsimonious explanation for the unusual epidemiology of human A/H5N1 cases and warrant further investigation.

Influenza can be a serious, sometimes deadly, disease, especially for people in high-risk groups such as the elderly and patients with underlying, severe disease. In this paper we estimated the influenza-related excess mortality in Norway for 1975–2004, comparing it with dominant virus types and estimates of the reproduction number. Analysis was done using Poisson regression, explaining the weekly all-cause mortality by rates of reported influenza-like illness, together with markers for seasonal and year-to-year variation. The estimated excess mortality was the difference between the observed and predicted mortality, removing the influenza contribution from the prediction. We estimated the overall influenza-related excess mortality as 910 deaths per season, or 2·08% of the overall deaths. Age-grouped analyses indicated that the major part of the excess mortality occurred in the ⩾65 years age group, but that there was also a significant contribution to mortality in the 0–4 years age group. Estimates of the reproduction number R, ranged from about 1 to 1·69.

Although rabies incidence in humans in Western Europe is low, the repeated importation of rabid animals from enzootic areas threatens the rabies-free status of terrestrial animals and challenges the public health systems in this area. Most rabid animals imported into the European Union (EU) in recent years came from Morocco. The aim of this study was to develop a probabilistic risk assessment model to estimate the probability of rabies introduction, which was applied to the risk to the EU from dogs coming from Morocco. The mean annual probability of rabies introduction was 0·21 (90% CI 0·02–0·65). The pathways that contributed the most to this probability were: (a) EU citizens who adopted a dog in Morocco (59% of the total probability) and (b) EU citizens who travelled with their dog to Morocco by ferry (34% of the total probability). The model showed a marked seasonality in the risk of rabies with almost 40% of the annual probability occurring during the months of July and August. The application of stricter border controls (assuming 100% compliance) would result in a >270-fold reduction in the likelihood of rabies introduction into the EU from Morocco.

In Finland, rabies in bats was suspected for the first time in 1985 when a bat researcher, who had multiple bat bites, died in Helsinki. The virus isolated from the researcher proved to be antigenically related to rabies viruses previously detected in German bats. Later, the virus was typed as EBLV-2b. Despite an epidemiological study in bats 1986 and subsequent rabies surveillance, rabies in bats was not detected in Finland until the first case in a Daubenton's bat (Myotis daubentonii) was confirmed in August 2009. The bat was paralysed, occasionally crying, and biting when approached; it subsequently tested positive for rabies. The virus was genetically typed as EBLV-2. This is the northernmost case of bat rabies ever detected in Europe. Phylogenetic analyses showed that the EBLV-2b isolate from the human case in 1985 and the isolate from the bat in 2009 were genetically closely related, demonstrating that EBLV-2 may have been circulating in Finland for many years.

In February 2008, three white-nosed coatis (Nasua narica) were found dead in a recreational park in Cancun, Mexico. The diagnosis of rabies virus (RABV) infection was confirmed by direct immunofluorescence test. The phylogenetic analysis performed with the complete RABV nucleoprotein gene positioned this isolate close to a sequence of a human rabies case reported during 2008 from Oaxaca, Mexico, sharing 93% similarity. In turn, these two variants are related to another variant found in rabid Tadarida brasiliensis mexicana bats across North America. Anti-RABV neutralizing activity (1·3 IU/ml) was found in the serum of one white-nosed coati captured with another five that cohabited with the dead animals. Enhanced rabies surveillance and pathogenesis studies should be conducted in coatis and insectivorous bats of the region to clarify the role of these species as potential emergent or long-term unidentified RABV reservoirs.

Pseudorabies virus (PrV) infections appear to be more widely distributed in the European wild boar (Sus scrofa) population than assumed. In Europe, attempts to isolate and characterize the causative agents have been limited so far. We therefore collected and examined a total of 35 PrV isolates obtained from wild boar or hunting dogs in Germany, France, Spain, Italy, Slovakia and Hungary between 1993 and 2008. Restriction enzyme analysis of genomic DNA using BamHI showed that all isolates, except one, belonged to genogroup I but different subtypes were evident. For further investigations of the phylogenetic relationships, a 732-bp fragment of the glycoprotein C (gC) gene was amplified by PCR. Sequence analysis revealed about 40 variant positions within this fragment. Comparison of the nucleotide sequences supported the separation into a clade containing isolates from North-Rhine Westphalia, Rhineland-Palatinate (Germany), France and Spain (clade B) and an apparently more variable clade comprising isolates from Brandenburg, Baden-Wurttemberg, Saxony, Saxony-Anhalt (Germany), Slovakia, Hungary, Italy and France (clade A).

In 2005, a serological study was carried out on horses in five ecologically contrasted zones of the Senegal River basin (Senegal) to assess West Nile virus (WNV) transmission and investigate underlying environmental risk factors. In each study zone, horses were randomly selected and blood samples taken. A land-cover map of the five study areas was built using two satellite ETM+ images. Blood samples were screened by ELISA for anti-WNV IgM and IgG and positive samples were confirmed by seroneutralization. Environmental data were analysed using a principal components analysis. The overall IgG seroprevalence rate was 85% (n=367; 95% CI 0·81–0·89). The proximity to sea water, flooded banks and salted mudflats were identified as protective factors. These environmental components are unfavourable to the presence of Culex mosquitoes suggesting that in Senegal, the distribution of the vector species is more limiting for WNV transmission than for the hosts' distribution.

Incarcerated persons comprise about 0·4% of the Croatian population, of whom 25–30% misuse drugs. We attempted to determine the structure of the prison population, prevalence of HBV, HCV, HIV markers, co-infections with HBV, HCV and HIV and acute HBV, HCV and HIV infection. In total, 25·9% of prisoners were positive for some markers for viral hepatitis (HBV 11·3%, HCV 8·3%, HBV/HCV 6·3%). Prevalence of HBV infection in intravenous drug users (IDUs) was 26·2% (highly promiscuous group 20·4%, individuals with psychiatric diseases and personality disorders 16·0%). HCV infection in IDUs was 52·0% and 4·9% in the highly promiscuous group. HBV/HCV co-infection was registered in 34·9% of prisoners positive for HBV markers (203/582). Acute HBV infection was detected in 0·5%, and HCV in 1·2%. Only 0·15% (5/3348) of prisoners were anti-HIV positive. It appears that individuals with psychiatric diseases and personality disorders could be an additional risk population for these viral infections.

The success of childhood vaccination against hepatitis B relies on persistence of immunity into adolescence and adulthood. In 2000, two hexavalent vaccines with a hepatitis B component (Hexavac®, Infanrix hexa®) were introduced in Germany. Hexavac was withdrawn in 2005 amidst concerns about its long-term hepatitis B protection. We compared hepatitis B surface antibody (anti-HBs) levels in children fully vaccinated with Hexavac or Infanrix hexa (n=477) in a secondary data analysis of a large cross-sectional health survey in Germany. On average 2·4 years after vaccination, 25·3% of Hexavac vaccinees had anti-HBs levels <10 mIU/ml (95% CI 19·0–32·8) compared to 4·7% of Infanrix hexa vaccinees (95% CI 2·4–8·9). These findings suggest that short-term hepatitis B immunogenicity in Hexavac vaccinees may also be weaker. Further studies are warranted to assess whether Hexavac vaccinees should be re-vaccinated or receive a booster vaccination before these birth cohorts reach adolescence.

In February 2007 an outbreak of Nipah virus (NiV) encephalitis in Thakurgaon District of northwest Bangladesh affected seven people, three of whom died. All subsequent cases developed illness 7–14 days after close physical contact with the index case while he was ill. Cases were more likely than controls to have been in the same room (100% vs. 9·5%, OR undefined, P<0·001) and to have touched him (83% vs. 0%, OR undefined, P<0·001). Although the source of infection for the index case was not identified, 50% of Pteropus bats sampled from near the outbreak area 1 month after the outbreak had antibodies to NiV confirming the presence of the virus in the area. The outbreak was spread by person-to-person transmission. Risk of NiV infection in family caregivers highlights the need for infection control practices to limit transmission of potentially infectious body secretions.

This study attempted to examine the relatedness between RAPD–PCR, PFGE and VcA VNTR results with those of conventional phage typing of V. cholerae strains and to evaluate VcA VNTR as an indispensable molecular-typing tool that accomplishes the urgent need for effective epidemiological surveillance. All the O1 El Tor strains were predominantly clustered into phage type T27 with the new phage-typing scheme. Using RAPD–PCR, a total of 69 O1 El Tor strains were grouped under 16 different electrophoretic patterns. A total of 33 pulsotypes were identified in these strains by PFGE. VcA VNTR revealed high VcA polymorphism in all V. cholerae strains incorporated in this study. Our results underline the considerable potential of VcA VNTR analysis as a tool for molecular typing of V. cholerae.

Post-infectious irritable bowel syndrome (PI-IBS) has been established as a sequel of infectious intestinal disease (IID). The aim of this study was to estimate the burden of PI-IBS caused by the pathogens Campylobacter, Salmonella and Shigella, and to compare this with other outcomes associated with these pathogens. The attributable risk of PI-IBS due to bacterial pathogens was calculated and linked to national data on gastroenteritis incidence and measures for severity and duration of illness in order to estimate the burden of PI-IBS. One year post-infection, IBS developed in 9% of patients with bacterial IID. The burden of PI-IBS adds over 2300 disability adjusted life years to the total annual disease burden for the selected pathogens. PI-IBS is a frequent sequel of IID, resulting in a considerable disease burden compared to other outcomes. If this relationship is not considered, this will result in an underestimation of the disease burden of IID.

A cross-sectional study based on a questionnaire survey was conducted to determine the distribution of lumpy skin disease (LSD) and associated risk factors in three main agro-climatic zones of Ethiopia. A total of 330 questionnaire surveys were collected from 44 peasant associations (PA) distributed in 15 districts. Across agro-climate zones, herd-level LSD prevalence in the midland agro-climate was significantly higher 55·2% [95% confidence interval (CI) 47·5–62·6] than in highland and lowland agro-climate zones. Overall observed LSD prevalence at animal-level was 8·1% (95% CI 7·3–8·9) and observed mortality was 2·12% (95% CI 1·73–2·6). The odds ratio (OR) of LSD occurrence in midland vs. highland and lowland vs. highland zones was 3·86 (95% CI 2·61–5·11) and 4·85 (95% CI 2·59–7·1), respectively. Significantly high risk of LSD occurrence was associated with communal grazing and watering management (OR 4·1, 95% CI 2·02–6·18) and introduction of new cattle (OR 8·5, 95% CI 6·0–11·0). Our findings describe the distribution of LSD in different agro-climates in Ethiopia along with associated risk factors, and can help shed light on the epidemiology of LSD in other African countries suffering from the disease.

In July 2008, office workers in Dublin complained of influenza-like illness preceding and interspersing two cases of notified Legionnaires' disease. Legionella pneumophila serogroup 1 was identified in both cooling towers supplying the office. A retrospective cohort study was undertaken to investigate possible Pontiac fever (PF). Forty-seven employees (23%) met the clinical case definition for PF but confirmatory testing was negative. Exposure to the smoking area situated beside the cooling towers was associated with an increased risk of PF (RR 2·4, 95% CI 1·5–3·8). The diagnosis of PF should be considered when many persons exposed to a possible reservoir of Legionella spp. present with flu-like symptoms. More sensitive microbiological tests would allow better confirmation and more comprehensive reporting of PF. Early detection is vital to prevent potentially severe illness and outbreaks of PF or Legionnaires' disease.

Estimation of prevalence of disease, including construction of confidence intervals, is essential in surveys for screening as well as in monitoring disease status. In most analyses of survey data it is implicitly assumed that the diagnostic test has a sensitivity and specificity of 100%. However, this assumption is invalid in most cases. Furthermore, asymptotic methods using the normal distribution as an approximation of the true sampling distribution may not preserve the desired nominal confidence level. Here we proposed exact two-sided confidence intervals for the prevalence of disease, taking into account sensitivity and specificity of the diagnostic test. We illustrated the advantage of the methods with results of an extensive simulation study and real-life examples.