Rising numbers of campylobacteriosis case notifications in Switzerland resulted in an increased attention to acute gastroenteritis (AG) in general. Patients with a laboratory-confirmed Campylobacter infection perceive their disease as severe and around 15% of these patients are hospitalized. This study aimed at estimating healthcare costs due to AG and campylobacteriosis in Switzerland. We used official health statistics, data from different studies and expert opinion for estimating individual treatment costs for patients with different illness severity and for extrapolating overall costs due to AG and campylobacteriosis. We estimated that total Swiss healthcare costs resulting from these diseases amount to €29–45 million annually. Data suggest that patients with AG consulting a physician without a stool diagnostic test account for €9·0–24·2 million, patients with a negative stool test result for Campylobacter spp. for €12·3 million, patients testing positive for Campylobacter spp. for €1·8 million and hospitalized campylobacteriosis patients for €6·5 million/year. Healthcare costs of campylobacteriosis are high and most likely increasing in Switzerland considering that campylobacteriosis case notifications steadily increased in the past decade. Costs and potential cost savings for the healthcare system should be considered when designing sectorial and cross-sectorial interventions to reduce the burden of human campylobacteriosis in Switzerland.

Clinical manifestations of acute bronchiolitis (AB) vary from minimal disease to severe respiratory failure. The response to respiratory viral infections is possibly influenced by genetic polymorphisms linked to the regulation of the inflammatory response. In the present study, we investigated whether interleukin-8 (IL-8) and interleukin-17 (IL-17) genetic variants are associated with the severity of AB. A group of Brazilian infants hospitalized with AB and a control group (infants with no or mild AB, without hospitalization) were genotyped for four IL-8/IL-17 variations. For replication, we studied an Argentinean population sample of infants with mild and severe AB. IL-8 polymorphism (rs 2227543) and IL-17 (rs2275913) variants showed significant associations with the severity of AB. The effect of the IL-8 variation could be replicated in the Argentinean sample. This finding suggests that IL-8 variations may influence the severity of AB in young infants. Further genetic association studies in low- or middle-income populations are necessary with the aim of expanding knowledge in this area.

There is a paucity of information on the risk from potable water in non-passenger merchant vessels (NPMVs) particularly with regard to Legionella and other bacteria. This retrospective study examined water samples from 550 NPMVs docked in eight UK ports. A total of 1027 samples from 412 NPMVs were examined for total aerobic colony counts (ACC), coliforms, Escherichia coli and enterococci; 41% of samples yielded ACC above the action level (>1 × 103 c.f.u./ml) and 4·5% contained actionable levels (>1 c.f.u./100 ml) of faecal indicator bacteria. Eight hundred and three samples from 360 NPMVs were cultured specifically for Legionella and 58% of vessels proved positive for these organisms with 27% of samples showing levels greater than the UK upper action limit of 1 × 103 c.f.u./l. Cabin showers (49%) and hospital shower (45%) were frequently positive. A subset of 106 samples was analysed by quantitative polymerase chain reaction for Legionella and identified a further 11 Legionella-positive NPMVs, returning a negative predictive value of 100%. There was no correlation between NPMV age or size and any microbial parameters (P > 0·05). Legionella pneumophila serogroup 1 was isolated from 46% of NPMVs and sequence-based typing of 17 isolates revealed four sequence types (STs) previously associated with human disease. These data raise significant concerns regarding the management of microbial and Legionella risks on board NPMVs and suggest that better guidance and compliance are required to improve control.

Most vector-borne diseases infect multiple host species, but disentangling the relative importance of different host species to transmission can be complex. Here we study how host species’ abundance and competence (duration and titre of parasitaemia) influence host importance during epidemic scenarios. We evaluate this theory using Ross River virus (RRV, family Togaviridae, genus Alphavirus), a multi-host mosquito-borne disease with significant human health impacts across Australia and Papua New Guinea. We used host contribution models to find the importance of key hosts (possums, wallabies, kangaroos, horses, humans) in typical mammal communities around five Australian epidemic centres. We found humans and possums contributed most to epidemic RRV transmission, owing to their high abundances, generally followed by macropods. This supports humans as spillover hosts, and that human–mosquito and possum–mosquito transmission is predominant during epidemics. Sensitivity analyses indicate these findings to be robust across epidemic centres. We emphasize the importance of considering abundance and competence in identifying key hosts (during epidemics in this case), and that competence alone is inadequate. Knowledge of host importance in disease transmission may help to equip health agencies to bring about greater effectiveness of disease mitigation strategies.

Eastern equine encephalitis (EEE) is a rare but severe emerging vector-borne disease affecting human and animal populations in the northeastern United States where it is endemic. Key knowledge gaps remain about the epidemiology of EEE virus (EEEV) in areas where its emergence has more recently been reported. In Eastern Canada, viral activity has been recorded in mosquitoes and horses throughout the 2000s but cases of EEEV in humans have not been reported so far. This study was designed to provide an assessment of possible EEEV human exposure by modelling environmental risk factors for EEEV in horses, identifying high-risk environments and mapping risk in the province of Quebec, Canada. According to logistic models, being located near wooded swamps was a risk factor for seropositivity or disease in horses [odds ratio (OR) 4·15, 95% confidence interval (CI) 1·16–14·8) whereas being located on agricultural lands was identified as protective (OR 0·75, 95% CI 0·62–0·92). A better understanding of the environmental risk of exposure to EEEV in Canada provides veterinary and public health officials with enhanced means to more effectively monitor the emergence of this public health risk and design targeted surveillance and preventive measures.

Since the 1990s, New Zealand (NZ) has seen an increasing incidence of paediatric skin infections leading to hospitalization. We sought to describe the epidemiology of these infections over time. Hospital discharge data were analysed for all children admitted to any NZ public hospital from 2004 to 2014. We found the age-standardized incidence of hospitalizations due to skin infections increased during this period from 522/100 000 in 2004 to a peak of 644/100 000 in 2011, after which it declined to 524/100 000 in 2014. This decline in incidence was driven primarily by the decline in hospitalization rates in high-risk groups including children living in the most deprived areas as well as Māori and Pacific children. Recent targeted policies focused on improving healthcare access through school-based and primary care-based interventions in these high-risk groups could potentially explain the decline in hospitalization rates. However, even with the closing of the inequality gap, significant socioeconomic and ethnic health disparities persist.

Malaria and leishmaniasis are among the two most important health problems of many developing countries especially in the Middle East and North Africa. It is common for vector-borne infectious diseases to have similar hotspots which may be attributed to the overlapping ecological distribution of the vector. Hotspot analyses were conducted to simultaneously detect the location of local hotspots and test their statistical significance. Spatial scan statistics were used to detect and test hotspots of malaria and cutaneous leishmaniasis (CL) in Afghanistan in 2009. A multivariate negative binomial model was used to simultaneously assess the effects of environmental variables on malaria and CL. In addition to the dependency between malaria and CL disease counts, spatial and temporal information were also incorporated in the model. Results indicated that malaria and CL incidence peaked at the same periods. Two hotspots were detected for malaria and three for CL. The findings in the current study show an association between the incidence of malaria and CL in the studied areas of Afghanistan. The incidence of CL disease in a given month is linked with the incidence of malaria in the previous month. Co-existence of malaria and CL within the same geographical area was supported by this study, highlighting the presence and effects of environmental variables such as temperature and precipitation. People living in areas with malaria are at increased risk for leishmaniasis infection. Local healthcare authorities should consider the co-infection problem by recommending systematic malaria screening for all CL patients.

Following an unusually heavy rainfall in June 2009, a community-wide outbreak of Campylobacter gastroenteritis occurred in a small Danish town. The outbreak investigation consisted of (1) a cohort study using an e-questionnaire of disease determinants, (2) microbiological study of stool samples, (3) serological study of blood samples from cases and asymptomatic members of case households, and (4) environmental analyses of the water distribution system. The questionnaire study identified 163 cases (respondent attack rate 16%). Results showed a significant dose-response relationship between consumption of tap water and risk of gastroenteritis. Campylobacter jejuni belonging to two related flaA types were isolated from stool samples. Serum antibody levels against Campylobacter were significantly higher in cases than in asymptomatic persons. Water samples were positive for coliform bacteria, and the likely mode of contamination was found to be surface water leaking into the drinking-water system. This geographically constrained outbreak presented an ideal opportunity to study the serological response in persons involved in a Campylobacter outbreak. The serology indicated that asymptomatic persons from the same household may have been exposed, during the outbreak period, to Campylobacter at doses that did not elicit symptoms or alternatively had been exposed to Campylobacter at a time prior to the outbreak, resulting in residual immunity and thus absence of clinical signs.

The establishment of Aedes albopictus in southern France, a recognized competent vector for several arboviruses, represents a new threat for the local transmission and spread of what were until recently considered as tropical diseases. A preparedness and response plan, based on vigilance of both clinicians and laboratories, has introduced significant changes in guidelines and behaviour regarding patients’ care specifically during the activity period of mosquitoes. In the present study, we report the results of a 1-year activity in arboviral infection diagnosis. A total of 141 patients were included in this retrospective study. The number of suspected imported and autochthonous cases was 69 and 72, respectively. A diagnosis of arboviral infection was confirmed for 15 (21·7%) suspected imported cases, with identification of 13 dengue viruses, one chikungunya virus and one Zika virus. No autochthonous cases were detected. This report illustrates the increase in requests for arboviral infection diagnosis and confirms the challenge with identifying autochthonous arboviral infection cases in many unspecific febrile syndromes.

The intensity of annual Spanish influenza activity is currently estimated from historical data of the Spanish Influenza Sentinel Surveillance System (SISSS) using qualitative indicators from the European Influenza Surveillance Network. However, these indicators are subjective, based on qualitative comparison with historical data of influenza-like illness rates. This pilot study assesses the implementation of Moving Epidemic Method (MEM) intensity levels during the 2014–2015 influenza season within the 17 sentinel networks covered by SISSS, comparing them to historically reported indicators. Intensity levels reported and those obtained with MEM at the epidemic peak of the influenza wave, and at national and regional levels did not show statistical difference (P = 0·74, Wilcoxon signed-rank test), suggesting that the implementation of MEM would have limited disrupting effects on the dynamic of notification within the surveillance system. MEM allows objective influenza surveillance monitoring and standardization of criteria for comparing the intensity of influenza epidemics in regions in Spain. Following this pilot study, MEM has been adopted to harmonize the reporting of intensity levels of influenza activity in Spain, starting in the 2015–2016 season.

Computer models can be useful in planning interventions against novel strains of influenza. However such models sometimes make unsubstantiated assumptions about the relative infectivity of asymptomatic and symptomatic cases, or conversely assume there is no impact at all. Using household-level data from known-index studies of virologically confirmed influenza A infection, the relationship between an individual's infectiousness and their symptoms was quantified using a discrete-generation transmission model and Bayesian Markov chain Monte Carlo methods. It was found that the presence of particular respiratory symptoms in an index case does not influence transmission probabilities, with the exception of child-to-child transmission where the donor has phlegm or a phlegmy cough.

HBsAg reappearance may constitute not only a risk for liver disease but also an infectious source. We aimed to determine whether HBsAg may reappear after spontaneous HBsAg seroclearance. A cohort of 2999 HBsAg-positive subjects aged 30–55 years was recruited in Guangxi, China in 2004. HBsAg was tested every 6 months from July 2004 to June 2007, then, one more time in December 2013. The results showed that spontaneous HBsAg seroclearance occurred in 41 subjects in the first 3 years, giving a 0·54% annual seroclearance rate. Thirteen of the 41 subjects were randomly tested for HBsAg in 2013. Four subjects became HBsAg positive. S gene sequences of HBV were analysed from serum collected before seroclearance and after reappearance, respectively, for subject QS840 (11 and 12 clones), subject TN98 (13 and 13 clones) and subject WX227 (10 and 8 clones). Serotype, subgenotype and amino-acid substitution pattern in each sample collected after reappearance was observed in the sample collected before HBsAg seroclearance. Nucleotide similarity between the two sequences from each subject was >99% and five sequences from subject TN98 were the same. In conclusion, following reactivation, HBsAg may reappear in individuals with spontaneous HBsAg seroclearance many years previously.

A recent countrywide MRSA spa-type 1081 outbreak in The Netherlands predominantly affected nursing homes, generating questions on how infection spreads within and between nursing homes despite a low national prevalence. Since the transfer of residents between nursing homes is uncommon in The Netherlands, we hypothesized that staff exchange plays an important role in transmission. This exploratory study investigated the extent of former (last 2 years) and current staff exchange within and between nursing homes in The Netherlands. We relied on a questionnaire that was targeted towards nursing-home staff members who had contact with residents. We found that 17·9% and 12·4% of the nursing-home staff formerly (last 2 years) or currently worked in other healthcare institutes besides their job in the nursing home through which they were selected to participate in this study. Moreover, 39·7% of study participants worked on more than one ward. Our study shows that, in The Netherlands, nursing-home staff form a substantial number of links between wards within nursing homes and nursing homes are linked to a large network of healthcare institutes through their staff members potentially providing a pathway for MRSA transmission between nursing homes and throughout the country.

More than 2 million visits for skin and soft tissue infections (SSTIs) are seen in US emergency departments (EDs) yearly. Up to 50% of patients with SSTIs, suffer from recurrences, but associated factors remain poorly understood. We performed a retrospective study of patients with primary diagnosis of SSTI between 2005 and 2011 using California ED discharge data from the State Emergency Department Databases and State Inpatient Databases. Using a multivariable logistic regression, we examined factors associated with a repeat SSTI ED visits up to 6 months after the initial SSTI. Among 197 371 SSTIs, 16·3% were associated with a recurrent ED visit. We found no trend in recurrent visits over time (χ 2 trend = 0·68, P = 0·4). Race/ethnicity, age, geographical location, household income, and comorbidities were all associated with recurrent visits. Recurrent ED visits were associated with drug/alcohol abuse or liver disease [odds ratio (OR) 1·4, 95% confidence interval (CI) 1·3–1·4], obesity (OR 1·3, 95% CI 1·2–1·4), and in infections that were drained (OR 1·1, 95% CI 1·1–1·1) and inversely associated with hospitalization after initial ED visit (OR 0·4, 95% CI 0·3–0·4). In conclusion, we found several patient-level factors associated with recurrent ED visits. Identification of these high-risk groups is critical for future ED-based interventions.

We investigated the first laboratory-confirmed human case of cowpox virus infection in Russia since 1991. Phylogenetic studies of haemagglutinin, TNF-α receptor-like protein and thymidine kinase regions showed significant differences with known orthopoxviruses, including unique amino-acid substitutions and deletions. The described cowpox virus strain, taking into account differences, is genetically closely related to strains isolated years ago in the same geographical region (European part of Russia and Finland), which suggests circulation of viral strains with common origin in wild rodents without spread over long distances and appearance in other parts of the world.

We studied the evolution, genotypes, and the molecular clock of dengue virus serotype 1 (DENV-1), between 2001 and 2014 in Guangzhou, China. The analysis of the envelope (E) gene sequences of 67 DENV-1 strains isolated in Guangzhou, together with 58 representative sequences downloaded from NCBI, have shown shifts in viral genotypes. The genotype changed several times, from genotype I to IV in 2002, from IV to I in 2005, and from I to V in 2014. These genotype shifts may be the cause of DENV outbreaks. The diversity of genotypes and clades demonstrates a high risk of future outbreaks in Guangzhou. The mean rate of virus nucleotide substitution in Guangzhou was determined to be 7·77 × 10−4 per site per year, which represents a medium substitution rate compared to two other countries. Our research can point to different ancestors of the isolated strains, which may further reveal the different origins and transmission of DENV-1 strains in Guangzhou.

Although most non-typhoidal Salmonella illnesses are self-limiting, antimicrobial treatment is critical for invasive infections. To describe resistance in Salmonella that caused foodborne outbreaks in the United States, we linked outbreaks submitted to the Foodborne Disease Outbreak Surveillance System to isolate susceptibility data in the National Antimicrobial Resistance Monitoring System. Resistant outbreaks were defined as those linked to one or more isolates with resistance to at least one antimicrobial drug. Multidrug resistant (MDR) outbreaks had at least one isolate resistant to three or more antimicrobial classes. Twenty-one per cent (37/176) of linked outbreaks were resistant. In outbreaks attributed to a single food group, 73% (16/22) of resistant outbreaks and 46% (31/68) of non-resistant outbreaks were attributed to foods from land animals (P < 0·05). MDR Salmonella with clinically important resistance caused 29% (14/48) of outbreaks from land animals and 8% (3/40) of outbreaks from plant products (P < 0·01). In our study, resistant Salmonella infections were more common in outbreaks attributed to foods from land animals than outbreaks from foods from plants or aquatic animals. Antimicrobial susceptibility data on isolates from foodborne Salmonella outbreaks can help determine which foods are associated with resistant infections.

In Singapore, influenza vaccination is recommended for persons at higher risk of complications of seasonal influenza, including those with chronic medical conditions and the elderly (individuals aged ⩾65 years). We investigated the factors associated with influenza vaccine uptake based on a nationally representative sample of community-dwelling adults aged >50 years. The data for this study were obtained from the National Health Surveillance Survey (NHSS) 2013. The association between influenza vaccine uptake and socio-demographic and health-related variables was analysed using univariable and multivariable logistic regression models. Of 3700 respondents aged ⩾50 years in the NHSS, 15·2% had received seasonal influenza vaccination in the past year. Older age, single marital status and economic inactivity were the socio-demographic variables independently associated with vaccine uptake. Health-related factors which were predictive of influenza vaccine uptake were sufficient total physical activity, better self-rated health, having at least one medical condition at risk of influenza complications and a regular family doctor/general practitioner. Influenza vaccine uptake in community-dwelling older adults was low. Our findings are of relevance in the formulation of public health policies and targeted health promotion strategies to increase vaccine uptake in this population group.

Australian abattoir workers, farmers, veterinarians and people handling animal birthing products or slaughtering animals continue to be at high risk of Q fever despite an effective vaccine being available. National Notifiable Diseases Surveillance System data were analysed for the period 1991–2014, along with enhanced risk factor data from notified cases in the states of New South Wales and Queensland, to examine changes in the epidemiology of Q fever in Australia. The national Q fever notification rate reduced by 20% [incident rate ratio (IRR) 0·82] following the end of the National Q fever Management Program in 2006, and has increased since 2009 (IRR 1·01–1·34). Highest rates were in males aged 40–59 years (5·9/100 000) and 87% of Q fever cases occurred in New South Wales and Queensland. The age of Q fever cases and proportion of females increased over the study period. Based on the enhanced risk factor data, the most frequently listed occupation for Q fever cases involved contact with livestock, followed by ‘no known risk’ occupations. More complete and comparable enhanced risk factor data, at the State/Territory and national levels, would aid in further understanding of the epidemiology of Q fever.

Although high hepatitis C virus (HCV) prevalence has been observed in people who inject drugs (PWID) for decades, research suggests incidence is falling. We examined whether PWIDs’ use of opioid substitution therapy (OST) and their needle-and-syringe sharing behaviour explained HCV incidence. We assessed HCV incidence in 235 PWID in Melbourne, Australia, and performed discrete-time survival with needle-sharing and OST status as independent variables. HCV infection, reinfection and combined infection/reinfection incidences were 7·6 [95% confidence interval (CI) 4·8–11·9], 12·4 (95% CI 9·1–17·0) and 9·7 (95% CI 7·4–12·6) per 100 person-years, respectively. Needle-sharing was significantly associated with higher incidence of naive HCV infection [hazard ratio (HR) 4·9, 95% CI 1·3–17·7] but not reinfection (HR 1·85, 95% CI 0·79–4·32); however, a cross-model test suggested this difference was sample specific. Past month use of OST had non-significant protective effects against naive HCV infection and reinfection. Our data confirm previous evidence of greatly reduced HCV incidence in PWID, but not the significant protective effect of OST on HCV incidence detected in recent studies. Our findings reinforce the need for greater access to HCV testing and prevention services to accelerate the decline in incidence, and HCV treatment, management and support to limit reinfection.