Chronic disease patients are at high risk of developing serious influenza-related complications. This study investigated the prevalence of seasonal influenza vaccination (IV) and associated factors in such patients. A random sample of 704 Chinese adults with chronic disease was anonymously interviewed by telephone; 35·8% of them had ever taken up IV and 22·7% did so during the last flu season. The most frequently mentioned facilitator was recommendation made by a healthcare worker (HCW). Knowledge that IV is required annually, perceived severe health impacts of influenza, and recommendation made by a HCW were positively associated with previous IV and intention to take up IV in the next year, while perceived side-effects was inversely associated with previous IV and intention to take up IV. The coverage of IV in this study population was low. HCWs should clarify IV-related health beliefs in chronic disease patients and actively advise them to take up IV.

A prospective longitudinal study was conducted on 96 smallholder duck farms in Indonesia over a period of 14 months in 2007 and 2008 to monitor bird- and flock-level incidence rates of H5 highly pathogenic avian influenza (HPAI) infection in duck flocks, and to identify risk factors associated with these flocks becoming H5 seropositive. Flocks that scavenged around neighbouring houses within the village were at increased risk of developing H5 antibodies, as were flocks from which carcases of birds that died during the 2 months between visits were consumed by the family. Duck flock confinement overnight on the farm and sudden deaths of birds between visits were associated with lower risk of the flock developing H5 antibodies. Scavenging around neighbouring houses and non-confinement overnight are likely to be causal risk factors for infection. With this study we have provided insights into farm-level risk factors of HPAI virus introduction into duck flocks. Preventive messages based on these risk factors should be included in HPAI awareness programmes.

Although social networks are known to play an important role in drug-using behaviours associated with hepatitis C virus (HCV) infection, literature on social networks and HCV is inconsistent. This exploratory study examined HCV RNA distribution within a social network of anti-HCV-positive non-medical prescription opioid users (NMPOUs) in rural Appalachia. Participants were tested serologically for HCV RNA, and behavioural, demographic, and network data were collected using interview-administered questionnaires. Multivariate analyses were performed using logistic regression. Behavioural and demographic characteristics did not differ by RNA status. In the multivariate model, recent injecting drug users (IDUs) were more likely to be RNA positive [odds ratio (OR) 4·06, 95% confidence interval (CI) 1·04–15·83], and turnover into an IDU's drug network was significantly protective (OR 0·15, 95% CI 0·03–0·75). This is the first study to date to examine HCV distribution in rural NMPOUs from a network perspective and demonstrates that network characteristics significantly contribute to the epidemiology of HCV in this understudied, high-risk population.

Dengue is the most frequent arboviral disease and is expanding geographically. Dengue is also increasingly being reported in travellers, in particular in travellers to Thailand. However, data to quantify the risk of travellers acquiring dengue when travelling to Thailand are lacking. Using mathematical modelling, we set out to estimate the risk of non-immune persons acquiring dengue when travelling to Thailand. The model is deterministic with stochastic parameters and assumes a Poisson distribution for the mosquitoes' biting rate and a Gamma distribution for the probability of acquiring dengue from an infected mosquito. From the force of infection we calculated the risk of dengue acquisition for travellers to Thailand arriving in a typical year (averaged over a 17-year period) in the high season of transmission. A traveller arriving in the high season of transmission and remaining for 7 days has a risk of acquiring dengue of 0·2% (95% CI 0·16–0·23), whereas the risk for travel of 15 and 30 days' duration is 0·46% (95% CI 0·41–0·50) and 0·81% (95% CI 0·76–0·87), respectively. Our data highlight that the risk of non-immune travellers acquiring dengue in Thailand is substantial. The incidence of 0·81% after a 1-month stay is similar to that reported in prospective seroconversion studies in Israeli travellers to Thailand, highlighting that our models are consistent with actual data. Risk estimates based on mathematical modelling offer more detailed information depending on various travel scenarios, and will help the travel medicine provider give better evidence-based advice for travellers to dengue-endemic countries.

Thailand was a hyper-endemic country for dengue with co-circulation of four serotypes and tens of thousands of infected cases annually. Taking into consideration the large number of local dengue virus (DENV) sequences available in GenBank, Thailand was the most ideal locality to study co-evolution of DENV. Therefore, we undertook a large-scale molecular epidemiological analysis of all DENV strains isolated in Thailand. In this study, we demonstrated that DENV strains of four serotypes post-1990 grouped into distinct clades, and that specific mutations in the envelope protein were first confirmed in these clades. Compared to the DENV1, DENV2 and DENV3 clades, the DENV4 clade evolved markedly more slowly (6·4 × 10−5 substitutions/site per year). Our results also showed that the genetic diversity of the predominant genotype of each serotype tended to slightly increase over time with fluctuating changes, followed by a stationary phase after 2000. This suggests that the four DENV clades became the predominant strains due to DENV possessing improved fitness after long-term selection.

Lumpy skin disease (LSD) is an economically important, acute or sub-acute, viral disease of cattle that occurs across Africa and in the Middle East. The aim of this study was to investigate if lumpy skin disease virus (LSDV) can be transmitted mechanically by African brown ear ticks (Rhipicephalus appendiculatus Neum.). Laboratory-bred R. appendiculatus males were fed on experimentally infected viraemic ‘donor’ cattle. Partially fed male ticks were then transferred to feed on an uninfected ‘recipient’ cow. The recipient animal became viraemic, showed mild clinical signs of LSD and seroconverted. Additionally, R. appendiculatus males were found to transmit LSDV through feeding on skin lacking visible lesions, demonstrating that viraemic animals without lesions at the feeding site of ticks may be a source of infection. This is the first time that transmission of poxviruses by a tick species has been demonstrated and the importance of this mode of transmission in the spread of LSDV in endemic settings is discussed.

This study provides a comprehensive epidemio-clinical picture of sporadic, domestically acquired cases of amoebiasis, cryptosporidiosis and giardiasis in one Canadian community based on patient symptom, outcome and exposure data from an enhanced surveillance system. It yields valuable data for estimating the burden of those diseases including the proportion of bloody diarrhoea, hospitalization, and disease duration. Age differences were observed by incidence rate and for some clinical information and exposures to risk factors. For each of the three diseases, the animal/environment-to-person route was the most common possible main transmission route according to the exposure reported, whereas the person-to-person route was the least common. Exposure was higher for the 10–24 years age group of giardiasis cases for swimming in recreational waters (79%) and attending a barbeque (50%). Therefore, comparisons between groups of cases or extrapolation of results when estimating the burden of illness should be adjusted for age.

Visceral leishmaniasis (VL) is an endemic parasitic disease transmitted by the bite of sand flies. To describe trends and demographics of reported VL cases, we reviewed surveillance data from 1990–2009. Reported VL incidence per 100 000 population was 2·6 in 2007, 3·1 in 2008, and 4·8 in 2009, mostly in children aged <5 years. The number of cases varied greatly in step with prevailing economic and security conditions, raising concerns about the completeness and quality of surveillance data. Nevertheless, we conclude that VL remains an important endemic disease in Iraq and that surveillance system is recovering the capacity to detect cases as the country experiences greater stability. We recommend conducting formal entomological investigations, and evaluating existing control measures.