We present and analyse data collected during a severe epidemic of foot-and-mouth disease (FMD) that occurred between July and September 2000 in a region of northeastern Greece with strategic importance since it represents the southeastern border of Europe and Asia. We implement generic Bayesian methodology, which offers flexibility in the ability to fit several realistically complex models that simultaneously capture the presence of ‘excess’ zeros, the spatio-temporal dependence of the cases, assesses the impact of environmental noise and controls for multicollinearity issues. Our findings suggest that the epidemic was mostly driven by the size and the animal type of each farm as well as the distance between farms while environmental and other endemic factors were not important during this outbreak. Analyses of this kind may prove useful to informing decisions related to optimal control measures for potential future FMD outbreaks as well as other acute epidemics such as FMD.

Climate change experts predict the number of nuisance-biting arthropods in England will increase but there is currently no known surveillance system in place to monitor or assess the public health impact of arthropod bites. This retrospective ecological study utilized arthropod bites requiring healthcare from five national real-time syndromic surveillance systems monitoring general practitioner (GP) consultations (in-hours and out-of-hours), emergency department (ED) attendances and telephone calls to remote advice services to determine baseline incidence in England between 2000 and 2013 and to assess the association between arthropod bites and temperature. During summer months (weeks 20–40) we estimated that arthropod bites contribute a weekly median of ~4000 GP consultations, 750 calls to remote advice services, 700 ED and 1300 GP out-of-hours attendances. In all systems, incidence was highest during summer months compared to the rest of the year. Arthropod bites were positively associated with temperature with incidence rate ratios (IRRs) that ranged between systems from 1·03 [95% confidence interval (CI) 1·01–1·06] to 1·14 (95% CI 1·11–1·16). Using syndromic surveillance systems we have established and described baseline incidence of arthropod bites and this can now be monitored routinely in real time to assess the impact of extreme weather events and climate change.

Workplaces are one of the most important regular meeting places in society. The aim of this study was to use simulation experiments to examine the impact of different workplace cultures on influenza dissemination during pandemics. The impact is investigated by experiments with defined social-mixing patterns at workplaces using semi-virtual models based on authentic sociodemographic and geographical data from a North European community (population 136 000). A simulated pandemic outbreak was found to affect 33% of the total population in the community with the reference academic-creative workplace culture; virus transmission at the workplace accounted for 10·6% of the cases. A model with a prevailing industrial-administrative workplace culture generated 11% lower incidence than the reference model, while the model with a self-employed workplace culture (also corresponding to a hypothetical scenario with all workplaces closed) produced 20% fewer cases. The model representing an academic-creative workplace culture with restricted workplace interaction generated 12% lower cumulative incidence compared to the reference model. The results display important theoretical associations between workplace social-mixing cultures and community-level incidence rates during influenza pandemics. Social interaction patterns at workplaces should be taken into consideration when analysing virus transmission patterns during influenza pandemics.

Three epidemic waves of human influenza A(H7N9) were documented in several different provinces in China between 2013 and 2015. With limited understanding of the potential for human-to-human transmission, it was difficult to implement control measures efficiently or to inform the public adequately about the application of interventions. In this study, the human-to-human transmission rate for the epidemics that occurred between 2013 and 2015 in Zhejiang Province, China, was analysed. The reproduction number (R), a key indicator of transmission intensity, was estimated by fitting the number of infections from poultry to humans and from humans to humans into a mathematical model. The posterior mean R for human-to-human transmission was estimated to be 0·27, with a 95% credible interval of 0·14–0·44 for the first wave, whereas the posterior mean Rs decreased to 0·15 in the second and third waves. Overall, these estimates indicate that a human H7N9 pandemic is unlikely to occur in Zhejiang. The reductions in the viral transmissibility and the number of poultry-transmitted infections after the first epidemic may be attributable to the various intervention measures taken, including changes in the extent of closures of live poultry markets.

Listeria monocytogenes is a foodborne pathogen that can cause bacteraemia, meningitis, and complications during pregnancy. In July 2012, molecular subtyping identified indistinguishable L. monocytogenes isolates from six patients and two samples of different cut and repackaged cheeses. A multistate outbreak investigation was initiated. Initial analyses identified an association between eating soft cheese and outbreak-related illness (odds ratio 17·3, 95% confidence interval 2·0–825·7) but no common brand. Cheese inventory data from locations where patients bought cheese and an additional location where repackaged cheese yielded the outbreak strain were compared to identify cheeses for microbiological sampling. Intact packages of imported ricotta salata yielded the outbreak strain. Fourteen jurisdictions reported 22 cases from March–October 2012, including four deaths and a fetal loss. Six patients ultimately reported eating ricotta salata; another reported eating cheese likely cut with equipment also used for contaminated ricotta salata, and nine more reported eating other cheeses that might also have been cross-contaminated. An FDA import alert and US and international recalls followed. Epidemiology-directed microbiological testing of suspect cheeses helped identify the outbreak source. Cross-contamination of cheese highlights the importance of using validated disinfectant protocols and routine cleaning and sanitizing after cutting each block or wheel.

High rates of immigration from endemic countries contribute to the high chronic hepatitis B (HBV) prevalence in New York City (NYC) compared to the United States overall, i.e. about 1 million individuals. We describe the impact of HBV infection on mortality and specific causes of death in NYC. We matched surveillance and vital statistics mortality data collected from 2000 to 2011 by the New York City Department of Health and Mental Hygiene (DOHMH) and analysed demographics and premature deaths (i.e. whether death occurred at <65 years) in persons with and without chronic HBV or HIV infection (excluding those with hepatitis C). From 2000 to 2011, a total of 588 346 adults died in NYC. Of all decedents, 568 753 (97%) had no report of HIV or HBV, and 4346 (0·7%) had an HBV report. Of HBV-infected decedents, 1074 (25%) were HIV co-infected. Fifty-five percent of HBV mono-infected and 95% of HBV/HIV co-infected decedents died prematurely. HBV disproportionately impacts two subgroups: Chinese immigrants and HIV-infected individuals. These two subgroups are geographically clustered in different neighbourhoods of NYC. Tailoring prevention and treatment messages to each group is necessary to reduce the overall burden of HBV in NYC.

During the 1970s there was a gross loss of public confidence in infant diphtheria-tetanus-pertussis (DTP) vaccination in the UK. As well as febrile reactions and convulsions, permanent neurological damage was ascribed to the pertussis component of the vaccine, and those concerns resonated worldwide. The subsequent recognition of human herpes virus 6 (HHV-6) and 7 (HHV-7) as common sources of fever in infancy suggests that they were the main underlying cause of what was reported as DTP constitutional side-effects. With more precise data on the incidence of HHV-6/7 and other virus infections in early life it would be possible to model the concurrence of viral illnesses with routine immunizations. Adventitious viral infections may be the cause of side-effects ascribed to the numerous childhood immunizations now being given.

A measles outbreak occurred in a school in a small town in the South East of Ireland in September–November 2013. Most (and all early) cases had one dose of the measles-mumps- rubella (MMR) vaccination. All suspected cases were followed up, in order to advise on sampling and provide public health advice to them and their contacts. MMR vaccination control measures were instituted in the town. These included early second MMR in primary schools and childcare facilities, bringing forward the planned school MMR catch-up programme, early first MMR dose for children aged 6–12 months and targeted advice to unvaccinated children. There were 20 cases (17 confirmed) of measles associated with the outbreak. Fifteen cases occurred in the index school, with four in pre-school-age children (<4 years) who had clear epidemiological links with children at the school. This was a well-circumscribed outbreak occurring, unusually, in a well-vaccinated population. The outbreak came late to the attention of Department of Public Health staff but prompt action, once notified, and institution of control measures resulted in quick termination of the outbreak and prevention of cases in a neighbouring city.

A significant proportion of Q fever patients from the first Dutch Q fever outbreak in 2007 showed impairment in health status up to 1 year after infection. Interested in whether this decrease in health status persisted, we set out to determine the health status in the same cohort of patients, 4 years after primary infection and to compare health status scores at the individual patient level between 1 and 4 years follow-up. Health status was assessed with the Nijmegen Clinical Screening Instrument (NCSI). Patients were serologically tested to exclude patients with possible, probable or proven chronic Q fever. Results on the NCSI sub-domains at group level [2008 (n = 54) and 2011 (n = 46)] showed a persistent significant percentage of patients exhibiting clinically relevant (‘severe’) scores for all NCSI sub-domains. After 4 years, undue fatigue was present in 46% and exactly half of all patients experienced a severely impaired general quality of life. Patients with NCSI scores available in both 2008 and 2011 (n = 37) showed no difference in all sub-domain scores, except for a small decrease in dyspnoea emotions in 2011. In this group, a significant proportion of patients either improved or worsened in one or more sub-domains of health status. We conclude that at the group level, health status of Q fever patients remained impaired 4 years after primary infection. At the individual patient level, health status may change.

A survey of Coxiella burnetii infection (Q fever) in sheep flocks and goat herds in Great Britain was undertaken. A total of 5791 sheep (384 flocks) and 522 goats (145 herds) were examined for C. burnetii antibodies using an ELISA. Overall, 53 sheep (37 flocks), and four goats (four herds), tested positive. Estimates of individual animal, between-flock/-herd and within-flock/-herd crude prevalences were 0·9%, 10·2% and 9·0%, respectively, for sheep, and 0·8%, 3% and 26·3%, respectively, for goats. With sheep, the likelihood of an animal testing positive increased with total flock size (P = 0·002) and number of breeding ewes in the flock (P = 0·021). It also increased with number of goats within a 10 km radius (P = 0·038). There was no evidence for spatial clustering of positive herds above that expected by chance alone. No analysis of risk factors was attempted for goats because of the paucity of positives.

A regional, multistate investigation into a June–August 2013 cyclosporiasis outbreak was conducted in Nebraska, Iowa, and neighbouring states. Cases were confirmed on the basis of laboratory and clinical findings. Of 227 cases in Iowa (n = 140) and Nebraska (n = 87) residents, 162 (71%) reported dining at chain A/B restaurants – 96% reported house salad consumption. A case-control study identified chain A/B house salad as the most likely vehicle. Traceback was conducted to ascertain production lot codes of bagged salad mix (iceberg and romaine lettuce, red cabbage, and carrots) served as house salad in implicated restaurants. A single production lot code of salad mix supplied by both a common producer and distributor was linked to the majority of confirmed cases in persons reporting regional chain A/B exposure. The salad mix linked to illnesses contained imported romaine lettuce from two separate single-grower fields-of-origin and ⩾1 additional field from another grower.

From 2009 to 2013 the diversity of noroviruses (NoVs) in children (⩽5 years) hospitalized with gastroenteritis in South Africa was investigated. NoVs were genotyped based on nucleotide sequence analyses of partial RNA-dependent RNA polymerase (RdRp) and capsid genes. Seventeen RdRp genotypes (GI.P2, GI.P3, GI.P6, GI.P7, GI.P not assigned (NA), GI.Pb, GI.Pf, GII.P2, GII.P4, GII.P7, GII.P13, GII.P16, GII.P21, GII.Pc, GII.Pe, GII.Pg, GII.PNA) and 20 capsid genotypes (GI.1, GI.2, GI.3, GI.5, GI.6, GI.7, GI.NA, GII.1, GII.2, GII.3, GII.4, GII.6, GII.7, GII.10, GII.12, GII.13, GII.14, GII.16, GII.17, GII.21) were identified. The combined RdRp/capsid genotype was determined for 275 GII strains. Fifteen confirmed recombinant NoV strains circulated during the study period. NoV GII.P4/GII.4 (47%) and GII.Pe/GII.4 (18%) predominated, followed by GII.PNA/GII.3 (10%) and GII.P21/GII.3 (7%). Other prevalent strains included GII.Pg/GII.12 (6%) and GII.Pg/GII.1 (3%). Two novel recombinants, GII.Pg/GII.2 and GII.Pg/GII.10 were identified. In 2013 the replacement of GII.4 New Orleans 2009 and GII.P21/GII.3, which predominated during the early part of the study, with GII.4 Sydney 2012 and GII.PNA/GII.3 was observed. This study presents the most comprehensive recent data on NoV diversity in Africa.

The reasons for the unprecedented mortality during the 1918 influenza pandemic remain poorly understood. We examined morbidity records from three military cohorts from years prior to and during the 1918 pandemic period to assess the effects of previous respiratory illnesses on experiences during the pandemic. Clinical registers and morbidity lists were examined to identify all medical encounters for acute respiratory illnesses in students at two U.S. military officer training academies and Australian soldiers deployed in Europe. Influenza-like illness prior to the major pandemic wave of 1918 predisposed Australian soldiers [relative risk (RR) 1·37, 95% confidence interval (CI) 1·18–1·60, P < 0·0001] and US officer trainees at West Point (RR 3·10, 95% CI 2·13–4·52, P < 0·0001) and Annapolis (RR 2·03, 95% CI 1·65–2·50, P < 0·0001) to increased risks of medically treated illnesses in late 1918. The findings suggest that susceptibility to and/or clinical expressions of the 1918 pandemic influenza virus depended on previous experiences with respiratory infectious agents. The findings are consistent with observations during the 2009 pandemic in Canada and may reflect antibody-dependent enhancement of influenza infection.

Fifteen confirmed cases and 15 possible cases of Shiga toxin-producing Escherichia coli (STEC) O157 phage type 21/28 were linked to direct contact with lambs at a ‘Lambing Live’ event in the North West of England between 29 March and 21 April 2014. Twenty-one (70%) of the cases were female, 23 (77%) were children aged <16 years, of whom 14 (46%) were in the 0–5 years age group. Five children developed haemolytic uraemic syndrome. Multilocus variable number tandem repeat analysis (MLVA) profiles on 14 human cases were indistinguishable, and 6/10 animal isolates had a MLVA profile identical to the outbreak profile. Whole-genome sequencing analysis revealed that all isolates, both human and animal, fell within a 5-single nucleotide polymorphism cluster indicating the isolates belonged to the same point source. On inspection of the premises, extensive and uncontrolled physical contact between visitors and animals was occuring within the animal pens and during bottle-feeding. Public areas were visibly contaminated with animal faeces. Information to visitors, and the infection control awareness demonstrated by staff, was inadequate. Managing the risk to visitors of STEC O157 infection at animal petting events and open farms requires implementation of stringent control measures by the operator, as outlined in the industry code of practice. Enforcement action is sometimes required to prevent high-risk activities taking place at both permanent and temporary attractions.

Prevention of secondary household transmission of Shiga toxin-producing Escherichia coli (STEC) is important in outbreak settings. We examined factors contributing to secondary household transmission during STEC outbreaks in daycare centres in Japan. Suspected STEC outbreaks in daycare centres were identified by the National Epidemiological Surveillance of Infectious Diseases. Questionnaires were sent to local health centres that responded to outbreaks. Secondary household transmission rates were calculated, and factors affecting secondary household transmission rate were analysed by multilevel analysis. The secondary household transmission rates in 16 outbreaks ranged from 0% to 34·4% (median 4·4%). The highest rate (23·0%) was observed in siblings aged 6–9 years, and the infection rate was significantly higher for mothers than for fathers and grandparents (P < 0·05). Using multilevel analysis, the following variables were selected in the best model: information provided face-to-face (vs. letter or telephone) to families of children in daycare centres (at initial response), STEC type and lag time (days) between onset and providing information. Early response and hygiene education by visiting local health centre staff may be effective measures to prevent secondary household transmission in STEC outbreaks. Hygiene education should be emphasized for children aged 6–9 years, as well as for younger children.

Verotoxigenic Escherichia coli (VTEC) are significant for their low infectious dose, their potential clinical severity and the frequency with which they generate outbreaks. To describe the relative importance of different outbreak transmission routes for VTEC infection in Ireland, we reviewed outbreak notification data for the period 2004–2012, describing the burden and characteristics of foodborne, waterborne, animal contact and person-to-person outbreaks. Outbreaks where person-to-person spread was reported as the sole transmission route accounted for more than half of all outbreaks and outbreaks cases, most notably in childcare facilities. The next most significant transmission route was waterborne spread from untreated or poorly treated private water supplies. The focus for reducing incidence of VTEC should be on reducing waterborne and person-to-person transmission, by publicizing Health Service Executive materials developed for consumers on private well management, and for childcare facility managers and public health professionals on prevention of person-to-person spread.

Hepatitis B virus (HBV) vaccination has been part of the Expanded Programme of Immunization (EPI) in Tunisia since 1995. The aim of this study was to evaluate, for the first time, the impact of mass vaccination in Tunisia 17 years after this programme was implemented, and in parallel, assess the long-term persistence of anti-HBs antibody in the vaccinated Tunisian population. A total of 1422 students were recruited (703 vaccinated, 719 non-vaccinated). HBV seromarkers were checked. None of the students from either group had positive HBsAg. The overall prevalence of anti-HBc was 0·8%. A Significantly higher prevalence of anti-HBc was noted in unvaccinated students than in vaccinated (1·4% vs. 0·3%, P = 0·02). The overall seroprotection rate (anti-HBs titre ⩾10 mIU/ml) was 68·9% in vaccinated subjects. Seroprotection rates and geometric mean titres decreased significantly with increasing age, reflecting waning anti-HBs titre over time. No significant difference was detected between seroprotection rates and gender or students’ area of origin. Incomplete vaccination was the only factor associated with an anti-HBs titre <10 mIU/ml. This study demonstrates the excellent efficacy of the HBV vaccination programme in Tunisia 17 years after its launch. However, a significant decline of anti-HBs seroprotection has been observed in ⩾15-year-old adolescents which places them at risk of infection. Additional studies are needed in hyperendemic regions in Tunisia.

During June–August 2013, 25 US states reported 631 cyclosporiasis cases including Nebraska and Iowa where a regional investigation implicated common-source imported salad mix served in two chain restaurants. At least two common-origin growing fields were likely sources of contaminated romaine lettuce. Using producer- and distributor-provided data, we conducted a grower-specific traceforward investigation to reveal exposures of ill US residents elsewhere who reported symptom onset during 11 June–1 July 2013, the time period established in the Nebraska and Iowa investigation. Romaine lettuce shipped on 2–6 June from one of these Mexico-origin growing fields likely caused cyclosporiasis in 78 persons reporting illness onsets from 11 June to 1 July in Nebraska, Texas, and Florida. Nationwide, 97% (314/324) of persons confirmed with cyclosporiasis with symptom onset from 11 June to 1 July 2013 resided in 11 central and eastern US states receiving approximately two-thirds of romaine lettuce from this field. This grower's production practices should be investigated to determine potential sources of contamination and to develop recommendations to prevent future illnesses.

Large outbreaks of Q fever have recently increased the awareness of this disease as a public health issue. Knowledge of the general impact of Q fever relies mainly on seroprevalence studies and it is fundamental that seroprevalence is assessed accurately. Therefore we evaluated the few enzyme-linked immunosorbent assays (ELISAs) commercially available for this purpose. An outbreak in 2005 in Jena, a city of 100 000 inhabitants, gave us the opportunity for the evaluation. However, we found disappointingly low sensitivities for two (42% and 51%) of three commercial ELISAs for detecting past infection. Nevertheless, all assays had good classification potential but cut-off adaptation is needed. Based on the unequal worldwide distribution of the differently performing tests in studies, Q fever seroprevalence is likely to be underestimated in studies from Europe whereas the data from North America and Australia are likely to be more reliable.