In March 2013, a veterinary student tested positive for Cryptosporidium; four classmates reported similar gastrointestinal symptoms. We aimed to identify source(s) and risk factors for Cryptosporidium infection in university persons symptomatic between 21 January and 14 April 2013. Sixty-four (79%) students from a cohort of 81 fourth-year veterinary students completed questionnaires, identifying 13 cases; four were Cryptosporidium parvum GP60 subtype IIaA16G1R1b, two were IIdA24G1, seven did not submit stool samples. Thirteen cases attended the university's field clinic before symptom onset (13/37 attendees, 35%); 11 visited at least one of four farms where students recalled seeing calves with diarrhoea. C. parvum subtype IIaA16G1R1b was identified in calves at one of the farms. Entering pens of calves with diarrhoea [relative risk (RR) 7·6, 95% confidence interval (CI) 1·7–33·5] and eating in clinic cars (RR 9·1, 95% CI 1·3–65·8) were associated with being a case. Washing hands at least twice per farm visit (0 cases, P = 0·03) was protective. This outbreak investigation was notable for rapid and effective collaboration between public health, veterinary and environmental sectors, leading to swift identification of a microbiological and epidemiological link between cases, infected calves and their farms. We recommend frequent hand-washing using proper technique and dissuasion from eating in clinic cars to minimize possible exposure to contaminated surfaces.

This descriptive longitudinal study was conducted to investigate the faecal shedding of Shiga toxin-producing E. coli (STEC) in finishing swine and to characterize the swine STEC isolates that were recovered. Three cohorts of finishing swine (n = 50/cohort; total 150 pigs) were included in the longitudinal study. Individual faecal samples were collected every 2 weeks (8 collections/pig) from the beginning (pig age 10 weeks) to the end (pig age 24 weeks) of the finishing period. STEC isolates were recovered in at least one sample from 65·3% (98/150) of the pigs, and the frequency distribution of first-time STEC detection during the finishing period resembled a point-source outbreak curve. Nineteen O:H serotypes were identified among the STEC isolates. Most STEC isolates (n = 148) belonged to serotype O59:H21 and carried the stx 2e gene. One O49:H21 STEC isolate carried the stx 2e and eae genes. High prevalence rates of STEC during the finishing period were observed, and STEC isolates in various non-O157 serogroups were recovered. These data enhance understanding of swine STEC epidemiology, and future research is needed to confirm whether or not swine STEC are of public health concern.

Monitoring infections and risk in people who inject drugs (PWID) is important for informing public health responses. In 2011, a novel hepatitis C antibody (anti-HCV) avidity-testing algorithm to identify samples compatible with recent primary infection was introduced into a national surveillance survey. PWID are recruited annually, through >60 needle-and-syringe programmes and prescribing services. Of the 980 individuals that could have been at risk of HCV infection, there were 20 (2%) samples that were compatible with recent primary infection. These were more common among: those imprisoned ⩾5 times [8/213; adjusted odds ratio (aOR) 8·7, 95% confidence interval (CI) 2·04–37·03]; women (8/230; aOR 3·8, 95% CI 1·41–10·38); and those ever-infected with hepatitis B (5/56; aOR 6·25, 95% CI 2·12–18·43). This study is the first to apply this algorithm and to examine the risk factors associated with recently acquired HCV infection in a national sample of PWID in the UK. These findings highlight underlying risks and suggest targeted interventions are needed.

Knowledge of mechanisms of infection in vulnerable populations is needed in order to prepare for future outbreaks. Here, using a unique dataset collected during a 2009 outbreak of influenza A(H1N1)pdm09 in a university town, we evaluated mechanisms of infection and identified that an epidemiological model containing partial protection of susceptibles best describes H1N1 dynamics in a rural university environment. We found that the protected group was over 14 times less susceptible to H1N1 infection than unprotected susceptibles. Our estimates show that the basic reproductive rate, R0, was 5·96 (95% confidence interval 5·83–6·61), and, importantly, R0 could be decreased to below 1 and similar epidemics could be avoided by increasing the proportion of the initial protected group. Moreover, several weeks into the epidemic, this protected group generated more new infections than the unprotected susceptible group, and thus, such protected groups should be taken into account while studying influenza epidemics in similar settings.

Notification of infectious disease is essential for prompt public health action and epidemiological analysis. The aim of this study was to compare national hospitalization data to national notification data in order to assess if there was significant under-reporting of hospitalized notifiable infectious diseases in recent years in Ireland. All in-patient discharges from public hospitals in the Republic of Ireland from 2006 to 2011 with a principal diagnosis of a notifiable disease were compared with national notification data. It was found that only a potential 1·8% of extra notifications could have arisen due to these hospitalization events and would represent a tenfold reduction on a previous estimate of under-reporting in the Irish context. Viral meningitis, viral encephalitis, bacterial meningitis not otherwise specified and malaria were the most common diseases for which there were more hospitalizations than notifications reported. The results of this study support the conclusion that the reduction in under-reporting can mainly be accounted for by the introduction of laboratories as notifiers in conjunction with the roll out of the Computerized Infectious Disease Reporting system (CIDR). However, for the diseases highlighted, the notification data underestimates the true burden of disease and this has implications for understanding the epidemiology of these diseases.

Since measles is a highly contagious respiratory infection with significant airborne transmission risk in hospitals, effective prevention measures are crucial. After a mother accompanying her child on a paediatric ward lacking a negative pressure room was diagnosed with measles, exposed persons without evidence of immunity (documentary evidence of receiving two doses of measles-mumps-rubella vaccine) were treated with vaccination or intravenous immunoglobulin (IVIG). The interruption of transmission with these treatments was evaluated. There were 44 children and 101 adults exposed to the index patient. Twenty-five children and 88 adults were considered immune, providing evidence of immunity. Nineteen children and 13 adults were either given vaccination or IVIG for post-exposure prophylaxis (PEP). There were no additional cases of measles after 3 weeks follow-up. We conclude that measles is highly preventable by adequate PEP with vaccination or IVIG in a healthcare setting that lacks the benefit of a negative pressure room.

To understand the clinical epidemiology and molecular characteristics of human bocavirus (HBoV) infection in children with diarrhoea in Guangzhou, South China, we collected 1128 faecal specimens from children with diarrhoea from July 2010 to December 2012. HBoV and five other major enteric viruses were examined using real-time polymerase chain reaction. Human rotavirus (HRV) was the most prevalent pathogen, detected in 250 (22·2%) cases, followed by enteric adenovirus (EADV) in 76 (6·7%) cases, human astrovirus (HAstV) in 38 (3·4%) cases, HBoV in 17 (1·5%) cases, sapovirus (SaV) in 14 (1·2%) cases, and norovirus (NoV) in 9 (0·8%) cases. Co-infections were identified in 3·7% of the study population and 23·5% of HBoV-positive specimens. Phylogenetic analysis revealed 14 HBoV strains to be clustered into species HBoV1 with only minor variations among them. Overall, the detection of HBoV appears to partially contribute to the overall detection gap for enteric infections, single HBoV infection rarely results in severe clinical outcomes, and HBoV sequencing data appears to support conserved genomes across strains identified in this study.

Portugal, a medium- to low-level endemic country (21·6 cases/100 000 population in 2012), has one of the highest European Union tuberculosis (TB) incidences. Although incidence is declining progressively, the country's heterogeneity in both regional endemics and their evolution suggests the importance of a better understanding of subnational epidemiology to customize TB control efforts. We aimed to update knowledge on municipality-years pulmonary TB incidence clustering, identify areas with different time trends, and show the potential of combining complementary clustering methods in control of infectious diseases. We used national surveillance municipality-level data (mainland Portugal, 2000–2010). Space–time clustering and spatial variation in temporal trends methods were applied. Space–time critical clusters identified (P < 0·001) were still the Lisbon and Oporto regions. The global incidence declined at a 5·81% mean annual percentage change, with high space–time heterogeneity and distinct time trend clusters (P < 0·001). Municipalities with incidences declining more rapidly belonged to critical areas. In particular, the Oporto trend cluster had a consistent −8·98% mean annual percentage change. Large space–time heterogeneities were identified, with critical incidences in the greater Lisbon and Oporto regions, but declining more rapidly in these regions. Oporto showed a consistent, steeper decrease and could represent a good example of local control strategy. Combining results from these approaches gives promise for prospects for infectious disease control and the design of more effective, focused interventions.

Syndromic surveillance (SyS) systems currently exploit various sources of health-related data, most of which are collected for purposes other than surveillance (e.g. economic). Several European SyS systems use data collected during meat inspection for syndromic surveillance of animal health, as some diseases may be more easily detected post-mortem than at their point of origin or during the ante-mortem inspection upon arrival at the slaughterhouse. In this paper we use simulation to evaluate the performance of a quasi-Poisson regression (also known as an improved Farrington) algorithm for the detection of disease outbreaks during post-mortem inspection of slaughtered animals. When parameterizing the algorithm based on the retrospective analyses of 6 years of historic data, the probability of detection was satisfactory for large (range 83–445 cases) outbreaks but poor for small (range 20–177 cases) outbreaks. Varying the amount of historical data used to fit the algorithm can help increasing the probability of detection for small outbreaks. However, while the use of a 0·975 quantile generated a low false-positive rate, in most cases, more than 50% of outbreak cases had already occurred at the time of detection. High variance observed in the whole carcass condemnations time-series, and lack of flexibility in terms of the temporal distribution of simulated outbreaks resulting from low reporting frequency (monthly), constitute major challenges for early detection of outbreaks in the livestock population based on meat inspection data. Reporting frequency should be increased in the future to improve timeliness of the SyS system while increased sensitivity may be achieved by integrating meat inspection data into a multivariate system simultaneously evaluating multiple sources of data on livestock health.

The purpose of this paper was to determine how contact behaviour change influences the indoor transmission of influenza A(H1N1)pdm09 among school children. We incorporated transmission rate matrices constructed from questionnaire responses into an epidemiological model to simulate contact behaviour change during an influenza epidemic. We constructed a dose–response model describing the relationships between contact rate, viral load, and respiratory symptom scores using published experimental human infection data for A(H1N1)pdm09. Findings showed that that mean numbers of contacts were 5·66 ± 6·23 and 1·96 ± 2·76 d−1 in the 13–19 and 40–59 years age groups, respectively. We found that the basic reproduction number (R0) was <1 during weekends in pandemic periods, implying that school closures or class suspensions are probably an effective social distancing policy to control pandemic influenza transmission. We conclude that human contact behaviour change is a potentially influential factor on influenza infection rates. For substantiation of this effect, we recommend a future study with more comprehensive control measures.

Significant gaps in immunity to polio, measles, and rubella may exist in adults in Cambodia and threaten vaccine-preventable disease (VPD) elimination and control goals, despite high childhood vaccination coverage. We conducted a nationwide serological survey during November–December 2012 of 2154 women aged 15–39 years to assess immunity to polio, measles, and rubella and to estimate congenital rubella syndrome (CRS) incidence. Measles and rubella antibodies were detected by IgG ELISA and polio antibodies by microneutralization testing. Age-structured catalytic models were fitted to rubella serological data to predict CRS cases. Overall, 29·8% of women lacked immunity to at least one poliovirus (PV); seroprevalence to PV1, PV2 and PV3 was 85·9%, 93·4% and 83·3%, respectively. Rubella and measles antibody seroprevalence was 73·3% and 95·9%, respectively. In the 15–19 years age group, 48·2% [95% confidence interval (CI) 42·4–54·1] were susceptible to either PV1 or PV3, and 40·3% (95% CI 33·0–47·5) to rubella virus. Based on rubella antibody seroprevalence, we estimate that >600 infants are born with CRS in Cambodia annually. Significant numbers of Cambodian women are still susceptible to polio and rubella, especially those aged 15–19 years, emphasizing the need to include adults in VPD surveillance and a potential role for vaccination strategies targeted at adults.

In February 2012, an outbreak of gastroenteritis was reported in school A; a successive outbreak was reported at school B. A retrospective cohort study conducted in school A showed that seasoned green seaweed with radishes (relative risk 7·9, 95% confidence interval 1·1–56·2) was significantly associated with illness. Similarly, a case-control study of students at school B showed that cases were 5·1 (95% confidence interval 1·1–24·8) times more likely to have eaten seasoned green seaweed with pears. Multiple norovirus genotypes were detected in samples from students in schools A and B. Norovirus GII.6 isolated from schools A and B were phylogenetically indistinguishable. Green seaweed was supplied by company X, and norovirus GII.4 was isolated from samples of green seaweed. Green seaweed was assumed to be linked to these outbreaks. To our knowledge, this is the first reported norovirus outbreak associated with green seaweed.

The EPIET Alumni Network (EAN) is an association of professionals who have completed field epidemiology or public health microbiology training programmes in the European Union. In 2013, we conducted a survey of EAN members to investigate this network's role within European public health. We distributed an online questionnaire to members registered at the time, collecting data on demographics, professional background, and attitudes towards EAN. Out of 362 registered members, 189 (52%) responded; 97% were from Europe; 65% were female. Their mean age was 39 years. The highest academic qualification was PhD for 44% and Master's degree for 55%. The majority (60%) worked in public health institutes. They were especially satisfied with having access to job offers and professional networking via EAN, but requested more learning opportunities and knowledge-sharing between members. EAN is a unique platform where highly skilled professionals can connect to control infectious diseases locally and internationally. Having a network of professionals that know each other, speak the same ‘language’, and can easily access each other's expertise, represents an important resource for European and global public health, which should be nurtured by encouraging more collaborations devoted to professional development.

A Bayesian modelling approach comparing the occurrence of Salmonella serovars in animals and humans was used to attribute salmonellosis cases to broilers, turkeys, pigs, laying hens, travel and outbreaks in 24 European Union countries. Salmonella data for animals and humans, covering the period from 2007 to 2009, were mainly obtained from studies and reports published by the European Food Safety Authority. Availability of food sources for consumption was derived from trade and production data from the European Statistical Office. Results showed layers as the most important reservoir of human salmonellosis in Europe, with 42·4% (7 903 000 cases, 95% credibility interval 4 181 000–14 510 000) of cases, 95·9% of which was caused by S. Enteritidis. In Finland and Sweden, most cases were travel-related, while in most other countries the main sources were related to the laying hen or pig reservoir, highlighting differences in the epidemiology of Salmonella, surveillance focus and eating habits across the European Union.

Measles mortality fell prior to the introduction of vaccines or antibiotics. By examining historical mortality reports we sought to determine how much measles mortality was due to epidemiological factors such as isolation from major population centres or increased age at time of infection. Age-specific records were available from Aberdeen; Scotland; New Zealand and the states of Australia at the end of the 19th and beginning of the 20th centuries. Despite the relative isolation of Australia, measles mortality was concentrated in very young children similar to Aberdeen. In the more isolated states of Tasmania, Western Australia and Queensland adults made up 14–15% of measles deaths as opposed to 8–9% in Victoria, South Australia and New South Wales. Mortality in Iceland and Faroe Islands during the 1846 measles epidemic was used as an example of islands isolated from respiratory pathogens. The transition from crisis mortality across all ages to deaths concentrated in young children occurred prior to the earliest age-specific mortality data collected. Factors in addition to adult age of infection and epidemiological isolation such as nutritional status and viral virulence may have contributed to measles mortality outcomes a century ago.

Vaccines are the cornerstone of influenza control policy, but can suffer from several drawbacks. Seasonal influenza vaccines are prone to production problems and low efficacies, while pandemic vaccines are unlikely to be available in time to slow a rapidly spreading global outbreak. Antiviral therapy was found to be beneficial during the influenza A(H1N1)pdm09 pandemic even with limited use; however, antiviral use has decreased further since then. We sought to determine the role antiviral therapy can play in pandemic and seasonal influenza control using conservative estimates of antiviral efficacy, and to assess if conservative but targeted strategies could be employed to optimize the use of antivirals. Using an age-structured contact network model for an urban population, we compared the transmission-blocking ability of a conservative antiviral therapy strategy to the susceptibility-reducing effects of a robust influenza vaccine. Our results show that while antiviral therapy cannot replace a robust influenza vaccine, it can play a role in reducing attack rates and eliminating outbreaks, and could significantly reduce public health burden when vaccine is either unavailable or ineffective. We also found that antiviral therapy, by treating those who are infected, is naturally a highly optimized strategy, and need not be improved upon with expensive targeted campaigns.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern associated with residence in a long-term care facility (LTCF). The aim of this prospective study was to characterize MRSA isolated from residents over a 1-year period and their physical environment over a 2-year period. MRSA was recovered from 17/64 residents (R) of a LTCF and from 42 environmental (E) sites. All isolates carried the mecA gene and lacked the mecC and Panton–Valentine leukocidin (PVL) genes. Thirteen spa types were identified with t032 being the most frequent (41% of total; n = 8R, 16E), followed by t727 (22% of total; n = 13E), and t8783 (10% of total; n = 6E). Five spa types were each represented by single isolates. Thirty-nine isolates were of spa types associated with the multilocus sequence type ST22 (t032, 41%; spa-CC22, 68%) and reflect the predominance of ST22 in Irish hospitals. The uncommon spa types t727, t8783, t1372, t3130, t10038 were present in the environment but not detected in residents and are infrequently observed in Ireland.