Syndromic surveillance systems in England have demonstrated utility in the early identification of seasonal gastrointestinal illness (GI) tracking its spatio-temporal distribution and enabling early public health action. There would be additional public health utility if syndromic surveillance systems could detect or track subnational infectious disease outbreaks. To investigate using syndromic surveillance for this purpose we retrospectively identified eight large GI outbreaks between 2009 and 2014 (four randomly and four purposively sampled). We then examined syndromic surveillance information prospectively collected by the Real-time Syndromic Surveillance team within Public Health England for evidence of possible outbreak-related changes. None of the outbreaks were identified contemporaneously and no alerts were made to relevant public health teams. Retrospectively, two of the outbreaks – which happened at similar times and in proximal geographical locations – demonstrated changes in the local trends of relevant syndromic indicators and exhibited a clustering of statistical alarms, but did not warrant alerting local health protection teams. Our suite of syndromic surveillance systems may be more suited to their original purposes than as means of detecting or monitoring localized, subnational GI outbreaks. This should, however, be considered in the context of this study's limitations; further prospective work is needed to fully explore the use of syndromic surveillance for this purpose. Provided geographical coverage is sufficient, syndromic surveillance systems could be able to provide reassurance of no or minor excess healthcare systems usage during localized GI incidents.

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.

Because sentinel surveillance systems cannot obtain information about patients who visit non-sentinel medical facilities, the characteristics of patients identified by these systems may be biased. In this study, we evaluated the representativeness of a methicillin-resistant Staphylococcus aureus (MRSA) surveillance system using health insurance claim (HIC) data, which does not depend on physician notification. We calculated the age-specific incidence of MRSA patients using data from the Japan Nosocomial Infections Surveillance (JANIS) programme, which is based on sentinel surveillance systems, and inpatient HICs submitted to employee health insurance organizations in 2011, and then computed age-specific incidence ratios between the HIC and JANIS data. Age-specific MRSA incidence in both datasets followed J-shaped curves with similar shapes. For all age groups, the ratios between HIC and JANIS data were around 10. These findings indicate that JANIS notification of MRSA cases was not affected by patients’ age.

Chikungunya virus (CHIKV) and Ross River virus (RRV) of the genus Alphavirus, family Togaviridae are mainly transmitted by Aedes mosquitoes and the symptoms they cause in patients are similar to dengue. A chikungunya (CHIK) outbreak re-emerged in several Asian countries during 2005–2006. This study aimed to clarify the prevalence of CHIKV infection in suspected dengue patients in six countries in South Asia and Southeast Asia. Seven hundred forty-eight serum samples were from dengue-suspected patients in South Asia and Southeast Asia, and 52 were from patients in Fiji. The samples were analysed by CHIKV IgM capture ELISA, CHIKV IgG indirect ELISA and focus reduction neutralization test against CHIKV or RRV. CHIK-confirmed cases in South Asia, particularly Myanmar and Sri Lanka, were 4·6%, and 6·1%, respectively; and in Southeast Asia, particularly Indonesia, the Philippines and Vietnam, were 27·4%, 26·8% and 25·0%, respectively. It suggests that CHIK was widely spread in these five countries in Asia. In Fiji, no CHIK cases were confirmed; however, RRV-confirmed cases represented 53·6% of suspected dengue cases. It suggests that RRV is being maintained or occasionally entering from neighbouring countries and should be considered when determining a causative agent for dengue-like illness in Fiji.

Dengue has become a global problem in past few decades, with half of the world's population at risk of infection. For some countries of Asia and Latin America, severe dengue is a major cause of serious illness and even death in children. Pakistan has been reported as a hyperendemic area for dengue infection. Our study aimed to find seroprevalence of past dengue infection in asymptomatic children of Lahore with no previous history of dengue infection. A total of 400 samples were collected from children aged 1–12 years in Lahore using random sampling. The inclusion criteria were children aged 1–12 years, who had no previous symptoms of dengue fever during their lives. Children with known immunodeficiency status or fever at the time of recruitment were excluded from the study. Commercially available ELISA kits were used to determine the IgG status in sera of children. The data obtained was entered and analysed using SPSS v. 20.0. The overall prevalence of asymptomatic dengue infection was found to be 25%. There was no statistically significant difference between prevalence of infection in male and female children. There was, however, a strong relationship between increasing age of the child and number of cases with infection, with low incidence in children aged ⩽5 years.

The first reported New Zealand-acquired case of murine typhus occurred near Auckland in 1989. Since then, 72 locally acquired cases have been recorded from northern New Zealand. By 2008, on the basis of the timing and distribution of cases, it appeared that murine typhus was escalating and spreading southwards. To explore the presence of Rickettsia typhi in the Waikato region, we conducted a seroprevalence study, using indirect immunofluorescence, Western blot, and cross-adsorption assays of blood donor samples. Of 950 human sera from Waikato, 12 (1·3%) had R. typhi antibodies. The seroprevalence for R. typhi was slightly higher in northern Waikato (1·4%) compared to the south (1·2%; no significant difference, χ2P = 0·768 at P < 0·05). Our results extend the reported southern range of R. typhi by 140 km and indicate it is endemic in Waikato. Evidence of past Rickettsia felis infections was also detected in six sera. Globally, R. felis is an emerging disease of concern and this pathogen should also be considered when locally acquired rickettsiosis is suspected. If public health interventions are to be implemented to reduce the risk of rickettsioses as a significant public health problem, improvements in rickettsial diagnostics and surveillance will be necessary.

Influenza vaccination has been shown to be the most effective preventive strategy to reduce influenza-related morbidity and mortality in high-risk groups. Despite healthcare personnel (HCP) being considered part of such high-risk groups, their vaccination coverage is low in Europe. In January 2012, we distributed an 18-question survey regarding influenza vaccination to HCP at Gregorio Marañon Paediatric Hospital, in Madrid, Spain. After we documented that only ~30% of HCP were vaccinated an educational programme was implemented in October 2012 before the next influenza season. In January 2013, the same survey delivered again to all HCP documented a significant increase in vaccination rates (from 30% to 40%, P = 0·007) mainly among physicians and for patients' protection. In summary we found that a simple and inexpensive educational programme significantly improved the uptake of influenza vaccination in HCP in our centre. Nevertheless, vaccination rates remained low, and broader and updated campaigns are needed to overcome perception barriers.

We studied the spread of influenza in the community between 1993 and 2009 using primary-care surveillance data to investigate if the onset of influenza was age-related. Virus detections [A(H3N2), B, A(H1N1)] and clinical incidence of influenza-like illness (ILI) in 12·3 million person-years in the long-running Royal College of General Practitioners-linked clinical-virological surveillance programme in England & Wales were examined. The number of days between symptom onset and the all-age peak ILI incidence were compared by age group for each influenza type/subtype. We found that virus detection and ILI incidence increase, peak and decrease were in unison. The mean interval between symptom onset to peak ILI incidence in virus detections (all ages) was: A(H3N2) 20·5 [95% confidence interval (CI) 19·7–21·6] days; B, 18·8 (95% CI 15·8·0–21·7) days; and A(H1N1) 17·0 (95% CI 15·6–18·4) days. Differences by age group were examined using the Kruskal–Wallis test. For A(H3N2) and A(H1N1) viruses the interval was similar in each age group. For influenza B there were highly significant differences by age group (P = 0·0001). Clinical incidence rates of ILI reported in the 8 weeks preceding the period of influenza virus activity were used to estimate a baseline incidence and threshold value (upper 95% CI of estimate) which was used as a marker of epidemic progress. Differences between the age groups in the week in which the threshold was reached were small and not localized to any age group. In conclusion we found no evidence to suggest that influenza A(H3N2) and A(H1N1) occurs in the community in one age group before another. For influenza B, virus detection was earlier in children aged 5–14 years than in persons aged ⩾25 years.

Most influenza virus infections are associated with mild disease. One approach to estimate the occurrence of influenza virus infections in individuals is via repeated measurement of humoral antibody titres. We used baseline and convalescent antibody titres measured by haemagglutination inhibition (HI) and viral neutralization (VN) assays against influenza A(H1N1), A(H3N2) and B viruses to investigate the characteristics of antibody rises following virologically confirmed influenza virus infections in participants in a community-based study. Multivariate models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titres following influenza A virus infections. In 122 participants with PCR-confirmed influenza A virus infection, homologous antibody titres rose by geometric means of 1·2- to 10·2-fold after infection with A(H1N1), A(H3N2) and A(H1N1)pdm09. Significant cross-reactions were observed between A(H1N1)pdm09 and seasonal A(H1N1). Antibody titre rises for some subtypes and assays varied by age, receipt of oseltamivir treatment, and recent receipt of influenza vaccination. In conclusion, we provided a quantitative description of the mean and variation in rises in influenza virus antibody titres following influenza virus infection. The multivariate patterns in boosting of antibody titres following influenza virus infection could be taken into account to improve estimates of cumulative incidence of infection in seroepidemiological studies.

Data were pooled from three Australian sentinel general practice influenza surveillance networks to estimate Australia-wide influenza vaccine coverage and effectiveness against community presentations for laboratory-confirmed influenza for the 2012, 2013 and 2014 seasons. Patients presenting with influenza-like illness at participating GP practices were swabbed and tested for influenza. The vaccination odds of patients testing positive were compared with patients testing negative to estimate influenza vaccine effectiveness (VE) by logistic regression, adjusting for age group, week of presentation and network. Pooling of data across Australia increased the sample size for estimation from a minimum of 684 to 3,683 in 2012, from 314 to 2,042 in 2013 and from 497 to 3,074 in 2014. Overall VE was 38% [95% confidence interval (CI) 24–49] in 2012, 60% (95% CI 45–70) in 2013 and 44% (95% CI 31–55) in 2014. For A(H1N1)pdm09 VE was 54% (95% CI–28 to 83) in 2012, 59% (95% CI 33–74) in 2013 and 55% (95% CI 39–67) in 2014. For A(H3N2), VE was 30% (95% CI 14–44) in 2012, 67% (95% CI 39–82) in 2013 and 26% (95% CI 1–45) in 2014. For influenza B, VE was stable across years at 56% (95% CI 37–70) in 2012, 57% (95% CI 30–73) in 2013 and 54% (95% CI 21–73) in 2014. Overall VE against influenza was low in 2012 and 2014 when A(H3N2) was the dominant strain and the vaccine was poorly matched. In contrast, overall VE was higher in 2013 when A(H1N1)pdm09 dominated and the vaccine was a better match. Pooling data can increase the sample available and enable more precise subtype- and age group-specific estimates, but limitations remain.

The 2014 Ebola epidemic was the largest on record. It evidenced the need for improved models of the spread of Ebola. In this research we focus on modelling Ebola within a small village or community. Specifically, we investigate the potential of basic Susceptible-Exposed-Infectious-Recovered (SEIR) models to describe the initial Ebola outbreak, which occurred in Meliandou, Guinea. Data from the World Health Organization is used to compare the accuracy of various models in order to select the most accurate models of transmission and disease-induced responses. Our results suggest that (i) density-dependent transmission and mortality-induced behavioural changes shaped the course of the Ebola epidemic in Meliandou, while (ii) frequency-dependent transmission, disease-induced emigration, and infection-induced behavioural changes are not consistent with the data from this epidemic.

The Ebola virus disease (EVD) outbreak in West Africa may affect healthcare attendance. We describe, in the Guinean prefecture of Guéckédou, trends in attendance of public healthcare structures and the main reported diagnoses over the year following the EVD outbreak notification (March 2014). Monthly numbers of visits and main diagnoses such as malaria, schistosomiasis and measles reported by Guéckédou health centres and health posts were described from January 2012 to March 2015. The median number of visits was 15 724/month. From 1 April to 30 September 2014 (EVD outbreak peak), 90 947 visits were reported, representing decreases of 4·8% and 7·4% compared to 2013 and 2012, respectively. Following December 2014 (last EVD notification in Guéckédou), visits increased from 12 540 in January to 16 032 in March 2015. Malaria seasonality was observed in 2014 with 22 519 notifications from 1 April to 31 July. No seasonality was observed for intestinal schistosomiasis (median 485 cases/month); however, a peak was notified in March 2014 (824 cases). Over the study period, all measles cases were notified in 2015 (183 cases). Reduction in healthcare attendance in Guéckédou was modest during the EVD outbreak. Enhanced infectious disease surveillance is a challenge in this context, due to the impact of EVD on traditional prevention programmes.

Healthcare workers (HCWs) reporting no history of varicella frequently receive varicella vaccination (vOka) if they test varicella-zoster virus (VZV) immunoglobulin G (IgG) negative. In this study, the utilities of VZV-IgG time-resolved fluorescence immunoassay (VZV-TRFIA) and a commercial VZV-IgG purified glycoprotein enzyme immunoassay (gpEIA) currently used in England for confirming VZV immunity have been compared to the fluorescent-antibody-to-membrane-antigen assay (FAMA). A total of 110 HCWs received two doses of vOka vaccine spaced 6 weeks apart and sera collected pre-vaccination (n = 100), at 6 weeks post-completion of vaccination (n = 86) and at 12–18 months follow-up (n = 73) were analysed. Pre-vaccination, by FAMA, 61·0% sera were VZV IgG negative, and compared to FAMA the sensitivities of VZV-TRFIA and gpEIA were 74·4% [95% confidence interval (CI) 57·9–87·0] and 46·2% (95% CI 30·1–62·8), respectively. Post-completion of vaccination the seroconversion rate by FAMA was 93·7% compared to rates of 95·8% and 70·8% determined by VZV-TRFIA and gpEIA, respectively. At 12–18 months follow-up seropositivity rates by FAMA, VZV-TRFIA and gpEIA were 78·1%, 74·0% and 47·9%, respectively. Compared to FAMA the sensitivities of VZV-TRFIA and gpEIA for measuring VZV IgG following vaccination were 96·4% (95% CI 91·7–98·8) and 74·6% (95% CI 66·5–81·6), respectively. Using both FAMA and VZV-TRFIA to identify healthy adult VZV susceptibles and measure seroconversion showed that vOka vaccination of HCWs is highly immunogenic.

Hand, foot, and mouth disease (HFMD) has caused public health concerns worldwide. We aimed to investigate the effect of meteorological factors on the HFMD epidemic in Qingdao, a port city in China. A total of 78641 cases were reported in Qingdao between January 2007 and December 2014. Of those, 71084 (90·39%) occurred in children aged 0–5 years, with an incidence of 1691·2/100000. The incidence increased from early spring, peaked between spring and summer, and decreased in late summer. Aetiological agents in all severe cases and selected mild cases were characterized by examining throat swabs. Except for enterovirus 71 (EV71) and coxsackievirus A16 (CA16), other EVs caused >50% of the HFMD cases between 2011 and 2014. EV71 was more frequent in the off-peak months than in the peak months and prone to causing more severe cases compared to CA16 (χ2 = 46·3, P < 0·001). CA10 caused more severe HFMD than did CA6 (χ2 = 20·49, P < 0·001) and all non-CA10 EVs (χ2 = 41·01, P < 0·001). Community-derived HFMD cases accounted for 65·11%. Spearman rank correlation analysis showed that HFMD incidence in children aged 0–5 years was positively correlated with atmospheric temperature (rs = 0·77, P < 0·001), relative humidity (rs = 0·507, P < 0·001), and precipitation (rs = 0·328, P < 0·001). Climate changes and CA10 surveillance in communities should be integrated into the current prophylactic programme.

To describe the consequences of medical care interruptions (MCIs) we selected patients with at least two medical encounters between January 2006 and June 2013 in the Dat'AIDS cohort. Patients with any time interval >15 months between two visits were defined as having a MCI, as opposed to uninterrupted follow-up (UFU). Patients’ characteristics at the time of HIV diagnosis and at the censoring date were compared between groups. Cox proportional hazards models were built to assess the role of interruptions on survival (total and AIDS-free). Of 11 116 patients, 824 had at least one MCI. These patients were younger at the time of HIV diagnosis (30 vs. 33 years, P < 0·0001). MCI was less frequent in men having sex with men vs. heterosexual patients [odds ratio (OR) 0·81, 95% confidence interval (CI) 0·69–0·96)], and a centre effect was described. MCI was independently associated with AIDS (OR 2·54, 95% CI 2·10–3·09) and death (OR 2·65, 95% CI 1·94–3·61). At the censoring date, 52·2% of patients with at least one MCI had viral load below detection vs. 85·3% of the UFU group (P < 0·0001). In conclusion, MCIs were associated with patients’ survival and with the proportion of viral loads below detection in our cohort, compromising individual and collective treatment benefits.

West Nile virus (WNV) is a mosquito-borne neurotropic viral pathogen maintained in an enzootic cycle between mosquitoes (vectors) and birds (natural hosts) with equids, humans, and other vertebrates acting as dead-end hosts. WNV activity in Mexico has been reported in several domestic and wild fauna and in humans, and the virus has been isolated from birds, mosquitoes, and humans. However, no serological studies have been conducted in monkeys, and only two in a limited number of crocodiles (Crocodylus moreletii). Here we present data on the prevalence of neutralizing antibodies against WNV in 53 healthy wild monkeys (49 Ateles geoffroyi and four Alouatta pigra), and 80 semi-captive healthy crocodiles (60 C. acutus and 20 C. acutus–C. moreletti hybrids) sampled during 2012. None of the monkey sera neutralized WNV, whereas 55% of the crocodile sera presented neutralizing antibodies against WNV. These results can contribute to the design of surveillance programmes in Mexico.

Invasive meningococcal disease (IMD) completeness of reporting has never been assessed in New York City (NYC). We conducted a capture–recapture study to assess completeness of reporting, comparing IMD reports made to the NYC Department of Health and Mental Hygiene (DOHMH) and records identified in the New York State hospital discharge database [Statewide Planning and Research Cooperative System (SPARCS)] by ICD-9 codes from 1989 to 2010. Reporting completeness estimates were calculated for the entire study period, and stratified by year, age group, clinical syndrome, and reporting system. A chart review of hospital medical records from 2008 to 2010 was conducted to validate hospital coding and to adjust completeness estimates. Overall, 2194 unique patients were identified from DOHMH (n = 1300) and SPARCS (n = 1525); 631 (29%) were present in both. Completeness of IMD reporting was 41% [95% confidence interval (CI) 40–43]. Differences in completeness were found by age, clinical syndrome, and reporting system. The chart review found 33% of hospital records from 2008 to 2010 had no documentation of IMD. Removal of those records improved completeness of reporting to 51% (95% CI 49–53). Our data showed a low concordance between what is reported to DOHMH and what is coded by hospitals as IMD. Additional guidance to clinicians on IMD reporting criteria may improve completeness of IMD reporting.

Australia implemented conjugate meningococcal C immunization in 2003 with a single scheduled dose at age 12 months and catch-up for individuals aged 2–19 years. Several countries have recently added one or more booster doses to their programmes to maintain disease control. Australian disease surveillance and vaccine coverage data were used to assess longer term vaccine coverage and impact on invasive serogroup C disease incidence and mortality, and review vaccine failures. Coverage was 93% in 1-year-olds and 70% for catch-up cohorts. In 10 years, after adjusting for changes in diagnostic practices, population invasive serogroup C incidence declined 96% (95% confidence interval 94–98) to 0·4 and 0·6 cases/million in vaccinated and unvaccinated cohorts, respectively. Only three serogroup C deaths occurred in 2010–2012 vs. 68 in 2000–2002. Four (<1/million doses) confirmed vaccine failures were identified in 10 years with no increasing trend. Despite published evidence of waning antibody over time, an ongoing single dose of meningococcal C conjugate vaccine in the second year of life following widespread catch-up has resulted in near elimination of serogroup C disease in all age groups without evidence of vaccine failures in the first decade since introduction. Concurrently, serogroup B incidence declined independently by 55%.

Environmental samples are considered to be a cost-effective method of identifying Mycobacterium avium subsp. paratuberculosis (MAP)-positive dairy herds, but evidence for beef cow-calf herds is weak. This study aims at evaluating this approach in a total of 20 German herds that were characterized by individual faecal samples (n = 2545) of all cows. For 14 MAP-positive herds having at least one MAP-positive animal, the within-herd prevalence was calculated from concurrent individual faecal culture-based testing. Six herds certified as ‘MAP free’ based on the negative results of previous years served as MAP-negative controls. On average, six environmental samples were taken at the end of winter from areas with high cow traffic and tested for MAP by faecal culture. According to the environmental samples, nine (64·3%) out of the 14 MAP-positive cow-calf herds were infected. The percentage of positive environmental samples and the apparent within-herd prevalence (Spearman's P = 0·73, P < 0·001) as well as the herd-level test results (positive and negative) and the herd's status based on individual testing (Fisher's exact test, P = 0·014) showed a positive association. Considering limitations in low-prevalence herds, MAP-positive beef cow-calf herds are detectable by environmental samples in temperate climate zones.

We investigated the seasonality of age-specific tuberculosis (TB) in Japan. To allow the development of TB control strategies for different age groups we used a time-series analysis, including a spectral analysis and least squares method, to analyse the monthly age-specific numbers of newly registered cases of all forms of active TB in Japan from January 1998 to December 2013. The time-series data are reported in 10-year age groups: 0–9, 10–19, …, 70–79, and ⩾80 years. We defined the contribution ratio of the 1-year cycle, Q1, as the contribution of the amplitude of a 1-year cycle to the whole amplitude of the time-series data. The Q1 values in the age groups corresponding to adolescence and middle life (10–39 years) and old age (⩾70 years) were high. The peaks in the active TB epidemics for the ⩾70 years age group occurred in August and September, 1–2 months behind the peaks for the 10–39 years age group (June and July). An active TB epidemic might be attributable to travel by public transport and irregular employment in the 10–39 years age group and immune system suppression by low winter temperatures in the ⩾70 years age group.