Awareness of rabies prevention and control measures among public health workers in Northern Vietnam.

OBJECTIVES: To assess and compare rabies related knowledge and awareness of public health workers at provincial and district levels in the seven provinces with the highest number of deaths from human rabies in northern Vietnam. STUDY DESIGN: A cross-sectional study. METHOD: A survey was administered to a convenience sample of public health workers attending four workshops on rabies disease, control and prevention between 16 October and 21 November, 2012. Total knowledge scores (maximum 38 points) were categorized into: 'high' (>30 points) 'moderate' (21-30) and 'low' (<21). The Chi-square test was used to evaluate the statistical significance of the differences in responses between the respondents. RESULTS: Of the 105 public health workers attending the workshops: 57% were male; 76% worked at the district level compared with 24% who worked at provincial level; and 45% had worked in rabies control for <1 year compared with 11% who had worked in rabies control for >5 years. Overall knowledge was patchy and ranked as 'moderate'. Important gaps in knowledge were identified particularly in relation to indications for rabies vaccine and rabies immunoglobulin, and routes of exposure to rabies virus. One in ten respondents did not know that rabies virus could be transmitted by the bite of an infected animal. When examining the overall mean knowledge scores, marginally significant differences were identified. The average scores for district level health workers (DLHW) and provincial level health workers (PLHW) were 28 ± 3 and 29 ± 3 points respectively (p = 0.098), which fell within the study definition of 'moderate' knowledge. In contrast, when 'high' knowledge scores were compared, a significantly greater proportion of PLHW achieved >30 points compared to DLHW (44.0% vs 22.5%, p = 0.044). CONCLUSIONS: Important gaps in knowledge and awareness of public health workers were identified particularly in relation to routes of exposure to rabies virus and indications for rabies vaccine and rabies immunoglobulin. Overall, comparison of knowledge scores revealed significant differences between district and provincial public health workers. The results obtained suggest that in order for rabies control programmes to succeed public health workers at all levels need to have accurate and evidence-based knowledge. This may be facilitated by improving the quantity and quality of their training and education.

Measuring the effect of influenza A(H1N1)pdm09: the epidemiological experience in the West Midlands, England during the 'containment' phase.

The West Midlands was the first English region to report sustained community transmission during the 'containment' phase of the influenza A(H1N1)pdm09 pandemic in England. To describe the epidemiological experience in the region, West Midlands and national datasets containing laboratory-confirmed A(H1N1)pdm09 virus cases in the region during the 'containment' phase were analysed. The region accounts for about 10·5% of England's population, but reported about 42% of all laboratory-confirmed cases. Altogether 3063 cases were reported, with an incidence rate of 56/100 000 population. School-associated cases accounted for 25% of cases. Those aged <20 years, South Asian ethnic groups, and residents of urban and socioeconomically deprived areas were disproportionately affected. Imported cases accounted for 1% of known exposures. Regional R 0 central estimates between 1·41 and 1·43 were obtained. The West Midlands experience suggests that interpretation of transmission rates may be affected by complex interactions within and between sub-populations in the region.

Challenges and lessons learned from implementing a risk-based approach to school advice and closure during the containment phase of the 2009 influenza pandemic in the West Midlands, England.

OBJECTIVE: School closure as a social distancing measure was used in some countries during the initial phases of the influenza A(H1N1)pdm09 pandemic. The objective of this paper is to describe the use of a risk-based approach to public health interventions for schools during the 'containment phase' of the pandemic and to describe lessons learnt. METHODS: The development of a framework for risk assessment and decision-making to determine school closures in the West Midlands, England, during the 'containment phase' of influenza A(H1N1)pdm09 pandemic is described. RESULTS: Using the framework developed during the 'containment phase', assessments were conducted for 344 educational institutions who reported confirmed cases or 'particularly high absenteeism'. Of these, 209 (60%) had confirmed cases and 65 were closed, mainly for public health or operational reasons. Schools were closed on an individual basis, during the most intense period of the pandemic and for an average period of six days (maximum 11 days). The risk-based approach evolved as experience and knowledge of influenza A(H1N1)pdm09 pandemic virus increased, however some decisions were difficult to communicate to parents, schools and stakeholders particularly when the number of schools affected escalated and the pandemic response phases changed. CONCLUSION: The management of school closures is an 'uncertain art'. Numerous challenges and lessons were identified in attempting, during the containment phase of the influenza A(H1N1)pdm09 pandemic, to ensure consistency and transparency in an increasingly complex process. The overall approach described could be further developed to improve decision-making for infectious diseases in schools.

Absenteeism in schools during the 2009 influenza A(H1N1) pandemic: a useful tool for early detection of influenza activity in the community?

Certain influenza outbreaks, including the 2009 influenza A(H1N1) pandemic, can predominantly affect school-age children. Therefore the use of school absenteeism data has been considered as a potential tool for providing early warning of increasing influenza activity in the community. This study retrospectively evaluates the usefulness of these data by comparing them with existing syndromic surveillance systems and laboratory data. Weekly mean percentages of absenteeism in 373 state schools (children aged 4-18 years) in Birmingham, UK, from September 2006 to September 2009, were compared with established syndromic surveillance systems including a telephone health helpline, a general practitioner sentinel network and laboratory data for influenza. Correlation coefficients were used to examine the relationship between each syndromic system. In June 2009, school absenteeism generally peaked concomitantly with the existing influenza surveillance systems in England. Weekly school absenteeism surveillance would not have detected pandemic influenza A(H1N1) earlier but daily absenteeism data and the development of baselines could improve the timeliness of the system.

Influenza A(H1N1)pdm09 and flu response centres: characteristics of flu response centre staff in the West Midlands.

OBJECTIVE: To assess the operational experience and knowledge of staff who worked in the West Midlands Flu Response Centre (FRC) during the 'containment' phase of influenza A(H1N1)pdm09. STUDY DESIGN: Evaluation study. METHODS: Cross-sectional survey of staff who worked in the West Midlands FRC between 18 May 2009 and 10 July 2009 using an online self-administered questionnaire. The questionnaire included sections related to the respondents' FRC experience, knowledge about influenza A(H1N1)pdm09 and the containment phase. RESULTS: This study had a 51% (89/176) response rate. Of the respondents, 59% were female, 64% were of White ethnicity, 55% were clinicians, 46% were aged 25-44 years, and 67% had no previous call centre experience. A significant proportion (P < 0.001) of respondents believed that the FRC had made a positive contribution to the public health management of the containment phase. Nearly all respondents indicated that they were familiar with the terms 'pandemic flu' or 'influenza pandemic' (99%), understood the aim of the containment phase (90%), and knew the severity of the illness caused by the virus (97%). However, specific knowledge was lacking regarding a number of public health interventions, and overall knowledge scores for clinicians and non-clinicians were similar. CONCLUSION: This study is the first to report on the characteristics of FRC staff during the containment phase of influenza A(H1N1)pdm09 pandemic. Although overall, staff evaluation of the West Midlands FRC was very positive, a number of knowledge gaps were identified. This study provides valuable insights which can contribute to preparedness planning.

Early spread of the 2009 influenza A(H1N1) pandemic in the United Kingdom--use of local syndromic data, May-August 2009.

Following the confirmation of the first two cases of pandemic influenza on 27 April 2009 in the United Kingdom (UK), syndromic surveillance data from the Health Protection Agency (HPA)/QSurveillance and HPA/NHS Direct systems were used to monitor the possible spread of pandemic influenza at local level during the first phase of the outbreak. During the early weeks, syndromic indicators sensitive to influenza activity monitored through the two schemes remained low and the majority of cases were travel-related. The first evidence of community spread was seen in the West Midlands region following a school-based outbreak in central Birmingham. During the first phase several Primary Care Trusts had periods of exceptional influenza activity two to three weeks ahead of the rest of the region. Community transmission in London began slightly later than in the West Midlands but the rates of influenza-like illness recorded by general practitioners (GPs) were ultimately higher. Influenza activity in the West Midlands and London regions peaked a week before the remainder of the UK. Data from the HPA/NHS Direct and HPA/QSurveillance systems were mapped at local level and used alongside laboratory data and local intelligence to assist in the identification of hotspots, to direct limited public health resources and to monitor the progression of the outbreak. This work has demonstrated the utility of local syndromic surveillance data in the detection of increased transmission and in the epidemiological investigation of the pandemic and has prompted future spatio-temporal work.

Investigating a cluster of Legionnaires' cases: public health implications.

OBJECTIVES: To describe the multidisciplinary investigation and management of a rapidly increasing number of cases of Legionnaires' disease in the North Shropshire area, UK during August 2006. STUDY DESIGN: Epidemiological and environmental investigation of a cluster of cases of Legionnaires' disease. METHODS: Outbreak investigation included: agreeing case definitions; case finding; epidemiological survey; identification and environmental investigation of potential sources; microbiological analysis of clinical and environmental samples; mapping the location of potential sources; and the movement and residence of cases. RESULTS: Three cases of Legionnaires' disease were admitted to a local hospital between 30 and 31 August 2006. Two of these cases were Shropshire residents, with the third living in Wales. A fourth case was also identified which, it was thought, may have been linked to this cluster as the patient had a history of travel to the same area as the two Shropshire residents. Over the next few weeks, three more cases were identified, two of whom were admitted to hospital. Subsequent detailed environmental, epidemiological and microbiological investigation did not support the hypothesis that any of these cases could be linked to a common source. CONCLUSIONS: The results of this investigation strongly suggest that a single source was not responsible for the cluster, and it was concluded that this incident was a pseudo-outbreak. This investigation serves as a reminder that clusters can and do occur, and that an apparent outbreak may be a collection of sporadic cases distinguishable only by rigorous epidemiological, environmental and microbiological investigation.

The international follow-up of individuals potentially exposed to polonium-210 in London 2006.

OBJECTIVES: Following a death from polonium-210 ((210)Po), contamination was found at several sites in London. This paper describes the UK Health Protection Agency's follow-up and assessment of individuals resident overseas who were potentially exposed to (210)Po. STUDY DESIGN: Descriptive follow-up study. METHODS: Individuals were classified into three exposure groups (higher, lower and unknown). Presence and degree of internal contamination were measured by 24-h urinary (210)Po activity (mBq/day). Results over 30mBq/day were taken to indicate probable contact with (210)Po in this incident. Dose assessments were conducted to determine degree of exposure and to identify individuals requiring further follow-up. RESULTS: Overall, 664 potentially exposed persons from 52 countries and territories were identified. Of these, 157 (24%) were in the higher exposure category, and urinary measurements were reported for 31% (48/157). Results for 19% (9/48) of those at higher exposure were more than 30mBq/day. For those at lower exposure, the percentage was 4% (3/68). Results above 30mBq/day were significantly more likely to be reported for the higher exposure category than the lower exposure category (Fisher's exact test P=0.010). Reported dose assessments suggested that identified individuals were not at increased health risk in the long term. Challenges and practical lessons were identified during the investigation. CONCLUSION: The results suggest that it is unlikely that any overseas resident had significant internal contamination with (210)Po. However, this incident clearly demonstrated the scale of international involvement likely to be necessary in other public health emergencies in large cities. The lessons identified have implications for the international health community, particularly with regard to the follow-up of individuals exposed to radiation in one country who then travel to another.

Trends in sexually transmitted infections (other than HIV) in older people: analysis of data from an enhanced surveillance system.

OBJECTIVE: This study examines the distribution of selected sexually transmitted infections (STIs) in older people (aged >/=45 years) attending genitourinary medicine (GUM) clinics in the West Midlands, UK. METHODS: Analysis of data from the regional enhanced STI surveillance system for the period 1996-2003. Selected STIs were chlamydia, genital herpes, genital warts, gonorrhoea and syphilis. RESULTS: Altogether, 4445 STI episodes were reported among older people during the study period. Between 1996 and 2003 older people accounted for 3.7% and 4.3%, respectively, of all GUM clinic attendances. The rate of STIs in older people more than doubled in 2003 compared with 1996 (p<0.0001). Rates for all five selected diagnoses were significantly higher in 2003 compared to 1996. A significantly increasing trend over time was seen overall (p<0.0001) and for each of the selected diagnoses. Overall, males and those aged 55-59 years of age were significantly more likely to be affected. CONCLUSIONS: This study provides evidence of significant increases in attendance at GUM clinics by older people. Although it is recognised that young people should remain the focus of sexual health programmes, the results indicate that sexual risk-taking behaviour is not confined to young people but also occurs among older people. There is therefore a need to develop and implement evidence-based multifaceted sexual health programmes that while aiming to reduce STI transmission among all age groups should include interventions aimed specifically at older people and address societal and healthcare attitudes, myths and assumptions about sexual activity among older people.

Understanding the evolution and spread of chikungunya virus in the Americas using complete genome sequences.

Local transmission of chikungunya virus (CHIKV) was first detected in the Americas in December 2013, after which it spread rapidly throughout the Caribbean islands and American mainland, causing a major chikungunya fever epidemic. Previous phylogenetic analysis of CHIKV from a limited number of countries in the Americas suggests that an Asian genotype strain was responsible, except in Brazil where both Asian and East/Central/South African (ECSA) lineage strains were detected. In this study, we sequenced thirty-three complete CHIKV genomes from viruses isolated in 2014 from fourteen Caribbean islands, the Bahamas and two mainland countries in the Americas. Phylogenetic analyses confirmed that they all belonged to the Asian genotype and clustered together with other Caribbean and mainland sequences isolated during the American outbreak, forming an 'Asian/American' lineage defined by two amino acid substitutions, E2 V368A and 6K L20M, and divided into two well-supported clades. This lineage is estimated to be evolving at a mean rate of 5 × 10-4 substitutions per site per year (95% higher probability density, 2.9-7.9 × 10-4) and to have arisen from an ancestor introduced to the Caribbean (most likely from Oceania) in about March 2013, 9 months prior to the first report of CHIKV in the Americas. Estimation of evolutionary rates for individual gene regions and selection analyses indicate that (in contrast to the Indian Ocean Lineage that emerged from the ECSA genotype followed by adaptive evolution and with a significantly higher substitution rate) the evolutionary dynamics of the Asian/American lineage are very similar to the rest of the Asian genotype and natural selection does not appear to have played a major role in its emergence. However, several codon sites with evidence of positive selection were identified within the non-structural regions of Asian genotype sequences outside of the Asian/American lineage.

Knowledge of Rabies Prevention in Vietnamese Public Health and Animal Health Workers.

Rabies is an invariably fatal, but preventable zoonotic disease. Despite a national programme for its prevention and control, the number of rabies associated deaths in Vietnam has increased in recent years. A cross-sectional survey was undertaken in 2012 to assess and compare the knowledge, awareness and practices of 189 public health workers (PHW) and animal health workers (AHW) attending a joint training course for professionals from provinces in northern Vietnam with the highest number of deaths from rabies. Questionnaires facilitating self-evaluation were provided, and total knowledge scores were calculated (maximum 38 points) and categorized into: 'high' (>30 points), 'moderate' (21-30) and 'low' (<21). The response rate was 100%, and among the 189 participants, 56% were PHW compared to 44% who were AHW. Although most respondents knew rabies could be transmitted through the bite of an animal, most commonly a dog, and that rabies is a preventable disease, significant differences between groups were identified. Major areas included poor knowledge of common rabies reservoirs, wound management and guidance on post-exposure prophylaxis. Overall, the total mean knowledge scores for PHW was significantly higher (P = 0.011) compared to those for AHW, but both scores fell within the 'moderate' knowledge range. However, proportionately more PHW than AHW achieved 'high' knowledge scores (P = 0.0098). To our knowledge this is the first published study to simultaneously assess the knowledge and awareness of animal health and public health professionals attending joint training activities aimed at strengthening rabies prevention and control. To ensure effective prevention and control of rabies requires that AHW and PHW not only coordinate and collaborate, but have a common knowledge and understanding of rabies prevention and control measures. This study provides important baseline data in a relatively unexplored area of research that can focus future interventions and research.

Changing socioeconomic risk factors for invasive H. influenzae disease after the introduction of conjugate vaccine.

OBJECTIVES: To determine socioeconomic risk factors for invasive Haemophilus influenzae (HI) disease before and after the introduction of HI type b (Hib) conjugate vaccine in the West Midlands, UK. METHODS: Study population consisted of children aged <5 years with laboratory confirmed invasive disease. Linear associations between disease rates and socioeconomic variables were examined 2-years before and 2-years after the introduction of conjugate vaccine. RESULTS: Pre-vaccine there were no trends in disease incidence. Post-vaccine there was an absolute reduction in disease incidence and significant disease differentials between affluent and deprived populations were identified for non-owner-occupancy (P=0.032) and car access (P=0.049). CONCLUSIONS: Our results suggest that changes in socioeconomic risk factor for invasive HI occurred after the introduction of conjugate vaccine. This may have implications for future immunisation strategies.

Temporal and seasonal variation in the occurrence of chemical incidents.

AIMS: To determine whether there were temporal or seasonal patterns in the occurrence of chemical incidents reported to the West Midlands Chemical Incident Surveillance System, UK. METHODS: A retrospective analysis of reports maintained on a computerised database was carried out for information received from January 1997 to December 2001. RESULTS: Annual numbers of events increased significantly from 77 (7.5%) in 1997 to 282 (27.4%) in 2001. Compared to the average of other seasons, proportionately more incidents occurred in the summer (29.3%). Compared with the average of other days, incidents were more likely to occur on Thursdays (17.1%) and least likely on Saturdays (8.9%). When grouped together on a six hourly basis incidents were most frequent between 12 00 and 17 59 (31.1%) and least frequent between 00 00 and 05 59 (21.2%). CONCLUSIONS: The surveillance system shows that chemical incidents do not occur randomly but have marked temporal and seasonal variation. These results have implications for service provision, training, and the development of preventive strategies.

Seroepidemiology of hepatitis A infection in India: changing pattern.

OBJECTIVE: Recent changes in the epidemiology of hepatitis A virus (HAV) infection and the availability of effective vaccines have renewed interest in this infection. We determined the age-related prevalence of anti-HAV antibodies in India and looked for differences by known risk factors for HAV infection. METHODS: In this prospective study, serum samples obtained from 1612 subjects aged 1 to 60 at six centers in five cities (Calcutta, Cochin, Indore, Jaipur and Patna) during the period February to August 1998 were tested for anti-HAV antibodies. Demographic and socio-economic information was obtained by questionnaire. RESULTS: The overall seroprevalence rate was 65.9%, varying from 26.2% to 85.3% in various cities; there was no difference between males and females. Seropositivity increased with age from 52.2% in the 1-5 year age group to 80.8% in those aged 16 years or more. Seroprevalence rates were significantly lower in those aged 1-5 years compared with other age groups (p<0.0001). There was no difference in seroprevalence between those with monthly family income Rs 5001. Multivariate analysis showed that anti-HAV seroprevalence varied significantly by source of water supply, being highest when the supply was municipal. CONCLUSION: Our results indicate an epidemiological pattern of intermediate endemicity. This finding has public health implications as it indicates that a significant proportion of the Indian adolescent and adult population is at risk of HAV infection.

Seroepidemiology of varicella-zoster in Pakistan.

The availability of safe and effective vaccines has renewed interest in the epidemiology of varicella worldwide. To date published data on the epidemiology of varicella in Pakistan is very scarce. Therefore, we conducted a study to determine the age-specific seroprevalence rate of varicella-zoster virus (VZV) antibodies in Pakistan. Between December 1997 and March 1998, 1,509 healthy volunteers aged between 1 month and 30 years were recruited from the Islamabad, Karachi, Lahore and Rawalpindi areas. Demographic information, socioeconomic status and past medical history were obtained by questionnaire. Serum samples were assayed for IgG antibodies against VZV by enzyme-linked immunosorbent assay. Overall 41.8% (600/1,435) of those tested were found to be seropositive for VZV antibodies. No difference was found in results obtained from the different cities. A higher seroprevalence was observed among women (45.2%) compared to men (39.6%). Seroprevalence rates increased with age and were 28.4% in those aged 0-5 years, 41.5% in the 6-10 year age group, 42.5% in the 11-15 year age group, 46.7% in the 16-20 year age group and 53.6% in those aged 21-30 years. Socioeconomic status was not a significant risk factor for VZV seropositivity. This is the first report of the seroepidemiology of VZV in Pakistan. The results indicate that seroprevalence of VZV increases with age in the Pakistani population studied. As in other tropical countries, there is greater susceptibility to varicella among the adolescent and young adult population. The results of this study suggest that these at-risk groups should be included in vaccination programs aimed at reducing the public health impact of varicella.

Volume of print media coverage and diagnostic testing for influenza A(H1N1)pdm09 virus during the early phase of the 2009 pandemic.

BACKGROUND: Impact of an infectious disease on public health diagnostic health services may be affected by the volume of media coverage which can amplify risk perception and increase demand for services. OBJECTIVES: To examine the association between volume of newspaper reports and laboratory testing for influenza A(H1N1)pdm09 in one English health region during the early phase of the pandemic. STUDY DESIGN: Cross-sectional retrospective review identifying newspaper articles on A(H1N1)pdm09 in major regional (sub-national) newspapers from 27 April 2009 through 5 July 2009, and comparing the weekly frequency of articles with the weekly number, and positivity rate, of laboratory-confirmed cases of A(H1N1)pdm09 during the same time period. RESULTS: A positive correlation (r=0.67; p=0.02) was seen between the volume of school-related articles and the number of laboratory-confirmed cases. Increased testing during the most intense period of the pandemic was mainly seen in school-aged children (5-15 years) and adults (≥16 years). Adults accounted for the highest number of tests, but had the lowest positivity rates, which were highest among school-aged children. As the volume of media coverage decreased this was followed one week later by a fall in the number of tests and positivity rates in each age-group. CONCLUSION: The results presented suggest a temporal association between volume of media reporting and number of laboratory tests. The increased volume of media reporting, in particular the intense school-related coverage, may have raised population concern leading to an increased demand for diagnostic testing. These results have potential implications for future pandemic preparedness planning.