Association between Obesity and Cardiometabolic Health Risk in Asian-Canadian Sub-Groups

Objectives

To quantify and compare the association between the World Health Organizations’ Asian-specific trigger points for public health action [‘increased risk’: body mass index (BMI) ≥23 kg/m², and; ‘high risk’: BMI ≥27.5 kg/m²] with self-reported cardiovascular-related conditions in Asian-Canadian sub-groups.

Methods

Six cycles of the Canadian Community Health Survey (2001–2009) were pooled to examine BMI and health in Asian sub-groups (South Asians, Chinese, Filipino, Southeast Asians, Arabs, West Asians, Japanese and Korean; N = 18 794 participants, ages 18–64 y). Multivariable logistic regression, adjusting for demographic, lifestyle characteristics and acculturation measures, was used to estimate the odds of cardiovascular-related health (high blood pressure, heart disease, diabetes, ‘at least one cardiometabolic condition’) outcomes across all eight Asian sub-groups.

Results

Compared to South Asians (OR = 1.00), Filipinos had higher odds of having ‘at least one cardiometabolic condition’ (OR = 1.29, 95% CI: 1.04–1.62), whereas Chinese (0.63, 0.474–0.9) and Arab-Canadians had lower odds (0.38, 0.28–0.51). In ethnic-specific analyses (with ‘acceptable’ risk weight as the referent), ‘increased’ and ‘high’ risk weight categories were the most highly associated with ‘at least one cardiometabolic condition’ in Chinese (‘increased’: 3.6, 2.34–5.63; ‘high’: 8.9, 3.6–22.01). Compared to normal weight South Asians, being in the ‘high’ risk weight category in all but the Southeast Asian, Arab, and Japanese ethnic groups was associated with approximately 3-times the likelihood of having ‘at least one cardiometabolic condition’.

Conclusion

Differences in the association between obesity and cardiometabolic health risks were seen among Asian sub-groups in Canada. The use of WHO’s lowered Asian-specific BMI cut-offs identified obesity-related risks in South Asian, Filipino and Chinese sub-groups that would have been masked by traditional BMI categories. These findings have implications for public health messaging, especially for ethnic groups at higher odds of obesity-related health risks.     

Seasonal Patterns in Human A (H5N1) Virus Infection: Analysis of Global Cases

Background

Human cases of highly pathogenic avian influenza (HPAI) A (H5N1) have high mortality. Despite abundant data on seasonal patterns in influenza epidemics, it is unknown whether similar patterns exist for human HPAI H5N1 cases worldwide. Such knowledge could help decrease avian-to-human transmission through increased prevention and control activities during peak periods.

Methods

We performed a systematic search of published human HPAI H5N1 cases to date, collecting month, year, country, season, hemisphere, and climate data. We used negative binomial regression to predict changes in case incidence as a function of season. To investigate hemisphere as a potential moderator, we used AIC and the likelihood-ratio test to compare the season-only model to nested models including a main effect or interaction with hemisphere. Finally, we visually assessed replication of seasonal patterns across climate groups based on the Köppen-Geiger climate classification.

Findings

We identified 617 human cases (611 with complete seasonal data) occurring in 15 countries in Southeast Asia, Africa, and the Middle East. Case occurrence was much higher in winter (n = 285, p = 0.03) than summer (n = 64), and the winter peak occurred across diverse climate groups. There was no significant interaction between hemisphere and season.

Interpretation

Across diverse climates, HPAI H5N1 virus infection in humans increases significantly in winter. This is consistent with increased poultry outbreaks and HPAI H5N1 virus transmission during cold and dry conditions. Prioritizing prevention and control activities among poultry and focusing public health messaging to reduce poultry exposures during winter months may help to reduce zoonotic transmission of HPAI H5N1 virus in resource-limited settings.     

Impact of Chikungunya on Health Related Quality of Life Chennai,South India

Background

Chikungunya Virus (CHIKV) infection affects large populations and leads to prolonged and debilitating pain affecting health related quality of life (HRQoL). We assess the impact of CHIKV on HRQoL of clinical CHIKV (C-CHIKV) patients in a suburban locality of Chennai City, South India. Further, we determined factors associated with clinical recovery among C-CHIKV patients.

Methods

We followed-up 403 of 425 adult C-CHIKV cases identified during an outbreak. On the basis of a reassessment of their current clinical status through self-reporting, we categorized them as ‘clinically recovered’ (n = 308) or ‘not recovered’ (n = 95). In the absence of base-line information on HRQoL, we included a comparison group of healthy normal’s recruited by frequency matching for age and sex from the neighbourhood (n = 308). We conducted a comparative cross-sectional study of these three groups and estimated HRQoL scores using SF-36 questionnaire. We tested the differences in the median scores by Kruksall Wallistest. We identified factors associated with ‘recovery’ as compared to not-recovery by calculating Adjusted Odds Ratio (AOR) and 95% Confidence Intervals through multiple regression analysis.

Results

As compared to ‘normals’, we observed a 20 and five-fold reductions in HRQoL scores for C-CHIKV patients ‘not recovered’ and ‘recovered’ respectively. Differences in HRQoL scores for all the domains were statistically significant between three groups (p<0·001). Younger age, male, absence of rashes, affliction of less than five types of joints and two weeks of joint swelling were significantly associated with recovery. HRQoL scores improved with time among those ‘clinically recovered’.

Conclusion

This study provides evidence for sharp reductions in quality of life not only during active C-CHIKV associated illness but also for several months after clinical recovery compared to healthy normals. This has implications for developing intervention programmes in countries with high risk of CHIKV outbreaks.     

Social Engagement,Health, and Changes in Occupational Status: Analysis of the Korean Longitudinal Study of Ageing (KLoSA)

Background

We focused on whether changes in the occupational status of older male adults can be influenced by social engagement and health status measured at the baseline.

Methods

This study used a sample of the Korean Longitudinal Study of Aging (KLoSA), and the study population was restricted to 1.531 men who were aged 55 to 80 years at the 2006 baseline survey and participated in the second survey in 2008. Social engagement and health status, measured by the number of chronic diseases, grip strength, and depressive symptoms as well as covariates (age, marital status, educational level, and household income) were based on data from the 2006 baseline survey. Occupational engagement over the first and second survey was divided into four categories: ‘consistently employed’ (n = 892), ‘employed-unemployed’ (n = 152), ‘unemployed-employed’ (n = 138), and ‘consistently unemployed’ (n = 349).

Results

In the multinomial model, the ‘consistently employed’ and ‘unemployed-employed’ groups had significantly higher social engagement (1.19 and 1.32 times, respectively) than the referent. The number of chronic diseases was significantly associated with four occupational changes, and the ‘unemployed-employed’ had the fewest chronic conditions.

Conclusion

Our finding suggests that social engagement and health status are likely to affect opportunities to continue working or to start working for older male adults.     

Early Life Exposure to Famine and Colorectal Cancer Risk: A Role for Epigenetic Mechanisms

Background

Exposure to energy restriction during childhood and adolescence is associated with a lower risk of developing colorectal cancer (CRC). Epigenetic dysregulation during this critical period of growth and development may be a mechanism to explain such observations. Within the Netherlands Cohort Study on diet and cancer, we investigated the association between early life energy restriction and risk of subsequent CRC characterized by the (promoter) CpG island methylation phenotype (CIMP).

Methodology/Principal Findings

Information on diet and risk factors was collected by baseline questionnaire (n = 120,856). Three indicators of exposure were assessed: place of residence during the Hunger Winter (1944–45) and World War II years (1940–44), and father''s employment status during the Economic Depression (1932–40). Methylation specific PCR (MSP) on DNA from paraffin embedded tumor tissue was performed to determine CIMP status according to the Weisenberger markers. After 7.3 years of follow-up, 603 cases and 4631 sub-cohort members were available for analysis. Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals for CIMP+ (27.7%) and CIMP- (72.3%) tumors according to the three time periods of energy restriction, adjusted for age and gender. Individuals exposed to severe famine during the Hunger Winter had a decreased risk of developing a tumor characterized by CIMP compared to those not exposed (HR 0.65, 95%CI: 0.45–0.92). Further categorizing individuals by an index of ‘0–1’ ‘2–3’ or ‘4–7’ genes methylated in the promoter region suggested that exposure to the Hunger Winter was associated with the degree of promoter hypermethylation (‘0–1 genes methylated’ HR = 1.01, 95%CI:0.74–1.37; ‘2–3 genes methylated’ HR = 0.83, 95% CI:0.61–1.15; ‘4–7 genes methylated’ HR = 0.72, 95% CI:0.49–1.04). No associations were observed with respect to the Economic Depression and WWII years.

Conclusions

This is the first study indicating that exposure to a severe, transient environmental condition during adolescence and young adulthood may result in persistent epigenetic changes that later influence CRC development.     

Pandemic Influenza A(H1N1)pdm09 Seroprevalence in Sweden before and after the Pandemic and the Vaccination Campaign in 2009

The immunity to pandemic influenza A(H1N1)pdm09 in Sweden before and after the outbreaks in 2009 and 2010 was investigated in a seroepidemiological study. Serum samples were collected at four time points: during 2007 (n = 1968), in October 2009 (n = 2218), in May 2010 (n = 2638) and in May 2011 (n = 2513) and were tested for hemagglutination inhibition (HI) antibodies. In 2007, 4.9% of the population had pre-existing HI titres ≥40, with the highest prevalence (20.0%) in 15–24 year-olds, followed by ≥80 year-olds (9.3%). The overall prevalence of HI titres ≥40 had not changed significantly in October 2009. In May 2010 the prevalence had increased to 48.6% with the highest percentages in 5–14 year-olds (76.2%) andlowest in 75–79 year-olds (18.3%). One year later the prevalence of HI titres ≥40 had increased further to 52.2%. Children 5–14 years had the highest incidence of infection and vaccine uptake as well as the highest post-pandemic protective antibody levels. In contrast, the elderly had high vaccine uptake and low attack rate but low levels of protective antibodies, underlining that factors other than HI antibodies are involved in protection against influenza A(H1N1)pdm09. However, for all age-groups the seroprevalence was stable or increasing between 2010 and 2011, indicating that both vaccine- and infection-induced antibodies were long-lived.     

Comparing the Immunogenicity of AS03-Adjuvanted 2009 Pandemic H1N1 Vaccine with Clinical Protection in Priority Risk Groups in England

In England, during pandemic 2009 H1N1, vaccine efficacy and immunogenicity population studies in priority groups were rolled out in parallel to evaluate the pandemic vaccination programme. This provided a unique opportunity to compare immunogenicity and clinical protection in the same population and thus provide insights into the correlates of protection for the pandemic H1N1 2009 vaccine in risk groups. While clinical protection from AS03-adjuvanted pandemic 2009 H1N1 vaccine was high in those aged <25 years and pregnant women, effectiveness in older adults with chronic conditions has been found to be surprisingly poor. Here we present results from the immunogenicity study derived from the same population. Individuals from priority groups eligible for pandemic vaccination attending participating general practices were recruited. Pre and post-vaccination blood samples were collected and HI antibody testing to assess immune response to vaccination performed. The final cohort consisted of 610 individuals: 60 healthy children aged <5 years; 32 healthy pregnant women; 518 individuals from risk groups. Seroconversion rate in healthy children aged <5 years (87%, 95% CI: 75% to 94%) was higher than that of risk groups combined (65%, 95% CI: 61% to 69%) (p<0.001). Multivariable analysis of risk groups showed that the size of response in those who did seroconvert was lower in those who received the 2009/10 seasonal TIV (Fold effect: 0.52, 0.35 to 0.78). Predicted immunological boosting from higher pre-vaccine titres after 2009 pandemic H1N1 vaccination only occurred in children (seroconversion rate = 92%) and not in individuals aged 10 to 39 from risk groups (seroconversion rate = 74%). The lack of clinical protection identified in the same population in older adults from risk groups could be attributed to these lower seroresponses. Current immunogenicity licensing criteria for pandemic influenza vaccine may not correlate with clinical protection in individuals with chronic disease or immunocompromised.     

Correlates of severe disease in patients with 2009 pandemic influenza (H1N1) virus infection

Background

In the context of 2009 pandemic influenza (H1N1) virus infection (pandemic H1N1 influenza), identifying correlates of the severity of disease is critical to guiding the implementation of antiviral strategies, prioritization of vaccination efforts and planning of health infrastructure. The objective of this study was to identify factors correlated with severity of disease in confirmed cases of pandemic H1N1 influenza.

Methods

This cumulative case–control study included all laboratory-confirmed cases of pandemic H1N1 influenza among residents of the province of Manitoba, Canada, for whom the final location of treatment was known. Severe cases were defined by admission to a provincial intensive care unit (ICU). Factors associated with severe disease necessitating admission to the ICU were determined by comparing ICU cases with two control groups: patients who were admitted to hospital but not to an ICU and those who remained in the community.

Results

As of Sept. 5, 2009, there had been 795 confirmed cases of pandemic H1N1 influenza in Manitoba for which the final treatment location could be determined. The mean age of individuals with laboratory-confirmed infection was 25.3 (standard deviation 18.8) years. More than half of the patients (417 or 52%) were female, and 215 (37%) of 588 confirmed infections for which ethnicity was known occurred in First Nations residents. The proportion of First Nations residents increased with increasing severity of disease (116 [28%] of 410 community cases, 74 [54%] of 136 admitted to hospital and 25 [60%] of 42 admitted to an ICU; p < 0.001), as did the presence of an underlying comorbidity (201 [35%] of 569 community cases, 103 [57%] of 181 admitted to hospital and 34 [76%] of 45 admitted to an ICU; p < 0.001). The median interval from onset of symptoms to initiation of antiviral therapy was 2 days (interquartile range, IQR 1–3) for community cases, 4 days (IQR 2–6) for patients admitted to hospital and 6 days (IQR 4–9) for those admitted to an ICU (p < 0.001). In a multivariable logistic model, the interval from onset of symptoms to initiation of antiviral therapy (odds ratio [OR] 8.24, 95% confidence interval [CI] 2.82–24.1), First Nations ethnicity (OR 6.52, 95% CI 2.04–20.8) and presence of an underlying comorbidity (OR 3.19, 95% CI 1.07–9.52) were associated with increased odds of admission to the ICU (i.e., severe disease) relative to community cases. In an analysis of ICU cases compared with patients admitted to hospital, First Nations ethnicity (OR 3.23, 95% CI 1.04–10.1) was associated with increased severity of disease.

Interpretation

Severe pandemic H1N1 influenza necessitating admission to the ICU was associated with a longer interval from onset of symptoms to treatment with antiviral therapy and with the presence of an underlying comorbidity. First Nations ethnicity appeared to be an independent determinant of severe infection. Despite these associations, the cause and outcomes of pandemic HINI influenza may involve many complex and interrelated factors, all of which require further research and analysis.In April 2009, Canada’s first wave of pandemic influenza (H1N1) virus infections (pandemic H1N1 influenza) began. The highest burden of severe illness in Canada occurred in the province of Manitoba, where 45 Manitobans and 9 out-of-province patients were admitted to an intensive care unit (ICU). In this first wave, ICU staff and equipment were mobilized to expand bed capacity and ventilator capabilities to accommodate clinical need.Although many individuals presented with mild, self-limited symptoms and no sign of pulmonary involvement, some people required admission to an ICU and received maximal life support measures.^1–3 Predicting disease and mitigating hazard in at-risk populations is an important aim of public heath epidemiology, and in preparation for future waves of pandemic H1N1 influenza, determining correlates of the severity of disease may be very important. Initial reports have suggested that, in addition to many of the previously known risk factors for complications of seasonal influenza, obesity⁴ and other underlying comorbidities^3,5 may be risk factors for severe disease. The interval from onset of symptoms to initiation of antiviral therapy or other treatment and supportive care was also associated with adverse outcome in a recent case series.⁶ In a Canadian study of severe pandemic H1N1 influenza, First Nations people were proportionally overrepresented among patients in the ICU.² However, it is unclear if this association was independent of potential confounding factors. The ability to determine correlates of severe pandemic H1N1 disease and subsequent need for ICU resources in at-risk populations would provide opportunities for public and population health analysis and action, public education, strategic prioritization of vaccination efforts, efficient and equitable allocation and use of antiviral drugs, and development of infrastructure within the health system.The objectives of this study were to identify factors that were correlated with severity of disease in confirmed cases of pandemic H1N1 influenza. Our hypothesis, which was based on existing literature, was that obesity, First Nations ethnicity and longer interval from onset of symptoms to treatment would be important determinants of the severity of disease.     

Morbid Obesity as a Risk Factor for Hospitalization and Death Due to 2009 Pandemic Influenza A(H1N1) Disease

Background

Severe illness due to 2009 pandemic A(H1N1) infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1), independent of chronic medical conditions considered by the Advisory Committee on Immunization Practices (ACIP) to increase the risk of influenza-related complications.

Methodology/Principal Findings

We used a case-cohort design to compare cases of hospitalizations and deaths from 2009 pandemic A(H1N1) influenza occurring between April–July, 2009, with a cohort of the U.S. population estimated from the 2003–2006 National Health and Nutrition Examination Survey (NHANES); pregnant women and children <2 years old were excluded. For hospitalizations, we defined categories of relative weight by body mass index (BMI, kg/m²); for deaths, obesity or morbid obesity was recorded on medical charts, and death certificates. Odds ratio (OR) of being in each BMI category was determined; normal weight was the reference category. Overall, 361 hospitalizations and 233 deaths included information to determine BMI category and presence of ACIP-recognized medical conditions. Among ≥20 year olds, hospitalization was associated with being morbidly obese (BMI≥40) for individuals with ACIP-recognized chronic conditions (OR = 4.9, 95% CI 2.4–9.9) and without ACIP-recognized chronic conditions (OR = 4.7, 95%CI 1.3–17.2). Among 2–19 year olds, hospitalization was associated with being underweight (BMI≤5^th percentile) among those with (OR = 12.5, 95%CI 3.4–45.5) and without (OR = 5.5, 95%CI 1.3–22.5) ACIP-recognized chronic conditions. Death was not associated with BMI category among individuals 2–19 years old. Among individuals aged ≥20 years without ACIP-recognized chronic medical conditions death was associated with obesity (OR = 3.1, 95%CI: 1.5–6.6) and morbid obesity (OR = 7.6, 95%CI 2.1–27.9).

Conclusions/Significance

Our findings support observations that morbid obesity may be associated with hospitalization and possibly death due to 2009 pandemic H1N1 infection. These complications could be prevented by early antiviral therapy and vaccination.     

Associations between Family-Related Factors,Breakfast Consumption and BMI among 10- to 12-Year-Old European Children: The Cross-Sectional ENERGY-Study

Objective

To investigate associations of family-related factors with children’s breakfast consumption and BMI-z-score and to examine whether children’s breakfast consumption mediates associations between family-related factors and children’s BMI-z-score.

Subjects

Ten- to twelve-year-old children (n = 6374; mean age = 11.6±0.7 years, 53.2% girls, mean BMI-z-score = 0.4±1.2) and one of their parents (n = 6374; mean age = 41.4±5.3 years, 82.7% female, mean BMI = 24.5±4.2 kg/m²) were recruited from schools in eight European countries (Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia, Spain, and Switzerland). The children self-reported their breakfast frequency per week. The body weight and height of the children were objectively measured. The parents responded to items on family factors related to breakfast (automaticity, availability, encouragement, paying attention, permissiveness, negotiating, communicating health beliefs, parental self-efficacy to address children’s nagging, praising, and family breakfast frequency). Mediation analyses were performed using multi-level regression analyses (child-school-country).

Results

Three of the eleven family-related variables were significantly associated with children’s BMI-z-score. The family breakfast frequency was negatively associated with the BMI-z-score; permissiveness concerning skipping breakfast and negotiating about breakfast were positively associated with the BMI-z-score. Children’s breakfast consumption was found to be a mediator of the two associations. All family-related variables except for negotiating, praising and communicating health beliefs, were significantly associated with children’s breakfast consumption.

Conclusions

Future breakfast promotion and obesity prevention interventions should focus on family-related factors including the physical home environment and parenting practices. Nevertheless, more longitudinal research and intervention studies to support these findings between family-related factors and both children’s breakfast consumption and BMI-z-score are needed.     

Assessment of Local Public Health Workers' Willingness to Respond to Pandemic Influenza through Application of the Extended Parallel Process Model

Background

Local public health agencies play a central role in response to an influenza pandemic, and understanding the willingness of their employees to report to work is therefore a critically relevant concern for pandemic influenza planning efforts. Witte''s Extended Parallel Process Model (EPPM) has been found useful for understanding adaptive behavior in the face of unknown risk, and thus offers a framework for examining scenario-specific willingness to respond among local public health workers. We thus aim to use the EPPM as a lens for examining the influences of perceived threat and efficacy on local public health workers'' response willingness to pandemic influenza.

Methodology/Principal Findings

We administered an online, EPPM-based survey about attitudes/beliefs toward emergency response (Johns Hopkins∼Public Health Infrastructure Response Survey Tool), to local public health employees in three states between November 2006 – December 2007. A total of 1835 responses were collected for an overall response rate of 83%. With some regional variation, overall 16% of the workers in 2006-7 were not willing to “respond to a pandemic flu emergency regardless of its severity”. Local health department employees with a perception of high threat and high efficacy – i.e., those fitting a ‘concerned and confident’ profile in the EPPM analysis – had the highest declared rates of willingness to respond to an influenza pandemic if required by their agency, which was 31.7 times higher than those fitting a ‘low threat/low efficacy’ EPPM profile.

Conclusions/Significance

In the context of pandemic influenza planning, the EPPM provides a useful framework to inform nuanced understanding of baseline levels of – and gaps in – local public health workers'' response willingness. Within local health departments, ‘concerned and confident’ employees are most likely to be willing to respond. This finding may allow public health agencies to design, implement, and evaluate training programs focused on emergency response attitudes in health departments.     

Low Acceptability of A/H1N1 Pandemic Vaccination in French Adult Population: Did Public Health Policy Fuel Public Dissonance?

Background

In July 2009, French public health authorities embarked in a mass vaccination campaign against A/H1N1 2009 pandemic-influenza. We explored the attitudes and behaviors of the general population toward pandemic vaccination.

Methodology/Principal Findings

We conducted a cross-sectional online survey among 2,253 French representative adults aged 18 to 64 from November 17 to 25, 2009 (completion rate: 93.8%). The main outcome was the acceptability of A/H1N1 vaccination as defined by previous receipt or intention to get vaccinated (“Yes, certainly”, “Yes, probably”). Overall 17.0% (CI 95%, 15.5% to 18.7%) of respondents accepted A/H1N1 vaccination. Independent factors associated with acceptability included: male sex (p = .0001); older age (p = .002); highest or lowest level of education (p = .016); non-clerical occupation (p = .011); having only one child (p = .008); and having received seasonal flu vaccination in prior 3 years (p<.0001). Acceptability was also significantly higher among pregnant women (37.9%) and other at risk groups with chronic diseases (34.8%) (p = .002). Only 35.5% of respondents perceived A/H1N1 influenza illness as a severe disease and 12.7% had experienced A/H1N1 cases in their close relationships with higher acceptability (p<.0001 and p = .006, respectively). In comparison to 26.0% respondents who did not consult their primary care physician, acceptability was significantly higher among 8.0% respondents who were formally advised to get vaccinated, and lower among 63.7% respondents who were not advised to get vaccinated (respectively: 15.8%, 59.5% and 11.7%- p<.0001). Among respondents who refused vaccination, 71.2% expressed concerns about vaccine safety.

Conclusions/Significance

Our survey occurred one week before the peak of the pandemic in France. We found that alarming public health messages aiming at increasing the perception of risk severity were counteracted by daily personal experience which did not confirm the threat, while vaccine safety was a major issue. This dissonance may have been amplified by having not involved primary care physicians in the mass vaccination campaign.     

Seroprevalence Following the Second Wave of Pandemic 2009 H1N1 Influenza in Pittsburgh,PA, USA

Background

In April 2009, a new pandemic strain of influenza infected thousands of persons in Mexico and the United States and spread rapidly worldwide. During the ensuing summer months, cases ebbed in the Northern Hemisphere while the Southern Hemisphere experienced a typical influenza season dominated by the novel strain. In the fall, a second wave of pandemic H1N1 swept through the United States, peaking in most parts of the country by mid October and returning to baseline levels by early December. The objective was to determine the seroprevalence of antibodies against the pandemic 2009 H1N1 influenza strain by decade of birth among Pittsburgh-area residents.

Methods and Findings

Anonymous blood samples were obtained from clinical laboratories and categorized by decade of birth from 1920–2009. Using hemagglutination-inhibition assays, approximately 100 samples per decade (n = 846) were tested from blood samples drawn on hospital and clinic patients in mid-November and early December 2009. Age specific seroprevalences against pandemic H1N1 (A/California/7/2009) were measured and compared to seroprevalences against H1N1 strains that had previously circulated in the population in 2007, 1957, and 1918. (A/Brisbane/59/2007, A/Denver/1/1957, and A/South Carolina/1/1918). Stored serum samples from healthy, young adults from 2008 were used as a control group (n = 100). Seroprevalences against pandemic 2009 H1N1 influenza varied by age group, with children age 10–19 years having the highest seroprevalence (45%), and persons age 70–79 years having the lowest (5%). The baseline seroprevalence among control samples from 18–24 year-olds was 6%. Overall seroprevalence against pandemic H1N1 across all age groups was approximately 21%.

Conclusions

After the peak of the second wave of 2009 H1N1, HAI seroprevalence results suggest that 21% of persons in the Pittsburgh area had become infected and developed immunity. Extrapolating to the entire US population, we estimate that at least 63 million persons became infected in 2009. As was observed among clinical cases, this sero-epidemiological study revealed highest infection rates among school-age children.     

Longitudinal Investigation of Public Trust in Institutions Relative to the 2009 H1N1 Pandemic in Switzerland

Background

The 2009 H1N1 pandemic left a legacy of mistrust in the public relative to how outbreaks of emerging infectious diseases are managed. To prepare for future outbreaks, it is crucial to explore the phenomenon of public trust in the institutions responsible for managing disease outbreaks. We investigated the evolution of public trust in institutions during and after the 2009 pandemic in Switzerland. We also explored respondents’ perceptions of the prevention campaign and the roles of the government and media.

Methodology/Principal Findings

A two-wave longitudinal survey was mailed to 2,400 members of the Swiss public. Wave 1 was in Spring 2009. Wave 2 was in Spring 2010. Six hundred and two participants responded in both waves. Participants indicated moderate to high levels of trust in medical organizations, the WHO, the Swiss government, the pharmaceutical industry, and the EU. On the other hand, trust in the media was low. Moreover, trust in almost all institutions decreased over time. Participants were satisfied with the amount of information received and indicated having followed official recommendations, but widespread concerns about the vaccine were evident. A large majority of participants agreed the vaccine might have unknown or undesirable side effects. Perceptions of the government’s and the media’s role in handling the outbreak were characterized by a substantial degree of skepticism and mistrust.

Conclusions/Significance

Results show clear patterns of skepticism and mistrust on the part of the public relative to various institutions and their actions. Results underscore the importance of systematically investigating trust of the public relative to epidemics. Moreover, studies investigating the evolution of the public’s memories of the pandemic over the coming years may be important to understand reactions to future pandemics. A systematic research program on trust can inform public health communication campaigns, enabling tailored communication initiatives.     

Influenza Aerosols in UK Hospitals during the H1N1 (2009) Pandemic – The Risk of Aerosol Generation during Medical Procedures

Background

Nosocomial infection of health-care workers (HCWs) during outbreaks of respiratory infections (e.g. Influenza A H1N1 (2009)) is a significant concern for public health policy makers. World Health Organization (WHO)-defined ‘aerosol generating procedures’ (AGPs) are thought to increase the risk of aerosol transmission to HCWs, but there are presently insufficient data to quantify risk accurately or establish a hierarchy of risk-prone procedures.

Methodology/Principal Findings

This study measured the amount of H1N1 (2009) RNA in aerosols in the vicinity of H1N1 positive patients undergoing AGPs to help quantify the potential risk of transmission to HCWs. There were 99 sampling occasions (windows) producing a total of 198 May stages for analysis in the size ranges 0.86–7.3 µm. Considering stages 2 (4–7.3 µm) and 3 (0.86–4 µm) as comprising one sample, viral RNA was detected in 14 (14.1%) air samples from 10 (25.6%) patients. Twenty three air samples were collected while potential AGPs were being performed of which 6 (26.1%) contained viral RNA; in contrast, 76 May samples were collected when no WHO 2009 defined AGP was being performed of which 8 (10.5%) contained viral RNA (unadjusted OR = 2.84 (95% CI 1.11–7.24) adjusted OR = 4.31 (0.83–22.5)).

Conclusions/Significance

With our small sample size we found that AGPs do not significantly increase the probability of sampling an H1N1 (2009) positive aerosol (OR (95% CI) = 4.31 (0.83–22.5). Although the probability of detecting positive H1N1 (2009) positive aerosols when performing various AGPs on intensive care patients above the baseline rate (i.e. in the absence of AGPs) did not reach significance, there was a trend towards hierarchy of AGPs, placing bronchoscopy and respiratory and airway suctioning above baseline (background) values. Further, larger studies are required but these preliminary findings may be of benefit to infection control teams.     

Knowledge,Attitudes, Practices and Emotional Reactions among Residents of Avian Influenza (H5N1) Hit Communities in Vietnam

Background

Awareness of individuals’ knowledge and predicting their behavior and emotional reactions is crucial when evaluating clinical preparedness for influenza pandemics with a highly pathogenic virus. Knowledge, attitude, and practice (KAP) relating to avian influenza (H5N1) virus infection among residents in communities where H5N1 patients occurred in Vietnam has not been reported.

Methods and Principal Findings

Face-to-face interviews including KAP survey were conducted in Bac Kan province, located in the northeast mountainous region of Vietnam. Participants were residents who lived in a community where H5N1 cases have ever been reported (event group, n = 322) or one where cases have not been reported (non-event group, n = 221). Data on emotional reactions of participants and healthcare-seeking behavior after the event in neighboring areas were collected as well as information on demographics and environmental measures, information sources, and KAP regarding H5N1. These data were compared between two groups. Higher environmental risk of H5N1 and improper poultry-handling behaviors were identified in the event group. At the time of the event, over 50% of the event group sought healthcare for flu-like symptoms or because they were scared. Awareness of the event influenced KAP scores. Healthcare-seeking behavior and attention to H5N1 poultry outbreaks diminished in the event group as time passed after the outbreak compared with the non-event group. Factors that motivated participants to seek healthcare sooner were knowledge of early access to healthcare and the risk of eating sick/dead poultry, and perception of the threat of H5N1.

Conclusions

Awareness of H5N1 patients in neighboring areas can provoke panic in residents and influence their healthcare-seeking behavior. Periodic education to share experiences on the occurrence of H5N1 patients and provide accurate information may help prevent panic and infection and reduce mortality. Local conditions should be taken into account when emphasizing the need for early access to healthcare.     

Compliance to Oseltamivir among Two Populations in Oxfordshire,United Kingdom Affected by Influenza A(H1N1)pdm09, November 2009 – A Waste Water Epidemiology Study

Antiviral provision remains the focus of many pandemic preparedness plans, however, there is considerable uncertainty regarding antiviral compliance rates. Here we employ a waste water epidemiology approach to estimate oseltamivir (Tamiflu®) compliance. Oseltamivir carboxylate (oseltamivir''s active metabolite) was recovered from two waste water treatment plant (WWTP) catchments within the United Kingdom at the peak of the autumnal wave of the 2009 Influenza A (H1N1)pdm09 pandemic. Predictions of oseltamivir consumption from detected levels were compared with two sources of national government statistics to derive compliance rates. Scenario and sensitivity analysis indicated between 3–4 and 120–154 people were using oseltamivir during the study period in the two WWTP catchments and a compliance rate between 45–60%. With approximately half the collected antivirals going unused, there is a clear need to alter public health messages to improve compliance. We argue that a near real-time understanding of drug compliance at the scale of the waste water treatment plant (hundreds to millions of people) can potentially help public health messages become more timely, targeted, and demographically sensitive, while potentially leading to less mis- and un-used antiviral, less wastage and ultimately a more robust and efficacious pandemic preparedness plan.     

Risk-Based Learning Games Improve Long-Term Retention of Information among School Pupils

Risk heightens motivation and, if used appropriately, may have the potential to improve engagement in the classroom. We have developed a risk-based learning game for school pupils in order to test whether such learning games can improve later recall of information. The study was performed during a series of public engagement workshops delivered by undergraduate students. Undergraduate neuroscience students delivered 90-minute science workshops to 9–10 year old school pupils (n = 448) that were divided into ‘Risk’, ‘No risk’ and ‘Control’ classes. ‘Risk’ classes received periodic multiple-choice questions (MCQs) during the workshops which required small teams of pupils to assign tokens to the answer(s) they believed to be correct. Tokens assigned to the correct answer were returned to the group and an equal number given back as a prize; tokens assigned to incorrect answers were lost. Participation was incentivised by the promise of a brain-related prize to the team with the most tokens at the end of the workshop. ‘No risk’ classes received MCQs without the risk component whilst the ‘Control’ classes received no MCQs. When presented with a neuroscience quiz based on workshop content at the end of the workshop, pupils in the ‘Risk’ classes exhibited significantly greater recall of information one week later. Quiz scores were higher than scores from the day of the workshop which suggested pupils may have discussed the workshop content outside of the classroom, thereby increasing knowledge over and above what was learned during the workshop. This is supported by feedback from pupils in ‘Risk’ classes which indicated that ‘Risk’ workshops were more interesting than ‘No risk’ and ‘Control’ workshops. These data suggest that there is a role for risk in the classroom but further investigations are required to elucidate the causal mechanisms of improved retention of information.     

Genetic Variation in OAS1 Is a Risk Factor for Initial Infection with West Nile Virus in Man

West Nile virus (WNV) is a re-emerging pathogen that can cause fatal encephalitis. In mice, susceptibility to WNV has been reported to result from a single point mutation in oas1b, which encodes 2′–5′ oligoadenylate synthetase 1b, a member of the type I interferon-regulated OAS gene family involved in viral RNA degradation. In man, the human ortholog of oas1b appears to be OAS1. The ‘A’ allele at SNP rs10774671 of OAS1 has previously been shown to alter splicing of OAS1 and to be associated with reduced OAS activity in PBMCs. Here we show that the frequency of this hypofunctional allele is increased in both symptomatic and asymptomatic WNV seroconverters (Caucasians from five US centers; total n = 501; OR = 1.6 [95% CI 1.2–2.0], P = 0.0002 in a recessive genetic model). We then directly tested the effect of this SNP on viral replication in a novel ex vivo model of WNV infection in primary human lymphoid tissue. Virus accumulation varied markedly among donors, and was highest for individuals homozygous for the ‘A’ allele (P<0.0001). Together, these data identify OAS1 SNP rs10774671 as a host genetic risk factor for initial infection with WNV in humans.