Costing infectious disease outbreaks for economic evaluation: a review for hepatitis A

The Burden of Hepatitis A Outbreaks in the United States: Health Outcomes, Economic Costs, and Management Strategies

BACKGROUND

Hepatitis A (HepA) vaccines are recommended for US adults at risk of HepA. Ongoing United States (US) HepA outbreaks since 2016 have primarily spread person-to-person, especially among at-risk groups. We investigated the health outcomes, economic burden, and outbreak management considerations associated with HepA outbreaks from 2016 onwards.

METHODS

A systematic literature review was conducted to assess HepA outbreak-associated health outcomes, health care resource utilization (HCRU), and economic burden. A targeted literature review evaluated HepA outbreak management considerations.

RESULTS

Across 33 studies reporting on HepA outbreak-associated health outcomes/HCRU, frequently reported HepA-related morbidities included acute liver failure/injury (n = 6 studies of 33 studies) and liver transplantation (n = 5 of 33); reported case fatality rates ranged from 0% to 10.8%. Hospitalization rates reported in studies investigating person-to-person outbreaks ranged from 41.6% to 84.8%. Ten studies reported on outbreak-associated economic burden, with a national study reporting an average cost of over $16 000 per hospitalization. Thirty-four studies reported on outbreak management; challenges included difficulty reaching at-risk groups and vaccination distrust. Successes included targeted interventions and increasing public awareness.

CONCLUSIONS

This review indicates a considerable clinical and economic burden of ongoing US HepA outbreaks. Targeted prevention strategies and increased public awareness and vaccination coverage are needed to reduce HepA burden and prevent future outbreaks.

Non-typhoidal Salmonella in Nigeria: do outcomes of 'multisectoral' surveillance, treatment and control justify the intervention costs?

Non-typhoidal salmonellosis (NTS) is significant and an economic burden in Nigeria. To determine whether investment in NTS control is economically justifiable, Outbreak Costing Tool (OCT) was used to estimate the robust funding of public and animal health systems for epidemio-surveillance and control of multisectoral NTS outbreaks in Nigeria. Health, production, and economic data were collected and used to populate the tool for evaluation. The multisectoral NTS burden for the year 2020 in Nigeria was US$ 930,887,379.00. Approximately 4,835 technical officers, and 3,700 non-technical staff (n = 8,535) were needed with an investment of >2.2 million work hours. The investment cost for NTS control was US$ 53,854,660.87. The non-labour-related cost was 89.21% of the total intervention costs. The overall intervention's investment was 374.15% of the estimated national and subnational systems' annual budget for diarrhoeal diseases, and the outbreak response period attracted the highest costs (53%) of the total intervention. In conclusion, intervention against NTS was beneficial (benefit - cost ratio: 17.29), hence justifying the need for multisectoral surveillance-response against NTS in Nigeria. Complex sectoral silos must give way to coordinated collaborations to optimize benefits; and over-centralization of health interventions' associated delays must be removed through decentralized sub-national-focused framework that empowers rapid investigation, response, control, data collection, and analyses. It should assist anticipatory planning, and outbreak investigation and reduce critical response time. Anticipatory planning tools, when applied pre-emptively, can benefit budgeting, identify gaps, and assist in the delivery of cost-saving and effective measures against infectious disease.

Social preferences for adopting new vaccines in the national immunization program: A discrete choice experiment

Governments regularly have to decide whether new vaccines should be adopted in their national immunization program. These choices imply complex trade-offs of epidemiological, medical and socio-economic criteria. We investigated how the population in Flanders (Belgium) wants their government to set vaccine-funding priorities. In December 2019, we executed a discrete choice experiment in a sample of the Flemish population (N = 1636). In total, we analysed 16 360 choices between vaccines competing for funding, described in terms of eight characteristics. Using a panel mixed logit model, we quantified the relative importance of each characteristic and investigated differences in preferences across respondent groups. The observed vaccine priorities were different from those that would be identified through cost-effectiveness analysis. People valued the health impact from infectious diseases differently than their weight expressed in QALYs would suggest. Mortality and frequently occurring mild illness were valued higher, whereas lasting morbidity received lower weight. Contribution of the vaccine to disease eradication and uncertainty in vaccine effectiveness were both highly influential factors. Health equity impact was also important whereas the economic impact of the disease did not matter at all. Our results can be used to incorporate public values into vaccine decision-making.

An Investigation on Chinese Public Acceptance of COVID-19 Prevention Measures

China has basically succeeded in bringing the COVID-19 epidemic under control, thanks to a timely series of effective prevention and control measures taken by the Chinese government. In this study, a public acceptance questionnaire of epidemic prevention measures was designed to investigate the influencing factors of public acceptance. A total of 2062 samples were collected from 8 March 2020 to 9 April 2020, and Independent-Samples T-Test and One-way ANOVA were used to analyze the data collected in the questionnaire in SPSS version 22.0. The results show that age and educational level have a significant influence on public acceptance. With the development of the epidemic, the acceptability grew generally higher. The public acceptance of traffic measures is the highest. This study summarises China’s scientific experience in the fight against COVID-19 and the differences in public acceptance. It can provide a positive reference for the development of epidemic prevention in other countries.

Multisectoral cost analysis of a human and livestock anthrax outbreak in Songwe Region, Tanzania (December 2018-January 2019), using a novel Outbreak Costing Tool

OBJECTIVES

We applied a novel Outbreak Costing Tool (OCT), developed by the US Centers for Disease Control and Prevention (CDC), to estimate the costs of investigating and responding to an anthrax outbreak in Tanzania. We also evaluated the OCT's overall utility in its application to a multisectoral outbreak response.

METHODS

We collected data on direct costs associated with a human and animal anthrax outbreak in Songwe Region (December 2018 to January 2019) using structured questionnaires from key-informants. We performed a cost analysis by entering direct costs data into the OCT, grouped into seven cost categories: labor, office, travel and transport, communication, laboratory support, medical countermeasures, and consultancies.

RESULTS

The total cost for investigating and responding to this outbreak was estimated at 102,232 United States dollars (USD), with travel and transport identified as the highest cost category (62,536 USD) and communication and consultancies as the lowest, with no expenditure, for the combined human and animal health sectors.

CONCLUSIONS

Multisectoral investigation and response may become complex due to coordination challenges, thus allowing escalation of public health impacts. A standardized framework for collecting and analysing cost data is vital to understanding the nature of outbreaks, in anticipatory planning, in outbreak investigation and in reducing time to intervention. Pre-emptive use of the OCT will also reduce overall and specific (response period) intervention costs for the disease. Additional aggregation of the costs by government ministries, departments and tiers will improve the use of the tool to enhance sectoral budget planning for disease outbreaks in a multisectoral response.

Cost-effectiveness of routine catch-up hepatitis a vaccination in the United States: Dynamic transmission modeling study

BACKGROUND

Despite routine vaccination of children against hepatitis A (HepA), a large segment of the United States population remains unvaccinated, imposing a risk of hepatitis A virus (HAV) to adolescents and adults. In July of 2020, the Advisory Committee on Immunization Practices recommended that all children and adolescents aged 2-18 years who have not previously received a HepA vaccine be vaccinated. We evaluated the public health impact and cost-effectiveness of this HepA catch-up vaccination strategy.

METHODS

We used a dynamic transmission model to compare adding a HepA catch-up vaccination of persons age 2-18 years to a routine vaccination of children 12-23 months of age with routine vaccination only in the United States. The model included various health compartments: maternal antibodies, susceptible, exposed, asymptomatic infectious, symptomatic infectious (outpatient, hospitalized, liver transplant, post- liver transplant, death), recovered, and vaccinated with and without immunity. Using a 3% annual discount rate, we estimated the incremental cost per quality-adjusted life year (QALY) gained from a societal perspective over a 100-year time horizon. All costs were converted into 2020 US dollars.

FINDINGS

Compared with the routine vaccination policy at 12-23 months of age over 100 years, the catch-up program for unvaccinated children and adolescents aged 2-18 years, prevented 70,072 additional symptomatic infections, 51,391 outpatient visits, 16,575 hospitalizations, and 413 deaths. The catch-up vaccination strategy was cost-saving when compared with the routine vaccination strategy. In scenario analysis allowing administering a second dose to partially vaccinated children, the cost-effectiveness of was not favorable at a higher vaccination coverage ($196,701/QALY at 5% and $476,241/QALY at 50%).

INTERPRETATION

HepA catch-up vaccination in the United States is expected to reduce HepA morbidity and mortality and save cost. The catch-up program would be optimized when focusing on unvaccinated children and adolescents and maximizing their first dose coverage.

Value Frameworks for Vaccines: Which Dimensions Are Most Relevant?

In addition to more narrow criteria such as safety, effectiveness and cost-effectiveness, vaccines can also be evaluated based on broader criteria such as their economic impact, contribution to disease eradication objectives, caregiver aspects, financial protection offered, equity or social acceptability. We summarize a survey executed in a sample of the population (n = 1000) in Flanders, Belgium, in which we investigated support for using these broader criteria to evaluate vaccines for funding decisions. By means of both favourable and unfavourable framings of a hypothetical vaccine across 40 value dimensions, we find support for the view that people indeed consider a broad range of medical and socio-economic criteria relevant. Several of these are not incorporated in standard evaluation frameworks for vaccines. The different results we find for different framings highlight the importance of developing a consistent a priori value framework for vaccine evaluation, rather than evaluating vaccines on an ad hoc basis.

Commentary: Why Has Uptake of Pneumococcal Vaccines for Children Been So Slow? The Perils of Undervaluation

Pediatric pneumococcal disease exacts a substantial burden on global health, much of which is vaccine-preventable. Despite this considerable burden and the demonstrably high efficacy of pneumococcal conjugate vaccines (PCVs), the overall level of PCV uptake remains concerningly low, especially compared with that of other childhood-recommended vaccines, such as tuberculosis and polio. A broad set of plausible explanations exists for this low uptake, including logistical challenges, psychosocial factors and affordability. One additional and systematic cause of low uptake, which is the focus of our discussion, is economists' and policymakers' tendency to undervalue vaccination in general by adopting a narrow health sector perspective when performing economic evaluations of vaccines. We present an alternative, societal framework for economic evaluations that encompasses a broader set of socioeconomic benefits in addition to health benefits. Quantifying a more comprehensive taxonomy of PCV's benefits will help to address potential undervaluation and may be sufficient not only to justify recommendation and reimbursement but also to stimulate efforts and investment toward closing coverage gaps.

Preparedness Through Urban Resilience

This book explores the topic of resilience at the city level. The focus is more on outbreak events at the city level, or how cities should prepare and react in facing the larger events of epidemic and pandemic.

Responding to a Mumps Outbreak Impacting Immigrants and Low-English-Proficiency Populations

OBJECTIVES

To examine outbreak response-associated costs, lessons learned, and challenges encountered during a local health department's response to a mumps outbreak.

DESIGN

We conducted semistructured interviews with individuals directly involved in the response to a mumps outbreak and analyzed outbreak response-associated cost data.

SETTING

In March-July 2018, a mumps outbreak occurred in Chester County, Pennsylvania. The outbreak primarily affected an immigrant community, some of whom spoke little or no English and were uninsured and/or undocumented. This necessitated an urgent response from the Chester County Health Department, which implemented a variety of public health interventions, including outreach to local health care providers and the execution of vaccination clinics at 2 local mushroom farms where case contacts worked. A total of 39 suspected or confirmed mumps cases were reported in Chester County, and 22 suspected or confirmed cases were reported by 2 neighboring jurisdictions.

PARTICIPANTS

Health department employees (n = 7) and community partners (n = 2). Areas of expertise included emergency preparedness, nursing, medicine, disease surveillance, and epidemiology.

MAIN OUTCOME MEASURE

Operational challenges encountered and lessons learned during the mumps outbreak response, including outbreak response-associated costs, which could inform other communities' planning and preparedness for outbreaks in similar populations and improve outbreak response operations.

RESULTS

Immigration status emerged as a key challenge, which highlighted the importance of building trust through community outreach and partnerships and the need for culturally competent communication. In addition, vaccine availability, accessibility, and cost played a major role in response operations and necessitated the involvement of community partners to mitigate these barriers. Outbreak response-associated costs totaled $35 305.

CONCLUSIONS

The challenges that occurred in this outbreak are broadly relevant to outbreaks that affect similar immigrant communities. Health departments that serve such populations can utilize these lessons to develop improved outbreak response plans that account for these challenges.

The effectiveness and limitation of the national childhood hepatitis A vaccination program in the Republic of Korea: Findings from the Korean National Health and Nutrition Examination Survey (KNHANES), 2015

Background

Vaccination for hepatitis A virus (HAV) has been implemented as one of the national vaccination programs despite the epidemiological transition of HAV in the Republic of Korea. While the national HAV vaccination program is largely associated with the shift of socioeconomic trend in the country, concerns have been raised on the effectiveness of the HAV immunization. The objective of this study was to examine the epidemiological trend of HAV and assess the effectiveness of the nationwide HAV vaccination policy based on a nationally representative sample of the Korean population collected in 2015.

Methods

We analyzed anti-HAV of 5,856 respondents aged ≥10 years collected from Korean National Health and Nutrition Examination Survey (KNHANES) data in 2015. We estimated age-adjusted anti-HAV prevalence by sociodemographic and other characteristics. We evaluated the factors associated with anti-HAV positivity among each age group (10–19, 20–29, 30–45 and over 45 years old).

Results

The prevalence of anti-HAV among adults aged ≥10 years was 72.5% (95% confidence interval, CI, 73.7–71.4) in 2015. The lowest age-specific prevalence was among adults aged 20–29 years with 11.9% (95% CI 9.3–15.1%). The prevalence of anti-HAV among those aged 10–14 and 15–19 years was 59.7% (95% CI 52.7–66.4) and 24.0% (95% CI 19.5–29.3), respectively. The prevalence of anti-HAV among adults aged between 30 and 44 years rapidly increased from below 20% to above 90%. The prevalence of anti-HAV among adults aged ≥45 years was 97.8% (95% CI 96.0–97.6). Factors significantly associated with anti-HAV positivity among those aged 10–19 years old were young age, higher house income and high influenza vaccination rate. Compared to the respondents aged 10–19 years (those who were subject to the national childhood vaccine recommendation), those aged 20–29 years (those who were not subject to the recommendation) had low adjusted odds ratio (OR, 0.52 95% CI 0.34–.81 P-value = 0.004) for anti-HAV positivity.

Conclusions

The age-adjusted anti-HAV prevalence showed a U-shaped association, implying the high dependence of anti-HAV prevalence on age and the epidemiological shift. The inclusion of the hepatitis A vaccine into the national immunization recommendation was effective shown by the increase of immunity in the general population. However, the vaccination rate was low in the low-income group. Young adults aged 20–39 years may benefit from inclusion in the HAV vaccination program due to the significantly low vaccination rate.

The economic burden of a Salmonella Thompson outbreak caused by smoked salmon in the Netherlands, 2012-2013

Background

In 2012, the Netherlands experienced the most extensive food-related outbreak of Salmonella ever recorded. It was caused by smoked salmon contaminated with Salmonella Thompson during processing. In total, 1149 cases of salmonellosis were laboratory confirmed and reported to RIVM. Twenty percent of cases was hospitalised and four cases were reported to be fatal. The purpose of this study was to estimate total costs of the Salmonella Thompson outbreak.

Methods

Data from a case-control study were used to estimate the cost-of-illness of reported cases (i.e. healthcare costs, patient costs and production losses). Outbreak control costs were estimated based on interviews with staff from health authorities. Using the Dutch foodborne disease burden and cost-of-illness model, we estimated the number of underestimated cases and the associated cost-of-illness.

Results

The estimated number of cases, including reported and underestimated cases was 21 123. Adjusted for underestimation, the total cost-of-illness would be €6.8 million (95% CI €2.5-€16.7 million) with productivity losses being the main cost driver. Adding outbreak control costs, the total outbreak costs are estimated at €7.5 million.

Conclusion

In the Netherlands, measures are taken to reduce salmonella concentrations in food, but detection of contamination during food processing remains difficult. As shown, Salmonella outbreaks have the potential for a relatively high disease and economic burden for society. Early warning and close cooperation between the industry, health authorities and laboratories is essential for rapid detection, control of outbreaks, and to reduce disease and economic burden.

Seroprevalence and susceptibility to hepatitis A in the European Union and European Economic Area: a systematic review

Most of the European Union (EU) and European Economic Area (EEA) is considered a region of very low hepatitis A virus (HAV) endemicity; however, geographical differences exist. We did a systematic review with the aim of describing seroprevalence and susceptibility in the general population or special groups in the EU and EEA. We searched databases and public health national institutes websites for HAV seroprevalence records published between Jan 1, 1975, and June 30, 2014, with no language restrictions. An updated search was done on Aug 10, 2016. We defined seroprevalence profiles (very low, low, and intermediate) as the proportion of the population with age-specific anti-HAV antibodies at age 15 and 30 years, and susceptibility profiles (low, moderate, high, and very high) as the proportion of susceptible individuals at age 30 and 50 years. We included 228 studies from 28 of 31 EU and EEA countries. For the period 2000-14, 24 countries had a very low seroprevalence profile, compared with five in 1975-89. The susceptibility among adults ranged between low and very high and had a geographical gradient, with three countries in the low susceptibility category. Since 1975, EU and EEA countries have shown decreasing seropositivity; however, considerable regional variability exists. The main limitations of this study are that the studies retrieved for analysis might not be representative of all EU and EEA publications about HAV and might have poor national representativeness. A large proportion of EU and EEA residents are now susceptible to HAV infection. Our Review supports the need to reconsider specific prevention and control measures, to further decrease HAV circulation while providing protection against the infection in the EU and EEA, and could be used to inform susceptible travellers visiting EU and EEA countries with different HAV endemicity levels.

Cost-effectiveness of hepatitis A vaccination in Indonesia

OBJECTIVE

This study aims to assess the cost-effectiveness of hepatitis A immunization in Indonesia, including an explicit comparison between one-dose and two-dose vaccines.

METHODS

An age-structured cohort model based on a decision tree was developed for the 2012 Indonesia birth cohort. Using the model, we made a comparison on the use of two-dose and one-dose vaccines. The model involved a 70-year time horizon with 1-month cycles for children less than 2 years old and annually thereafter. Monte Carlo simulations were used to examine the economic acceptability and affordability of the hepatitis A vaccination.

RESULTS

Vaccination would save US$ 3,795,148 and US$ 2,892,920 from the societal perspective, for the two-dose and one-dose vaccine schedules, respectively, in the context of hepatitis A treatment. It also would save 8917 and 6614 discounted quality-adjusted-life-years (QALYs), respectively. With the vaccine price of US$ 3.21 per dose, the implementation of single dose vaccine would yield an incremental cost-effectiveness ratio (ICER) of US$ 4933 per QALY gained versus no vaccination, whereas the two-dose versus one-dose schedule would cost US$ 14 568 per QALY gained. Considering the 2012 gross-domestic-product (GDP) per capita in Indonesia of US$ 3557, the results indicate that hepatitis A vaccination would be a cost-effective intervention, both for the two-dose and one-dose vaccine schedules in isolation, but two-dose vaccination would no longer be cost-effective if one-dose vaccination is a feasible option. Vaccination would be 100% affordable at budgets of US$ 71,408 000 and US$ 37,690,000 for the implementation of the two-dose and one-dose vaccine schedules, respectively.

CONCLUSIONS

The implementation of hepatitis A vaccination in Indonesia would be a cost-effective health intervention under the market vaccine price. Given the budget limitations, the use of a one-dose-vaccine schedule would be more realistic to be applied than a two-dose schedule. The vaccine price, mortality rate and discount rate were the most influential parameters impacting the ICERs.

Public Health Impact and Cost-Effectiveness of Hepatitis A Vaccination in the United States: A Disease Transmission Dynamic Modeling Approach

OBJECTIVE

To assess the population-level impact and cost-effectiveness of hepatitis A vaccination programs in the United States.

METHODS

We developed an age-structured population model of hepatitis A transmission dynamics to evaluate two policies of administering a two-dose hepatitis A vaccine to children aged 12 to 18 months: 1) universal routine vaccination as recommended by the Advisory Committee on Immunization Practices in 2006 and 2) Advisory Committee on Immunization Practices's previous regional policy of routine vaccination of children living in states with high hepatitis A incidence. Inputs were obtained from the published literature, public sources, and clinical trial data. The model was fitted to hepatitis A seroprevalence (National Health and Nutrition Examination Survey II and III) and reported incidence from the National Notifiable Diseases Surveillance System (1980-1995). We used a societal perspective and projected costs (in 2013 US $), quality-adjusted life-years, incremental cost-effectiveness ratio, and other outcomes over the period 2006 to 2106.

RESULTS

On average, universal routine hepatitis A vaccination prevented 259,776 additional infections, 167,094 outpatient visits, 4781 hospitalizations, and 228 deaths annually. Compared with the regional vaccination policy, universal routine hepatitis A vaccination was cost saving. In scenario analysis, universal vaccination prevented 94,957 infections, 46,179 outpatient visits, 1286 hospitalizations, and 15 deaths annually and had an incremental cost-effectiveness ratio of $21,223/quality-adjusted life-year when herd protection was ignored.

CONCLUSIONS

Our model predicted that universal childhood hepatitis A vaccination led to significant reductions in hepatitis A mortality and morbidity. Consequently, universal vaccination was cost saving compared with a regional vaccination policy. Herd protection effects of hepatitis A vaccination programs had a significant impact on hepatitis A mortality, morbidity, and cost-effectiveness ratios.

Hepatitis A virus in the Middle East and North Africa region: a new challenge

During the past three decades, a gradual shift in the age of infection with hepatitis A virus (HAV) from early childhood to adulthood has been observed. There is a general lack of updated data on HAV burden of disease, incidence and age-specific seroprevalence in countries of the Middle East and North Africa (MENA) region. The aim of this article is to review the published data on anti-HAV seroprevalence, an important tool to monitor infections rates, in countries of the MENA region and associated risk factors including water and socioeconomic data when available. Data on anti-HAV seroprevalence were found for 12 of 25 MENA countries. We show that MENA countries, similar to other areas in the world, have a clear shift in HAV incidence with a decline among young age groups and an increase among adults and older individuals. This would likely be associated with increased morbidity and increased risks of outbreaks among younger age groups. Consequently, the continuous surveillance of hepatitis A cases and the inclusion of hepatitis A vaccine in the expanded immunization programmes are needed in countries of the MENA.

Case report of a transfusion-associated hepatitis A infection

BACKGROUND

Documented transfusion-associated hepatitis A (TAHA) is rare, and blood donors in the United States are not routinely screened for this infection. We report a case of TAHA associated with a donation made 8 days after a donor returned from a trip to South America.

STUDY DESIGN AND METHODS

This is a review of donor and recipient records and a review of the literature.

RESULTS

A donor developed symptoms of hepatitis 20 days after donation (28 days after returning from South America). The donor reported the illness 56 days after donation when contacted to schedule another visit. By this time, the red blood cell and frozen plasma components had been transfused. The recipient of the plasma, a 15-month-old female, tested positive for immunoglobulin M antibody to hepatitis A virus 43 days after transfusion. The recipient had displayed mild, nonspecific symptoms approximately 2 weeks after transfusion. Hospital infection control investigated the potential for further spread within the hospital because the recipient had been an inpatient for most of the posttransfusion period. The risk of transmission to other patients was determined to be negligible because the patient had been in isolation for other reasons. Family members, who included a health care professional, were counseled and offered prophylaxis.

CONCLUSION

TAHA may be underrecognized. This case was identified only because of a donor report at the time of recruitment. Asymptomatic donor viremia has been documented in plasma donors. Although TAHA rarely results in severe disease, the risk it creates of secondary transmission especially within the hospital setting is not inconsequential.

Hepatitis A immunity in the District of Aveiro (Portugal): an eleven-year surveillance study (2002-2012)

Hepatitis A is a common viral liver disease and brings serious health and economic problems as its epidemiologic pattern changes over time. National serosurveys from developed countries have indicated a decline in HAV (hepatitis A virus) seroprevalence over time due to the improvement of economic and sanitation levels. The hepatitis A virus (HAV) immunity rate was surveyed throughout an eleven-year period by sex and age group in Aveiro District. In this retrospective study, blood samples from patients of Aveiro District, in ambulatory regime, collected at the Clinical Analysis Laboratory Avelab between 2002 and 2012 were screened for the presence of antibodies against HAV antigen using a chemiluminescence immunoassay. The global immunity (positive total anti-HAV) was 60% and only 0.3% of the patients presented recent infection by HAV (positive IgM anti-HAV). The HAV immunity was age-dependent (p < 0.05), but no significant differences (p > 0.05) between sexes were observed. The immunity was similar throughout the study period (p > 0.05). The results of this study indicate that young people (especially under 25 years old) from District of Aveiro are susceptible to HAV infection, constituting a high risk group. The elderly should be also a concern in the future of Hepatitis A infection.

Economic consequences of the vaccination against hepatitis A in the Bulgarian healthcare setting

The purpose of the present analysis is to calculate and compare the costs and results of the implication of the inactivated vaccine against hepatitis A virus (HAV) in the Bulgarian healthcare setting in the period of 2002-2012. A combined pharmacoeconomic and epidemiological study was performed on the basis of the prevalence of hepatitis A infection in this 10-year period. The investments in the vaccination were considered as costs and the avoided costs in the case of vaccination of all one-year old children in the population - as benefits. The results show that the vaccination of one-year-old children would be cost effective to the healthcare system in the years with an epidemiologic outbreak, as in these years the total cost of treatment of patients with hepatitis A infection exceeds the cost for vaccination of the whole one-year-old cohort. The critical threshold is 4600 infected patients per year that equalize the benefits to costs. The inclusion of HAV vaccine in the National Immunization Calendar would be cost effective for the healthcare system when the vaccination is performed in certain risk groups and could help to decrease the circulation of the virus in the general population.

Economic evaluations of hepatitis A vaccination in middle-income countries

Economic evaluations of hepatitis A vaccination are important to assist national and international policy makers in different jurisdictions on making effective decisions. Up to now, a comprehensive review of the potential health and economic benefits on hepatitis A vaccination in middle-income countries (MICs) has not been performed yet. In this study, we reviewed the literature on the cost-effectiveness of hepatitis A vaccination in MICs. Most of the studies confirmed that hepatitis A vaccination was cost effective or even cost saving under certain conditions. We found that vaccine price, medical costs, incidence and discount rate were the most influential parameters on the sensitivity analyses. Vaccine price has been shown as a barrier for MICs in implementing universal vaccination of hepatitis A. Given their relatively limited financial resources, implementation of single-dose vaccination could be considered. Despite our findings, we argue that further economic evaluations in MICs are still required in the near future.

Declining prevalence of hepatitis A virus antibodies among children from low socioeconomic groups reinforces the need for the implementation of hepatitis A vaccination in Brazil

Age-related seroprevalence studies that have been conducted in Brazil have indicated a transition from a high to a medium endemicity of hepatitis A virus (HAV) infection in the population. However, most of these studies have focused on urban populations that experience lower incidence rates of HAV infection. In the current study, the prevalence of anti-HAV antibodies was investigated in children with a low socioeconomic status (SES) that live on the periphery of three capital cities in Brazil. A total of 1,162 dried blood spot samples were collected from individuals whose ages ranged from one-18 years and tested for anti-HAV antibodies. A large number of children under five years old (74.1-90%) were identified to be susceptible to HAV infection. The anti-HAV antibody prevalence reached ≥ 50% among those that were 10-14 years of age or older. The anti-HAV prevalence rates observed were characteristics of regions with intermediate level of hepatitis A endemicity. These data indicated that a large proportion of children with a low SES that live at the periphery of urban cities might be at risk of contracting an HAV infection. The hepatitis A vaccine that is currently offered in Brazil is only available for high-risk groups or at private clinics and is unaffordable for individuals with a lower SES. The results from this study suggest that the hepatitis A vaccine should be included in the Brazilian National Program for Immunisation.

The burden of liver disease in Europe: a review of available epidemiological data

To survey the burden of liver disease in Europe and its causes 260 epidemiological studies published in the last five years were reviewed. The incidence and prevalence of cirrhosis and primary liver cancer are key to understand the burden of liver disease. They represent the end-stage of liver pathology and thus are indicative of the associated mortality. About 0.1% of Hungarian males will die of cirrhosis every year compared with 0.001% of Greek females. WHO estimate that liver cancer is responsible for around 47,000 deaths per year in the EU. Harmful alcohol consumption, viral hepatitis B and C and metabolic syndromes related to overweight and obesity are the leading causes of cirrhosis and primary liver cancer in Europe. Chronic hepatitis B affects 0.5-0.7% of the European population. In the last decade the prevalence of chronic hepatitis C was 0.13-3.26%. It is of great concern that about 90% of people in Europe infected by viral hepatitis are unaware of their status. Available data suggest the prevalence rate of NAFLD is 2-44% in the general European population (including obese children) and 42.6-69.5% in people with type 2 diabetes. Each of these four major causes of liver disease is amenable to prevention and treatment, reducing the burden of liver disease in Europe and saving lives. Further surveys are urgently needed to implement cost-effective prevention programmes and novel treatments to tackle this problem.

Mutual Moral Obligations in the Prevention of Infectious Diseases

Not so long ago health policy was about little more than the provision of medical care. The availability of treatment is important for those in need of cure, but by now it is a well-shown fact that health is generally determined to a much greater extent by other factors. Genetic constitution, lifestyle choices and socio-economic environment largely explain why some of us become ill or die earlier than others who remain healthy (Mackenbach 1996; McKeown 1976; Wilkinson and Marmot 2003). While some of these factors fall under the control of an individual, the majority does not. Research increasingly indicates how remarkably sensitive our health seems to be to what has become known as the ‘social determinants of health’. These factors generally fall beyond the control of an individual, but can nonetheless be influenced on a population level. This causes a shift in the focus of health policy from the classic provision of health care to policies specifically designed to influence the causal factors of ill-health in different non-medical fields. The flipside of that evolution is a significant increase of the state’s influence in the sphere of individual lives. A pertinent question remains the one that asks for the legitimate role of governments in modifying, discouraging or prohibiting behaviors that lead to ill-health. To what extent can and should we hold public policy responsible for us leading a healthy life? Most scholars will argue that governments indeed have a role to play, but that the limits will be reached when public health measures would imply large sacrifices of individual liberty.

Use of PCR for detection of faecal HAV as a screening tool in an outbreak of hepatitis A in daycare centres

Using polymerase chain reaction (PCR) to detect faecal hepatitis A virus (HAV) can be a useful tool for investigating HAV outbreaks, especially in low-endemic countries. We describe the use of faecal HAV PCR as a non-invasive tool for screening. Two Dutch children visiting different daycare centres were diagnosed with hepatitis A in 2011. A systematic contact investigation was started in the daycare centres and relevant contacts were screened. The faecal HAV PCR test was used to screen the children. The employees were screened with a serum IgM. The faecal HAV PCR test proved to be an appropriate tool for screening. The screening of a total of 135 children and employees in the daycare centres resulted in evidence of eight asymptomatic infections and transmission to three related daycare centres. Control measures were taken including immunization. Compared to an epidemiological investigation without screening, 144 extra contacts were vaccinated based on the screening results. This most likely led to improved prevention of expansion of the outbreak.

Rapid increase in the national treatment costs for hepatitis A infections in Korea

The number of symptomatic hepatitis A cases has progressively been increasing during the last several years in Korea. Available cost estimates indicate a growing burden to the public. The purpose of this study was to determine the extent of treatment costs for patients with hepatitis A and to analyze the influential factors with nationwide data. We collected data on 72,921 patients with hepatitis A from 5-year National Health Insurance claim archives between 2004 and 2008. Multiple regression analyses were conducted to examine influential factors affecting treatment costs for hepatitis A. Total treatment costs for patients with hepatitis A during the 5-year period were US$47,902,087 and increased significantly each year. In total, 91.4% of treatment costs were used for hospitalization, and the proportion of inpatients increased gradually throughout the study period. The most influential factor on treatment costs was treatment duration. Our results show that the soaring number of patients with hepatitis A followed by the hospitalization-focused treatment practice is a major factor associated with the rapid increase in treatment costs. Appropriate policies should be promptly developed to control treatment costs and economic burden of hepatitis A infections.

Epidemiological changes in hepatitis A in Korea: increasing age and its effect on clinical outcomes

Korea has recently experienced an increasing number of acute hepatitis A cases. We investigated the dynamics of hepatitis A and changes in the mean age of patients in a hospital in Seoul, Korea. Mean age increased consistently from 19 years in 1996 to 30 years in 2009 (P < 0·0001). Between two acute hepatitis A outbreaks in 1998–1999 and in 2008–2009, mean age increased from 23 to 30 years (P < 0·001). However, the hepatitis A clinical outcomes were similar between the outbreaks. Duration of hospital stay, creatinine level and prothrombin time did not differ. Throughout the study period, individuals born in the 1970s and 1980s comprised the largest proportion (84%) of patients. As this susceptible generation ages, the mean age of hepatitis A patients in Korea will increase consistently. However, at present, the impact of increasing age on clinical outcomes is not apparent.

Factors associated to duration of hepatitis a outbreaks: implications for control

Even though hepatitis A mass vaccination effectiveness is high, outbreaks continue to occur. The aim of this study was to investigate the association between duration and characteristics of hepatitis A outbreaks. Hepatitis A (HA) outbreaks reported between 1991 and 2007 were studied. An outbreak was defined as ≥2 epidemiologically-linked cases with ≥1 case laboratory-confirmed by detection of HA immunoglobulin M (IgM) antibodies. Relationships between explanatory variables and outbreak duration were assessed by logistic regression. During the study period, 268 outbreaks (rate 2.45 per million persons-year) and 1396 cases (rate 1.28 per 10(5) persons-year) were reported. Factors associated with shorter duration were time to intervention (OR = 0.96; 95% CI: 0.94-0.98) and school setting (OR = 0.39; 95% CI: 0.16-0.92). In person-to-person transmission outbreaks only time to intervention was associated with shorter outbreak duration (OR = 0.96; 95% CI: 0.95-0.98). The only variables associated with shorter outbreak duration were early administration of IG or vaccine and a school setting. Timely reporting HA outbreaks was associated with outbreak duration. Making confirmed HA infections statutory reportable for clinical laboratories could diminish outbreak duration.

Searching for the most cost-effective strategy for controlling epidemics spreading on regular and small-world networks

We present a combined epidemiological and economic model for control of diseases spreading on local and small-world networks. The disease is characterized by a pre-symptomatic infectious stage that makes detection and control of cases more difficult. The effectiveness of local (ring-vaccination or culling) and global control strategies is analysed by comparing the net present values of the combined cost of preventive treatment and illness. The optimal strategy is then selected by minimizing the total cost of the epidemic. We show that three main strategies emerge, with treating a large number of individuals (global strategy, GS), treating a small number of individuals in a well-defined neighbourhood of a detected case (local strategy) and allowing the disease to spread unchecked (null strategy, NS). The choice of the optimal strategy is governed mainly by a relative cost of palliative and preventive treatments. If the disease spreads within the well-defined neighbourhood, the local strategy is optimal unless the cost of a single vaccine is much higher than the cost associated with hospitalization. In the latter case, it is most cost-effective to refrain from prevention. Destruction of local correlations, either by long-range (small-world) links or by inclusion of many initial foci, expands the range of costs for which the NS is most cost-effective. The GS emerges for the case when the cost of prevention is much lower than the cost of treatment and there is a substantial non-local component in the disease spread. We also show that local treatment is only desirable if the disease spreads on a small-world network with sufficiently few long-range links; otherwise it is optimal to treat globally. In the mean-field case, there are only two optimal solutions, to treat all if the cost of the vaccine is low and to treat nobody if it is high. The basic reproduction ratio, R(0), does not depend on the rate of responsive treatment in this case and the disease always invades (but might be stopped afterwards). The details of the local control strategy, and in particular the optimal size of the control neighbourhood, are determined by the epidemiology of the disease. The properties of the pathogen might not be known in advance for emerging diseases, but the broad choice of the strategy can be made based on economic analysis only.

Challenges to mapping the health risk of hepatitis A virus infection

Background

World maps are among the most effective ways to convey public health messages such as recommended vaccinations, but creating a useful and valid map requires careful deliberation. The changing epidemiology of hepatitis A virus (HAV) in many world regions heightens the need for up-to-date risk maps. HAV infection is usually asymptomatic in children, so low-income areas with high incidence rates usually have a low burden of disease. In higher-income areas, many adults remain susceptible to the virus and, if infected, often experience severe disease.

Results

Several challenges associated with presenting hepatitis A risk using maps were identified, including the need to decide whether prior infection or continued susceptibility more aptly indicates risk, whether to display incidence or prevalence, how to distinguish between different levels of risk, how to display changes in risk over time, how to present complex information to target audiences, and how to handle missing or obsolete data.

Conclusion

For future maps to be comparable across place and time, we propose the use of the age at midpoint of population susceptibility as a standard indicator for the level of hepatitis A endemicity within a world region. We also call for the creation of an accessible active database for population-based age-specific HAV seroprevalence and incidence studies. Health risk maps for other conditions with rapidly changing epidemiology would benefit from similar strategies.

Antibody persistence and immune memory in healthy adults following vaccination with a two-dose inactivated hepatitis A vaccine: long-term follow-up at 15 years

Long-term persistence of vaccine-induced immune response in adults was assessed annually for 15 years following primary immunization with a two-dose inactivated hepatitis A vaccine. In 1992, 119 and 194 subjects aged 17-40 years and naïve for hepatitis A virus (HAV) were enrolled in two studies to receive 1,440 ELISA units (El.U) of inactivated hepatitis A vaccine (Havrix™, GlaxoSmithKline Biologicals, Belgium) according to a standard 0, 6 or an extended 0, 12 months schedule, respectively. Serum samples were taken 1 month after the second vaccine dose and every consecutive year up to 15 years after primary vaccination for measurement of anti-HAV antibody concentrations (NCT00291876 and NCT00289757). At year 15, 100% (48/48) and 97.3% (108/111) of subjects vaccinated at 0, 6 or 0, 12 months remained seropositive for anti-HAV antibodies, with geometric mean concentrations (GMCs) of 289.2 and 367.4 mIU/ml, respectively. An additional dose of HAV vaccine (1,440 El.U) was administered to the six subjects who had become seronegative for anti-HAV antibodies since year 11. All subjects mounted a humoral immune response to the additional HAV challenge dose, although post-challenge anti-HAV antibody levels remained low in one subject. These studies represent the longest annual follow-up of hepatitis A vaccine in healthy adults. The immune response induced by two doses of this inactivated HAV vaccine was shown to persist for at least 15 years. No difference in long-term antibody persistence was observed between the two primary vaccination schedules, reinforcing the potential for flexibility in the timing of the second primary vaccine dose.

An outbreak of hepatitis A among primary and secondary contacts of an international adoptee

The Advisory Committee on Immunization Practices recommends that susceptible people traveling to developing countries receive hepatitis A vaccine or immune globulin prior to departure. Until 2009, the recommendations did not address non-traveling family members or other close contacts of international adoptees. We report an outbreak of hepatitis A in 2008 that occurred in Maine. Eight members of an extended family developed hepatitis A following the arrival of an asymptomatic infant from Ethiopia who was brought to the United States by an adoption agency. Two children in the family attended an elementary school where five additional cases of hepatitis A were subsequently identified. Only three (1%) of 208 students at the school had previously been immunized against hepatitis A. This outbreak highlights the need to immunize household members and other close contacts of families adopting children from countries where hepatitis A is endemic, as well as all children at one year of age.

Cost and disease burden of dengue in Cambodia

Background

Dengue is endemic in Cambodia (pop. estimates 14.4 million), a country with poor health and economic indicators. Disease burden estimates help decision makers in setting priorities. Using recent estimates of dengue incidence in Cambodia, we estimated the cost of dengue and its burden using disability adjusted life years (DALYs).

Methods

Recent population-based cohort data were used to calculate direct and productive costs, and DALYs. Health seeking behaviors were taken into account in cost estimates. Specific age group incidence estimates were used in DALYs calculation.

Results

The mean cost per dengue case varied from US$36 - $75 over 2006-2008 respectively, resulting in an overall annual cost from US$3,327,284 in 2008 to US$14,429,513 during a large epidemic in 2007. Patients sustain the highest share of costs by paying an average of 78% of total costs and 63% of direct medical costs. DALY rates per 100,000 individuals ranged from 24.3 to 100.6 in 2007-2008 with 80% on average due to premature mortality.

Conclusion

Our analysis confirmed the high societal and individual family burden of dengue. Total costs represented between 0.03 and 0.17% of Gross Domestic Product. Health seeking behavior has a major impact on costs. The more accurate estimate used in this study will better allow decision makers to account for dengue costs particularly among the poor when balancing the benefits of introducing a potentially effective dengue vaccine.

Hepatitis A virus seroprevalence by age and world region, 1990 and 2005

OBJECTIVE

To estimate current age-specific rates of immunity to hepatitis A virus (HAV) in world regions by conducting a systematic review and meta-analysis of published data. The estimation of the global burden of hepatitis A and policies for public health control are dependent on an understanding of the changing epidemiology of this viral infection.

METHODS

Age-specific IgG anti-HAV seroprevalence data from more than 500 published articles were pooled and used to fit estimated age-seroprevalence curves in 1990 and 2005 for each of 21 world regions (as defined by the Global Burden of Disease 2010 Study).

FINDINGS

High-income regions (Western Europe, Australia, New Zealand, Canada, the United States, Japan, the Republic of Korea, and Singapore) have very low HAV endemicity levels and a high proportion of susceptible adults, low-income regions (sub-Saharan Africa and parts of South Asia) have high endemicity levels and almost no susceptible adolescents and adults, and most middle-income regions have a mix of intermediate and low endemicity levels.

CONCLUSION

Anti-HAV prevalence estimates in this analysis suggest that middle-income regions in Asia, Latin America, Eastern Europe, and the Middle East currently have an intermediate or low level of endemicity. The countries in these regions may have an increasing burden of disease from hepatitis A, and may benefit from new or expanded vaccination programs.

Control of hepatitis A by universal vaccination of children and adolescents: an achieved goal or a deferred appointment?

Temporal trends of Hepatitis A cases and vaccination coverage data against Hepatitis A Virus have been investigated to analyse the impact of the universal routine vaccination strategy more than 10 years from its introduction in Puglia (region of Southern Italy). The basic reproductive number (R(0)) before vaccination introduction and the effective reproductive number (R(e)) after introduction have been calculated. A progressive decrease in incidence has been recorded in Puglia during last 10 years. Vaccination coverage is actually 64.8% (95% CI: 52.7-76.9%) for children aged 12-24 months and of 67.6% (95% CI: 58.4-76.8%) for 12-year-old adolescents. R(0) estimated in 1996 was 2.01; actually R(e) is 0.651. Theoretical age at infection is 31.82 years. Universal routine vaccination aimed at the control of direct transmission remains the milestone in the strategy for the containment of the disease in settings at an intermediate level of endemicity.