Cost-effectiveness of varicella and herpes zoster vaccination in Sweden: An economic evaluation using a dynamic transmission model.

OBJECTIVES: Comprehensive cost-effectiveness analyses of introducing varicella and/or herpes zoster vaccination in the Swedish national vaccination programme. DESIGN: Cost-effectiveness analyses based on epidemiological results from a specifically developed transmission model. SETTING: National vaccination programme in Sweden, over an 85- or 20-year time horizon depending on the vaccination strategy. PARTICIPANTS: Hypothetical cohorts of people aged 12 months and 65-years at baseline. INTERVENTIONS: Four alternative vaccination strategies; 1, not to vaccinate; 2, varicella vaccination with one dose of the live attenuated vaccine at age 12 months and a second dose at age 18 months; 3, herpes zoster vaccination with one dose of the live attenuated vaccine at 65 years of age; and 4, both vaccine against varicella and herpes zoster with the before-mentioned strategies. MAIN OUTCOME MEASURES: Accumulated cost and quality-adjusted life years (QALY) for each strategy, and incremental cost-effectiveness ratios (ICER). RESULTS: It would be cost-effective to vaccinate against varicella (dominant), but not to vaccinate against herpes zoster (ICER of EUR 200,000), assuming a cost-effectiveness threshold of EUR 50,000 per QALY. The incremental analysis between varicella vaccination only and the combined programme results in a cost per gained QALY of almost EUR 1.6 million. CONCLUSIONS: The results from this study are central components for policy-relevant decision-making, and suggest that it was cost-effective to introduce varicella vaccination in Sweden, whereas herpes zoster vaccination with the live attenuated vaccine for the elderly was not cost-effective-the health effects of the latter vaccination cannot be considered reasonable in relation to its costs. Future observational and surveillance studies are needed to make reasonable predictions on how boosting affects the herpes zoster incidence in the population, and thus the cost-effectiveness of a vaccination programme against varicella. Also, the link between herpes zoster and sequelae need to be studied in more detail to include it suitably in health economic evaluations.

Health Impact and Cost-effectiveness Assessment for the Introduction of Universal Varicella Vaccination in Switzerland.

BACKGROUND: Varicella, caused by the varicella-zoster virus, is a highly contagious infectious disease with substantial health and economic burden to society. Universal varicella vaccination (UVV) is not yet recommended by the Swiss National Immunization Program, which instead recommends catch-up immunization for children, adolescents and adults 11-40 years of age who have no reliable history of varicella or are varicella-zoster virus-IgG seronegative. The objective of this study was to perform an assessment of health impact and cost-effectiveness comparing UVV with current practice and recommendations in Switzerland. METHODS: A dynamic transmission model for varicella was adapted to Switzerland comparing 2 base-case schedules (no infant vaccination and 10% coverage with infant vaccination) to 3 different UVV schedules using quadrivalent (varicella vaccine combined with measles-mumps-rubella) and standalone varicella vaccines administered at different ages. Modeled UVV coverage rates were based on current measles-mumps-rubella coverage of approximately 95% (first dose) and 90% (second dose). Direct medical costs and societal perspectives were considered, with cost and outcomes discounted and calculated over a 50-year time horizon. RESULTS: UVV would reduce the number of varicella cases by 88%-90%, hospitalizations by 62%-69% and deaths by 75%-77%. UVV would increase direct medical costs by Swiss Franc (CHF) 39-49 (US $43-54) per capita and costs from a societal perspective by CHF 32-40 (US $35-44). Incremental quality-adjusted life-years per capita increased by 0.0012-0.0014. Incremental cost-effectiveness ratios for the UVV schedules versus the base-case were CHF 31,194-35,403 (US $34,452-39,100) per quality-adjusted life-year from the direct medical cost perspective and CHF 25,245-29,552 (US $27,881-32,638) from the societal perspective. CONCLUSIONS: UVV appears highly effective and cost-effective when compared with current clinical practice and recommendations in Switzerland from both a direct medical costs perspective and societal perspective.

Cost-effectiveness analysis of universal varicella vaccination in Turkey using a dynamic transmission model.

BACKGROUND: In 2013, Turkey introduced one-dose universal varicella vaccination (UVV) at 12 months of age. Inclusion of a second dose is being considered. METHODS: We developed a dynamic transmission model to evaluate three vaccination strategies: single dose at 12 months (1D) or second dose at either 18 months (2D-short) or 6 years of age (2D-long). Costs and utilization were age-stratified and separated into inpatient and outpatient costs for varicella and herpes zoster (HZ). We ran the model including and excluding HZ-related costs and impact of exogenous boosting. RESULTS: Five years post-introduction of UVV (1D), the projected varicella incidence rate decreases from 1,674 cases pre-vaccine to 80 cases/100,000 person-years. By 25 years, varicella incidence equilibrates at 39, 12, and 16 cases/100,000 person-years for 1D, 2D-short, and 2D-long strategies, respectively, using a highly effective vaccine. With or without including exogenous boosting impact and/or HZ-related costs and health benefits, the 1D strategy is least costly, but 2-dose strategies are cost-effective considering a willingness-to-pay threshold equivalent to the gross domestic product. The model predicted a modest increase in HZ burden during the first 20-30 years, after which time HZ incidence equilibrates at a lower rate than pre-vaccine. CONCLUSIONS: Our findings support adding a second varicella vaccine dose in Turkey, as doing so is highly cost-effective across a wide range of assumptions regarding the burden associated with varicella and HZ disease.

Distribution of Health Effects and Cost-effectiveness of Varicella Vaccination are Shaped by the Impact on Herpes Zoster.

INTRODUCTION: Varicella zoster virus (VZV) is the etiological agent of varicella and herpes zoster (HZ). It has been hypothesised that immune boosting of latently infected persons by contact with varicella reduces the probability of HZ. If true, universal varicella vaccination may increase HZ incidence due to reduced VZV circulation. To inform decision-making, we conduct cost-effectiveness analyses of varicella vaccination, including effects on HZ. METHODS: Effects of varicella vaccination are simulated with a dynamic transmission model, parameterised with Dutch VZV seroprevalence and HZ incidence data, and linked to an economic model. We consider vaccination scenarios that differ by whether or not they include immune boosting, and reactivation of vaccine virus. RESULTS: Varicella incidence decreases after introduction of vaccination, while HZ incidence may increase or decrease depending on whether or not immune boosting is present. Without immune boosting, vaccination is expected to be cost-effective or even cost-saving. With immune boosting, vaccination at 95% coverage is not expected to be cost-effective, and may even cause net health losses. CONCLUSIONS: Cost-effectiveness of varicella vaccination depends strongly on the impact on HZ and the economic time horizon. Our findings reveal ethical dilemmas as varicella vaccination may result in unequal distribution of health effects between generations.

Challenges with controlling varicella in prison settings: experience of California, 2010 to 2011.

This article describes the epidemiology of varicella in one state prison in California during 2010 and 2011, control measures implemented, and associated costs. Eleven varicella cases were reported, of which nine were associated with two outbreaks. One outbreak consisted of three cases and the second consisted of six cases with two generations of spread. Among exposed inmates serologically tested, 98% (643/656) were varicella-zoster virus seropositive. The outbreaks resulted in > 1,000 inmates exposed, 444 staff exposures, and > $160,000 in costs. The authors documented the challenges and costs associated with controlling and managing varicella in a prison setting. A screening policy for evidence of varicella immunity for incoming inmates and staff and vaccination of susceptible persons has the potential to mitigate the impact of future outbreaks and reduce resources necessary to manage cases and outbreaks.

Analysis of occupational infections among health care workers in Limpopo province of South Africa.

OBJECTIVE: Occupational infections particularly hospital-acquired infections (HAIs) are a serious problem in the healthcare industry worldwide. This study purported to investigate their prevalence and risk factors among healthcare workers from Limpopo province of South Africa. METHODS: Cases about occupational infectious diseases of healthcare workers from Limpopo province that were submitted to the Compensation Commissioner from January 2006 to December 2009 were reviewed. RESULTS: The total number of cases of infectious diseases reported during the study period was 56; of these, 83.9% (47) of cases were for tuberculosis, 10.7% (6) for cholera, and 5.4% (3) for chickenpox. Nurses were the most affected. Risk factors associated with the acquisition of infection diseases were as follows. The majority of those infected were female (67.9%), aged over 40 years (57.1%), and who had worked for over 10 years (59.2%). With regard to length of time it took for one to be infected, overall it took 13.6±9.7 years from the year of employment to being infected. This duration was just 5.7±4.2 years in HCWs younger than 40 years versus 18.4±9.0 years in those 40 years and over (p=0.001); and 11.4±10.3 years in nurses versus 17.1±7.8 years in non-professional staff members (p=0.046). Mopani district, situated in a rural setting was the most affected as 24 of the 47 cases of tuberculosis occurred there. CONCLUSION: In conclusion, the most common occupational infection or hospital acquired infection among healthcare workers in Limpopo province of South Africa was tuberculosis. It infected mainly nurses from the rural health district of Mopani. Younger age and being a nurse were significant risk factors associated with being infected early.

The economic value of childhood varicella vaccination in France and Germany.

OBJECTIVE: To determine the economic impact of childhood varicella vaccination in France and Germany. METHODS: A common methodology based on the use of a varicella transmission model was used for the two countries. Cost data (2002 per thousand) were derived from two previous studies. The analysis focused on a routine vaccination program for which three different coverage rates (CRs) were considered (90%, 70%, and 45%). Catch-up strategies were also analyzed. A societal perspective including both direct and indirect costs and a third-party payer perspective were considered (Social Security in France and Sickness Funds in Germany). RESULTS: A routine vaccination program has a clear positive impact on varicella-related morbidity in both countries. With a 90% CR, the number of varicella-related deaths was reduced by 87% in Germany and by 84% in France. In addition, with a CR of 90%, routine varicella vaccination induces savings in both countries from both societal (Germany 61%, France 60%) and third-party payer perspectives (Germany 51%, France 6.7%). For lower CRs, routine vaccination remains cost saving from a third-party payer perspective in Germany but not in France, where it is nevertheless cost-effective (cost per life-year gained of 6521 per thousand in the base case with a 45% CR). CONCLUSION: Considering the impact of vaccination on varicella morbidity and costs, a routine varicella vaccination program appears to be cost saving in Germany and France from both a societal and a third-party payer perspective. For France, routine varicella vaccination remains cost-effective in worst cases when a third-party payer perspective is adopted. Catch-up programs provide additional savings.

Economic evaluation of vaccination programs: the impact of herd-immunity.

The unique characteristic of vaccination is that it not only reduces the incidence of disease in those immunized but also indirectly protects nonvaccinated susceptibles against infection (produces herd-immunity). The bulk of economic evaluations of vaccination programs continue to use models that cannot take into account the indirect effects produced by herd-immunity. Here, the authors illustrate the importance of incorporating herd-immunity externalities when assessing the cost-effectiveness of vaccination progams. To do this, they compare 2 methods of estimating the benefits of routine mass vaccination: one that includes herd-immunity (dynamic approach) and one that does not (static approach). Finally, they use the results to clarify a number of misconceptions that are common in the literature concerning herd-immunity and dynamical effects produced by models.

The burden of uncomplicated cases of chickenpox in Israel.

OBJECTIVE: The aim of this study was to assess the direct medical burden and work loss associated with uncomplicated chickenpox in Israel. METHODS: A total of 155 otherwise healthy children and adolescents with chickenpox were recruited from 10 physician offices in central Israel. Direct and indirect medical burdens were determined by caregiver interview. RESULTS: Mean age was 3.3 +/- 2.3 years. 51% of the patients were under three years of age. Each patient made on average 1.15 visits to a general practitioner. Most patients were taken to the Doctor's office only once during the illness while 23 patients (15%) were seen twice. Three patients were referred to the emergency room. Antihistamines (39%) and Calamine lotion (28%) were the most frequently prescribed medications, followed by acyclovir (17%) and antibiotics (6%). Following the patient's illness there were 72 cases of secondary spread of varicella to household members. The individuals who cared for the child missed a combined total of 2.5 days from work (on average per varicella episode). CONCLUSIONS: Israeli children acquire chickenpox at a younger age than children in North America and England and consume more prescribed medications. While the work loss in the present study was comparable to previous reports, the direct medical costs inflicted by this infection in Israel are not negligible even for uncomplicated cases.

Catapora: uma doença para ser levada a sério / viva Legal

Explica o que é a catapora, uma doença que costuma atacar as crianças, como ela é transmitida e o que fazer para evitá-la. Ensina a reconhecer os sintomas desta doença e quais são as melhores formas de tratamento. Informa também sobre os devidos cuidados que se deve ter quando se é contaminado e o por que a catapora é contraída uma única vez

Clinical and economic considerations of vaccination against varicella.

We evaluated the medical and economic literature pertaining to varicella vaccine in healthy children in an effort to provide perspective for both clinicians and those responsible for making payment policies. Chickenpox is relatively mild in most immunocompetent children; however, disease-related direct and indirect medical costs have been estimated at approximately $400 million/year. A vaccine effective in preventing the disease is now available in the United States and may offset some of these expected costs. Universal vaccination for patients older than 12 months of age without history of varicella infection or other contraindication is recommended by the American Academy of Pediatrics. It is estimated that it would save $0.90/dollar spent and $5.40/dollar spent from payers' and society's perspectives, respectively. Thus varicella vaccination is cost-beneficial only when considered from a societal perspective.

Prevention of varicella: Recommendations of the Advisory Committee on Immunization Practices (ACIP). Centers for Disease Control and Prevention.

These recommendations represent the first statement by the Advisory Committee on Immunization Practices (ACIP) on the use of live, attenuated varicella virus vaccine--VARIVAX--manufactured by Merck and Company, Inc. and licensed in March 1995 for use in healthy persons > or = 12 months of age. In addition to presenting information regarding vaccine, this statement updates previous recommendations concerning the use of varicella zoster immune globulin (VZIG) as prophylaxis against varicella (MMWR 1984; 33:84-90, 95-100).

Assessment of a school exclusion policy during a chickenpox outbreak.

Two Ohio schools experienced an outbreak of over 200 cases of chickenpox during the period from October 5 to December 21, 1988, despite adherence to the 1986 American Academy of Pediatrics' recommendation that children be excluded from school for 1 week or until all lesions have crusted. In grades kindergarten through four, the attack rate for susceptibles was 51% (167/329). With the use of person-time analysis, classmates of a child with chickenpox in grades kindergarten through four were 3.6 times more likely to become a case 12-17 days (the range of one incubation period) after the last day the child with subsequent chickenpox was in class than at any other time during the 2.5-month study period (95% confidence interval (Cl) 2.4-5.4). This was even more pronounced during the first half of the outbreak (relative risk (RR), 10.8; 95% Cl 4.4-26.5). Cases were not more likely to aggregate 12-17 days after a child returned to school after having chickenpox (RR, 0.9; 95% Cl 0.5-1.5). No cases occurred in classmates 12-17 days after the 15 children absent less than 5 days returned to class. Because substantial chickenpox transmission may occur before rash onset, exclusion practices may have a limited effect on outbreak control and increase the indirect costs associated with chickenpox.

Impact and costs of varicella prevention in a university hospital.

Information regarding all patient and staff exposures to varicella-zoster virus (VZV) was prospectively accumulated from 1/1/86 to 12/31/86 at North Carolina Memorial Hospital. During this period of time 37 sources of exposure to VZV were reported: 10 outside and 27 within the hospital. Index cases for nosocomial exposure included: 12 patients with zoster, 9 patients with varicella, two staff with varicella, three visitors with varicella, and one staff with zoster. One hundred and twenty patients received nosocomial exposures; 28 had no history of VZV infection (23 per cent), of whom 11 were serosusceptible (39 per cent). Sources of nosocomial patient exposure included: other patients (85 per cent), staff (14 per cent), and a single visitor (1 per cent). More than 300 employees received nosocomial exposure; 158 had no history of VZV infection, of whom 49 were serosusceptible (31 per cent). Only a single employee and no patients developed clinical varicella as a result of nosocomial exposure. Costs associated with VZV control during 1986 totaled $55,934: $39,658 for work furloughs, $9,800 for serologies, $4,293 for patient isolation, $155 for varicella-zoster immune globulin, and $2,028 for infection control personnel time. These costs should be considered as part of any benefit-cost analysis of varicella immunization of health care personnel.

Hospital experience with varicella-zoster virus.

Varicella-zoster virus (VZV), one of the most common highly communicable agents of disease, stimulates aggressive infection control measures. In a 1-year period, at one hospital, at least 93 inpatients (82 adult patients, 11 pediatric patients) and 2 hospital staff with active varicella-zoster infections served as potential sources of nosocomial infection. Six incidents of exposure to the virus that occurred without the protection of standard infection control precautions were investigated by the infection control surveillance team. One hundred fifty-six patients and 353 hospital staff were exposed. Fifty-one patients had no history of varicella-zoster infection, but only five were susceptible by serologic testing. One hundred one staff members had no history of varicella-zoster, but only 11 were susceptible by serologic testing. These exposures resulted in three secondary varicella-zoster infections, six courses of varicella-zoster immune globulin prophylaxis and furlough of 13 staff members. Epidemiologic investigation consumed approximately 356 hours of staff time, and management of exposed persons cost approximately $41,500. Prospective knowledge of the immune status of health care workers would vastly decrease the time and effort required to control hospital VZV exposures.

Herpes zoster causing varicella (chickenpox) in hospital employees: cost of a casual attitude.

Varicella is a benign exanthematous disease of childhood, with adult infection usually occurring in the immunocompromised patient. Hospital employees may be exposed to the varicella virus through contact with patients having either varicella or herpes zoster. Two nurses developed varicella 11 and 15 days after contact with a patient with disseminated herpes zoster. Twenty-five susceptible employees were excluded from work. The cost to the hospital for this paid leave was $10,941. Additional nurses were hired to staff the 189 uncovered supplementary nursing shifts; the accrued cost was $8,093. Ninety patients were exposed. There were no secondary cases in either employees or patients. Nosocomial varicella in hospital employees can be both costly to the hospital and disruptive of patient care. Measures to prevent such an occurrence are discussed.