Cost-benefit analyses of supplementary measles immunisation in the highly immunized population of New Zealand

Evaluating active leprosy case identification methods in six districts of Nepal

BACKGROUND

Nepal has achieved and sustained the elimination of leprosy as a public health problem since 2009, but 17 districts and 3 provinces with 41% (10,907,128) of Nepal's population have yet to eliminate the disease. Pediatric cases and grade-2 disabilities (G2D) indicate recent transmission and late diagnosis, respectively, which necessitate active and early case detection. This operational research was performed to identify approaches best suited for early case detection, determine community-based leprosy epidemiology, and identify hidden leprosy cases early and respond with prompt treatment.

METHODS

Active case detection was undertaken in two Nepali provinces with the greatest burden of leprosy, Madhesh Province (40% national cases) and Lumbini Province (18%) and at-risk prison populations in Madhesh, Lumbini and Bagmati provinces. Case detection was performed by (1) house-to-house visits among vulnerable populations (n = 26,469); (2) contact examination and tracing (n = 7608); in Madhesh and Lumbini Provinces and, (3) screening prison populations (n = 4428) in Madhesh, Lumbini and Bagmati Provinces of Nepal. Per case direct medical and non-medical costs for each approach were calculated.

RESULTS

New case detection rates were highest for contact tracing (250), followed by house-to-house visits (102) and prison screening (45) per 100,000 population screened. However, the cost per case identified was cheapest for house-to-house visits [Nepalese rupee (NPR) 76,500/case], followed by contact tracing (NPR 90,286/case) and prison screening (NPR 298,300/case). House-to-house and contact tracing case paucibacillary/multibacillary (PB:MB) ratios were 59:41 and 68:32; female/male ratios 63:37 and 57:43; pediatric cases 11% in both approaches; and grade-2 disabilities (G2D) 11% and 5%, respectively. Developing leprosy was not significantly different among household and neighbor contacts [odds ratios (OR) = 1.4, 95% confidence interval (CI): 0.24-5.85] and for contacts of MB versus PB cases (OR = 0.7, 95% CI 0.26-2.0). Attack rates were not significantly different among household contacts of MB cases (0.32%, 95% CI 0.07-0.94%) and PB cases (0.13%, 95% CI 0.03-0.73) (χ2 = 0.07, df = 1, P = 0.9) and neighbor contacts of MB cases (0.23%, 0.1-0.46) and PB cases (0.48%, 0.19-0.98) (χ2 = 0.8, df = 1, P = 0.7). BCG vaccination with scar presence had a significant protective effect against leprosy (OR = 0.42, 0.22-0.81).

CONCLUSIONS

The most effective case identification approach here is contact tracing, followed by house-to-house visits in vulnerable populations and screening in prisons, although house-to-house visits are cheaper. The findings suggest that hidden cases, recent transmission, and late diagnosis in the community exist and highlight the importance of early case detection.

State dependence in immunization and the role of discouragement

We investigate whether having a child immunized at a prior schedule genuinely increases the likelihood of vaccinating the child at the subsequent schedule. We use longitudinal data from the Growing Up in New Zealand study and apply a dynamic random-effects model that also controls for the initial immunization status. Prior to any covariate-adjusted estimations, our data shows that almost 96% of the children immunized at the previous schedule are also immunized at the subsequent schedule. In comparison, only 29% of children who were not immunized at the prior schedule receive immunization at the next milestone, thereby indicating an unadjusted state dependence in immunization of 67 percentage points (p.p.). Upon controlling for relevant covariates and unobserved heterogeneities, the genuine state dependence in immunization is, on average, estimated to be 20 p.p. Importantly, the magnitude of the state dependence is greater for Māori (by 5 p.p.) and also greater for mothers that report being discouraged from having their child immunized during the antenatal period (by 10 p.p.).

Comparing catch-up vaccination programs based on analysis of 2012-13 rubella outbreak in Kawasaki City, Japan

During the 2012–13 rubella outbreak in Japan, local governments implemented subsidy programs for catch-up vaccination to mitigate the rubella outbreak and prevent congenital rubella syndrome (CRS). In most local governments, to prevent CRS, eligible persons of the subsidy program were women who were planning to have a child and men who were partners of pregnant women. On the other hand, in Kawasaki City, unimmunized men aged 23–39 years were additionally included in the eligible persons, because they were included in an unimmunized men group resulting from the historical transition of the national routine vaccination in Japan. The number of rubella cases in the city decreased earlier than that in the whole Japan. First, in order to estimate the effect of the catch-up vaccination campaign in Kawasaki City on the epidemic outcome, we performed numerical simulations with a Susceptible-Vaccinated-Exposed-Infectious-Recovered (SVEIR) model incorporating real data. The result indicated that the catch-up vaccination campaign showed a beneficial impact on the early decay of the rubella cases. Second, we numerically compared several different implementation strategies of catch-up vaccinations under a fixed amount of total vaccinations. As a result, we found that early and intensive vaccinations are vital for significant reduction in the number of rubella cases and CRS occurrences. Our study suggests that mathematical models with epidemiological and social data can contribute to identifying the most effective vaccination strategy.

Vaccine-preventable disease in healthcare workers in Sicily (Italy): seroprevalence against measles

Aim: Measles is one of the most infectious communicable diseases. The objective of this study was to determine the immunity to measles of healthcare workers (HCWs) operating in three hospitals of Catania. Methods: A total of 549 HCWs underwent measles screening. A 5 ml blood sample was taken from each worker to measure IgG antibody levels. Results: Overall seroprotection was 86%. Unvaccinated HCWs agreed to undergo the vaccination offered by the hospital. Furthermore, it was found that younger workers are less seroprotected than older ones. Conclusion: Model legislation may be helpful to countries wishing to implement immunization requirements in healthcare settings in order to virtually eliminate the risk of acquiring and spreading measles in healthcare settings.

Measles vaccination in an increasingly immunized and developed world

Increased measles immunization has led to a significant decline in measles incidence and mortality. During 2016 it is estimated that fewer than 100,000 died from measles for the first time in recorded history. In highly immunized countries measles epidemiology has changed. Threats to national elimination goals and public health include aging cohorts of naïve people that exist from imperfect vaccination rates during the early years of immunization programs. This may be complemented by some loss of immunity in vaccinated populations. While childhood immunization must remain a focus for control efforts, due to higher mortality in the very young, these naïve adolescents and adults also accumulate as they age and add to the pool of susceptible people, perhaps beyond the view of those that are focused on childhood immunization. Here, features of measles epidemiology and control in highly immunized populations are reviewed, providing global data where necessary, to highlight why countries with high immunization coverage are still threatened by measles outbreaks and how changing dynamics may alter disease control.

Cost-benefit analysis of vaccination: a comparative analysis of eight approaches for valuing changes to mortality and morbidity risks

BACKGROUND

There is increasing interest in estimating the broader benefits of public health interventions beyond those captured in traditional cost-utility analyses. Cost-benefit analysis (CBA) in principle offers a way to capture such benefits, but a wide variety of methods have been used to monetise benefits in CBAs.

METHODS

To understand the implications of different CBA approaches for capturing and monetising benefits and their potential impact on public health decision-making, we conducted a CBA of human papillomavirus (HPV) vaccination in the United Kingdom using eight methods for monetising health and economic benefits, valuing productivity loss using either (1) the human capital or (2) the friction cost method, including the value of unpaid work in (3) human capital or (4) friction cost approaches, (5) adjusting for hard-to-fill vacancies in the labour market, (6) using the value of a statistical life, (7) monetising quality-adjusted life years and (8) including both productivity losses and monetised quality-adjusted life years. A previously described transmission dynamic model was used to project the impact of vaccination on cervical cancer outcomes. Probabilistic sensitivity analysis was conducted to capture uncertainty in epidemiologic and economic parameters.

RESULTS

Total benefits of vaccination varied by more than 20-fold (£0.6-12.4 billion) across the approaches. The threshold vaccine cost (maximum vaccine cost at which HPV vaccination has a benefit-to-cost ratio above one) ranged from £69 (95% CI £56-£84) to £1417 (£1291-£1541).

CONCLUSIONS

Applying different approaches to monetise benefits in CBA can lead to widely varying outcomes on public health interventions such as vaccination. Use of CBA to inform priority setting in public health will require greater convergence around appropriate methodology to achieve consistency and comparability across different studies.

Economic evaluations and their use in infection prevention and control: a narrative review

Background

The objective of this review is to provide a comprehensive overview of the different types of economic evaluations that can be utilized by Infection Prevention and Control practitioners with a particular focus on the use of the quality adjusted life year, and its associated challenges. We also highlight existing economic evaluations published within Infection Prevention and Control, research gaps and future directions.

Design

Narrative Review.

Conclusions

To date the majority of economic evaluations within Infection Prevention and Control are considered partial economic evaluations. Acknowledging the challenges, which include variable utilities within infection prevention and control, a lack of randomized controlled trials, and difficulty in modelling infectious diseases in general, future economic evaluation studies should strive to be consistent with published guidelines for economic evaluations. This includes the use of quality adjusted life years. Further research is required to estimate utility scores of relevance within Infection Prevention and Control.

Measles lessons in an anti-vaccination era: public health is a social duty, not a political option

Background

Measles virus, member of the genus Morbillivirus in the family Paramyxoviridae, is a highly contagious human pathogen. An effective live-attenuated vaccine is available and its use has the potential to eradicate the disease from the human population. Although the vaccine was introduced in national vaccination schedules, several measles outbreaks have occurred because of insufficient vaccination coverage. Since early January 2017, a new outbreak of measles in Italy has been observed.

Methods

We analyzed all the patients admitted to the Emergency Department of Bambino Gesù Children Hospital of Rome from the 1st of January 2017 to the end of May 2017 and discharged with diagnosis of suspected or confirmed measles or admitted to the Pediatric and Infectious Disease Unit. For each confirmed case, demographic data, vaccination history, exposure to source case, clinical presentation, date of onset of symptoms, hospitalization, laboratory test results, complications and therapy were collected.

Results

From the 1st of January 2017 to the 31st of May 2017, we enrolled 139 patients who were conducted to the Emergency Department of Bambino Gesù Children’s Hospital because of measles: 33 patients were discharged with the diagnosis of suspected measles by clinical manifestations; 33 discharged with the diagnosis of confirmed measles by laboratory tests and 73 were admitted to the Pediatric and Infectious Disease Unit. Seven patients, who were exposed to mothers with measles, were admitted to receive treatment with Measles Immune Globulin intravenously. Among the 66 patients admitted to the hospital with measles, 31 cases (47%) occurred in unvaccinated individuals who were age-eligible for measles vaccination; 29 (44%) were infants too young to be vaccinated; only five patients (8%) received one dose of measles-containing vaccine.

Out of the 66 patients, 35 (53%) developed complications. Acute respiratory failure was the most reported complications (20%). Death, due to multiorgan failure by measles, occurred in one 9-girl-year-age patient with genetic disorders who was unvaccinated.

Conclusions

Measles still represents a serious public health problem worldwide. Vaccination against measles is safe, effective, and cost-effective.

High vaccination coverage (>95%) with two doses of measles vaccine is crucial to elimination. Health care professionals play an important role in vaccination uptake and prevention of measles spread during an outbreak.