Thrombophilia in childhood: to test or not to test

Inherited thrombophilia is defined as a genetically determined tendency to develop venous thromboembolism. In children, inherited thrombophilia contributes to the development of pediatric thromboembolic disease. As a consequence, pediatric hematologists are increasingly requested to test thrombophilia in pediatric patients with thrombosis or asymptomatic children from thrombophilic families. This article reviews the benefits and limitations of testing for thrombophilic disorders, for example, factor V Leiden, prothrombin mutation, and deficiencies of antithrombin, protein C, or protein S in childhood.     

To test or not to test — To treat or not to treat

The inability to consider explicitly factors that should enter into clinical judgment compromises physician efforts to make cost-effective decisions regarding diagnostic testing and treatment. The authors describe the decision-threshold approach, a decision-analysis strategy that helps physicians identify an optimal test-treatment decision based upon the prior probability of disease, the characteristics of the test (sensitivity, specificity, risk), and the benefits/costs of treatment. They also present a microcomputer graphics program that makes the decision-threshold approach readily available to physicians.     

To test or not to test: psychosocial barriers to HIV testing in high-income countries

To contribute to the evidence-based understanding of the psychosocial factors that influence individuals' uptake of testing for HIV, we assessed and synthesized the pertinent published literature in the fields of public health, behavioural medicine, and (health) psychology. Although the evidence base appears too limited to allow firm conclusions and definition on psychological barriers to HIV testing in high-income countries, we identified convergent themes from the available studies. Testing for HIV seems to be more likely when individuals perceive that they have been at risk, though this association is not perfectly observed. Fear of the consequences of testing positive –mainly worries related to discrimination and rejection – also hinders HIV testing. Finally, individuals appear more likely to test for HIV when they perceive more benefits from testing. The perspective of targeted individuals, in particular the social connotations and consequences of HIV diagnoses, is crucial to understand testing decisions.     

Varicella vaccination in Australia and New Zealand

Varicella-zoster virus has been responsible for a significant disease burden, including hospitalizations and deaths in Australia and New Zealand. Varicella vaccine has been available in Australia since 1999 and, since November 2005, has been funded under the National Immunisation Program for use in all children as a single dose at 18 months of age and in a school-based catch-up program at 10-13 years of age. Recent hospitalization data from Australia show a decline in varicella hospitalizations in children 1-4 years of age, most likely related to vaccination. In New Zealand, varicella vaccine has been available since 1999 but is currently not recommended or funded on the New Zealand national immunization schedule. The anticipated licensure of combination measles-mumps-rubella-varicella vaccines in both countries may lead to future schedule changes.     

Varicella vaccine effectiveness in the US vaccination program: a review

Varicella vaccine (Varivax, Merck) has been available in the United States since 1995. We reviewed published results of postlicensure studies of vaccine effectiveness. Among 19 studies, 17 reported on the effectiveness of vaccine received before exposure, and 2 reported on effectiveness after exposure. Studies used retrospective and prospective cohort, case-control, and secondary attack rate (household contact) designs. The majority of estimates assessed protection against clinically diagnosed varicella. One dose of varicella vaccine was 84.5% effective (median; range, 44%-100%) in preventing all varicella and 100% effective (mean and median) in preventing severe varicella. When administered after exposure, varicella vaccine was highly effective in preventing or modifying varicella. Although 1 dose of varicella vaccine has provided excellent protection, a higher degree of effectiveness is needed in order to interrupt transmission and to prevent outbreaks in settings with high contact rates. Monitoring the effectiveness of the newly recommended 2-dose childhood vaccine schedule for varicella vaccine is a priority.     

Varicella: epidemiological aspects and vaccination coverage in the Veneto Region

Background  

With the control of many infections through national vaccination programmes, varicella is currently the most widespread preventable childhood disease in industrialized nations. In 2005 varicella vaccination was added to the Veneto Region routine immunization schedule for all children at 14 months of age and 12 year-old susceptible adolescents through an active and a free of charge offer. To evaluate parameters at the start of the programme, we conducted a study to describe the epidemiology of varicella infection and coverage rates for varicella vaccine in the Veneto Region (North-East Italy).     

Varicella zoster virus vaccination policies and surveillance strategies in Europe

The incorporation of varicella zoster virus (ZVV) vaccination in childhood immunisation schedules is becoming an increasingly common option in Europe. The current study forms part of the European Sero-Epidemiology Network 2 (ESEN2) organisational analysis for VZV and describes current passive immunisation policies, as well as current and proposed active immunisation strategies, and existing surveillance systems for diseases caused by the varicella zoster virus in ESEN countries. A questionnaire was compiled and distributed to 23 participating countries. A VZV vaccine is currently licensed in 14 of the 20 participating ESEN countries. Germany is the only country to have incorporated VZV vaccination into its routine childhood immunisation programme. Three further countries currently recommend vaccination of children against VZV and five countries are also considering introducing routine immunisation against VZV for children. However, of the eight countries with or considering introducing childhood VZV immunisation, only six have case-based mandatory notification of varicella, and only two countries have primary care surveillance data available for herpes zoster.     

Varicella vaccination in HIV-1-infected children after immune reconstitution

BACKGROUND: HIV-1-infected children have an increased risk of severe chickenpox. However, vaccination is not recommended in severely immunocompromised children. OBJECTIVE: Can the live-attenuated varicella zoster virus (VZV) Oka strain be safely and effectively given to HIV-1-infected children despite previously low CD4 T-cell counts? METHODS: VZV vaccine was administered twice to 15 VZV-seronegative HIV-1-infected children when total lymphocyte counts were greater than 700 lymphocytes/microl, and six HIV-negative VZV-seronegative siblings. Weekly clinical follow-up and sampling were performed. RESULTS: None of the children developed any clinical symptom or serious adverse reaction after immunization. Only nine (60%) of the HIV-1-infected children had VZV-specific antibodies after two immunizations, whereas 100% of the siblings seroconverted. Age at baseline was negatively correlated with the VZV IgG titre at 6 weeks after the second vaccination in HIV-1-infected children. VZV-specific antibody titres after two immunizations were at a similar level to those found after wild-type infection in non-vaccinated HIV-1-infected patients, but significantly lower than in HIV-negative siblings. Importantly, VZV-specific T-cell responses increased after vaccination and were comparable in both groups over time. Documented wild-type VZV contact in three vaccinated patients did not result in breakthrough infections. CONCLUSION: VZV vaccination of previously immunocompromised HIV-1-infected children was safe. Vaccination induced specific immune responses in some of the vaccinated HIV-1-infected children, suggesting that previously immunocompromised individuals are protected against severe forms of varicella.     

Varicella vaccination in Japan, South Korea, and Europe

The most extensive use of varicella vaccine has been in the United States and Canada, where it is universally recommended. However, a number of other countries now have recommendations for use of the vaccine, which has been expanding in Europe and Latin America. In this article, we review information concerning varicella vaccination in Japan, where the vaccine was first developed, and in South Korea and parts of Europe. Despite the worldwide availability of an efficient vaccine, varicella vaccination policy is highly variable from country to country. The recent development of a tetravalent vaccine against measles, mumps, rubella, and varicella could modify this variability in the future. It is evident that efforts to control varicella will spread gradually to all continents.     

Colleagues: to protect or not?

I have presented a basic approach for the clinical gastroenterologist to follow in the event that he is asked by his patient whether or not to sue a fellow practitioner. Although there is a dearth of information in the literature concerning this topic, it is probably more important than generally realized. I conclude that basic honesty is paramount. White lies, equivocation, and obfuscation are discouraged. The importance of restricting the gastroenterologist's opinion to medical matters and avoiding legal determinations and advice is stressed. The dilemma of acting as an expert witness is mentioned. Finally, a few basic elements of the tort of defamation are presented within the context of the discussion.     

Silent ischemia: to treat or not

As worded, the question "Should silent ischemia be treated?" needs to be examined carefully, assuming that silent ischemia is even the correct topic of the question. The way the question is phrased influences the answer. The more the question's permutations are examined, the clearer it becomes that the problem is one of definition. Our conceptualization of the ischemic process is still incomplete, and the question of whether to treat silent ischemia remains. Ultimately, the decision will depend on demonstrable benefit for prognosis. Every acute ischemic syndrome is indicative of poor prognosis, independent of other factors associated with adverse outcome and of the method of measurement. The true determinant of the need to treat is the total ischemic pattern, and how silent ischemia and angina fit within that context is not yet known.     

Varicella epidemiology and cost-effectiveness analysis of universal varicella vaccination program in Taiwan

Varicella zoster virus is highly contagious and affects people worldwide. In this study, we collected local epidemiological data and evaluated the cost-effectiveness of varicella vaccination program in Taiwan. To examine the economical consequences of universal vaccination, a model of the incidence and the associated costs in a hypothetical cohort was created each year for 30 years. The incidence increased sharply after the infancy and peaked in children aged 5 years. The hospitalization rate among cases was the highest in infants, followed by adults 30 to 44 years old. The benefit-cost analysis showed that one dollar invested in the program would cost extra 46 cents in direct medical expense, but would save extra 45 cents considering the societal expenses. Substantial economical benefits can occur due to the averted unproductive days for parents. Sensitive surveillance of both varicella and zoster is essential in countries that have implemented or are about to implement varicella vaccination.