Tick-borne encephalitis in patients vaccinated against this disease.

BACKGROUND: Information on tick-borne encephalitis (TBE) in patients already vaccinated against the disease is limited. OBJECTIVES: To compare the course and outcome in patients with vaccination breakthrough TBE with findings in patients who developed TBE without previous vaccination. METHODS: All adult patients diagnosed with TBE at a single medical centre during a 16-year period and who had received at least two doses of TBE vaccine before the onset of illness qualified for the study. For each patient with breakthrough TBE, two unvaccinated sex- and age-matched patients, diagnosed with TBE in the same year, were included for comparison. RESULTS: Amongst 2332 patients diagnosed with TBE in the period 2000-2015, 39 (1.7%) had been vaccinated against the disease. Their median age was 59 (20-83) years; 22 of 39 (56.4%) were male. In comparison with unvaccinated patients with TBE, those with breakthrough disease more often experienced a monophasic course of illness (P = 0.006), had a higher CSF leucocyte count (P = 0.005), more often had urine retention (P = 0.012), more often needed ICU treatment (P = 0.009), were hospitalized for longer (P = 0.002) and had more severe acute illness (P = 0.004 for simple clinical assessment, P = 0.001 for severity score). CONCLUSION: In addition to several findings corroborating previous results in patients with vaccination breakthrough TBE, such as older age and the presence of a particular specific serum antibody pattern indicating anamnestic response, findings in this study indicate that the acute illness in patients with breakthrough TBE is more severe than in unvaccinated sex- and age-matched patients who develop the disease.

Respiratory viruses in patients and employees in an intensive care unit.

PURPOSE: To evaluate the frequency of respiratory viruses in a nonselected population of intensive care unit patients and employees and to investigate the clinical as well as the epidemiological association with virological findings. METHODS: Between 12 January and 5 March 2009, nasopharyngeal swabs were collected from 55 intensive care unit (ICU) patients and 41 medical personnel at 16 different time-points and tested for 11 respiratory viruses by single real-time PCR using TaqMan or MGB probes. RESULTS: Among the 55 ICU patients tested, there were 30 virus-positive respiratory specimens (30/173, 17.3%) and 23 patients who tested positive at least once for respiratory viruses (23/55, 41.8%). Only the time from admission to the ICU was associated with the probability of testing positive, with the probability of testing positive decreasing with increasing length of stay (P < 0.001). Of the 418 respiratory specimens collected from the healthcare personnel, 27 (6.5%) tested positive. Seventeen employees tested positive at least once for respiratory viruses (17/41, 41.5%). Among the employees, calendar time (P = 0.03) and having sick contacts at home (P = 0.006) were significantly associated with swab positivity. Among the study population, patients had a significantly higher probability of having a positive swab result than employees. The distribution of viruses differed between the two groups. CONCLUSIONS: Our results suggest that when hygiene precautions are adopted, the possibility of transmitting selected respiratory viruses between patients and personnel is limited. They also point to a greater importance of the community over the hospital environment for acquisition of viral respiratory infections by ICU patients and employees.

Cost-effectiveness of a potential anti-tick vaccine with combined protection against Lyme borreliosis and tick-borne encephalitis in Slovenia.

This study assessed cost-effectiveness of a potential anti-tick vaccine that would protect against both Lyme borreliosis (LB) and tick-borne encephalitis (TBE) in a highly endemic setting of Slovenia. A Markov model was developed to estimate cost-effectiveness of a vaccine with potential combined protection against LB and TBE from the societal perspective. The model expressed time in annual cycles, followed a target population through their lifetime, and applied an annual discounting of 3%. A target population entered the model in a susceptible state, with time dependent probabilities to acquire LB/TBE. Disease manifestations were either resolved within one cycle, or a patient developed LB/TBE sequelae. The vaccination consisted of initial immunization and one revaccination. Estimates of LB/TBE direct and indirect costs, and data on natural course of LB/TBE were obtained from Slovenian databases. Effectiveness of the vaccine with potential combined protection against LB/TBE was derived from studies on existing TBE and LB vaccines, while utility estimates were collected from various literature sources. A vaccine with potential combined protection against LB/TBE was predicted to have an incremental cost of €771,300 per 10,000 vaccinated persons, an incremental utility of 17QALYs and a base-case incremental cost-effectiveness ratio (ICER) of 46,061€/QALY. Vaccine cost, effectiveness and discount rates were identified as the most influential model parameters. A wholesale price for a vaccine shot of €9.13 would lead to cost savings followed by health gains for the vaccination strategy. The base-case ICER was below commonly accepted thresholds of cost-effectiveness, indicating that a combined LB/TBE vaccine might be a cost-effective option in Slovenia. With early Health Technology Assessment becoming increasingly important, this analysis still represents a rare example of cost-effectiveness assessment prior to market authorisation. Although obviously in such a situation some key parameters are unknown, our model sets up a tool to analyse pharmacoeconomic criteria that can help development of a cost-effective health technology, in this case a combined tick-borne diseases vaccine.