Results of screening for antibodies to varicella-zoster virus in healthcare workers of a multidisciplinary hospital in Moscow

Introduction. Given the unfavorable epidemic situation with chickenpox and shingles in Russia, there is a high risk of virus introduction and spread in healthcare settings, including among medical staff who are not immune to varicella zoster virus (VZV). The objective of this study is to assess the immunity of employees of a multidisciplinary hospital in Moscow to VZV. Materials and methods. A selective screening study was carried out. Venous blood serum samples were taken from 1546 hospital employees as material for detection of IgG antibodies to VZV antigens using a commercial solid-phase enzyme immunoassay (ELISA) test system "Vecto VZV-IgG". All employees were questioned to obtain information about their infectious and vaccine history in relation to VZV. Results and discussion. Screening for antibodies to VZV in the hospital workers revealed that 6.3% of those workers are not immune to VZV. The proportion of seronegative individuals was the highest (12.6 ± 2.4%) in the age group of 29 years and younger. VZV seronegative healthcare workers were found in various departments, but the presence of non-immune individuals among the staff of the obstetrics and gynecology departments (6.5%) is of epidemiologic concern. The results of the survey showed that documented data on infection and vaccination history cannot be used to assess the protection of healthcare workers against VZV infection. Conclusion. The results of serologic screening for antibodies to VZV made it possible to identify a significant number of susceptible employees of the multidisciplinary hospital. In order to prevent the formation of multiple epidemic foci of varicella in medical organizations, it is advisable to include anti-VZV testing of medical staff in the state prevention programs with subsequent vaccination of non-immune individuals

Platelet function and blood coagulation system status in childhood essential thrombocythemia

Childhood essential thrombocythemia (ET) is a rare chronic myeloproliferative disorder. The quality of life of ET patients may decrease as a result of ischemic and hemorrhagic complications of unclear origin. Our goal was to characterize the hemostatic system in children with ET. We genotyped and investigated blood samples from 20 children with ET in a prospective case series study using platelet aggregation, functional flow cytometry (FC) assay and standard clotting assays. Three children had a JAK2V617F mutation, 4 had mutations in CALR and 13 were triple-negative. Myelofibrosis in stage 1-2 was detected in 3 children. Three patients had bleeding episodes and seven had ischemic events. Aggregation in response to collagen, adenosine diphosphate, and ristomycin was decreased in all patients. In FC, significant changes in the whole patient group compared to the healthy children control group were decrease in the resting forward scatter and PAC1 binding (activated GPIIb/IIIa) level. For the activated platelets, dense granules release (by mepacrine), PAC1, and GPIIb/IIIa levels were significantly decreased. GPIb/V/IX, P-selectin, and phosphatidylserine levels manifested only moderate differences. Forward and side scatter changes in response to stimulation (representing shape change) and dense granules release were significantly lower in the 3 patients with bleeding than in the 17 patients without hemorrhage. Activated partial thromboplastin time was slightly prolonged, prothrombin index was slightly shortened and thrombin time was normal, while fibrinogen was mildly decreased in the ET patients. It could be concluded that the observed platelet function defects could be related to bleeding in ET, and be potentially used as a marker