Currently available antiviral therapy for children with acute and chronic tick-borne encephalitis
Authors:   Children’s Research and Clinical Center for Infectious Diseases of the Federal Medical and Biological Agency of Russia, Saint Petersburg, Russian Federation, Skripchenko N.V. ,   Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russian Federation, Ivanova G.P. ,   Clinical Hospital «Russian Railways-Medicine», Saint Petersburg, Russian Federation, Skripchenko E.Yu. ,   Children’s Research and Clinical Center for Infectious Diseases of the Federal Medical and Biological Agency of Russia, Saint Petersburg, Russian Federation,   Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russian Federation, Vilnitz A.A. ,   Children’s Research and Clinical Center for Infectious Diseases of the Federal Medical and Biological Agency of Russia, Saint Petersburg, Russian Federation,   Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russian Federation, Murina E.A. ,   Children’s Research and Clinical Center for Infectious Diseases of the Federal Medical and Biological Agency of Russia, Saint Petersburg, Russian Federation, Pulman N.F. ,   Children’s Research and Clinical Center for Infectious Diseases of the Federal Medical and Biological Agency of Russia, Saint Petersburg, Russian Federation
Published: September 2021

Objective. To evaluate the efficacy of antiviral therapy and serotherapy for focal tick-borne encephalitis (TBE) in children with acute and chronic infection by assessing clinical and laboratory parameters, as well as MRI findings. Patients and methods. We followed-up 130 children aged 8 to 17 years with focal TBE affecting the central nervous system (CNS). Patients in groups 1 (n = 84) and 2 (n = 20) received therapy in the acute period of infection (on average 3.5 ± 1.3 days following disease onset). Patients in groups 3 (n = 15) and 4 (n = 11) received therapy for chronic TBE infection. Children from group 1 and 3 received antiviral therapy, including oral ribavirin, recombinant interferon-α2 (IFN-α2) (intramuscular injections or suppositories with antioxidants; Viferon®), and oral processed anti-IFN-γ antibodies (Anaferon for children). Children from groups 2 and 4 received serotherapy (anti-TBE immunoglobulin) and ribonuclease (intramuscular injections). Treatment duration depended on the disease phenotype; patients were followed-up for one year. Etiological diag-nostics included measurement of anti-TBE IgM and IgG and TBE antigen using enzyme-linked immunosorbent assays (ELISA), as well as detection of viral RNA in serum and cerebrospinal fluid (CSF) using polymerase chain reaction. All patients have undergone MRI of the brain and cervical spinal cord. Children were examined before treatment and then at several time-points during therapy. Results. In patients from group 1, the period of symptom increase was 4 days shorter than that in patients from group 2. In addition to that, their period of impaired consciousness and CSF pleocytosis was 5 days shorter than in group 2; they had more rapid viral clearance from CSF. Seventy patients from group 1 (83.3%) recovered without any deficit; none of them demonstrated progression of TBE infection. Six children from group 2 (30%) developed chronic TBE infection, whereas 11 patients (55%) had neurological deficit without progression as an outcome. The majority of patients from group 3 (86.7%) demonstrated improvement with one child who had complete regression of symptoms. In all participants from this group, virus replication was stopped. More than two-thirds of children from group 4 (72.7%) had aggravation of symptoms, persistent viral replication, and progression of atrophic CNS changes (according to MRI findings). Conclusion. Antiviral therapy (ribavirin, IFN-a2, and anti-IFN-γ antibodies) are most effective during the first 5 days of the disease; however, it was also effective in children with chronic TBE infection and ensured improvement with partial regression of symptoms. Anti-TBE immunoglobulin and ribonuclease were ineffective in children with focal TBE. Key words: viferon, children, tick-borne encephalitis, acute and chronic course, antiviral therapy, serotherapy