Active clinical trials for "Encephalitis, Tick-Borne"

In Europe, tick-borne encephalitis (TBE) virus causing TBE is transmitted by the bite of Ixodes ricinus tick, which can also transmit Lyme borreliae , the causative agent of Lyme borreliosis (LB). Since TBE and LB are both endemic with high incidence rates in Slovenia, we should be attentive to the possibility of double infections. Double infections with TBE virus and Lyme borreliae were reported to occur rarely even in endemic countries, however reliable data on coinfection rates are rather limited. Microbiological diagnosis of TBE virus infection is quite straightforward, and there is no specific therapy for TBE available so far. This markedly differs from borrelial infection, in which case interpretation of serological test results demands more caution, but there is highly efficient antibiotic treatment available for LB. This may lead to over prescribing of antibiotics to TBE patients with documented borrelial antibodies in serum indicating possible coinfection with Lyme borreliae, but missing clinical or microbiological criteria for proven borrelial coinfection. Approximately 10% of patients who had been treated appropriately for LB and about one third of patients after TBE report nonspecific subjective complaints, such as fatigue, headache, arthralgia, and myalgia, termed post-Lyme and post-encephalitic symptoms, respectively. These may not be differentiated clearly from nonspecific symptoms occurring with a rather substantial incidence also in the general population. A trend of ascribing medically unexplained nonspecific subjective symptoms to LB in subjects with positive borrelial antibodies in serum puzzles the situation further. The aim of this prospective observational study was to assess the proportion and clinical implication of proven and possible coinfection with Lyme borreliae in patients with TBE, and to evaluate the association between anti-borrelial antibiotic therapy and clinical outcome in the subgroup of patients with possible coinfection.

The proposed study is a collaboration between Microbiology, SU/Sahlgrenska and the Infectious Diseases clinic at SU/Östra as well as several Infectious Diseases clinics throughout Sweden aiming at improving microbiological diagnostic assays regarding the early identification of tick-borne microorganisms (including as of yet unidentified pathogens) capable of causing human disease using modern diagnostic tools. At the initial study visit (day 0) plasma, serum, urine, saliva, and PBMCs (and tick, if available) will be collected from patients developing fever within two weeks after a tick bite. Additional follow-up samples will be obtained after 9 and 30 days as well as after 6 months. The initial samples will be analyzed using (a) directed multiplex PCR analysis for Tick-Borne Encephalitis (TBE), Borrelia, Anaplasma, Neoerlichia, Rickettsia, Coxiella, Tularemia, and Babesiosis in plasma, whole blood and urine, (b) conventional IgM and IgG serology for TBE, (c) "Next Generation Sequencing" (NGS) for the detection of bacterial 16s rRNA as well as unknown viruses, (d) potential biomarkers, and (e) host genetic factors. Among patients where initial sampling indicates the presence of a potential pathogen or in patients developing neurological symptoms, a lumbar puncture will be performed and CSF will be further analyzed. Samples will also be evaluated regarding potential microbiological factors predisposing for severity of infection. The primary objective of the study is to improve diagnostic tools in the initial early phase of infections caused by tick-borne pathogens, especially TBE prior to the affliction of the central nervous system, and to attempt to identify which factors impact the course of infection as it is believed that approximately 75% of infected individuals resolve their infection in this first phase whereas others develop meningoencephalitis with significant subsequent neurological sequelae. Secondary objectives of the study include investigating for the presence of and treating other tick-borne pathogens, setting the stage for coming clinical trials evaluating novel anti-viral therapies for TBE.

The purpose of this study is to assess clinical outcome in patients with tick borne encephalitis.