Clinical and laboratory findings in tick-borne encephalitis virus infection

Nicole Barp; Alessandro Trentini; Mariachiara Di Nuzzo; Valeria Mondardini; Ermenegildo Francavilla; Carlo Contini

doi:10.1016/j.parepi.2020.e00160

Clinical and laboratory findings in tick-borne encephalitis virus infection

Parasite Epidemiol Control. 2020 Jun 19:10:e00160. doi: 10.1016/j.parepi.2020.e00160. eCollection 2020 Aug.

Authors

Nicole Barp¹, Alessandro Trentini², Mariachiara Di Nuzzo¹, Valeria Mondardini³, Ermenegildo Francavilla³, Carlo Contini¹

Affiliations

¹ Dept Medical Sciences, Section of Infectious Diseases, University of Ferrara, Italy.
² Dept Biomedical Sciences, Section of Biochemistry, Molecular Biology and Medical Genetics, University of Ferrara, Italy.
³ Infectious Diseases, Belluno Medical Hospital "San Martino", Ulss1 Dolomiti, Italy.

Abstract

Purpose: Tick-Borne Encephalitis (TBE), a disease caused by Tick-Borne Encephalitis Virus (TBEV), is emerging in Italy. This study aimed to characterize the epidemiological, clinical, laboratory, imaging and electroencephalogram characteristics in Belluno, North-East Italy.

Results: 76% were males, mean age 53 years; 50% did not report tick bite. 72% had a biphasic course, 42% a monophasic one, 8 cases of abortive TBE. Mostly no specific symptoms were observed, together with neurological signs and symptoms. None died, but 35% had sequelae at the one-month follow-up. Men had a higher risk of having neurological/neurocognitive sequelae; paresthesia or tremors were associated independently with sequelae. In terms of laboratory data, thrombocytopenia, neutropenia and lymphocytosis were associated with the first phase (p < .01), while monocytosis, lymphocytopenia, high levels of ESR and CRP with the second (p < .05). Other abnormal laboratory data were observed: high levels of transaminases, bilirubin, GGT, fibrinogen, amylase, LDH, CPK and electrolyte disorders. Most of the liquor showed pleocytosis and increased protein levels. No specific findings characterized imaging; electroencephalogram mainly reported general and focal anomalies in the temporal lobe.

Conclusions: Although patients have not reported a tick bite, TBEV infection should be considered for diagnosis. Usually no specific symptoms are reported along with neurological signs and symptoms. The biphasic course is more often described than the monophasic course; abortive TBE is sometimes present. Paresthesia and tremors are independently associated with neurological/neurocognitive sequelae; men have a higher risk of having sequelae. The first phase is probably associated with thrombocytopenia, neutropenia and lymphocytosis; the second with monocytosis, lymphocytopenia, high levels of CRP and ESR. Electrolyte disorders, high levels of transaminases, GGT, bilirubin, CPK, LDH, fibrinogen and amylase may characterize TBEV infection.

Keywords: Abnormal laboratory data; Biphasic course; Monophasic course; Neurological/neurocognitive sequelae; Tick-borne encephalitis; Tick-borne encephalitis virus (TBEV).