TBE in an Infant Living by the Forest

BACKGROUND: Tick-borne encephalitis (TBE) is a viral neuroinfection caused by the tick-borne encephalitis virus (TBEV), a Flavivirus, transmitted by Ixodes ticks in Asia and Europe. The infection typically evolves from a flu-like stage to neurological involvement, potentially leading to meningoencephalitis and long-term sequalae. While TBE can affect individuals of any age, infants are rarely affected, with only a few reported cases in children under one year of age in Europe. Children generally experience a milder course of illness compared to adults, but central nervous system involvement can still occur, even in infancy. CASE REPORT: A 10-month-old male infant living in an area endemic for TBE, presented with a 5-day history of fever, irritability, apathy, and hyperesthesia. Prior to this, he was hospitalized for pneumonia, and was re-hospitalized due to recurrent fever and neurological symptoms. Serological testing revealed positive IgM and IgG antibodies against TBEV. Cerebrospinal fluid (CSF) analysis showed a cytosis of 28 cells/µL, with no bacterial or viral pathogens detected by PCR. Empirical antibiotic therapy and intracranial pressure management were initiated, leading to clinical improvement. The infant was discharged in good general condition after a negative CSF culture. At a follow-up visit one month later, the infant had fully recovered. The infection was likely acquired through an unnoticed tick bite, as the mother was vaccinated and seropositive for TBE, and the infant was not vaccinated due to his age. CONCLUSIONS: This case highlights the importance of considering TBE in infants presenting with fever and neurological symptoms, especially in endemic regions. Early serological testing and CSF analysis are crucial for diagnosis. Although rare, TBE in infants can have a favorable outcome with prompt management. Public health measures, including vaccination and tick prevention, should be emphasized in high-risk areas to prevent such infections.