Tick-borne encephalitis in a child with previous history of completed primary vaccination

Area of Science:

• Neuroscience
• Infectious Diseases
• Immunology

Background:

• Tick-borne encephalitis virus (TBEV) is a significant cause of viral meningoencephalitis in endemic regions.
• Vaccination is the primary preventive measure against TBEV infection.
• Breakthrough infections, even after complete vaccination, can occur and may lead to severe disease.

Observation:

• A 13-year-old girl presented with symptoms of meningoencephalitis, including fever, headache, and nausea.
• Cerebrospinal fluid analysis revealed elevated leukocytes, consistent with central nervous system inflammation.
• Serological tests confirmed acute TBEV infection (IgG and IgM positive) despite a history of TBEV vaccination.

Findings:

• The patient's condition worsened despite intensive therapy, necessitating intensive care unit admission.
• This case demonstrates a TBEV vaccination breakthrough in a child, resulting in severe illness.
• The study suggests that immunized individuals may experience more severe TBEV disease due to altered immune responses, though mechanisms remain unclear.

Implications:

• Healthcare providers should consider TBEV vaccination breakthrough or missed booster doses in children presenting with meningoencephalitis symptoms and vaccination history.
• Further research is needed to elucidate the immunological mechanisms underlying severe TBEV disease in vaccinated individuals.
• Understanding these mechanisms could lead to improved TBEV prevention and treatment strategies.