Background: Pediatric co-infections are an emerging problem due to their ascending prevalence and tendency to blur typical clinical
presentation of particular diseases. Case presentation: The paper describes a verified case of Varicella-zoster virus and Borrelia
burgdorferi co-infection in a 7-year-old male patient. Neuroinfection manifested ten days after the onset of varicella episode.
Acyclovir IV was initiated for acute varicella zoster encephalitis. Concerned with the progression of neurological disorders we
performed additional cerebrospinal fluid PCR testing for other potential neuropathogens; Borrelia burgdorferi DNA was detected.
The patient denied any history of tick exposure. Combination of ceftriaxone and acyclovir IV was effective. Discussion: Co-infection
with Varicella-zoster virus and B. burgdorferi may have a permissive deleterious impact on the central nervous system with unclear
mechanisms. Testing for molecular biological and/or serological markers of Lyme disease should be a standard procedure in
patients with any severe neuroinfection in endemic regions regardless of anamnestic data.
Keywords: Varicella-zoster infection; Borrelia burgdorferi; Lyme disease; encephalitis; children