Direct molecular detection and genotyping of Borrelia burgdorferi sensu lato in the cerebrospinal fluid of children with Lyme neuroborreliosis.
The current diagnostic marker of Lyme neuroborreliosis (LNB), Borrelia burgdorferi sensu lato (Bb) antibody index (AI) in the cerebrospinal fluid (CSF), has insufficient sensitivity in the early phase of LNB. We aimed to elucidate the diagnostic value of Bb PCR in CSF from children with symptoms suggestive of LNB and explore Bb genotypes associated with LNB in children. Children were prospectively included into predefined groups with high or low likelihood of LNB based on diagnostic guidelines (LNB symptoms, CSF pleocytosis and Bb antibodies), or detection of other causative agents. CSF samples were analyzed by two Bb specific real-time PCR assays and, if Bb DNA was detected, further analyzed by five single-plex real-time PCR assays for genotype determination. In children diagnosed as LNB patients (58 confirmed and 18 probable) (n=76) or non-LNB controls (n=28) the sensitivity and specificity for Bb PCR in CSF were 46% and 100%. Bb DNA was detected in 26/58 (45%) children with AI positive LNB and in 7/12 (58%) with AI negative LNB and short symptom duration. In 36 children with detectable Bb DNA, genotyping indicated B. garinii (n=27) and non- B. garinii genotypes (n=1), eight samples remained untyped. Children with LNB caused by B. garinii did not have a distinct clinical picture. The detection rate of Bb DNA in CSF of children with LNB was higher, than previously reported. Bb PCR could be a useful supplemental diagnostic tool in unconfirmed LNB cases with short symptom duration. B. garinii was the predominant genotype in children with LNB.