Neuroborreliosis in patients hospitalised for Lyme borreliosis in the Czech Republic in 2003 - 2013.

Study Objective: The objective was to analyse and evaluate a cohort of Lyme borreliosis (LB) patients with neuroborreliosis (LNB) hospitalised in the Czech Republic in 2003-2013.

Material And Methods: Data analysed in this study were obtained from the National Register of Hospitalised Patients, which is a nationwide population register maintained at the Institute of Health Information and Statistics of the Czech Republic. Data collection from all departments of bed care establishments are regularly processed every year. Registration of basic hospitalisation diagnoses is performed in accordance with the 10th revision of the International Classification of Diseases (ICD-10). The study cohort consisted of 23,631 patients with clinically and laboratory confirmed LB hospitalised between 2003 and 2013.

Results: Nervous system involvement, i. e. LNB (ICD-10 codes G00-G99) was recorded in 27.1% (6,392) of LB patients. Hospital admissions for LB exhibited a slight downward trend with year-on-year fluctuations over the study period. In contrast, LNB showed an upward trend with slight year-on-year fluctuations (345-779 cases) (p = 0.003). Overall, 6,392 persons, 3,220 males and 3,172 females, were diagnosed with LNB over the 11-year study period. Some patients presented with multiple concomitant neurological symptoms. Overall, 6,392 hospitalised patients were diagnosed with 8,168 diseases of the nervous system. The most common diagnoses were facial nerve disorders (21.1%), meningitis (18.3%), polyneuropathies (13.6%), encephalitis, myelitis, and encephalomyelitis (11.3%), and nerve root and plexus disorders (4.9%). The average age of male and female patients hospitalised with LNB was 44.4 and 44.7 years, respectively. It varied significantly between the ICD-10 code groups (p < 0.001) from 38.0 to 63.0 years. The relative incidence of LB by five-year age group showed the first peak at the age of 5-9, followed by a considerable drop at the age of 20-24 and then by another higher peak at the age of 55-59 (the hospitalisation rate ratio comparing the peaks in the adults and children was 1.78). For LNB, the second peak shifted to the age of 65 to 74 years and was similar to the peak in children age groups (hospitalisation rate ratio of 0.95). The distribution of hospital admissions for LNB by month of admission showed the highest numbers of admissions in July and September and the lowest numbers of admissions in December and April. The length of hospital stay was significantly higher (mean of 12.4 days and median of 13 days) in LNB patients (p < 0.001) than in other LB patients (mean of 10.3 days and median of 10 days).

Conclusion: The basic prerequisite for reliable diagnosis of LNB is a multidisciplinary collaboration of highly experienced neurologists, infection disease specialists, and microbiologists. The cohort of 6,392 patients hospitalised for LNB was analysed by gender, length of hospital stay, and month of hospital admission. The study found LNB cases to occur in all age groups. LNB diagnosis performed in accordance with the ICD-10 enables valid comparison between neurological outcomes of LB patients at both the national and international levels.