Etiology, Clinical Presentation and Incidence of Infectious Meningitis and Encephalitis in Polish Children.

Little is known about the causes and the frequency of meningitis and encephalitis in Poland. We did a retrospective single-center cohort study of children under 18 years old hospitalized with infectious meningitis or encephalitis. Incidence rates were calculated using collected data from patients from the North-East Poland only. A total of 374 children hospitalized between 1 January 2015 and 31 December 2019 were included in the study. A total of 332 (89%) children had meningitis, and 42 (11%) had encephalitis. The etiology of the infection was established in 331 (89%) cases. Enteroviruses accounted for 224 (60%) of all patients. A total of 68 (18%) cases were tick-borne infections. Bacterial pathogens were detected in 26 (7%) children. The median length of hospital stay for children with enteroviral meningitis was 7 days (IQR 7-9), increasing to 11 days (8-13) in those treated with antibiotics. The incidence of meningitis was estimated to be 32.22 (95% CI, 25.33-40.98) per 100,000 and that of encephalitis to be 4.08 (95% CI, 2.07-8.02) per 100,000. By the broad use of molecular diagnostic methods, we managed to identify etiology of the infection in the majority of children. Our data suggest that thorough diagnostics of central nervous system infections are needed to rationalize treatment.

Evaluation of cerebrospinal fluid CXCL13 concentrations and lymphocyte subsets in tick-borne encephalitis.

OBJECTIVES: Recent studies suggest that the clinical presentation of tick-borne encephalitis (TBE) is determined by the host immune responses to the tick-borne encephalitis virus (TBEV). The aim of the study was to characterize immune responses in TBE to give a better insight into the immunopathogenesis of this disease. METHODS: Anti-TBEV antibody levels, cerebrospinal fluid (CSF) and blood lymphoid populations, and concentrations of CXCL13 (a potent B-cell and T-cell chemoattractant), were analyzed in 35 patients with TBE (20 adults and 15 children). RESULTS: When compared with the blood, the CSF lymphoid population was significantly enriched in CD4+ T-cells and relatively depleted in natural killer (NK) cells and B lymphocytes. In comparison with TBE meningitis, patients suffering from TBE meningoencephalitis (n = 11, 31%) had a 3.5-fold higher median CSF CXCL13 concentration, 1.8-fold higher CSF/serum ratio of anti-TBEV IgG antibodies, and 1.8-fold higher median CSF cell count. CSF CXCL13 levels did not change significantly in children with TBE meningitis receiving supportive treatment, but decreased in children with TBE meningoencephalitis who received intravenous steroids. CONCLUSIONS: CD4+ cells are abundant in the CSF of patients with TBE. CXCL13 may be involved in the neuropathology of TBE by attracting different subsets of lymphocytes to the CSF.

Challenges and new methods in the diagnosis of Lyme disease in children.

Despite the constant development of biotechnology, laboratory diagnostics of Lyme disease in children still poses a significant challenge. The aim of this article is to present the current methods of Lyme disease diagnosis and its future perspectives. A serological test is often the first step in supporting clinical diagnosis of Lyme disease in children. Recently, a new generation of enzyme-linked immunosorbent assays has been created. These assays use recombinant proteins or synthetic peptides in their antigenic spectrum. It is postulated that these tests may replace the classic immunoblot as the second step in the Lyme disease diagnostic protocol. Direct detection methods based on bacterial culture techniques or using the polymerase chain reaction (PCR) have inadequate sensitivity, which prevents their widespread use in clinical practice. Recently, a number of other tools have been developed that are of supportive importance. Among them, measuring of the CXCL13 chemokine concentration in the cerebrospinal fluid has the potential to become a routine procedure in the diagnosis of Lyme disease in children. Future diagnostic strategies of Lyme disease might include: innovative immunological tests using new antigens, combining serology with direct methods in order to increase sensitivity, standardization of selected unconventional tests, identification of host response biochemical metabolic markers or linking clinical symptoms reported by patients with appropriate test panels. In the absence a vaccine which protects against the disease, the preventive recommendations given to parents to prevent tick bites in children remain valid.