Epidemiology and diagnosis of Lyme borreliosis

Microbiological and serological diagnosis of Lyme borreliosis

In Europe, Lyme borreliosis is caused by Borrelia burgdorferi sensu stricto, B. afzelii, B. garinii and the recently described species B. spielmanii. For the development of diagnostic tools, the heterogeneity of the causative agents must be considered. The serological diagnosis should follow the principle of a two-step procedure: a sensitive enzyme-linked immunosorbent analysis as the first step, followed by immunoblot (IgM and IgG) if reactive. The sensitivity and standardization of immunoblots have been enhanced by the use of recombinant antigens instead of whole cell lysates. Improved sensitivity has resulted from the use of recombinant proteins primarily expressed in vivo (e.g. VlsE) and the combination of homologous proteins from different strains (e.g. DbpA). At present, detection rates for serum antibodies are 20-50% in localized, 70-90% in disseminated early and nearly 100% in late disease. Detection of the borreliae by culture or PCR should be confined to specific indications. The best results are obtained from skin biopsies (50-70% with culture or PCR) and synovial tissue or fluid (50-70% with PCR). Cerebrospinal fluid is positive in only 10-30%. Methods that are not recommended for diagnostic purposes include antigen tests in body fluids, PCR of urine and lymphocyte transformation tests.

Lyme carditis: Persistent local delayed enhancement by cardiac magnetic resonance imaging

Lyme borreliosis (LB) is the most common tick-born disease in the Northern Hemisphere. During early disseminated Lyme disease cardiac manifestation can occur. We report a case of isolated Lyme myocarditis with transitory total atrioventricular (AV)-block and myocardial necrosis indicated by a rise in Troponin-T (TNT). Antibiotic treatment resulted in complete resolution of the AV-block, but a local epimyocardial contrast enhancement persisted as shown by cardiac magnetic resonance imaging (MRI).

Lyme borreliosis

Lyme borreliosis is a tick-borne infectious disease caused by the spirochaetes Borrelia burgdorferi, B. garinii and B. afzelii. It comprises a wide spectrum of symptoms affecting skin, musculoskeletal system, heart, eyes, central and peripheral nervous system. The diagnosis is based on clinical findings in combination with detection of specific IgM and/or IgG antibodies. Diagnostic problems arise from patients with non-specific symptoms and positive IgG antibody detection. Adequate antibiotic therapy cures more than 90% of the patients. However, in some patients repeated therapy is necessary and a small number of patients develop chronic arthritis or other features. While there is currently no vaccine available, prevention of tick bite is the most effective prophylaxis.

Allozyme polymorphism of Mdh and alpha-Gpdh in Ixodes ricinus populations: comparison of borreliae-infected and uninfected ticks

Ixodes ricinus Linnaeus (Acari: Ixodidae) ticks are vectors of numerous infectious diseases in humans and animals. The allozyme variability of MDH and alpha-Gpdh was detected by native polyacrylamide gel electrophoresis in I. ricinus natural populations in three localities in Serbia. Four alleles of Mdh locus (MDH 1, MDH 2, MDH 3 and MDH X) and four alleles of alpha-Gpdh locus (VS, S, F and VF) were detected. Interpopulation differences in Mdh and alpha-Gpdh allele frequencies were statistically insignificant. Significant difference in alpha-Gpdh allele frequencies between males and females was recorded in the largest sample only. Differences in allele frequencies, detected between borreliae-infected and uninfected I. ricinus ticks, were close to the level of statistical significance, especially for alpha-Gpdh locus. Clear significant difference appeared in females when sexes were tested separatelly (P = 0.037). It is interesting that genotypes containing rarer alleles (MDH 1 and S) were infected in higher proportion in comparison to other genotypes. Our results point towards a possible role of Mdh and alpha-Gpdh loci in I. ricinus ticks in the determination of energy requirements for host seeking. Sex differences in alpha-Gpdh allele frequencies suggest that selective pressure, concerning efficiency of reserve materials utilisation, points to alpha-Gpdh rather than to Mdh locus.