Lyme disease in a British referral clinic.

BACKGROUND: Concerns about over-diagnosis and inappropriate management of Lyme disease (LD) are well documented in North America and supported by clinical data. There are few parallel data on the situation in the UK. AIM: To describe the patterns of referral, investigation, diagnosis and treatment of patients with suspected LD referred to an infectious disease unit in Liverpool, UK. Previous management by National Health Service (NHS) and non-NHS practitioners was reviewed. DESIGN: Descriptive study conducted by retrospective casenotes review. METHODS: Retrospective casenotes review of adults referred with possible LD to an infectious disease unit in Liverpool, UK, over 5 years (2006-2010). RESULTS: Of 115 patients, 27 (23%) were diagnosed with LD, 38 (33%) with chronic fatigue syndrome (CFS) and 13 (11%) with other medical conditions. No specific diagnosis could be made in 38 (33%). At least 53 unnecessary antibiotic courses had been given by non-NHS practitioners; 21 unnecessary courses had been prescribed by NHS practitioners. Among 38 patients, 17 (45%) with CFS had been misdiagnosed as having LD by non-NHS practitioners. CONCLUSION: A minority of referred patients had LD, while a third had CFS. LD is over-diagnosed by non-specialists, reflecting the complexities of clinical and/or laboratory diagnosis. Patients with CFS were susceptible to misdiagnosis in non-NHS settings, reinforcing concerns about missed opportunities for appropriate treatment for this group and about the use of inappropriate diagnostic modalities and anti-microbials in non-NHS settings.

Mendelian susceptibility to mycobacterial disease.

The host response to mycobacterial infection is mediated by the type I cytokine pathway (cell-mediated immunity). Deficiencies in this response result in susceptibility to poorly pathogenic mycobacterial species such as bacille Calmette-Guérin and environmental mycobacteria. In recent years a number of mutations in the genes encoding major components in the type I cytokine axis have been described which predispose to disseminated infection with these weakly virulent mycobacterial species. Affected individuals are also prone to extra-intestinal disease caused by non-typhoidal Salmonella. The genes involved display a high level of allelic heterogeneity, accounting for a number of distinct genetic disorders which vary in their mode of inheritance and clinical presentation. These disorders have been termed Mendelian susceptibility to mycobacterial disease and are discussed in this review article.