Tuberculosis Serology is Useful in Rural Areas

• Main Author: Roland Maes
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2017-01-01
• Series: Biomedical and Biotechnology Research Journal
• Subjects: Antibodies; Bacillus Calmette–Guérin vaccine; GeneXpert/RIF test; serology; tuberculosis
• Online Access: http://www.bmbtrj.org/article.asp?issn=2588-9834;year=2017;volume=1;issue=2;spage=85;epage=93;aulast=Maes

The fight on tuberculosis initiated after World War II with the imposition of the Bacillus Calmette–Guérin (BCG) vaccine by the WHO in 1950, and the discovery of the drug streptomycin, which was rapidly followed by a recommended 4 drug regimen (isoniazid, ethambutol, rifampicin, pyrazinamide, and streptomycin being reserved to resistant cases). The diagnostic that justified a treatment was based on the microscopic examination of bacterial presence in sputum, that is, the bacilloscopy, and on culture in vitro of the pathogen, which is more expensive and much more demanding on time. During the following 7 decennia, this approach remained unchanged: no new vaccines were developed despite the documented observed ineffectiveness of the BCG, and the 4 drug regimen (plus streptomycin) admitted additional drugs only from 2012 on. The ineffectiveness of the original 4 + 1-drug cocktail, that became obvious in France in 1994, is traced in part to the immunodepressing effect of some of them. The use of only four drugs also favors defensive mutations by the pathogen. The late addition of more antibiotics to the regular regimen applied to multidrug-resistant-cases may be useful on the immediate term but side effects are crimpling and evidently, measures in addition to “more drugs” must be taken to control the disease. A diagnostic based exclusively on antigen detection remained the norm during nearly 7 decennia. This detection benefited from technologically improved methods (e.g., the interferon test and the numerous nucleic acid amplification tests). The latest of these is the GeneXpert/RIF test. This newly devised antigen test is a quantitative improvement on previous tests detecting the presence of the antigen. However, due to its centralized system of analysis and inaccuracy, it is not suited for rural areas, and it does not favor communication between mycobacteriologist, immunologist, and clinician. In this review article, the concentration is on those rare publications that highlighted the problem posed by various diagnostic tests and their application.