Detection of extensively drug resistant pulmonary tuberculosis

Abstract

Introduction: The rise in human immune virus infections (HIV) and the neglect of tuberculosis (TB) control programs have enabled a resurgence of TB. The emergence of drug-resistant strains has also contributed to this new epidemic from 2000 to 2004, with, 20% of TB cases being resistant to standard treatments and 2% resistant to second-line drugs. The rate at which new TB cases occur varies widely, even in neighboring countries, apparently because of differences in health care systems. Aim of the work: The aim of the current study is to investigate susceptibility to anti-TB drugs in newly diagnosed and old TB patients (with persistent positive sputum smear after 2 months of anti-TB treatment) for detecting multi-drug resistance (MDR-TB) and extensively drug resistant TB (EDR-TB). As well, find out risk factors associated with the development of MDR and XDR-TB. Patients and methods: The study included 40 strains of mycobacterium TB. These strains were divided into two groups: Group I: 20 strains isolated from new cases (patients who had never treated for TB or who have taken anti TB drugs for less than 1 month). Group II: 20 strains isolated from old cases (Patients with persistent positive sputum smear after 2 months of anti-TB treatment). After taking an informed consent, all subjects were subjected to: Detailed history taking, complete clinical examination, anthropometric measurements, routine laboratory investigations, erythrocyte sedimentation rate (ESR), chest X-ray, microbiological investigations (including, direct microscopy examination, isolation and identification of mycobacterium TB, and testing sensitivity for anti-TB drugs). Results: MDR and XDR TB were more common among TB patients with persistent positive sputum despite anti TB treatment than newly diagnosed cases. Diabetes mellitus (DM), HIV and anemia were considered to be other risk factors for MDR-TB and XDR-TB. Management of MDR-TB and XDR TB is a challenge which should be undertaken by experienced clinicians at centers equipped with reliable laboratory service for mycobacterial culture and in vitro sensitivity testing as it requires prolonged use of expensive second-line drugs with a significant potential for toxicity. Conclusion: Emergence of MDR-TB and XDR TB has the potential to be a serious public health problem in Egypt and that strengthened TB control and improved monitoring of therapy is needed.

Keywords

• MDR-TB
• EDR-TB
• DOTS