Laboratory Diagnosis of Tuberculosis in Resource-Poor Countries: Challenges and Opportunities

Abstract

SUMMARY With an estimated 9.4 million new cases globally, tuberculosis (TB) continues to be a major public health concern. Eighty percent of all cases worldwide occur in 22 high-burden, mainly resource-poor settings. This devastating impact of tuberculosis on vulnerable populations is also driven by its deadly synergy with HIV. Therefore, building capacity and enhancing universal access to rapid and accurate laboratory diagnostics are necessary to control TB and HIV-TB coinfections in resource-limited countries. The present review describes several new and established methods as well as the issues and challenges associated with implementing quality tuberculosis laboratory services in such countries. Recently, the WHO has endorsed some of these novel methods, and they have been made available at discounted prices for procurement by the public health sector of high-burden countries. In addition, international and national laboratory partners and donors are currently evaluating other new diagnostics that will allow further and more rapid testing in point-of-care settings. While some techniques are simple, others have complex requirements, and therefore, it is important to carefully determine how to link these new tests and incorporate them within a country's national diagnostic algorithm. Finally, the successful implementation of these methods is dependent on key partnerships in the international laboratory community and ensuring that adequate quality assurance programs are inherent in each country's laboratory network.

Evaluation of Drug Induced Liver Injury in Tuberculosis and Hepatitis Coinfection by Liver Fibrosis Index Score

“…Our results are comparable with results of other investigator who found that the onset of DILI ranged from 13 days to 58 days (median, 26 days) after initiation of treatment [36]. And in another study, the median latent period for developing DILI was found to be 19 [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] days [37].…”

“…Culture was performed using solid (Lowenstein-Jensen) and liquid (MGIT BACTEC 960) media using standard methodologies [14,15].…”

РЕТРОСПЕКТИВНА ЕВАЛУАЦИЈА COBAS AMPLICOR MTB ТЕСТА У ДЕТЕКЦИЈИ Mycobacterium tuberculosis ИЗ РЕСПИРАТОРНИХ УЗОРАКА

“…Бројне студије су показале високу осјетљивост код препарат-позитивних респираторних (90-100%), те нижу код препарат-негативних респираторних (50-95.9%) и нереспираторних узорака (23.53-98%). За респираторне узорке, укупна осјетљивост теста варира од 83% до 100%, а укупна специфичност од 91.3% до 100% (Parsons et al, 2011;Tortoli et al, 2012). PPV COBAS AMPLICOR MTB Теста варира од 61.2% до 100%, док је негативна предиктивна вриједност (NPV) од 33.3% до 98.4%, у овисности од врсте респираторних узорака (Fegou et al, 2005).…”

“…COBAS AMPLICOR MTB Тест је показао нижу осјетљивост код препарат-негативних узорака која је у овом истраживању износила 83.33%. На основу резултата досадашњих студија примјена COBAS AMPLICOR MTB Теста код препарат-негативних узорака спутума је показала осјетљивост од 50% до 95.9% (Parsons et al, 2011). Rajalahti et al наводе да осјетљивост теста код препарат-негативних узорака може бити знатно повећана ако се анализе раде на три узастопна узорка спутума (Rajalahti et al).…”

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“…There are a variety of methods were used such as clinical findings, X-ray chest, Microscopy-AFB, Tuberculin sensitivity test (PPD), microbiological culture method, PCR and Histopathology [5]. The standard TB diagnostic method in developing countries continues to be the sputum smear microscopy [6]. It was developed in 1880 and has remained almost the identical given that it relies on the presence of acid-fast bacilli (AFB) in the stained smear [7].…”