Search

Disseminated tuberculosis is a rare form of tuberculosis that can cause severe illness if diagnosed and treated late. We present the case of a young Senegalese woman who had a miscarriage due to a pelvic inflammatory disease, followed by the development of a left pleural effusion. Despite laparoscopic findings and a salpinx biopsy that revealed necrotizing granulomas, only microbiological examinations of pleural biopsies revealed the final diagnosis of disseminated, drug-sensitive tuberculosis.

Tuberculosis (TB) resistance to rifampicin, the most powerful drug leads to increase in mortality. Globally, half a million new patients develop such resistant TB each year, coupled with both inappropriate diagnosis and treatment initiation.We report a case of rifampicin resistant Mycobacterium tuberculosis whose rifampicin resistance was missed by Xpert MTB/RIF Assay G4 but detected by the Xpert MTB/RIF Ultra assay at different time points leading to increased delays for MDR-TB treatment initiation at Mulago Hospital, Kampala, Uganda. Our case report compels greater urgency in accelerating the transition to the newer assay, Ultra, to benefit from higher sensitivity of rifampicin resistance detection.

Background: Diagnosis of tuberculosis (TB) in patients co-infected with HIV poses an important challenge because of the low sensitivity and specificity of microscopy, the standard diagnostic method. This study aimed to evaluate the performance of the XpertMTB/RIF tool for TB diagnosis among TB-HIV co-infected patients. Methods: This was a cross-sectional analytical study conducted at Kibong'oto Infectious Disease Hospital in northern Tanzania and involved 69 patients. The performance of the XpertMTB/RIF and microscopy using LJ culture were determined and compared. Demographic, clinical, laboratory and radiological data were collected. Results: XpertMTB/RIF had a higher sensitivity (100%), specificity (100%), positive predictive value (79.2%) and negative predictive value (98.9%) as compared to microscopy. There was a strong correlation between XpertMTB/RIF, microscopy and Löwenstein-Jensen (LJ) culture in terms of their sensitivity and specificity. Conclusion: While using TB symptoms screening tool alone in HIV infected individuals may result into overtreatment, relying on microscopy alone has the potential of TB under-diagnosing, miss-diagnosing and delayed treatment. Our results show XpertMTB/RIF to be highly sensitive and specific to detect all culture positive TB cases among HIV patients. We recommend the adoption of XpertMTB/RIF as an early TB diagnosis tool among HIV patients for early detection of TB among HIV patients. [ABSTRACT FROM AUTHOR]

Rifampin heteroresistance-where rifampin-resistant and -susceptible tuberculosis (TB) bacilli coexist-may result in failed standard TB treatment and potential spread of rifampin-resistant strains. The detection of rifampin heteroresistance in routine rapid diagnostic tests (RDTs) allows for patients to receive prompt and effective multidrug-resistant-TB treatment and may improve rifampin-resistant TB control. The limit of detection (LOD) of rifampin heteroresistance for phenotypic drug susceptibility testing by the proportion method is 1% and, yet, is insufficiently documented for RDTs. We, therefore, aimed to determine, for the four RDTs (XpertMTB/RIF, XpertMTB/RIF Ultra, GenoTypeMTBDR plus v2.0, and GenoscholarNTM+MDRTBII), the LOD per probe and mutation, validated by CFU counting and targeted deep sequencing (Deeplex-MycTB). We selected one rifampin-susceptible and four rifampin-resistant strains, with mutations D435V, H445D, H445Y, and S450L, respectively, mixed them in various proportions in triplicate, tested them with each RDT, and determined the LODs per mutation type. Deeplex-MycTB revealed concordant proportions of the minority resistant variants in the mixtures. The Deeplex-MycTB-validated LODs ranged from 20% to 80% for XpertMTB/RIF, 20% to 70% for Xpert Ultra, 5% to 10% for GenoTypeMTBDRplusv2.0, and 1% to 10% for GenoscholarNTM+MDRTBII for the different mutations. Deeplex-MycTB, GenoTypeMTBDR plus v2.0, and GenoscholarNTM+MDRTBII provide explicit information on rifampin heteroresistance for the most frequently detected mutations. Classic Xpert and Ultra report rifampin heteroresistance as rifampin resistance, while Ultra may denote rifampin heteroresistance through "mixed patterns" of wild-type and mutant melt probe, melt peak temperatures. Overall, our findings inform end users that the threshold for reporting resistance in the case of rifampin heteroresistance is the highest for Classic Xpert and Ultra to resolve phenotypic and genotypic discordant rifampin-resistant TB results., (Copyright © 2019 Ng et al.)

Bacteriological diagnosis of tuberculosis has benefited in recent years from many technological advances to improve rapidity and sensitivity of the techniques. Thus, new LED fluorescence microscopes are in the process of replacing the optical microscopes and the Ziehl-Neelsen technique, making the examination more precise, faster and easier. The manual and automatic liquid culture has improved Lowenstein-Jensen culture and helped shorten antibiotic sensitivity test, allowing appropriate management of patients. The development and standardization of molecular biology methods led to the rapid detection and identification of mycobacterium directly in clinical samples but also of resistance genes for early diagnosis of MDR-TB and dealing with them quickly. However, the performance of these techniques does not sufficiently cover the diagnosis of smear-negative tuberculosis, extrapulmonary forms, children- and immune-compromised tuberculosis where sensitivity is limited. The diagnosis of latent tuberculosis is reinforced by the in vitro release testing of gamma interferon overcoming the lack of specificity of the tuberculin skin test. Despite considerable progress, more amelioration is still needed to improve these techniques in order to extend them to the paucibacillary tuberculosis and to facilitate their access to low-resource countries., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)