Key learning points.

<p>Key learning points.</p

Primary studies in individuals with schistosomiasis and HIV infection.

<p>Primary studies in individuals with schistosomiasis and HIV infection.</p

Markers of renal dysfunction in HIV-infected children and HIV-uninfected siblings.

<p>*the primary study outcome (defined operationally as eGFR <60mL/min/1.73m² and/or albuminuria >20mg/L in a single urine test)</p><p>^†eGFR = estimated glomerular filtration rate by modified Schwartz equation</p><p>Markers of renal dysfunction in HIV-infected children and HIV-uninfected siblings.</p

Factors associated with renal dysfunction among HIV-infected children and HIV-uninfected siblings by univariable logistic regression.

<p>*For the 122 HIV-infected cases only</p><p>^†<i>Schistosoma</i> infection and intensity were both determined with the urine CAA assay.</p><p>Factors associated with renal dysfunction among HIV-infected children and HIV-uninfected siblings by univariable logistic regression.</p

Markers of renal dysfunction associated with <i>Schistosoma</i> infection by univariable logistic regression.

<p>*the primary study outcome (defined operationally as eGFR <60mL/min/1.73m² and/or albuminuria >20mg/L in a single urine test)</p><p>^†eGFR = estimated glomerular filtration rate as calculated by modified Schwartz equation</p><p>Markers of renal dysfunction associated with <i>Schistosoma</i> infection by univariable logistic regression.</p

Baseline characteristics of HIV-infected children and HIV-uninfected siblings.

<p>*Severe malnutrition has been defined as a BMI-for-age Z score ≤-3.</p><p>Baseline characteristics of HIV-infected children and HIV-uninfected siblings.</p

Key Barriers and Solutions to Implementing Prompt and Concurrent HAART and Anti- Tuberculosis Therapy Identified by Bugando Medical Centre Staff Members in Mwanza, Tanzania.

<p>Key: ART: antiretroviral therapy. HAART: highly active anti-retroviral therapy. PEP: post-exposure prophylaxis. TB: tuberculosis.</p

Whole Genome Sequencing Investigation of a Tuberculosis Outbreak in Port-au-Prince, Haiti Caused by a Strain with a “Low-Level” <i>rpoB</i> Mutation L511P – Insights into a Mechanism of Resistance Escalation

<div><p>The World Health Organization recommends diagnosing Multidrug-Resistant Tuberculosis (MDR-TB) in high burden countries by detection of mutations in Rifampin (RIF) Resistance Determining Region of <i>Mycobacterium tuberculosis rpoB</i> gene with rapid molecular tests GeneXpert MTB/RIF and Hain MTBDR<i>plus</i>. Such mutations are found in >95% of <i>Mycobacterium tuberculosis</i> strains resistant to RIF by conventional culture-based drug susceptibility testing (DST). However routine diagnostic screening with molecular tests uncovered specific “low level” <i>rpoB</i> mutations conferring resistance to RIF below the critical concentration of 1 μg/ml in some phenotypically susceptible strains. Cases with discrepant phenotypic (susceptible) and genotypic (resistant) results for resistance to RIF account for at least 10% of resistant diagnoses by molecular tests and urgently require new guidelines to inform therapeutic decision making. Eight strains with a “low level” <i>rpoB</i> mutation L511P were isolated by GHESKIO laboratory between 2008 and 2012 from 6 HIV-negative and 2 HIV-positive patients during routine molecular testing. Five isolates with a single L511P mutation and two isolates with double mutation L511P&M515T had MICs for RIF between 0.125 and 0.5 μg/ml and tested susceptible in culture-based DST. The eighth isolate carried a double mutation L511P&D516C and was phenotypically resistant to RIF. All eight strains shared the same spoligotype SIT 53 commonly found in Haiti but classic epidemiological investigation failed to uncover direct contacts between the patients. Whole Genome Sequencing (WGS) revealed that L511P cluster isolates resulted from a clonal expansion of an ancestral strain resistant to Isoniazid and to a very low level of RIF. Under the selective pressure of RIF-based therapy the strain acquired mutation in the M306 codon of <i>embB</i> followed by secondary mutations in <i>rpoB</i> and escalation of resistance level. This scenario highlights the importance of subcritical resistance to RIF for both clinical management of patients and public health and provides support for introducing <i>rpoB</i> mutations as proxy for MICs into laboratory diagnosis of RIF resistance. This study illustrates that WGS is a promising multi-purpose genotyping tool for high-burden settings as it provides both “gold standard” sequencing results for prediction of drug susceptibility and a high-resolution data for epidemiological investigation in a single assay.</p></div

Correlation between Genotypic and Phenotypic Testing for Resistance to Rifampin in <i>Mycobacterium tuberculosis</i> Clinical Isolates in Haiti: Investigation of Cases with Discrepant Susceptibility Results

<div><p>The World Health Organization has recommended use of molecular-based tests MTBDRplus and GeneXpert MTB/RIF to diagnose multidrug-resistant tuberculosis in developing and high-burden countries. Both tests are based on detection of mutations in the Rifampin (RIF) Resistance-Determining Region of DNA-dependent RNA Polymerase gene (<i>rpoB</i>). Such mutations are found in 95–98% of <i>Mycobacterium tuberculosis</i> strains determined to be RIF-resistant by the “gold standard” culture-based drug susceptibility testing (DST).</p><p>We report the phenotypic and genotypic characterization of 153 consecutive clinical <i>Mycobacterium tuberculosis</i> strains diagnosed as RIF-resistant by molecular tests in our laboratory in Port-au-Prince, Haiti. 133 isolates (86.9%) were resistant to both RIF and Isoniazid and 4 isolates (2.6%) were RIF mono-resistant in MGIT SIRE liquid culture-based DST. However the remaining 16 isolates (10.5%) tested RIF-sensitive by the assay.</p><p>Five strains with discordant genotypic and phenotypic susceptibility results had RIF minimal inhibitory concentration (MIC) close to the cut-off value of 1 µg/ml used in phenotypic susceptibility assays and were confirmed as resistant by DST on solid media. Nine strains had sub-critical RIF MICs ranging from 0.063 to 0.5 µg/ml. Finally two strains were pan-susceptible and harbored a silent <i>rpoB</i> mutation.</p><p>Our data indicate that not only detection of the presence but also identification of the nature of <i>rpoB</i> mutation is needed to accurately diagnose resistance to RIF in <i>Mycobacterium tuberculosis</i>. Observed clinical significance of low-level resistance to RIF supports the re-evaluation of the present critical concentration of the drug used in culture-based DST assays.</p></div

Clinical and microbiological characteristics of 8 patients in L511P cluster.

<p>* Delayed response</p><p>** Deceased</p><p>n.d. Not determined</p><p>Clinical and microbiological characteristics of 8 patients in L511P cluster.</p