Impact of a pilot mHealth intervention on treatment outcomes of TB patients seeking care in the private sector using Propensity Scores Matching-Evidence collated from New Delhi, India.

Mobile health applications called Digital Adherence Technologies (DATs), are increasingly used for improving treatment adherence among Tuberculosis patients to attain cure, and/or other chronic diseases requiring long-term and complex medication regimens. These DATs are found to be useful in resource-limited settings because of their cost efficiency in reaching out to vulnerable groups (providing pill and clinic visit reminders, relevant health information, and motivational messages) or those staying in remote or rural areas. Despite their growing ubiquity, there is very limited evidence on how DATs improve healthcare outcomes.

Digital health technology used in emergency large-scale vaccination campaigns in low- and middle-income countries: a narrative review for improved pandemic preparedness.

Introduction: Large-scale vaccination campaigns can benefit from using digital health tools, particularly in low- and middle-income countries (LMICs). Selecting the best tool to fit into a pre-existing digital landscape can be challenging.

Areas Covered: We conducted a narrative review in PubMed and the grey literature for data available within 5 years to provide an overview of digital health tools used in large-scale vaccination campaigns for outbreak response in LMICs.

"DOST" Model to Link and Support Drug Resistant TB Patients From Private Sector: An Experience From Delhi, India.

Background: The National TB Elimination Programme (NTEP) has quite successfully involved private sector for referral of presumptive drug resistant TB (DR-TB) patients for molecular testing and referral for DR-TB management. There was a challenge as all the referred patients were not reaching to the facilities. A "DOST" intervention model was implemented to strengthen the patient care pathway.

Reliable and Scalable SARS-CoV-2 qPCR Testing at a High Sample Throughput: Lessons Learned from the Belgian Initiative.

We present our approach to rapidly establishing a standardized, multi-site, nation-wide COVID-19 screening program in Belgium. Under auspices of a federal government Task Force responsible for upscaling the country's testing capacity, we were able to set up a national testing initiative with readily available resources, putting in place a robust, validated, high-throughput, and decentralized qPCR molecular testing platform with embedded proficiency testing. We demonstrate how during an acute scarcity of equipment, kits, reagents, personnel, protective equipment, and sterile plastic supplies, we introduced an approach to rapidly build a reliable, validated, high-volume, high-confidence workflow based on heterogeneous instrumentation and diverse assays, assay components, and protocols.

Comparison of the Idylla™ Respiratory (IFV-RSV) panel with the GeneXpert Xpert® Flu/RSV assay: a retrospective study with nasopharyngeal and midturbinate samples.

The objective of this study was to compare the performance of the Idylla™ Respiratory (IFV-RSV) panel to the GeneXpert Xpert® Flu/RSV assay and establish the performance of a midturbinate swab compared to nasopharyngeal sampling. Considering GeneXpert® assay as imperfect reference standard, a positive percentage agreement between both assays of 98-100% for influenza A and 96-99% for influenza B could be calculated when 354 nasopharyngeal and 325 midturbinate swabs were retrospectively analyzed. Comparing midturbinate samples to nasopharyngeal specimens of 321 subjects, positive percentage agreement varied from 42% to 94% depending on both target virus and assay used.

Rapid accumulation of HIV-1 thymidine analogue mutations and phenotypic impact following prolonged viral failure on zidovudine-based first-line ART in sub-Saharan Africa.

Background: Lack of viral load monitoring of ART is known to be associated with slower switch from a failing regimen and thereby higher prevalence of MDR HIV-1. Many countries have continued to use thymidine analogue drugs despite recommendations to use tenofovir in combination with a cytosine analogue and NNRTI as first-line ART. The effect of accumulated thymidine analogue mutations (TAMs) on phenotypic resistance over time has been poorly characterized in the African setting.

Development, Evaluation, and Integration of a Quantitative Reverse-Transcription Polymerase Chain Reaction Diagnostic Test for Ebola Virus on a Molecular Diagnostics Platform.

Background: The 2013-2016 Ebola epidemic in West Africa resulted in accelerated development of rapid diagnostic tests for emergency outbreak preparedness. We describe the development and evaluation of the Idylla™ prototype Ebola virus test, a fully automated sample-to-result molecular diagnostic test for rapid detection of Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV).

Methods: The Idylla™ prototype Ebola virus test can simultaneously detect EBOV and SUDV in 200 µL of whole blood.

Phenotypic and genotypic analyses to guide selection of reverse transcriptase inhibitors in second-line HIV therapy following extended virological failure in Uganda.

Objectives: We investigated phenotypic and genotypic resistance after 2 years of first-line therapy with two HIV treatment regimens in the absence of virological monitoring.

Methods: NORA [Nevirapine OR Abacavir study, a sub-study of the Development of AntiRetroviral Therapy in Africa (DART) trial] randomized 600 symptomatic HIV-infected Ugandan adults (CD4 cell count <200 cells/mm(3)) to receive zidovudine/lamivudine plus abacavir (cABC arm) or nevirapine (cNVP arm). All virological tests were performed retrospectively, including resistance tests on week 96 plasma samples with HIV RNA levels ≥1000 copies/mL.

Amplification and sequencing of the hepatitis C virus NS3/4A protease and the NS5B polymerase regions for genotypic resistance detection of clinical isolates of subtypes 1a and 1b.

Genotypic testing based on subtype-specific amplification and population Sanger sequencing for two nonstructural (NS) protein-coding regions, the NS3/4A protease and the NS5B polymerase, of the hepatitis C virus (HCV) genome is described here. The protocols include the molecular steps for RNA extraction, one-step RT-PCR followed by inner PCR and population Sanger sequencing, to obtain the sequence information of the target regions from the clinical isolates of HCV subtypes 1a and 1b, which can be used to detect any sequence change in the viral genome as for example caused by the development of drug resistance in these two common viral targets.

HIV-1 genotyping of the protease-reverse transcriptase and integrase genes to detect mutations that confer antiretroviral resistance.

Major advances in antiretroviral (ARV) therapy during the last decade have made HIV-1 infections a chronic, manageable disease. In spite of these significant advancements, ARV drug resistance remains a hurdle for HIV-infected patients who are committed to lifelong treatments. Several commercially marketed and/or laboratory-developed tests (LDT) are available to detect resistance-associated mutations (RAMs) in HIV-1, by genotyping.

Risk factors for raltegravir resistance development in clinical practice.

Objectives: To investigate the best conditions of raltegravir use to avoid the selection of resistance mutations in the three main genetic pathways: 148, 155 and 143.

Methods: A total of 161 patients failing on raltegravir with two consecutive HIV-1 viral loads >20 copies/mL were studied. Ten parameters [HIV-1 RNA and CD4 at baseline and failure, genotypic sensitivity score (GSS) of treatment associated with raltegravir, protease inhibitors used, time spent on raltegravir, subtype, sex and age] were tested in univariate and multivariate logistic regression analyses and compared with the emergence of resistance mutations to raltegravir at failure.

Broad phenotypic cross-resistance to elvitegravir in HIV-infected patients failing on raltegravir-containing regimens.

The failure of raltegravir (RAL) is generally associated with the selection of mutations at integrase position Y143, Q148, or N155. However, a relatively high proportion of failures occurs in the absence of these changes. Here, we report the phenotypic susceptibilities to RAL and elvitegravir (EVG) for a large group of HIV-infected patients failing on RAL-containing regimens.

Comparative analysis of drug resistance among B and the most prevalent non-B HIV type 1 subtypes (C, F, and CRF02_AG) in Italy.

In recent years, increasing numbers of patients infected with HIV-1 non-B subtypes have been treated with modern antiretroviral regimens. Therefore, a better knowledge of HIV drug resistance in non-B strains is crucial. Thus, we compared the mutational pathways involved in drug resistance among the most common non-B subtypes in Italy (F, C, and CRF02_AG) and the B subtype.

Development and performance of conventional HIV-1 phenotyping (Antivirogram®) and genotype-based calculated phenotyping assay (virco®TYPE HIV-1) on protease and reverse transcriptase genes to evaluate drug resistance.

Objectives: A wide array of monitoring tests is commercially available to gauge HIV-1 disease progression and the overall health status of an HIV-1-infected patient. Viral load tests provide a picture of viral activity, while CD4 cell counts shed light on the immune status and can help physicians to prevent the development of opportunistic infections in patients. On the other hand, genotypic and phenotypic resistance testing and therapeutic drug monitoring help to optimize HIV-1 antiretroviral therapy.

A non-infectious cell-based phenotypic assay for the assessment of HIV-1 susceptibility to protease inhibitors.

Objectives: HIV-1 genotyping is widely accepted as a diagnostic tool to optimize therapy changes in patients whose antiretroviral regimen is failing. Phenotyping can substantially complement the information obtained from genotyping, especially in the presence of complex mutational patterns. However, drug susceptibility tests are laborious and require biosafety facilities.

HIV-1 nucleotide mixture detection in the virco(®)TYPE HIV-1 genotyping assay: a comparison between Sanger sequencing and 454 pyrosequencing.

HIV-1 Protease (PR) and Reverse Transcriptase (RT) genotyping is well established for the management of antiretroviral (ARV) drug therapy, as it is able to detect gene mutations encoding resistance to ARV compounds or drug classes, that are associated with reduced drug susceptibility (i.e. phenotype).

A comparison of HIV-1 drug susceptibility as provided by conventional phenotyping and by a phenotype prediction tool based on viral genotype.

Concordance between the conventional HIV-1 phenotypic drug resistance assay, PhenoSense (PS), and vircoTYPE HIV-1 (vT), a drug resistance assay based on prediction of the phenotype, was investigated in a data set from the Stanford HIV Resistance database (hivdb). Depending on the drug, between 287 and 902 genotype-phenotype data pairs were available for comparisons. Test results (fold-change values) in the two assays were highly correlated, with an overall mean correlation coefficient of 0.

The impact of individual human immunodeficiency virus type 1 protease mutations on drug susceptibility is highly influenced by complex interactions with the background protease sequence.

The requirement for multiple mutations for protease inhibitor (PI) resistance necessitates a better understanding of the molecular basis of resistance development. The novel bioinformatics resistance determination approach presented here elaborates on genetic profiles observed in clinical human immunodeficiency virus type 1 (HIV-1) isolates. Synthetic protease sequences were cloned in a wild-type HIV-1 background to generate a large number of close variants, covering 69 mutation clusters between multi-PI-resistant viruses and their corresponding genetically closely related, but PI-susceptible, counterparts.

Additional HIV-1 mutation patterns associated with reduced phenotypic susceptibility to etravirine in clinical samples.

We investigated the phenotypic impact of a number of uncommon amino acid substitutions at HIV-1 reverse transcriptase positions 103 and 138, which are not part of the etravirine resistance score and were found in combination with the high-impact mutation K101P. Etravirine phenotypic fold changes were 380-1400 for K101P + E138A/G/Q + K103N/S/T + V179I and 12-130 for K101P + (K103S +/- V179I) in the absence of E138A/G/Q. Although the effect of K103S is unclear, additional position 138 substitutions seem important for etravirine susceptibility.

Nine-year trends in clinically relevant reduced susceptibility of HIV-1 to antiretrovirals.

Background: Temporal changes in HIV-1 resistance both reflect and influence the clinical use of antiretrovirals (ARVs).

Objective: To determine temporal trends in reduced susceptibility to ARVs and resistance mutations in routine clinical samples (RCS) from HIV infected patients.

Study Design: Calculated fold-changes (FC) for ARVs were determined for viral genotypes from RCS received between July 1998 and June 2007 using vircoTYPE HIV-1 (Version 4.

Phenotypic impact of resistance mutations on etravirine susceptibility in HIV patients with prior failure to nonnucleoside analogues.

The phenotypic impact on etravirine susceptibility was examined in plasma specimens from 40 nonnucleoside reverse transcriptase inhibitor-experienced HIV patients with distinct nonnucleoside reverse transcriptase inhibitor resistance-associated mutations. Some etravirine resistance-associated mutations produced larger reductions in fold change than others. Y181C in combination with at least one etravirine resistance-associated mutation caused, on average, a 12.

The HIV-1 protease resistance mutation I50L is associated with resistance to atazanavir and susceptibility to other protease inhibitors in multiple mutational contexts.

Background: The HIV-1 protease mutation I50 L causes atazanavir resistance but increases susceptibility to other PIs. Predicted phenotypic FC values were obtained from viral genotypes, using the virtual Phenotype-LM bioinformatics tool (powering vircoTYPE).

Objective: To evaluate I50 L's effect on susceptibility to 8 PIs, in a large genotype database.

Novel drug resistance pattern associated with the mutations K70G and M184V in human immunodeficiency virus type 1 reverse transcriptase.

We describe an unusual pathway of human immunodeficiency virus type 1 reverse transcriptase resistance during therapy with tenofovir-emtricitabine, characterized initially by the mutations K70E and M184V and later by K70G and M184V, with the two mutations coexisting on the same viral genome. Phenotypic resistance to lamivudine, emtricitabine, abacavir, didanosine, and tenofovir was observed, whereas susceptibility to zidovudine and stavudine was preserved.

Prevalence of the HIV-1 protease mutation I47A in clinical practice and association with lopinavir resistance.

Mutation proI47A has recently been associated with lopinavir/ritonavir (LPV/r) resistance. Only four out of 1859 specimens (0.2%) sent for drug resistance testing (219 drug-naive and 1650 antiretroviral-experienced) showed I47A.