Developing biomarker assays to accelerate tuberculosis drug development: defining target product profiles.

Drug development for tuberculosis is hindered by the methodological limitations in the definitions of patient outcomes, particularly the slow organism growth and difficulty in obtaining suitable and representative samples throughout the treatment. We developed target product profiles for biomarker assays suitable for early-phase and late-phase clinical drug trials by consulting subject-matter experts on the desirable performance and operational characteristics of such assays for monitoring of tuberculosis treatment in drug trials. Minimal and optimal criteria were defined for scope, intended use, pricing, performance, and operational characteristics of the biomarkers. Early-stage trial assays should accurately quantify the number of viable bacilli, whereas late-stage trial assays should match the number, predict relapse-free cure, and replace culture conversion endpoints. The operational criteria reflect the infrastructure and resources available for drug trials. The effective tools should define the sterilising activity of the drug and lower the probability of treatment failure or relapse in people with tuberculosis. The target product profiles outlined in this Review should guide and de-risk the development of biomarker-based assays suitable for phase 2 and 3 clinical drug trials.

Accuracy of the tuberculosis molecular bacterial load assay to diagnose and monitor response to anti-tuberculosis therapy: a longitudinal comparative study with standard-of-care smear microscopy, Xpert MTB/RIF Ultra, and culture in Uganda.

BACKGROUND: In 2018, the tuberculosis molecular bacterial load assay (TB-MBLA), a ribosomal RNA-based test, was acknowledged by WHO as a molecular assay that could replace smear microscopy and culture for monitoring tuberculosis treatment response. In this study, we evaluated the accuracy of TB-MBLA for diagnosis and monitoring of treatment response in comparison with standard-of-care tests. METHODS: For this longitudinal prospective study, patients aged 18 years or older with presumptive tuberculosis (coughing for at least 2 weeks, night sweats, and weight loss) were enrolled at China-Uganda Friendship Hospital Naguru (Kampala, Uganda). Participants were evaluated for tuberculosis by TB-MBLA in comparison with Xpert MTB/RIF Ultra (Xpert-Ultra) and smear microscopy, with Mycobacteria Growth Indicator Tube (MGIT) culture as a reference test. Participants who were positive on Xpert-Ultra were enrolled on a standard 6-month anti-tuberculosis regimen, and monitored for treatment response at weeks 2, 8, 17, and 26 after initiation of treatment and then 3 months after treatment. FINDINGS: Between Nov 15, 2019, and June 15, 2022, 210 participants (median age 35 years [IQR 27-44]) were enrolled. 135 (64%) participants were male and 72 (34%) were HIV positive. The pretreatment diagnostic sensitivities of TB-MBLA and Xpert-Ultra were similar (both 99% [95% CI 95-100]) but the specificity was higher for TB-MBLA (90% [83-96]) than for Xpert-Ultra (78% [68-86]). Ten participants were Xpert-Ultra trace positive, eight (80%) of whom were negative by TB-MBLA and MGIT culture. Smear microscopy had lower diagnostic sensitivity (75% [65-83]) but higher specificity (98% [93-100]) than TB-MBLA and Xpert-Ultra. Among participants who were smear microscopy negative, the sensitivity of TB-MBLA was 96% (95 CI 80-100) and was 100% (95% CI 86-100) in those who were HIV positive. 129 (61%) participants were identified as tuberculosis positive by Xpert-Ultra and these individuals were enrolled in the treatment group and monitored for treatment response. According to TB-MBLA, 19 of these patients cleared bacillary load to zero by week 2 of treatment and remained negative throughout the 6-month treatment follow-up. Positivity for tuberculosis decreased with treatment as measured by all tests, but the rate was slower with Xpert-Ultra. Consequently, 31 (33%) of 95 participants were still Xpert-Ultra positive at the end of treatment but were clinically well and negative on TB-MBLA and culture at 6 months of treatment. Two patients were still Xpert-Ultra positive with a further 3 months of post-treatment follow-up. The rate of conversion to negative of the DNA-based Xpert-Ultra was 3·3-times slower than that of the rRNA-based TB-MBLA. Consequently for the same patient, it would take 13 weeks and 52 weeks to reach complete tuberculosis negativity by TB-MBLA and Xpert-Ultra, respectively. Participants who were positive on smear microscopy at 8 weeks, who received an extra month of intensive treatment, had a similar TB-MBLA-measured bacillary load at 8 weeks to those who were smear microscopy negative. INTERPRETATION: TB-MBLA has a similar performance to Xpert-Ultra for pretreatment diagnosis of tuberculosis, but is more accurate at detecting and characterising the response to treatment than Xpert-Ultra and standard-of-care smear microscopy. FUNDING: European and Developing Countries Clinical Trials Partnership, Makerere University Research and Innovation Fund, US National Institutes of Health.

Treatment seeking behaviours, antibiotic use and relationships to multi-drug resistance: A study of urinary tract infection patients in Kenya, Tanzania and Uganda.

Antibacterial resistance (ABR) is a major public health threat. An important accelerating factor is treatment-seeking behaviour, including inappropriate antibiotic (AB) use. In many low- and middle-income countries (LMICs) this includes taking ABs with and without prescription sourced from various providers, including health facilities and community drug sellers. However, investigations of complex treatment-seeking, AB use and drug resistance in LMICs are scarce. The Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) Consortium collected questionnaire and microbiological data from adult outpatients with urinary tract infection (UTI)-like symptoms presenting at healthcare facilities in Kenya, Tanzania and Uganda. Using data from 6,388 patients, we analysed patterns of self-reported treatment seeking behaviours ('patient pathways') using process mining and single-channel sequence analysis. Among those with microbiologically confirmed UTI (n = 1,946), we used logistic regression to assess the relationship between treatment seeking behaviour, AB use, and the likelihood of having a multi-drug resistant (MDR) UTI. The most common treatment pathway for UTI-like symptoms in this sample involved attending health facilities, rather than other providers like drug sellers. Patients from sites in Tanzania and Uganda, where over 50% of patients had an MDR UTI, were more likely to report treatment failures, and have repeat visits to providers than those from Kenyan sites, where MDR UTI proportions were lower (33%). There was no strong or consistent relationship between individual AB use and likelihood of MDR UTI, after accounting for country context. The results highlight the hurdles East African patients face in accessing effective UTI care. These challenges are exacerbated by high rates of MDR UTI, suggesting a vicious cycle of failed treatment attempts and sustained selection for drug resistance. Whilst individual AB use may contribute to the risk of MDR UTI, our data show that factors related to context are stronger drivers of variations in ABR.

Predominance of multidrug-resistant bacteria causing urinary tract infections among symptomatic patients in East Africa: a call for action.

Background: In low- and middle-income countries, antibiotics are often prescribed for patients with symptoms of urinary tract infections (UTIs) without microbiological confirmation. Inappropriate antibiotic use can contribute to antimicrobial resistance (AMR) and the selection of MDR bacteria. Data on antibiotic susceptibility of cultured bacteria are important in drafting empirical treatment guidelines and monitoring resistance trends, which can prevent the spread of AMR. In East Africa, antibiotic susceptibility data are sparse. To fill the gap, this study reports common microorganisms and their susceptibility patterns isolated from patients with UTI-like symptoms in Kenya, Tanzania and Uganda. Within each country, patients were recruited from three sites that were sociodemographically distinct and representative of different populations. Methods: UTI was defined by the presence of >104 cfu/mL of one or two uropathogens in mid-stream urine samples. Identification of microorganisms was done using biochemical methods. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disc diffusion assay. MDR bacteria were defined as isolates resistant to at least one agent in three or more classes of antimicrobial agents. Results: Microbiologically confirmed UTI was observed in 2653 (35.0%) of the 7583 patients studied. The predominant bacteria were Escherichia coli (37.0%), Staphylococcus spp. (26.3%), Klebsiella spp. (5.8%) and Enterococcus spp. (5.5%). E. coli contributed 982 of the isolates, with an MDR proportion of 52.2%. Staphylococcus spp. contributed 697 of the isolates, with an MDR rate of 60.3%. The overall proportion of MDR bacteria (n = 1153) was 50.9%. Conclusions: MDR bacteria are common causes of UTI in patients attending healthcare centres in East African countries, which emphasizes the need for investment in laboratory culture capacity and diagnostic algorithms to improve accuracy of diagnosis that will lead to appropriate antibiotic use to prevent and control AMR.

Treatment seeking and antibiotic use for urinary tract infection symptoms in the time of COVID-19 in Tanzania and Uganda.

Background: There is still little empirical evidence on how the outbreak of coronavirus disease 2019 (COVID-19) and associated regulations may have disrupted care-seeking for non-COVID-19 conditions or affected antibiotic behaviours in low- and middle-income countries (LMICs). We aimed to investigate the differences in treatment-seeking behaviours and antibiotic use for urinary tract infection (UTI)-like symptoms before and during the pandemic at recruitment sites in two East African countries with different COVID-19 control policies: Mbarara, Uganda and Mwanza, Tanzania. Methods: In this repeated cross-sectional study, we used data from outpatients (pregnant adolescents aged >14 and adults aged >18) with UTI-like symptoms who visited health facilities in Mwanza, Tanzania and Mbarara, Uganda. We assessed the prevalence of self-reported behaviours (delays in care-seeking, providers visited, antibiotics taken) at three different time points, labelled as 'pre-COVID-19 phase' (February 2019 to February 2020), 'COVID-19 phase 1' (March 2020 to April 2020), and 'COVID-19 phase 2' (July 2021 to February 2022). Results: In both study sites, delays in care-seeking were less common during the pandemic than they were in the pre-COVID phase. Patients in Mwanza, Tanzania had shorter care-seeking pathways during the pandemic compared to before it, but this difference was not observed in Mbarara, Uganda. Health centres were the dominant sources of antibiotics in both settings. Over time, reported antibiotic use for UTI-like symptoms became more common in both settings. During the COVID-19 phases, there was a significant increase in self-reported use of antibiotics like metronidazole (<30% in the pre-COVID-19 phase to 40% in COVID phase 2) and doxycycline (30% in the pre-COVID-19 phase to 55% in COVID phase 2) that were not recommended for treating UTI-like symptoms in the National Treatment Guidelines in Mbarara, Uganda. Conclusions: There was no clear evidence that patients with UTI-like symptoms attending health care facilities had longer or more complex treatment pathways despite strict government-led interventions related to COVID-19. However, antibiotic use increased over time, including some antibiotics not recommended for treating UTI, which has implications for future antimicrobial resistance.

Localization and phenotyping of tuberculosis bacteria using a combination of deep learning and SVMs.

Successful treatment of pulmonary tuberculosis (TB) depends on early diagnosis and careful monitoring of treatment response. Identification of acid-fast bacilli by fluorescence microscopy of sputum smears is a common tool for both tasks. Microscopy-based analysis of the intracellular lipid content and dimensions of individual Mycobacterium tuberculosis (Mtb) cells also describe phenotypic changes which may improve our biological understanding of antibiotic therapy for TB. However, fluorescence microscopy is a challenging, time-consuming and subjective procedure. In this work, we automate examination of fields of view (FOVs) from microscopy images to determine the lipid content and dimensions (length and width) of Mtb cells. We introduce an adapted variation of the UNet model to efficiently localising bacteria within FOVs stained by two fluorescence dyes; auramine O to identify Mtb and LipidTox Red to identify intracellular lipids. Thereafter, we propose a feature extractor in conjunction with feature descriptors to extract a representation into a support vector multi-regressor and estimate the length and width of each bacterium. Using a real-world data corpus from Tanzania, the proposed method i) outperformed previous methods for bacterial detection with a 8% improvement (Dice coefficient) and ii) estimated the cell length and width with a root mean square error of less than 0.01%. Our network can be used to examine phenotypic characteristics of Mtb cells visualised by fluorescence microscopy, improving consistency and time efficiency of this procedure compared to manual methods.

Effect of seven anti-tuberculosis treatment regimens on sputum microbiome: a retrospective analysis of the HIGHRIF study 2 and PanACEA MAMS-TB clinical trials.

BACKGROUND: Respiratory tract microbiota has been described as the gatekeeper for respiratory health. We aimed to assess the impact of standard-of-care and experimental anti-tuberculosis treatment regimens on the respiratory microbiome and implications for treatment outcomes. METHODS: In this retrospective study, we analysed the sputum microbiome of participants with tuberculosis treated with six experimental regimens versus standard-of-care who were part of the HIGHRIF study 2 (NCT00760149) and PanACEA MAMS-TB (NCT01785186) clinical trials across a 3-month treatment follow-up period. Samples were from participants in Mbeya, Kilimanjaro, Bagamoyo, and Dar es Salaam, Tanzania. Experimental regimens were composed of different combinations of rifampicin (R), isoniazid (H), pyrazinamide (Z), ethambutol (E), moxifloxacin (M), and a new drug, SQ109 (Q). Reverse transcription was used to create complementary DNA for each participant's total sputum RNA and the V3-V4 region of the 16S rRNA gene was sequenced using the Illumina metagenomic technique. Qiime was used to analyse the amplicon sequence variants and estimate alpha diversity. Descriptive statistics were applied to assess differences in alpha diversity pre-treatment and post-treatment initiation and the effect of each treatment regimen. FINDINGS: Sequence data were obtained from 397 pre-treatment and post-treatment samples taken between Sept 26, 2008, and June 30, 2015, across seven treatment regimens. Pre-treatment microbiome (206 genera) was dominated by Firmicutes (2860 [44%] of 6500 amplicon sequence variants [ASVs]) at the phylum level and Streptococcus (2340 [36%] ASVs) at the genus level. Two regimens had a significant depressing effect on the microbiome after 2 weeks of treatment, HR20mg/kgZM (Shannon diversity index p=0·0041) and HR35mg/kgZE (p=0·027). Gram-negative bacteria were the most sensitive to bactericidal activity of treatment with the highest number of species suppressed being under the moxifloxacin regimen. By week 12 after treatment initiation, microbiomes had recovered to pre-treatment level except for the HR35mg/kgZE regimen and for genus Mycobacterium, which did not show recovery across all regimens. Tuberculosis culture conversion to negative by week 8 of treatment was associated with clearance of genus Neisseria, with a 98% reduction of the pre-treatment level. INTERPRETATION: HR20mg/kgZM was effective against tuberculosis without limiting microbiome recovery, which implies a shorter efficacious anti-tuberculosis regimen with improved treatment outcomes might be achieved without harming the commensal microbiota. FUNDING: European and Developing Countries Clinical Trials Partnership and German Ministry of Education and Research.

Evaluation of the diagnostic performance of the urine dipstick test for the detection of urinary tract infections in patients treated in Kenyan hospitals.

Introduction: Culture is the gold-standard diagnosis for urinary tract infections (UTIs). However, most hospitals in low-resource countries lack adequately equipped laboratories and relevant expertise to perform culture and, therefore, rely heavily on dipstick tests for UTI diagnosis. Research gap: In many Kenyan hospitals, routine evaluations are rarely done to assess the accuracy of popular screening tests such as the dipstick test. As such, there is a substantial risk of misdiagnosis emanating from inaccuracy in proxy screening tests. This may result in misuse, under-use or over-use of antimicrobials. Aim: The present study aimed to assess the accuracy of the urine dipstick test as a proxy for the diagnosis of UTIs in selected Kenyan hospitals. Methods: A hospital-based cross-sectional method was used. The utility of dipstick in the diagnosis of UTIs was assessed using midstream urine against culture as the gold standard. Results: The dipstick test predicted 1416 positive UTIs, but only 1027 were confirmed positive by culture, translating to a prevalence of 54.1 %. The sensitivity of the dipstick test was better when leucocytes and nitrite tests were combined (63.1 %) than when the two tests were separate (62.6 and 50.7 %, respectively). Similarly, the two tests combined had a better positive predictive value (87.0 %) than either test alone. The nitrite test had the best specificity (89.8 %) and negative predictive value (97.4 %) than leucocytes esterase (L.E) or both tests combined. In addition, sensitivity in samples from inpatients (69.2 %) was higher than from outpatients (62.7 %). Furthermore, the dipstick test had a better sensitivity and positive predictive value among female (66.0 and 88.6 %) than male patients (44.3 and 73.9 %). Among the various patient age groups, the dipstick test's sensitivity and positive predictive value were exceptionally high in patients ≥75 years old (87.5 and 93.3 %). Conclusion: Discrepancies in prevalence from the urine dipstick test and culture, the gold standard, indicate dipstick test inadequacy for accurate UTI diagnosis. The finding also demonstrates the need for urine culture for accurate UTI diagnosis. However, considering it is not always possible to perform a culture, especially in low-resource settings, future studies are needed to combine specific UTI symptoms and dipstick results to assess possible increases in the test's sensitivity. There is also a need to develop readily available and affordable algorithms that can detect UTIs where culture is not available.

Klebsiella pneumoniae carbapenamases in Escherichia coli isolated from humans and livestock in rural south-western Uganda.

BACKGROUND: The accumulation of resistance genes in Escherichia coli (E. coli) strains imposes limitations in the therapeutic options available for the treatment of infections caused by E.coli. Production of Klebsiella pneumoniae carbapenemase (KPC) by E. coli renders it resistant to broad-spectrum ß-lactam antibiotics. Globally there is existing evidence of spread of carbapenem-resistant E. coli in both humans and livestock driven by acquisition of the several other carbapenemase genes. Overall, there is little information regarding the extent of KPC gene distribution in E. coli. We set out to determine the prevalence, and evaluate the phenotypic and genotypic patterns of KPC in E. coli isolated from humans and their livestock in rural south western Uganda. METHODS: A laboratory-based, descriptive cross-sectional study was conducted involving 96 human and 96 livestock isolates collected from agro-pastoralist communities in Mbarara district in south western Uganda. Phenotypic and molecular methods (PCR) were used for presence and identification of KPC genes in the E. coli isolates. A chi-square test of independence was used to evaluate the differences in resistant patterns between carbapenems and isolates. RESULTS: The overall prevalence of carbapenem resistance by disk diffusion susceptibility testing (DST) for both humans and livestock isolates were 41.7% (80/192). DST-based resistance was identical in both human and livestock isolates (41.7%). The prevalence of carbapenem resistance based on Modified Hodge Test (MHT) was 5% (2/40) and 10% (4/40) for humans and livestock isolates respectively. Both human and livestock isolates, 48.7% (95/192) had the KPC gene, higher than phenotypic expression; 41.7% (80/192). blaKPC gene prevalence was overall similar in human isolates (51%; 49/96) vs livestock isolates (47.9%; 46/96). Approximately, 19% (15/80) of the isolates were phenotypically resistant to carbapenems and over 70% (79/112) of the phenotypically sensitive strains harbored the blaKPC gene. CONCLUSION: Our results suggest that both human and livestock isolates of E. coli in our setting carry the blaKPC gene with a high percentage of strains not actively expressing the blaKPC gene. The finding of fewer isolates carrying the KPC gene than those phenotypically resistant to carbapenems suggests that other mechanisms are playing a role in this phenomenon, calling for further researcher into this phenomenon.

Update on the diagnosis of tuberculosis.

BACKGROUND: Tuberculosis (TB) remains a global public health threat, and the development of rapid and precise diagnostic tools is the key to enabling the early start of treatment, monitoring response to treatment, and preventing the spread of the disease. OBJECTIVES: An overview of recent progress in host- and pathogen-based TB diagnostics. SOURCES: We conducted a PubMed search of recent relevant articles and guidelines on TB screening and diagnosis. CONTENT: An overview of currently used methods and perspectives in the following areas of TB diagnostics is provided: immune-based diagnostics, X-ray, clinical symptoms and scores, cough detection, culture of Mycobacterium tuberculosis and identifying its resistance profile using phenotypic and genotypic methods, including next-generation sequencing, sputum- and non-sputum-based molecular diagnosis of TB and monitoring of response to treatment. IMPLICATIONS: A brief overview of the most relevant advances and changes in international guidelines regarding screening and diagnosing TB is provided in this review. It aims at reviewing all relevant areas of diagnostics, including both pathogen- and host-based methods.

Unravelling patient pathways in the context of antibacterial resistance in East Africa.

BACKGROUND: A key factor driving the development and maintenance of antibacterial resistance (ABR) is individuals' use of antibiotics (ABs) to treat illness. To better understand motivations and context for antibiotic use we use the concept of a patient treatment-seeking pathway: a treatment journey encompassing where patients go when they are unwell, what motivates their choices, and how they obtain antibiotics. This paper investigates patterns and determinants of patient treatment-seeking pathways, and how they intersect with AB use in East Africa, a region where ABR-attributable deaths are exceptionally high. METHODS: The Holistic Approach to Unravelling Antibacterial Resistance (HATUA) Consortium collected quantitative data from 6,827 adult outpatients presenting with urinary tract infection (UTI) symptoms in Kenya, Tanzania, and Uganda between February 2019- September 2020, and conducted qualitative in-depth patient interviews with a subset (n = 116). We described patterns of treatment-seeking visually using Sankey plots and explored explanations and motivations using mixed-methods. Using Bayesian hierarchical regression modelling, we investigated the associations between socio-demographic, economic, healthcare, and attitudinal factors and three factors related to ABR: self-treatment as a first step, having a multi-step treatment pathway, and consuming ABs. RESULTS: Although most patients (86%) sought help from medical facilities in the first instance, many (56%) described multi-step, repetitive treatment-seeking pathways, which further increased the likelihood of consuming ABs. Higher socio-economic status patients were more likely to consume ABs and have multi-step pathways. Reasons for choosing providers (e.g., cost, location, time) were conditioned by wider structural factors such as hybrid healthcare systems and AB availability. CONCLUSION: There is likely to be a reinforcing cycle between complex, repetitive treatment pathways, AB consumption and ABR. A focus on individual antibiotic use as the key intervention point in this cycle ignores the contextual challenges patients face when treatment seeking, which include inadequate access to diagnostics, perceived inefficient public healthcare and ease of purchasing antibiotics without prescription. Pluralistic healthcare landscapes may promote more complex treatment seeking and therefore inappropriate AB use. We recommend further attention to healthcare system factors, focussing on medical facilities (e.g., accessible diagnostics, patient-doctor interactions, information flows), and community AB access points (e.g., drug sellers).

Urogenital pathogens in urine samples of clinically diagnosed urinary tract infected patients in Tanzania: A laboratory based cross-sectional study.

Background: Urogenital pathogens such as Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Trichomonas vaginalis have been reported to cause pyuria, however they are not routinely cultured from urine samples of patients clinically diagnosed to have urinary tract infections (UTI). In this study, pathogen specific PCR was done to identify the urogenital pathogens in the urine samples among clinically diagnosed UTI patients with negative routine urine culture. Methods: A cross-sectional study was conducted involving 227 archived urine samples from clinically diagnosed UTI patients with positive leucocyte esterase but negative urine culture results. The urogenital pathogens were detected using pathogen specific singleplex PCR. Data were cleaned and analyzed using STATA version 15. Results: The median age of patients was 31[IQR 23 - 51] years and the majority (174, 76.7%) were females. Two thirds of patients had history of antibiotic use two weeks prior to recruitment (154, 67.8%). A total of 62(27.3%) urine samples were positive for at least one urogenital pathogen. Of 62 positive samples, 9 had two urogenital pathogens and 1 had three urogenital pathogens. The most predominant urogenital pathogen detected was Neisseria gonorrhoeae 25(34.2%) and Trichomonas vaginalis 24(32.9%). Being female (aOR 2.4; 95% CI: 1.04 - 5.49; p-value 0.039) and having history of using antibiotics in the past two weeks (aOR 1.9; 95%CI: 1.04 - 3.60; p-value 0.036) was independently associated with the presence of urogenital pathogens. Conclusion: More than a quarter of female patients with clinical symptoms of UTI and routine urine culture negative results were infected with urogenital pathogens mainly Neisseria gonorrhoeae and Trichomonas vaginalis. Further research with a larger sample set in a range of settings is required to understand the implications of these finding generally.

Diagnostic accuracy of Xpert MTB/RIF Ultra and culture assays to detect Mycobacterium Tuberculosis using OMNIgene-sputum processed stool among adult TB presumptive patients in Uganda.

BACKGROUND: Stool is a potential sample for diagnosing Mycobacterium tuberculosis (Mtb) in patients with difficulty in expectorating. However, high mycobacterial culture contamination rates and Xpert MTB/RIF Ultra test error rates on stool samples have limited its use. OMNIgene SPUTUM (OM-S) is a sample transport reagent with characteristics of sputum decontamination while maintaining viable Mtb. We evaluated the impact of OM-S on Mtb diagnostic yield from stool using smear microscopy, Xpert MTB/RIF Ultra, and culture among presumptive TB patients. METHODS: Paired stool and expectorated sputum samples were collected from consecutive Ugandan adults undergoing diagnostic evaluation for pulmonary TB between June 2018 and June 2019. Stool was divided into 2 portions: one was homogenized in OM-S (OM-S stool) and the other in PBS (PBS stool) as control. Both sputum and processed stool were tested for Mtb using concentrated smear fluorescence microscopy (CFM), Xpert MTB/RIF Ultra (Xpert) and Mycobacteria Growth Indicator Tube (MGIT) culture. Sensitivity, specificity, and predictive values for each test were calculated against sputum MGIT culture as the reference standard. RESULTS: Of the 200 participants, 120 (60%) were male, 73 (37%) were HIV positive (median CD4 120 cells/uL (IQR 43-297)) and 128 (64%) had confirmed pulmonary TB by sputum MGIT culture. Seven (4%) OM-S stool Xpert samples reported errors while 47 (25%) and 103 (61%) were contaminated on OM-S stool MGIT and PBS stool MGIT, respectively. OM-S stool MGIT was able to accurately diagnose 56 of the contaminated PBS stool MGIT samples compared to only 5 of the contaminated OM-S stool MGIT samples diagnosed by PBS stool MGIT. Sensitivity (95% Confidence Interval, CI) 89% (83-94) for OM-S stool Xpert was higher compared to that of OM-S stool MGIT 60% (51-69) and PBS stool MGIT 42% (32-52). Specificity (95%CI) 91% (82-97) was also higher for OM-S stool Xpert compared to OM-S stool MGIT 64% (51-75) and PBS stool MGIT 26% (16-38). CONCLUSION: Stool processed with OM-S showed potential to improve Mtb diagnostic yield and reduce rates of indeterminate results when tested on Xpert and MGIT culture. The method may thus be of value in Mtb detection among patients with difficulty to expectorate.

Treatment seeking behaviours, antibiotic use and relationships to multi-drug resistance: A study of urinary tract infection patients in Kenya, Tanzania and Uganda.

Antibacterial resistance (ABR) is a major public health threat. An important accelerating factor is treatment-seeking behaviours, including inappropriate antibiotic (AB) use. In many low- and middle-income countries (LMICs) this includes taking ABs with and without prescription sourced from various providers, including health facilities and community drug sellers. However, investigations of complex treatment-seeking, AB use and drug resistance in LMICs are scarce. The Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) Consortium collected questionnaire and microbiological data from 6,827 adult outpatients with urinary tract infection (UTI)-like symptoms presenting at healthcare facilities in Kenya, Tanzania and Uganda. Among 6,388 patients we analysed patterns of self-reported treatment seeking behaviours ('patient pathways') using process mining and single-channel sequence analysis. Of those with microbiologically confirmed UTI (n=1,946), we used logistic regression to assessed the relationship between treatment seeking behaviour, AB use, and likelihood of having a multi-drug resistant (MDR) UTI. The most common treatment pathways for UTI-like symptoms included attending health facilities, rather than other providers (e.g. drug sellers). Patients from the sites sampled in Tanzania and Uganda, where prevalence of MDR UTI was over 50%, were more likely to report treatment failures, and have repeated visits to clinics/other providers, than those from Kenyan sites, where MDR UTI rates were lower (33%). There was no strong or consistent relationship between individual AB use and risk of MDR UTI, after accounting for country context. The results highlight challenges East African patients face in accessing effective UTI treatment. These challenges increase where rates of MDR UTI are higher, suggesting a reinforcing circle of failed treatment attempts and sustained selection for drug resistance. Whilst individual behaviours may contribute to the risk of MDR UTI, our data show that factors related to context are stronger drivers of ABR.

Antibiotic dispensing practices during COVID-19 and implications for antimicrobial resistance (AMR): parallel mystery client studies in Uganda and Tanzania.

BACKGROUND: Over-the-counter antibiotic access is common in low-and-middle-income countries and this may accelerate antimicrobial resistance. Our study explores critical aspects of the drug seller-client interaction and antibiotic dispensing patterns for simulated COVID-19 symptoms during the pandemic in two study sites in Tanzania and Uganda, countries with different government responses to the pandemic. METHODS: Research assistants posing as clients approached different types of drug sellers such as pharmacies (Pharms), drug shops (DSs), and accredited drug dispensing outlets (ADDOs) in Mwanza, Tanzania (nPharms = 415, nADDOs = 116) and Mbarara, Uganda (nPharms = 440, nDSs = 67), from June 10 to July 30, 2021. The mystery clients held no prescription and sought advice for simulated COVID-19 symptoms from the drug sellers. They documented the quality of their interaction with sellers and the type of drugs dispensed. RESULTS: Adherence to COVID-19 preventive measures and vigilance to COVID-19 symptoms was low in both sites but significantly higher in Uganda than in Tanzania. A higher percentage of drug sellers in Mbarara (Pharms = 36%, DSs = 35%, P-value = 0.947) compared to Mwanza (Pharms = 9%, ADDOs = 4%, P-value = 0.112) identified the client's symptoms as possibly COVID-19. More than three-quarters of drug sellers that sold prescription-only medicines in both Mbarara (Pharms = 86%, DSs = 89%) and Mwanza (Pharms = 93%, ADDOs = 97%) did not ask the MCs for a prescription. A relatively high percentage of drug sellers that sold prescription-only medicines in Mwanza (Pharms = 51%, ADDOs = 67%) compared to Mbarara (Pharms = 31%, DSs = 42%) sold a partial course without any hesitation. Of those who sold antibiotics, a higher proportion of drug sellers in Mbarara (Pharms = 73%, DSs = 78%, P-value = 0.580) compared to Mwanza (Pharms = 40% ADDOs = 46%, P-value = 0.537) sold antibiotics relevant for treating secondary bacterial infections in COVID-19 patients. CONCLUSION: Our study highlights low vigilance towards COVID-19 symptoms, widespread propensity to dispense prescription-only antibiotics without a prescription, and to dispense partial doses of antibiotics. This implies that drug dispensing related to COVID-19 may further drive AMR. Our study also highlights the need for more efforts to improve antibiotic stewardship among drug sellers in response to COVID-19 and to prepare them for future health emergencies.

Tuberculosis Molecular Bacterial Load Assay Reveals Early Delayed Bacterial Killing in Patients With Relapse.

Bacterial killing in patients with tuberculosis (TB) relapse was compared to that in patients achieving cure, measured by TB molecular bacterial load assay (TB-MBLA) or mycobacteria growth indicator tube (MGIT) time to positivity (TTP). TB-MBLA in 4 relapsed patients was significantly different compared to 132 cured patients after 2 weeks of treatment; MGIT TTP showed a significant difference from week 8.

A practical approach to render tuberculosis samples safe for application of tuberculosis molecular bacterial load assay in clinical settings without a biosafety level 3 laboratory.

BACKGROUND: Mycobacterium tuberculosis is a category B infectious pathogen requiring level-3-containment laboratories for handling. We assessed the efficacy of heat and Guanidine thiocyanate (GTC) to inactivate M. tuberculosis prior to performance of tuberculosis Molecular Bacterial Load Assay (TB-MBLA). METHOD: We performed in vitro experiments using M.tb, H37Rv reference strain and replicated in sputum specimens. A 0.5 MacFarland standard of M. tuberculosis was serially diluted to 1x101 CFU/mL and pooled sputum was homogenised prior to serial dilutions and Xpert MTB/RIF Ultra. Three replicates for each containing 1 mL for M. tuberculosis and sputum were inactivated at 80 °C for 20 min and with GTC for 15 min. Inactivated samples were processed for culture and TB-MBLA. RESULTS: No M. tuberculosis growth was observed in MGIT for GTC or heat treated H37Rv cultures. All untreated H37Rv dilutions were MGIT positive except the most diluted specimens. Heat and GTC treatment of H37Rv reduced TB-MBLA load by 2.1log10 (P = 0.7) and 1.8log10 (P = 0.7) respectively, compared to controls. In contrast, heat treated sputum had TB-MBLA bacterial load of 3.47 ± 3.53 log10 compared to 5.4 ± 3.1 log10 eCFU/mL for GTC (p = 0.57). All heat and GTC treated sputum were culture negative. CONCLUSION: Heat or GTC renders M. tuberculosis non-viable and eliminates the need for BSL3 laboratory for performing TB-MBLA in routine healthcare settings.

The role of multidimensional poverty in antibiotic misuse: a mixed-methods study of self-medication and non-adherence in Kenya, Tanzania, and Uganda.

BACKGROUND: Poverty is a proposed driver of antimicrobial resistance, influencing inappropriate antibiotic use in low-income and middle-income countries (LMICs). However, at subnational levels, studies investigating multidimensional poverty and antibiotic misuse are sparse, and the results are inconsistent. We aimed to investigate the relationship between multidimensional poverty and antibiotic use in patient populations in Kenya, Tanzania, and Uganda. METHODS: In this mixed-methods study, the Holistic Approach to Unravelling Antimicrobial Resistance (HATUA) Consortium collected data from 6827 outpatients (aged 18 years and older, or aged 14-18 years and pregnant) with urinary tract infection (UTI) symptoms in health-care facilities in Kenya, Tanzania, and Uganda. We used Bayesian hierarchical modelling to investigate the association between multidimensional poverty and self-reported antibiotic self-medication and non-adherence (ie, skipping a dose and not completing the course). We analysed linked qualitative in-depth patient interviews and unlinked focus-group discussions with community members. FINDINGS: Between Feb 10, 2019, and Sept 10, 2020, we collected data on 6827 outpatients, of whom 6345 patients had complete data; most individuals were female (5034 [79·2%]), younger than 35 years (3840 [60·5%]), worked in informal employment (2621 [41·3%]), and had primary-level education (2488 [39·2%]). Antibiotic misuse was more common among those least deprived, and lowest among those living in severe multidimensional poverty. Regardless of poverty status, difficulties in affording health care, and more familiarity with antibiotics, were related to more antibiotic misuse. Qualitative data from linked qualitative in-depth patient interviews (n=82) and unlinked focus-group discussions with community members (n=44 groups) suggested that self-medication and treatment non-adherence were driven by perceived inconvenience of the health-care system, financial barriers, and ease of unregulated antibiotic access. INTERPRETATION: We should not assume that higher deprivation drives antibiotic misuse. Structural barriers such as inefficiencies in public health care, combined with time and financial constraints, fuel alternative antibiotic access points and treatment non-adherence across all levels of deprivation. In designing interventions to reduce antibiotic misuse and address antimicrobial resistance, greater attention is required to these structural barriers that discourage optimal antibiotic use at all levels of the socioeconomic hierarchy in LMICs. FUNDING: UK National Institute for Health Research, UK Medical Research Council, and the Department of Health and Social Care.

A systematic review of strategies adopted to scale up COVID-19 testing in low-, middle- and high-income countries.

OBJECTIVE: We undertook a systematic review of strategies adopted to scale up COVID-19 testing in countries across income levels to identify successful approaches and facilitate learning. METHODS: Scholarly articles in English from PubMed, Google scholar and Google search engine describing strategies used to increase COVID-19 testing in countries were reviewed. Deductive analysis to allocate relevant text from the reviewed publications/reports to the a priori themes was done. MAIN RESULTS: The review covered 32 countries, including 11 high-income, 2 upper-middle-income, 13 lower-middle-income and 6 low-income countries. Most low- and middle-income countries (LMICs) increased the number of laboratories available for testing and deployed sample collection and shipment to the available laboratories. The high-income countries (HICs) that is, South Korea, Germany, Singapore and USA developed molecular diagnostics with accompanying regulatory and legislative framework adjustments to ensure the rapid development and use of the tests. HICs like South Korea leveraged existing manufacturing systems to develop tests, while the LMICs leveraged existing national disease control programmes (HIV, tuberculosis, malaria) to increase testing. Continent-wide, African Centres for Disease Control and Prevention-led collaborations increased testing across most African countries through building capacity by providing testing kits and training. CONCLUSION: Strategies taken appear to reflect the existing systems or economies of scale that a particular country could leverage. LMICs, for example, drew on the infectious disease control programmes already in place to harness expertise and laboratory capacity for COVID-19 testing. There however might have been strategies adopted by other countries but were never published and thus did not appear anywhere in the searched databases.