Incidence of tuberculous infection in a TB-endemic city.

Current metrics for TB transmission include TB notifications, disease mortality, and prevalence surveys. These metrics are helpful to national TB programs to assess the burden of disease, but they do not directly measure incident infection in the community.To estimate incidence of Mycobacterium tuberculosis infection in Kampala, Uganda, we performed a prospective cohort study between 2014 and 2017 which enrolled of 1,275 adult residents without signs of tuberculous infection (tuberculin skin test [TST] <5 mm and no signs of TB disease) and followed them for conversion of TST at 1 year.During follow-up, 194 participants converted the TST and 158 converted by one year. The incidence density of TST conversion was 13.2 conversions/100 person-year (95% CI 11.6-15.1), which corresponds to an annual cumulative incidence of tuberculous infection of 12.4% (95% CI 10.7-14.3). Cumulative incidence was greater among older participants and among men. Among participants who reported prior exposure to TB cases, the cumulative risk was highest among those reporting exposure during follow-up.The high annual incidence of infection suggests that residents of Kampala have adequate contact for infection with undetected, infectious cases of TB as they go about their daily lives..

Natural mycobacterium tuberculosis complex infection in a brown howler monkey (Alouatta guariba clamitans) in Brazil.

Neotropical primates rarely exhibit active tuberculosis. A brown howler monkey was found injured in an urban area. Histopathology revealed granulomatous inflammation in the lungs, lymph nodes, and liver. Immunohistochemistry and molecular analysis confirmed the presence of Mycobacterium tuberculosis complex. The findings highlight the importance of TB surveillance in nonhuman primates.

Unraveling tuberculosis patient cluster transmission chains: integrating WGS-based network with clinical and epidemiological insights.

Background: Tuberculosis remains a global health threat, and the World Health Organization reports a limited reduction in disease incidence rates, including both new and relapse cases. Therefore, studies targeting tuberculosis transmission chains and recurrent episodes are crucial for developing the most effective control measures. Herein, multiple tuberculosis clusters were retrospectively investigated by integrating patients' epidemiological and clinical information with median-joining networks recreated based on whole genome sequencing (WGS) data of Mycobacterium tuberculosis isolates. Methods: Epidemiologically linked tuberculosis patient clusters were identified during the source case investigation for pediatric tuberculosis patients. Only M. tuberculosis isolate DNA samples with previously determined spoligotypes identical within clusters were subjected to WGS and further median-joining network recreation. Relevant clinical and epidemiological data were obtained from patient medical records. Results: We investigated 18 clusters comprising 100 active tuberculosis patients 29 of whom were children at the time of diagnosis; nine patients experienced recurrent episodes. M. tuberculosis isolates of studied clusters belonged to Lineages 2 (sub-lineage 2.2.1) and 4 (sub-lineages 4.3.3, 4.1.2.1, 4.8, and 4.2.1), while sub-lineage 4.3.3 (LAM) was the most abundant. Isolates of six clusters were drug-resistant. Within clusters, the maximum genetic distance between closely related isolates was only 5-11 single nucleotide variants (SNVs). Recreated median-joining networks, integrated with patients' diagnoses, specimen collection dates, sputum smear microscopy, and epidemiological investigation results indicated transmission directions within clusters and long periods of latent infection. It also facilitated the identification of potential infection sources for pediatric patients and recurrent active tuberculosis episodes refuting the reactivation possibility despite the small genetic distance of ≤5 SNVs between isolates. However, unidentified active tuberculosis cases within the cluster, the variable mycobacterial mutation rate in dormant and active states, and low M. tuberculosis genetic variability inferred precise transmission chain delineation. In some cases, heterozygous SNVs with an allelic frequency of 10-73% proved valuable in identifying direct transmission events. Conclusion: The complex approach of integrating tuberculosis cluster WGS-data-based median-joining networks with relevant epidemiological and clinical data proved valuable in delineating epidemiologically linked patient transmission chains and deciphering causes of recurrent tuberculosis episodes within clusters.

Granulomatous meningoencephalitis and blindness associated with Mycobacterium tuberculosis complex infection in a senile female chimpanzee (Pan troglodytes).

A 40-year old female chimpanzee (Pan troglodytes) developed hyporexia, weight loss, followed by progressive and complete blindness. Tomography demonstrated an intracranial mass in the rostroventral brain involving the optic chiasm, with a presumptive diagnosis of neoplasm. However, histopathology revealed a granulomatous meningoencephalitis, and tissue samples tested positive for Mycobacterium tuberculosis.

[Progress in lipoarabinomannan antigen detection for tuberculosis diagnosis in people living with HIV/AIDS].

Tuberculosis (TB) is the leading cause of death among people living with HIV/AIDS (PLWHA), posing a significant disease burden. Early TB screening in PLWHA is a key intervention to reduce transmission and control disease progression. ​Lipoarabinomannan (LAM) is a glycolipid of Mycobacterium tuberculosis (MTB) that can be detected in the urine of tuberculosis patients. LAM is useful for the rapid and accurate diagnosis of tuberculosis. This article reviews LAM and its application and limitations in the diagnosis of PLWHA, hoping to provide a reference for the diagnosis of tuberculosis in PLWHA.

Population structure and spatial distribution of Mycobacterium tuberculosis in Ethiopia.

Ethiopia is one of the countries with a high tuberculosis (TB) burden, yet little is known about the spatial distribution of Mycobacterium tuberculosis (Mtb) lineages. This study identifies the spoligotyping of 1735 archived Mtb isolates from the National Drug Resistance Survey, collected between November 2011 and June 2013, to investigate Mtb population structure and spatial distribution. Spoligotype International Types (SITs) and lineages were retrieved from online databases. The distribution of lineages was evaluated using Fisher's exact test and logistic regression models. The Global Moran's Index and Getis-Ord Gi statistic were utilized to identify hotspot areas. Our results showed that spoligotypes could be interpreted and led to 4 lineages and 283 spoligotype patterns in 91% of the isolates, including 4% of those with multidrug/rifampicin resistance (MDR/RR) TB. The identified Mtb lineages were lineage 1 (1.8%), lineage 3 (25.9%), lineage 4 (70.6%) and lineage 7 (1.6%). The proportion of lineages 3 and 4 varied by regions, with lineage 3 being significantly greater than lineage 4 in reports from Gambella (AOR = 4.37, P < 0.001) and Tigray (AOR = 3.44, P = 0.001) and lineage 4 being significantly higher in Southern Nations Nationalities and Peoples Region (AOR = 1.97, P = 0.026) than lineage 3. Hotspots for lineage 1 were located in eastern Ethiopia, while a lineage 7 hotspot was identified in northern and western Ethiopia. The five prevalent spoligotypes, which were SIT149, SIT53, SIT25, SIT37 and SIT26 account for 42.8% of all isolates under investigation, while SIT149, SIT53 and SIT21 account for 52-57.8% of drug-resistant TB cases. TB and drug resistant TB are mainly caused by lineages 3 and 4, and significant proportions of the prevalent spoligotypes also influence drug-resistant TB and the total TB burden. Regional variations in lineages may result from both local and cross-border spread.

Drug-resistant Mycobacterium tuberculosis among Nepalese patients at a tuberculosis referral center.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB), characterized by isoniazid and rifampicin resistance, is caused by chromosomal mutations that restrict treatment options and complicate tuberculosis management. This study sought to investigate the prevalence of pre-extensively drug-resistant (pre-XDR) and extensively drug-resistant (XDR) tuberculosis, as well as mutation pattern, in Nepalese patients with MDR/rifampicin-resistant (RR)-TB strains. METHODS: A cross-sectional study was conducted on MDR/RR-TB patients at the German Nepal Tuberculosis Project from June 2017 to June 2018. The MTBDRsl line probe assay identified pre-XDR-TB and XDR-TB. Pre-XDR-TB included MDR/RR-TB with resistance to any fluoroquinolone (FLQ), while XDR-TB included MDR/RR-TB with resistance to any FLQ and at least one additional group A drug. Mutation status was determined by comparing bands on reaction zones [gyrA and gyrB for FLQ resistance, rrs for SILD resistance, and eis for low-level kanamycin resistance, according to the GenoType MTBDRsl VER 2.0, Hain Lifescience GmbH, Nehren, Germany definition of pre-XDR and XDR] to the evaluation sheet. SPSS version 17.0 was used for data analysis. RESULTS: Out of a total of 171 patients with MDR/RR-TB, 160 had (93.57%) had MTBC, of whom 57 (35.63%) had pre-XDR-TB and 10 (6.25%) had XDR-TB. Among the pre-XDR-TB strains, 56 (98.25%) were FLQ resistant, while 1 (1.75%) was SLID resistant. The most frequent mutations were found at codons MUT3C (57.14%, 32/56) and MUT1 (23.21%, 13/56) of the gyrA gene. One patient had SLID resistant genotype at the MUT1 codon of the rrs gene (100%, 1/1). XDR-TB mutation bands were mostly detected on MUT1 (30%, 3/10) of the gyrA and rrs, MUT3C (30%, 3/10) of the gyrA, and MUT1 (30%, 3/10) of the rrs. CONCLUSIONS: Pre-XDR-TB had a significantly higher likelihood than XDR-TB, with different specific mutation bands present in gyrA and rrs genes.

Prevalence and genetic basis of Mycobacterium tuberculosis resistance to pretomanid in China.

BACKGROUND: Pretomanid is a key component of new regimens for the treatment of drug-resistant tuberculosis (TB) which are being rolled out globally. However, there is limited information on the prevalence of pre-existing resistance to the drug. METHODS: To investigate pretomanid resistance rates in China and its underlying genetic basis, as well as to generate additional minimum inhibitory concentration (MIC) data for epidemiological cutoff (ECOFF)/breakpoint setting, we performed MIC determinations in the Mycobacterial Growth Indicator Tube™ (MGIT) system, followed by WGS analysis, on 475 Mycobacterium tuberculosis (MTB) isolated from Chinese TB patients between 2013 and 2020. RESULTS: We observed a pretomanid MIC distribution with a 99% ECOFF equal to 0.5 mg/L. Of the 15 isolates with MIC values > 0.5 mg/L, one (MIC = 1 mg/L) was identified as MTB lineage 1 (L1), a genotype previously reported to be intrinsically less susceptible to pretomanid, two were borderline resistant (MIC = 2-4 mg/L) and the remaining 12 isolates were highly resistant (MIC ≥ 16 mg/L) to the drug. Five resistant isolates did not harbor mutations in the known pretomanid resistant genes. CONCLUSIONS: Our results further support a breakpoint of 0.5 mg/L for a non-L1 MTB population, which is characteristic of China. Further, our data point to an unexpected high (14/475, 3%) pre-existing pretomanid resistance rate in the country, as well as to the existence of yet-to-be-discovered pretomanid resistance genes.

Immunohistochemistry and real-time Polymerase Chain Reaction: importance in the diagnosis of intestinal tuberculosis in a Peruvian population.

INTRODUCTION: The diagnosis of intestinal tuberculosis is challenging even nowadays. This study aims to report the positivity rates of new diagnostic methods such as immunohistochemistry and Real-Time Polymerase Chain Reaction in patients with intestinal tuberculosis, as well as describe the pathological and endoscopic features of intestinal tuberculosis in our population. METHODS: This was a retrospective observational study conducted in patients diagnosed with intestinal tuberculosis, between 2010 to 2023 from the Hospital Nacional Daniel Alcides Carrion and a Private Pathology Center, both located in Peru. Clinical data was obtained, histologic features were independently re-evaluated by three pathologists; and immunohistochemistry and real-time Polymerase Chain Reaction evaluation were performed. The 33 patients with intestinal tuberculosis who fulfilled the inclusion criteria were recruited. RESULTS: Immunohistochemistry was positive in 90.9% of cases, while real-time Polymerase Chain Reaction was positive in 38.7%. The ileocecal region was the most affected area (33.3%), and the most frequent endoscopic appearance was an ulcer (63.6%). Most of the granulomas were composed solely of epithelioid histiocytes (75.8%). Crypt architectural disarray was the second most frequent histologic finding (78.8%) after granulomas, but most of them were mild. CONCLUSION: Since immunohistochemistry does not require an intact cell wall, it demonstrates higher sensitivity compared to Ziehl-Neelsen staining. Therefore, it could be helpful for the diagnosis of paucibacillary tuberculosis.

Diagnostic Performance of STANDARD™ M10 Multidrug-resistant Tuberculosis Assay for Detection of Mycobacterium tuberculosis and Rifampicin and Isoniazid Resistance in Zimbabwe.

BACKGROUND: Although Zimbabwe has transitioned out of the 30 high-burden countries, it still remained in the 30 high multidrug-resistant (MDR)/rifampicin-resistant tuberculosis (TB) burden. Rapid detection of rifampicin (RIF) and isoniazid (INH) is essential for the diagnosis of MDR-TB. The World Health Organization has recommended the use of molecular WHO-recommended rapid diagnostic (mWRD) for TB and DR-TB. STANDARD™ M10 MDR-TB assay is a new molecular rapid diagnostic assay developed by SD Biosensor for the detection of Mycobacterium tuberculosis (MTB) and RIF and INF resistance. This study aims to determine the diagnostic accuracy of STANDARD™ M10 MDR-TB assay. METHODS: The study was conducted on 214 samples with different MTB and RIF and INH resistance status. The STANDARD™ M10 MDR-TB assay was performed according to the manufacturer's instructions. Xpert MTB/RIF Ultra, MGIT culture, and phenotypic drug susceptibility testing are used as comparative methods. RESULTS: The sensitivity and specificity of STANDARD™ M10 MDR-TB assay for the detection of MTB are 99% and 97.9%, respectively. The sensitivity and specificity of the assay for detection of MDR-TB were 97.8% and 100%, respectively. CONCLUSION: The STANDARD™ M10 MDR-TB assay demonstrated high diagnostic accuracy in the detection of MTB and RIF and INH resistance. This molecular assay can also be used as an alternative to other mWRD assays.

Two Difficult Pandemics: Tuberculosis and COVID-19.

BACKGROUND: The coinfection of Mycobacterium tuberculosis and SARS-CoV-2 is called tuberculosis and COVID-19 coinfection (TB-COVID-19). We aimed to share the clinical, radiological, and laboratory findings and treatment processes of our patients with TB-COVID-19 coinfection in our tertiary reference hospital. METHODS: Patients aged 18 years and over and hospitalized in the tuberculosis service between March 2020 and September 2022 were included. All coinfected patients whose COVID-19 polymerase chain reaction results were positive while receiving tuberculosis treatment or who were diagnosed with tuberculosis while receiving treatment for COVID-19 were included. RESULTS: The number of patients was 39; 61.6% of males; the mean age was 52 ± 17.1 years; 20% were foreign nationals; 92.5% were Asian; 69.5% had a bacteriological diagnosis; 84.6% had pulmonary tuberculosis; 10% had received antituberculosis treatment before; and 87.5% were sensitive to the first-line antituberculosis drugs. The most common comorbidities were diabetes and hypertension. 87.5% of the patients were diagnosed with tuberculosis and were superinfected with COVID-19 while receiving tuberculosis treatment. 49.5% of patients had received at least one dose of COVID-19 vaccine. The most common presenting symptom was cough and sputum; the prominent laboratory parameter was C-reactive protein increase, and thorax computed tomography finding was consolidation, tree-in-bud, and cavitation. While 45.9% of the patients were still under treatment, 1 (2.5%) patient also resulted in mortality. CONCLUSION: In this study, attention was drawn to two infectious diseases seen with respiratory tract symptoms. The mortality rate was found to be low. Neither disease was found to be a factor aggravating the course of each other.

Correlation of Cyclic Threshold Values Generated by GeneXpert Ultra MTB/RIF and Fluorescence Microscopy to Predict Mycobacterial Burden in Suspected Cases of Pulmonary Tuberculosis.

BACKGROUND: Smear microscopy for acid-fast bacilli visualization is important to assess the infectivity rate in patients with pulmonary tuberculosis (PTB), but it has limited sensitivity; hence, it is important to find an alternative strategy. The aim of our study was to compare the fluorescence microscopy grading by Auramine O phenol staining technique of respiratory samples with the cyclic threshold (Ct) values of GeneXpert Ultra (Mycobacterium tuberculosis/rifampicin [MTB/RIF]) and assess the diagnostic efficacy of GeneXpert Ultra (MTB/RIF) compared to microscopy in suspected cases of PTB. METHODS: The study was conducted in the Mycobacteriology Laboratory, Department of Microbiology, in Kasturba Hospital, Manipal. The study was a prospective, single-centered, cross-sectional study. Four hundred and fifty-two respiratory samples were included in the study. An optimal Ct cutoff value for ruling smear-positivity and smear-negativity and the mean Ct cutoff value were calculated. Clinical and radiological data from the requisition forms were assessed. IBM SPSS statistics software version 22 was used. The correlation between GeneXpert Ultra (MTB/RIF) Ct values and smear status was calculated by polychoric correlation. The extended McNemar's test was used to find the association between the variables. RESULTS: GeneXpert Ultra (MTB/RIF) yielded a higher positivity rate of 22.2% compared to smear microscopy 17.2%. Ct value and smear grading yielded a positive correlation (P = 0.8681; P < 0.05). GeneXpert Ultra (MTB/RIF) yielded nontuberculous mycobacteria in five undetected cases and speciated as Mycobacterium abscessus complex. CONCLUSIONS: Our study confirms the GeneXpert Ultra (MTB/RIF) Ct value levels as a predictor of smear positivity.

Spinal Tuberculosis: An Exhaustive Diagnosis.

BACKGROUND: The most common organ affected due to tuberculosis (TB) is the lungs. Extrapulmonary TB is less common. Musculoskeletal organs are affected in around 8% of all tubercular patients, of which the spine is affected in almost half of the patients. The criteria for diagnosing spinal TB are quite difficult and we use an array of investigations for the same. METHODS: A retrospective study was carried out in the Neurosurgery and Microbiology Department at IMS and SUM Hospital between January 2021 and November 2023, and data were collected and tabulated in an Excel sheet. One hundred patients with spinal TB were evaluated, and their age, sex, samples sent, diagnostic investigation, duration of diagnosis from hospital admission, histopathology results, and surgical intervention (done or not) were recorded. RESULTS: The best investigation done to diagnose spinal TB was imaging and surgical/computed tomography (CT)-guided biopsy. The earliest result to diagnose spinal TB was histopathology. The yield of positivity in pus culture, smear microscopy, and true nucleic acid amplification test (NAAT) was found to be low even though sensitivity was on the higher side. CONCLUSION: Even though we have an array of investigations for diagnosing spinal TB, the best and the earliest diagnosing test was imaging plus CT-guided biopsy. The confirmation is made in the biopsy. Finding acid-fast bacteria (AFB) and NAAT tests are additional beneficial tests to supplement the diagnosis. Hence, we can conclude that sending for tests like AFB in pus, NAAT, and GeneXpert is a wastage of biological samples and delays in diagnosis.

Risk factors of adult isoniazid-resistant and rifampicin-susceptible tuberculosis in Nanjing, 2019-2021.

INTRODUCTION: This study aimed to analyze the risk factors associated with isoniazid-resistant and rifampicin-susceptible tuberculosis (Hr-TB) in adults. METHOD: The clinical data of 1,844 adult inpatients diagnosed with culture-positive pulmonary tuberculosis (PTB) in Nanjing Second Hospital from January 2019 and December 2021 were collected. All culture positive strain from the patient specimens underwent drug susceptibility testing (DST). Among them, 166 patients with Hr-TB were categorized as the Hr-TB group, while the remaining 1,678 patients were classified as having drug-susceptible tuberculosis (DS-TB). Hierarchical logistic regression was employed for multivariate analysis to identify variables associated with Hr-TB. RESULTS: Multivariate logistic regression analysis revealed that individuals with diabetes mellitus (DM) (OR 1.472, 95% CI 1.037-2.088, p = 0.030) and a history of previous tuberculosis treatment (OR 2.913, 95% CI 1.971-4.306, p = 0.000) were at higher risk of developing adult Hr-TB, with this risk being more pronounced in male patients. Within the cohort, 1,640 patients were newly treated, and among them, DM (OR 1.662, 95% CI 1.123-2.461, p = 0.011) was identified as risk factors for Hr-TB. CONCLUSIONS: Diabetes mellitus is a risk factor for Hr-TB in adults, and the contribution of diabetes as a risk factor was more pronounced in the newly treatment or male subgroup. And previous TB treatment history is also a risk factor for Hr-TB in adults.

Impact of line probe assay-based molecular testing on individualized treatment in patients with rifampicin-resistant tuberculosis: data from the prospective INNOVA4TB cohort study in Ukraine.

BACKGROUND: Ukraine remains a high World Health Organization priority country for drug-resistant tuberculosis (TB). Rifampicin-resistant TB (RR-TB) has a more protracted, more complicated, and more expensive treatment. In 2021, Ukraine reported 4025 RR-TB cases - 5.4 times more (751) than all 30 European Union/ European Economic Area countries together. OBJECTIVES: The objective of the study was to determine the diagnostic accuracy of line probe assay (LPA), AID Autoimmun Diagnostika GmbH, for detecting resistance to anti-TB drugs and its clinical application for selecting treatment regimens. DESIGN: A prospective observational cohort study. METHODS: From May 2019 to June 2020, we consecutively enrolled patients with active TB hospitalized at the Regional Phthisiopulmonology Center (Vinnytsia, Ukraine), aged between 18 and 82 years. The LPA was performed in the Genetic Research Laboratory at National Pirogov Memorial Medical University, Vinnytsia, Ukraine. RESULTS: A total of 84 clinical specimens and 97 culture isolates from 126 TB patients were tested during the study. Accuracy (95% confidence interval) of LPA for clinical samples in comparison with phenotypic drug susceptibility test (DST) was 80.1 (68.5-89.0) for isoniazid (H), 74.7 (62.4-84.6) for rifampicin (R), 74.4 (62.5-84.1) for ethambutol, 71.4 (41.9-91.6) for streptomycin, 84.6 (62.4-96.5) for prothionamide/ethionamide, and 84.6 (73.6-92.3) for levofloxacin (Lfx), respectively. We found a significantly higher sensitivity of LPA for H, R, and Lfx for the culture isolates compared to clinical specimens (p < 0.05). LPA detected different mutations in 6 out of 17 (35.5%) patients susceptible to R by Xpert. A shorter treatment regimen with an injectable agent demonstrated a low suitability rate of 5% (8/156) in a cohort of RR-TB patients from Ukraine. CONCLUSION: Initial LPA testing accurately identifies resistance to anti-TB drugs and facilitates the selection of an appropriate treatment regimen, minimizing exposure to empirical therapy.

Study about the impact of rapid resistance detection on the treatment of patients with tuberculosis in Ukraine written by healthcare and biomedical professionals to better understand how we can improve the results of treatment and to prevent spreading of resistant bacteriaWhy was the study done? Ukraine has over 4000 patients with tuberculosis (TB) resistant to at least one drug (rifampicin) - five times that of all 30 European Union/European Economic Area countries combined. Unfortunately, only about 60% of such patients have been successfully treated in 2019. At that time, the majority of people suffering from tuberculosis in Ukraine, after checking resistance to rifampicin, initially received standard combinations of the first-line or second-line anti-TB medicines before the result of traditionally used tests (usually few weeks later) became available to individualize the treatment. Alternatively, the sputum could be transported to some overloaded reference laboratories located hundreds of km away from the treatment places.What did the researchers do? The INNOVA4TB team implemented rapid diagnostics of drug resistance in routine practice, guiding key antibiotics use in TB patients. A total of 181 samples from 126 individuals were tested during 2019-2020.What did the researchers find? This new diagnostic technology accurately detected resistance to 9 anti-TB drugs in sputum samples. It could be helpful to select appropriate TB treatment regimens, reducing time for decision from 1 month up to 2 days. Recommended at the study time 9-month shorter standardized treatment regimen with injectable agent was suitable only for 5% of patients for whom it was indicated in Vinnytsia region of Ukraine.What do the findings mean? The study has demonstrated successful implementation of the new molecular diagnostic technology from scratch in a country with restricted resources and limited TB laboratory capacity. This test can facilitate optimal distribution of available wards among patients with different profiles of resistance and correct choice between treatment options.

Determinants of sputum culture conversion time in multidrug-resistant tuberculosis patients in ALERT comprehensive specialized hospital, Addis Ababa, Ethiopia: A retrospective cohort study.

INTRODUCTION: The treatment response of multi-drug resistance tuberculosis (MDR-Tuberculosis) patients is mainly dictated by the sputum culture conversion. An earlier culture conversion is a remarkable indicator of the improvement in the treatment response. In this study, we aimed to determine the time to culture conversion and its associated factors among MDR-Tuberculosis patients in All Africa Leprosy, Tuberculosis and Rehabilitation Training Center (ALERT) Hospital, Addis Ababa, Ethiopia. METHODS: A retrospective cohort study was conducted on 120 MDR-Tuberculosis patients attending ALERT Hospital from 2018-2022. Kaplan-Meier methods were used to determine the time to initial sputum culture conversion. All relevant laboratory, socio-demographic characteristics, and other clinical data were collected by chart abstraction using a structure data extraction form. The log-rank test was used to determine the survival rate. To identify the predictors of culture conversion, bivariate and multivariate Cox proportional hazard regression analysis was used. The hazard ratio (HR) with a 95% confidence interval was used to estimate the effect of each variable on the initial culture conversion. A test with a P value of < 0.05 was considered statistically significant. RESULTS: From the total of 120 study participants, 89.2% (107/120) have shown a successful culture conversion. The median age of the participants was 30 years (IQR = 12). The study participants were followed for 408.6 person-months (34.05 person-years). The median time to initial sputum culture conversion was 80 days. The median time to initial sputum culture conversion among HIV-positive and HIV-negative participants was 61 days (IQR = 58-63.5) and 88 days (IQR = 75-91), respectively. HIV-negative and patients with previous treatment history were shown to be the predictor for a prolonged time to initial sputum culture conversion, (aHR = 0.24 (95% CI: 0.1-0.4), P value <0.001) and (aHR = 0.47 (95% CI: 0.31-0.71), P value <0.001) respectively. CONCLUSION: The median time to sputum culture conversion for HIV positive was found to be 61 days in our study. Notably, patients with a history of previous anti-tuberculosis treatment, HIV-negative status, and higher bacillary load at baseline exhibited delayed culture conversion. These findings underscore the importance of considering such patient characteristics in the management of MDR-TB cases, as tailored interventions and close monitoring may lead to more favorable treatment outcomes. By identifying individuals with these risk factors early in the treatment process, healthcare providers can implement targeted strategies to optimize patient care and improve overall treatment success rates in MDR-TB management programs.

Prospective multicentre accuracy evaluation of the FUJIFILM SILVAMP TB LAM test for the diagnosis of tuberculosis in people living with HIV demonstrates lot-to-lot variability.

There is an urgent need for rapid, non-sputum point-of-care diagnostics to detect tuberculosis. This prospective trial in seven high tuberculosis burden countries evaluated the diagnostic accuracy of the point-of-care urine-based lipoarabinomannan assay FUJIFILM SILVAMP TB LAM (FujiLAM) among inpatients and outpatients living with HIV. Diagnostic performance of FujiLAM was assessed against a mycobacterial reference standard (sputum culture, blood culture, and Xpert Ultra from urine and sputum at enrollment, and additional sputum culture ≤7 days from enrollment), an extended mycobacterial reference standard (eMRS), and a composite reference standard including clinical evaluation. Of 1637 participants considered for the analysis, 296 (18%) were tuberculosis positive by eMRS. Median age was 40 years, median CD4 cell count was 369 cells/ul, and 52% were female. Overall FujiLAM sensitivity was 54·4% (95% CI: 48·7-60·0), overall specificity was 85·2% (83·2-87·0) against eMRS. Sensitivity and specificity estimates varied between sites, ranging from 26·5% (95% CI: 17·4%-38·0%) to 73·2% (60·4%-83·0%), and 75·0 (65·0%-82·9%) to 96·5 (92·1%-98·5%), respectively. Post-hoc exploratory analysis identified significant variability in the performance of the six FujiLAM lots used in this study. Lot variability limited interpretation of FujiLAM test performance. Although results with the current version of FujiLAM are too variable for clinical decision-making, the lipoarabinomannan biomarker still holds promise for tuberculosis diagnostics. The trial is registered at clinicaltrials.gov (NCT04089423).

The geographic distribution, and the biotic and abiotic predictors of select zoonotic pathogen detections in Canadian polar bears.

Increasing Arctic temperatures are facilitating the northward expansion of more southerly hosts, vectors, and pathogens, exposing naïve populations to pathogens not typical at northern latitudes. To understand such rapidly changing host-pathogen dynamics, we need sensitive and robust surveillance tools. Here, we use a novel multiplexed magnetic-capture and droplet digital PCR (ddPCR) tool to assess a sentinel Arctic species, the polar bear (Ursus maritimus; n = 68), for the presence of five zoonotic pathogens (Erysipelothrix rhusiopathiae, Francisella tularensis, Mycobacterium tuberculosis complex, Toxoplasma gondii and Trichinella spp.), and observe associations between pathogen presence and biotic and abiotic predictors. We made two novel detections: the first detection of a Mycobacterium tuberculosis complex member in Arctic wildlife and the first of E. rhusiopathiae in a polar bear. We found a prevalence of 37% for E. rhusiopathiae, 16% for F. tularensis, 29% for Mycobacterium tuberculosis complex, 18% for T. gondii, and 75% for Trichinella spp. We also identify associations with bear age (Trichinella spp.), harvest season (F. tularensis and MTBC), and human settlements (E. rhusiopathiae, F. tularensis, MTBC, and Trichinella spp.). We demonstrate that monitoring a sentinel species, the polar bear, could be a powerful tool in disease surveillance and highlight the need to better characterize pathogen distributions and diversity in the Arctic.