Prevalence and associated risk factors for tuberculosis among people living with HIV in Nepal

Incidence Rate and Risk Factors for Developing Active Tuberculosis Among People Living With HIV in Georgia 2019-2020 Cohort

Background

Tuberculosis (TB) is a leading cause of morbidity and mortality among people with HIV (PHIV) globally. Our study is the first to evaluate TB incidence and its risk factors among PHIV in the country of Georgia, where previously no data were available.

Methods

A retrospective cohort study was conducted among persons newly diagnosed with HIV in Georgia during 2019-2020. Active TB incidence was calculated within a minimum of 2-year follow-up period from HIV diagnosis. Cox proportional hazard model was used for evaluating risk factors for TB development.

Results

The median age in the final cohort of 1165 PHIV was 38 (interquartile range, 30-48) and 76.3% were male. Twenty-nine percent of patients had a CD4 cell count <200 at HIV diagnosis and 89.9% initiated antiretroviral therapy (ART). TB incidence rate was 10/1000 person-years (p-y; 95% confidence interval [CI], 9.6-10.4), with rates being higher within several subgroups, mainly: PHIV aged 40-49 years (17.5/1 000 p-y [95% CI, 16.8-18.2]); those not receiving ART (22/1000 p-y [95% CI, 20.9-23.1]); those with CD4 < 200 at baseline (28/1000 p-y [95% CI, 27.4-28.6]); and those who developed AIDS (29.1/1 000 p-y [95% CI, 28.6-29.6]). Age (aHR, 1.2; 95% CI, 1.03-1.39; P = .01) and AIDS diagnosis (aHR, 3.2; 95% CI, 3.06-27.9; P = .001) were associated with TB development, whereas high CD4 count was protective against TB (aHR, 0.18; 95% CI, .06-.61; P = .005).

Conclusions

Study results highlight an imperative role of CD4 cell count management and the need for early HIV diagnosis and timely initiation of ART to ensure an effective immune response against tuberculosis, stressing the need for further in-depth evaluation of the TB preventive treatment delivery system's efficiency and gaps.

Concurrent TB and HIV therapies effectively control clinical reactivation of TB during co-infection but fail to eliminate chronic immune activation

The majority of Human Immunodeficiency Virus (HIV) negative individuals exposed to Mycobacterium tuberculosis (Mtb) control the bacillary infection as latent TB infection (LTBI). Co-infection with HIV, however, drastically increases the risk to progression to tuberculosis (TB) disease. TB is therefore the leading cause of death in people living with HIV (PLWH) globally. Combinatorial antiretroviral therapy (cART) is the cornerstone of HIV care in humans and reduces the risk of reactivation of LTBI. However, the immune control of Mtb infection is not fully restored by cART as indicated by higher incidence of TB in PLWH despite cART. In the macaque model of co-infection, skewed pulmonary CD4+ TEM responses persist, and new TB lesions form despite cART treatment. We hypothesized that regimens that concurrently administer anti-TB therapy and cART would significantly reduce TB in co-infected macaques than cART alone, resulting in superior bacterial control, mitigation of persistent inflammation and lasting protective immunity. We studied components of TB immunity that remain impaired after cART in the lung compartment, versus those that are restored by concurrent 3 months of once weekly isoniazid and rifapentine (3HP) and cART in the rhesus macaque (RM) model of LTBI and Simian Immunodeficiency Virus (SIV) co-infection. Concurrent administration of cART + 3HP did improve clinical and microbiological attributes of Mtb/SIV co-infection compared to cART-naïve or -untreated RMs. While RMs in the cART + 3HP group exhibited significantly lower granuloma volumes after treatment, they, however, continued to harbor caseous granulomas with increased FDG uptake. cART only partially restores the constitution of CD4 + T cells to the lung compartment in co-infected macaques. Concurrent therapy did not further enhance the frequency of reconstituted CD4+ T cells in BAL and lung of Mtb/SIV co-infected RMs compared to cART, and treated animals continued to display incomplete reconstitution to the lung. Furthermore, the reconstituted CD4+ T cells in BAL and lung of cART + 3HP treated RMs exhibited an increased frequencies of activated, exhausted and inflamed phenotype compared to LTBI RMs. cART + 3HP failed to restore the effector memory CD4+ T cell population that was significantly reduced in pulmonary compartment post SIV co-infection. Concurrent therapy was associated with the induction of Type I IFN transcriptional signatures and led to increased Mtb-specific TH1/TH17 responses correlated with protection, but decreased Mtb-specific TNFa responses, which could have a detrimental impact on long term protection. Our results suggest the mechanisms by which Mtb/HIV co-infected individuals remain at risk for progression due to subsequent infections or reactivation due of persisting defects in pulmonary T cell responses. By identifying lung-specific immune components in this model, it is possible to pinpoint the pathways that can be targeted for host-directed adjunctive therapies for TB/HIV co-infection.

Incidence and risk factors for HIV-tuberculosis coinfection in the Cologne-Bonn region: a retrospective cohort study

PURPOSE

The risk of developing active tuberculosis (TB) is considerably increased in people living with HIV/AIDS (PLWH). However, incidence of HIV/TB coinfection is difficult to assess as surveillance data are lacking in many countries. Here, we aimed to perform a quantitative analysis of HIV/TB coinfections within the Cologne/Bonn HIV cohort and to determine risk factors for active TB.

METHODS

We systematically evaluated data of patients with HIV/TB coinfection between 2006 and 2017. In this retrospective analysis, we compared HIV/TB-coinfected patients with a cohort of HIV-positive patients. The incidence density rate (IDR) was calculated for active TB cases at different time points.

RESULTS

During 2006-2017, 60 out of 4673 PLWH were diagnosed with active TB. Overall IDR was 0.181 cases/100 patient-years and ranged from 0.266 in 2006-2009 to 0.133 in 2014-2017. Patients originating from Sub-Saharan Africa had a significantly (p < 0.001) higher IDR (0.694/100 patient-years of observation, 95% CI [0.435-1.050]) in comparison to patients of German origin (0.053/100 patient-years of observation, 95% CI [0.028-0.091]). In terms of TB-free survival, individuals originating from countries with a TB incidence higher than 10/100,000 exhibited a markedly reduced TB-free survival compared to those originating from regions with lower incidence (p < 0.001). In 22 patients, TB and HIV infection were diagnosed simultaneously.

CONCLUSION

Overall, we observed a decline in the incidence density rate (IDR) of HIV/TB coinfections between 2006 and 2017. Patients originating from regions with high incidence bear a higher risk of falling ill with active TB. For PLWH born in Germany, the observed risk of active TB appears to be lower compared to other groups within the cohort. These findings should be considered when developing TB containment and screening strategies for PLWH in low-incidence countries.

Incidence and predictors of tuberculosis among HIV-infected children after initiation of antiretroviral therapy in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Globally, Tuberculosis (TB) is the main cause of morbidity and mortality among infectious disease. TB and Human Immune Virus (HIV) are the two deadly pandemics which interconnected each other tragically, and jeopardize the lives of children; particularly in Sub-Saharan Africa. Therefore, this review was aimed to determine the aggregated national pooled incidence of tuberculosis among HIV- infected children and its predictors in Ethiopia.

METHODS

An electronic search engine (HINARI, PubMed, Scopus, web of science), Google scholar and free Google databases were searched to find eligible studies. Quality of the studies was checked using the Joanna Briggs Institute (JBI) quality assessment checklists for cohort studies. Heterogeneity between studies was evaluated using Cochrane Q-test and the I2 statistics.

RESULT

This review revealed that the pooled national incidence of tuberculosis among children with HIV after initiation of ART was 3.63% (95% CI: 2.726-4.532) per 100-person-years observations. Being Anemic, poor and fair ART adherence, advanced WHO clinical staging, missing of cotrimoxazole and isoniazid preventing therapy, low CD4 cell count, and undernutrition were significant predictors of tuberculosis incidence.

CONCLUSION

The study result indicated that the incidence of TB among HIV- infected children is still high. Therefore, parents/guardians should strictly follow and adjust nutritional status of their children to boost immunity, prevent undernutrition and opportunistic infections. Cotrimoxazole and isoniazid preventive therapy need to continually provide for HIV- infected children for the sake of enhancing CD4/immune cells, reduce viral load, and prevent from advanced disease stages. Furthermore, clinicians and parents strictly follow ART adherence.

Magnetic resonance imaging findings in central nervous system tuberculosis: A pictorial review

Central nervous system (CNS) tuberculosis is a post-primary form of tuberculosis. It has high mortality and morbidity rates despite early diagnosis and treatment. CNS tuberculosis can manifest as subacute/chronic meningitis, parenchymal tuberculous lesions, and spinal tuberculosis. Hematogenous spread of tuberculous bacilli to the brain results in the development of so called "rich foci" on the pial surface, ependyma, and grey-white matter junction. Rupture of these "rich foci" into the subarachnoid space triggers an intense granulomatous inflammatory reaction. Tuberculous meningitis can manifest as leptomeningitis or pachymeningitis. Intracranial parenchymal tuberculous lesions may present as tuberculoma, tuberculous abscess, cerebritis, rhombencephalitis, and encephalopathy, with atypical presentations not uncommon. Complications of CNS tuberculosis encompass hydrocephalus, syrinx formation, vasculitis, infarcts, neuritis, and enduring neurological deficits. Post-contrast 3D fluid-attenuated inversion recovery (FLAIR) and post-contrast T1 spin-echo sequences excel in detecting tuberculous meningitis compared to other conventional magnetic resonance imaging (MRI) sequences. In proton magnetic resonance spectroscopy (PMRS), the presence of a lipid peak at 1.3 ppm is indicative of tuberculous lesions. Magnetization transfer (MT) imaging enhances the detection of tuberculous lesions, as the magnetization transfer ratio (MTR) of tuberculous pathologies, owing to their high lipid content, is lower than that in bacterial or fungal pathologies and higher than that in viral pathologies. This review article delves into the various typical and atypical imaging presentations of CNS tuberculosis in MRI, along with recent advances in imaging techniques.

Assessing intersectional gender analysis in Nepal's health management information system: a case study on tuberculosis for inclusive health systems

BACKGROUND

Tuberculosis (TB) remains a major public health problem in Nepal, high in settings marked by prevalent gender and social inequities. Various social stratifiers intersect, either privileging or oppressing individuals based on their characteristics and contexts, thereby increasing risks, vulnerabilities and marganilisation associated with TB. This study aimed to assess the inclusiveness of gender and other social stratifiers in key health related national policies and the Health Management Information System (HMIS) of National Tuberculosis Programme (NTP) by conducting an intersectional analysis of TB cases recorded via HMIS.

METHODS

A desk review of key policies and the NTP's HMIS was conducted. Retrospective intersectional analysis utilized two secondary data sources: annual NTP report (2017-2021) and records of 628 TB cases via HMIS 6.5 from two TB centres (2017/18-2018/19). Chi-square test and multi-variate analysis was used to assess the association between social stratifers and types of TB, registration category and treatment outcome.

RESULTS

Gender, social inclusion and concept of intersectionality are incorporated into various health policies and strategies but lack effective implementation. NTP has initiated the collection of age, sex, ethnicity and location data since 2014/15 through the HMIS. However, only age and sex disaggregated data are routinely reported, leaving recorded social stratifiers of TB patients static without analysis and dissemination. Furthermore, findings from the intersectional analysis using TB secondary data, showed that male more than 25 years exhibited higher odds [adjusted odds ratio (aOR) = 4.95, 95% confidence interval (CI): 1.60-19.06, P = 0.01)] of successful outcome compared to male TB patients less than 25 years. Similarly, sex was significantly associated with types of TB (P < 0.05) whereas both age (P < 0.05) and sex (P < 0.05) were significantly associated with patient registration category (old/new cases).

CONCLUSIONS

The results highlight inadequacy in the availability of social stratifiers in the routine HMIS. This limitation hampers the NTP's ability to conduct intersectional analyses, crucial for unveiling the roles of other social determinants of TB. Such limitation underscores the need for more disaggregated data in routine NTP to better inform policies and plans contributing to the development of a more responsive and equitable TB programme and effectively addressing disparities.

Determinants of tuberculosis among adult people living with HIV on antiretroviral therapy at public hospitals in Hawassa City, South Ethiopia

Background

The burden of tuberculosis (TB)/HIV co-infection is high in sub-Saharan African countries. The aim of the present study was to identify determinants of TB among people living with HIV (PLHIV) on antiretroviral therapy (ART) at public hospitals in Hawassa City Administration, Sidama Region, Ethiopia.

Methods

A facility-based case-control study was conducted between 30 March and 30 April 2023. We employed a systematic random sampling to recruit participants. The cases were all adult PLHIV who developed TB after ART initiation, and the group without TB were all adult PLHIV who did not develop TB after their ART initiation. Data were collected from patients' medical records using Kobo-tool and then exported to SPSS Version 26 for analysis. A multivariable logistic regression was used to identify the predictors of TB. Statistical significance was defined using the 95% confidence interval (CI).

Result

A total of 124 cases and 249 people without TB participated in the study. In a multivariable logistic regression analysis, we identified five independent determinants of TB. These include age (adjusted odds ratio (AOR) = 2.7; 95% CI 1.4-5.2), patients' residency (AOR = 6.4; 95% CI 2.8-14.5), WHO clinical stage III or IV (AOR = 6.7; 95% CI 3.2-14.0), isoniazid plus rifapentine (3HP) prophylaxis using (AOR = 0.5; 95% CI 0.2-0.9), and having other opportunistic infections (AOR = 3.6; 95% CI 1.7-7.6).

Conclusion and recommendation

Several risk factors for TB were identified among PLHIV. Strengthening TB screening in advanced disease conditions, encouraging use of 3HP prophylaxis, and early diagnosis and treatment of opportunistic infections were recommended to reduce the incidence of TB among PLHIV.

Heterogeneity in practitioner-reported barriers to use, cost considerations and priorities for point of care sexually transmitted infection tests on surveys across seven years

BACKGROUND

Point of care diagnostic tests (POCTs) for sexually transmitted infections (STIs) have the potential to improve STI care worldwide. However, barriers to adoption, cost considerations and practitioner priorities may not be uniform globally and over time. We conducted two surveys, 7 years apart, among members of the International Union Against Sexually Transmitted Infections (IUSTI), and compare results here.

METHODS

Surveys were given to members attending two IUSTI conferences in 2012 (Australia) and 2019 (Estonia). Descriptive analyses were performed and chi-square or Fisher's exact tests conducted.

RESULTS

Amongst N = 190 participants in 2012 and N = 166 in 2019, 61% in 2012 and 77% in 2019 were from high-income countries (HICs). In 2012, 84% of respondents from low- and middle-income countries (LMICs) and 70% from HICs thought cost of test was more important than amount of reimbursement. Trends were similar in 2019. In 2012, unreliability was considered the most important barrier to POCT use by all groups, followed by being laboratory-driven and complexity. In 2019, time frame was considered most important, followed by unreliability and being laboratory-driven. In 2012, the top priority for POCT development among LMIC respondents was early HIV seroconversion (31%), versus chlamydia (57%) for HICs. In 2019, chlamydia remained top priority for HICs (40%), followed by early HIV seroconversion (19%) and gonorrhea (17%); top priorities for LMICs were chlamydia (26%), HPV (24%), and early HIV seroconversion (21%).

CONCLUSIONS

Practitioner priorities for STI POCTs may be shifting. Cost may be critical to adoption in all settings. Larger studies are needed to verify findings.

Comparison of logistic regression with regularized machine learning methods for the prediction of tuberculosis disease in people living with HIV: cross-sectional hospital-based study in Kisumu County, Kenya

Background

Tuberculosis (TB) is a major public health concern, particularly among people living with the Human immunodeficiency Virus (PLWH). Accurate prediction of TB disease in this population is crucial for early diagnosis and effective treatment. Logistic regression and regularized machine learning methods have been used to predict TB, but their comparative performance in HIV patients remains unclear. The study aims to compare the predictive performance of logistic regression with that of regularized machine learning methods for TB disease in HIV patients.

Methods

Retrospective analysis of data from HIV patients diagnosed with TB in three hospitals in Kisumu County (JOOTRH, Kisumu sub-county hospital, Lumumba health center) between [dates]. Logistic regression, Lasso, Ridge, Elastic net regression were used to develop predictive models for TB disease. Model performance was evaluated using accuracy, and area under the receiver operating characteristic curve (AUC-ROC).

Results

Of the 927 PLWH included in the study, 107 (12.6%) were diagnosed with TB. Being in WHO disease stage III/IV (aOR: 7.13; 95%CI: 3.86-13.33) and having a cough in the last 4 weeks (aOR: 2.34;95%CI: 1.43-3.89) were significant associated with the TB. Logistic regression achieved accuracy of 0.868, and AUC-ROC of 0.744. Elastic net regression also showed good predictive performance with accuracy, and AUC-ROC values of 0.874 and 0.762, respectively.

Conclusions

Our results suggest that logistic regression, Lasso, Ridge regression, and Elastic net can all be effective methods for predicting TB disease in HIV patients. These findings may have important implications for the development of accurate and reliable models for TB prediction in HIV patients.

Single-Cell Transcriptomics of Mtb/HIV Co-Infection

Tuberculosis (TB) and Human Immunodeficiency Virus (HIV) co-infection continues to pose a significant healthcare burden. HIV co-infection during TB predisposes the host to the reactivation of latent TB infection (LTBI), worsening disease conditions and mortality. There is a lack of biomarkers of LTBI reactivation and/or immune-related transcriptional signatures to distinguish active TB from LTBI and predict TB reactivation upon HIV co-infection. Characterizing individual cells using next-generation sequencing-based technologies has facilitated novel biological discoveries about infectious diseases, including TB and HIV pathogenesis. Compared to the more conventional sequencing techniques that provide a bulk assessment, single-cell RNA sequencing (scRNA-seq) can reveal complex and new cell types and identify more high-resolution cellular heterogeneity. This review will summarize the progress made in defining the immune atlas of TB and HIV infections using scRNA-seq, including host-pathogen interactions, heterogeneity in HIV pathogenesis, and the animal models employed to model disease. This review will also address the tools needed to bridge the gap between disease outcomes in single infection vs. co-infection. Finally, it will elaborate on the translational benefits of single-cell sequencing in TB/HIV diagnosis in humans.

Prevalence and risk factors of tuberculosis among people living with HIV/AIDS in China: a systematic review and meta-analysis

OBJECTIVE

To estimate the prevalence and risk factors associated with tuberculosis (TB) among people living with human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS) in China.

METHODS

A systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. After the literature was screened based on the inclusion and exclusion criteria, STATA® version 17.0 software was used for the meta-analysis. The heterogeneity among study data was assessed using I2 statistics. Subgroup analysis and meta-regressions were performed to further explore the source of heterogeneity.

RESULTS

A total of 5241 studies were retrieved. Of these, 44 studies were found to be eligible. The pooled prevalence of HIV/TB co-infection was 6.0%. The risk factors for HIV/TB co-infection included a low CD4+ T cell count, smoking, intravenous drug use and several other sociodemographic and clinical factors. Bacillus Calmette-Guérin (BCG) vaccination history was a protective factor.

CONCLUSION

A high prevalence of TB was observed among people living with HIV/AIDS in China. Low CD4+ T cell count, smoking, and intravenous drug use were the primary risk factors for HIV/TB co-infection, whereas BCG vaccination history was a protective factor. Checking for TB should be prioritized in HIV screening and healthcare access.

SYSTEMATIC REVIEW REGISTRATION

Registered on PROSPERO, Identifier: CRD42022297754.

Utilization of artificial intelligence for tuberculosis screening in Nepal

BACKGROUNDS

Tuberculosis (TB) is an infectious disease that needs to be diagnosed and enrolled for treatment. Artificial intelligence for TB (AI4TB) software screens TB suspected cases at the point of care and helps in quick diagnosis. This study aims to explore the significance and usefulness of AI4TB by comparing its performance with different diagnostic test results.

METHODS

A cross-sectional study was conducted among 197 participants who had symptoms suggestive to TB. The chest X-ray images were analyzed by AI4TB software and human expert readers. The bacteriological test results were obtained, and Kappa test was applied to calculate the inter-reader reliability. The sensitivity, specificity, positive predictive value and negative predictive value was calculated and ROC curve was generated.

RESULTS

Among 85 sputum smear microscopy, about 21% of the had sputum positivity rate. At 0.4 threshold: 62.4%, at 0.5 threshold: 58.4% and at 0.6 threshold: 50.3% symptoms suggestive cases were identified having abnormal X-ray images. Reader-I identified 28.4% and Reader-II identified 37.1% of the symptoms suggestive cases of TB as positive cases. There was a significant substantial agreement between two human expert readers (k-0.783, p-value: <0.001). The ROC curve explored the fair sensitivity accuracy of the AI4TB test results at 0.5 threshold level (AUC = 0.72) and at 0.6 threshold level (AUC = 0.77).

CONCLUSION

The sensitivity of the AI4TB was higher compared to different human readers. AI4TB can be the relevant screening tool for the TB symptoms suggestive cases prior to the laboratory test in the countries like Nepal with deficient health manpower.

Feasibility of implementing public-private mix approach for tuberculosis case management in Pokhara Metropolitan City of western Nepal: a qualitative study

Background

The Public-Private Mix (PPM) approach is a strategic initiative that involves engaging all private and public health care providers in the fight against tuberculosis using international health care standards. For tuberculosis control in Nepal, the PPM approach could be a milestone. This study aimed to explore the barriers to a public-private mix approach in the management of tuberculosis cases in Nepal.

Methods

We conducted key informant interviews with 20 participants, 14 of whom were from private clinics, polyclinics, and hospitals where the PPM approach was used, two from government hospitals, and four from policymakers. All data were audio-recorded, transcribed, and translated into English. The transcripts of the interviews were manually organized, and themes were generated and categorized into 1. TB case detection, 2. patient-related barriers, and 3. health-system-related barriers.

Results

A total of 20 respondents participated in the study. Barriers to PPM were identified into following three themes: (1) Obstacles related to TB case detection, (2) Obstacles related to patients, and (3) Obstacles related to health-care system. PPM implementation was challenged by following sub-themes that included staff turnover, low private sector participation in workshops, a lack of trainings, poor recording and reporting, insufficient joint monitoring and supervision, poor financial benefit, lack of coordination and collaboration, and non-supportive TB-related policies and strategies.

Conclusion

Government stakeholders can significantly benefit by applying a proactive role working with the private in monitoring and supervision. The joint efforts with private sector can then enable all stakeholders to follow the government policy, practice and protocols in case finding, holding and other preventive approaches. Future research are essential in exploring how PPM could be optimized.

Expression profile of KIR3DS1/KIR3DL1 receptors in association with immunological responses in TB, HIV and HIV/TB infected patients

Several studies investigated KIR3DS1 and KIR3DL1 in the context of various infections. However, none of the studies were performed on KIR3DS1/L1 in association with IFN-ɣ/IL-10 in TB, HIV-1, and their confections. We aimed to evaluate KIR3DS1/KIR3DL1 expression in association with IFNɣ/IL-10 in HIV-1 and TB mono-infections and HIV-1/TB confection and compared with uninfected controls using RTq PCR. We also performed correlation analysis between KIR3DS1, KIR3DL1, IFN-ɣ and IL-10 in the respective cohorts. The overall expression of KIR3DS1 was found to be downregulated in all groups, whereas in HIV-1 and HIV-1/TB, the frequency of KIR3DS1⁽⁺⁾ expression was significantly (p < 0.05) associated with undetected HIV-1 viral load. However, expression of KIR3DL1 was found to be significantly (p < 0.05) upregulated in HIV-1 only. In addition, IFNɣ expression was significantly (p < 0.05) decreased in TB, whereas in HIV-1/TB, IFNɣ expression was significantly (p < 0.05) increased. In contrast, IL-10 expression was significantly (p < 0.05) increased in HIV-1 and HIV-1/TB but not in TB. Also, we found significant positive correlation (p < 0.05, r = 0.61) between KIR3DL1 and IFNɣ expression in TB and negative correlation (p < 0.05, r = - 0.62) between KIR3DS1 and IL-10 in HIV-1/TB. In conclusion, we suggest that expression of KIR3DS1/L1 is associated with IFNɣ/IL-10 responses and it is involved in modulating disease severity in HIV-1 and TB infections.

Spoligotyping of the Mycobacterium tuberculosis complex using on-Chip PCR

AIMS

The aim of this study was to develop a rapid PCR-based method for spoligotyping of Mycobacteria in the microarray format and to compare it to conventional spoligotyping by hybridization.

METHODS AND RESULTS

The method employs the on-Chip PCR technique with primers specific for 43 spacers that separate direct repeats (DRs) in the DR region of mycobacterial DNA. The primers were immobilized on gel-based microarrays, and PCR was performed directly on the chips. The PCR fluorescence images were acquired and processed using a portable fluorescence analyzer equipped with dedicated software. Analysis takes 1.5-2 hours and can be carried out on clinical samples without additional handling. The analytical sensitivity of the method was 103 copies of target DNA. The spoligotyping results of 51 samples produced by the proposed method and by conventional reverse hybridization approach were in full concordance.

CONCLUSIONS

High throughput capacity, computerized data analysis, compact equipment, and reliable results make the on-Chip PCR an attractive alternative to intra- and interspecific spoligotyping of Mycobacterium tuberculosis complex bacteria.

SIGNIFICANCE AND IMPACT OF STUDY

Fast microarray-based spoligotyping technique using on-Chip PCR was developed.

Line probe assay test in new cases of tuberculosis with rifampicin resistance not detected by Xpert MTB/RIF

Background

In Indonesia, the National guideline for tuberculosis only recommended taking the DST to check INH resistance only for re-treatment cases of rifampicin-susceptible TB (RS-TB) detected by Xpert MTB/RIF. This study was conducted mainly to evaluate the proportion of isoniazid resistance in new cases of RS-TB according to the Xpert MTB/RIF.

Methods

This was an observational descriptive study in RS-TB new patients diagnosed by Xpert MTB/RIF. Sputum samples were examined using first-line LPA and evaluated by culture-based DST. Results of first-line LPA and culture-based DST were compared and presented.

Results

Fifty-four new cases of RS-TB (according Xpert MTB/RIF) were enrolled in this study. INH resistance was detected in 4 (7.4%) using FL-LPA and in 5 (9.3%) using culture-based DST. RIF resistance was also found in 1 (1.9%) using FL-LPA and in 2 (3.7%) using culture-based DST. Ethambutol resistance was also detected in 4 (7.4%) using culture-based DST.

Conclusion

First-line LPA successfully revealed 4 (7.4%) of Hr-TB in new RS-TB cases detected by the Xpert MTB/RIF. In new cases with RS-TB detected by the Xpert MTB/RIF, FL- LPA can be used as rapid molecular DST to detect RIF and INH resistance followed by culture-based DST to examine other drug resistance.

Incidence of tuberculosis among PLHIV on antiretroviral therapy who initiated isoniazid preventive therapy: A multi-center retrospective cohort study

Introduction

Isoniazid preventive therapy (IPT) is effective in treating tuberculosis (TB) infection and hence limiting progression to active disease. However, the durability of protection, associated factors and cost-effectiveness of IPT remain uncertain in low-and-middle income countries, Uganda inclusive. The Uganda Ministry of health recommends a single standard-dose IPT course for eligible people living with HIV (PLHIV). In this study we determined the incidence, associated factors and median time to TB diagnosis among PLHIV on Antiretroviral therapy (ART) who initiated IPT.

Materials and methods

We conducted a retrospective cohort study at eleven The AIDS Support Organization (TASO) centers in Uganda. We reviewed medical records of 2634 PLHIV on ART who initiated IPT from 1^st January 2016 to 30^th June 2018, with 30^th June 2021 as end of follow up date. We analyzed study data using STATA v.16. Incidence rate was computed as the number of new TB cases divided by the total person months. A Frailty model was used to determine factors associated with TB incidence.

Results

The 2634 individuals were observed for 116,360.7 person months. IPT completion rate was 92.8%. Cumulative proportion of patients who developed TB in this cohort was 0.83% (22/2634), an incidence rate of 18.9 per 100,000 person months. The median time to TB diagnosis was 18.5 months (minimum– 0.47; maximum– 47.3, IQR: 10.1–32.4). World Health Organization (WHO) HIV clinical stage III (adjusted hazard ratio (aHR) 95%CI: 3.66 (1.08, 12.42) (P = 0.037) and discontinuing IPT (aHR 95%CI: 25.96(4.12, 169.48) (p = 0.001)), were associated with higher odds of TB diagnosis compared with WHO clinical stage II and IPT completion respectively.

Conclusion

Incidence rates of TB were low overtime after one course of IPT, and this was mainly attributed to high completion rates.