Gender differences among patients with drug resistant tuberculosis and HIV co-infection in Uganda: a countrywide retrospective cohort study

Factors associated with tuberculosis drug resistance among presumptive multidrug resistance tuberculosis patients identified in a DRTB surveillance study in western Kenya

Multidrug-resistant tuberculosis (MDR-TB) is caused by M. tuberculosis (Mtb) with resistance to the first-line anti-TB medicines isoniazid (INH) and rifampicin (RIF). In Western Kenya, there is reported low prevalence of drug resistant strains among HIV tuberculosis patients, creating a need to determine factors associated with drug resistance patterns among presumptive MDR-TB patients. To determine factors associated with drug resistance patterns among presumptive MDR-TB patients in western Kenya. Three hundred and ninety (3 9 0) sputum sample isolates from among presumptive multidrug TB patients, were analyzed for TB drug resistance as per Ministry of Health (MoH) TB program diagnostic algorithm. Frequency and percentages were used to summarize categorical data while median and interquartile range (IQR) were used for continuous data. Multivariable logistic regression was carried out to identify factors associated with TB drug resistance. Out of 390 participants enrolled, 302/390 (77.4 %) were males, with a median age of 34 years. The HIV-infected were 118/390 (30.3 %). Samples included 322 (82.6 %) from presumptive patients, while 68/390 (17.4 %) were either lost to follow-up patients, failures to first-line treatment or newly diagnosed cases. A total of 64/390 (16.4 %) of the isolates had at least some form of drug resistance. Out of 390, 14/390 (3.6 %) had MDR, 12 (3.1 %) were RIF mono-resistance, 34 (8.7 %) had INH, while 4 (1 %) had ethambutol resistance. The category of previously treated patients (those who received or are currently on TB treatment) had a 70 % reduced likelihood of resistance (aOR: 0.30; 95 % CI: 0.13-0.70). In contrast, older age was associated with an increased likelihood of resistance to INH and RIF, with an adjusted odds ratio of 1.04 per year (95 % CI: 1.00-1.08). Prompt MDR-TB diagnosis is essential for appropriate patient care, management, and disease prevention and control. We recommend active surveillance on drug resistant TB in these regions to detect drug resistance patterns for rapid disease management.

Achieving universal social protection for people with tuberculosis

As we mark World TB Day 2024, we take this opportunity to reflect on the 2023 UN General Assembly High-Level Meeting (HLM) on the fight against tuberculosis-a milestone in the commitment towards a more coordinated, comprehensive approach to end tuberculosis globally. The UN HLM declaration on the fight against tuberculosis includes a specific pledge that all people with tuberculosis should receive a social benefits package to mitigate financial hardship. However, it is not known how this specific pledge will be realised and through which concrete actions. The use of the term financial hardship instead of WHO's key End TB Strategy indicator of catastrophic costs might prove challenging for robust evaluation of both the socioeconomic impact of tuberculosis and the effectiveness of socioeconomic support strategies to mitigate this impact. Moreover, in contrast to the financial pledges made for biomedical interventions, there was an absence of explicit investment in social protection. Such investments are imperative to facilitate successful expansion of social protection to meet the needs of people with tuberculosis and their households. Successful expansion of social protection is also dependent on political commitment and protected budgets from relevant stakeholders, including across government ministries. These strategies will help to ensure that the commitments on social protection made in the UN HLM declaration are turned into tangible actions with measurable effects.

The clinical profile and outcomes of drug resistant tuberculosis in Central Province of Zambia

BACKGROUND

The emergence of Drug Resistant Tuberculosis (DR-TB) is one of the main public health and economic problems facing the world today. DR-TB affects mostly those in economically productive years and prevents them from being part of the workforce needed for economic growth. The aim of this study was to determine the Clinical Profile and Outcomes of DR-TB in Central Province of Zambia.

METHODS

This was a retrospective cross sectional study that involved a review of records of patients with confirmed DR-TB who were managed at Kabwe Central Hospital's Multi-Drug Resistant TB (MDR-TB) Ward from the year 2017 to 2021. 183 patients were managed during this period and all were recruited in the study. Data was collected from DR-TB registers and patient files and then entered in SPSS version 22 where all statistical analyses were performed.

RESULTS

The study revealed that the prevalence of DR-TB among registered TB patients in Central Province was 1.4%. Majority of those affected were adults between the ages of 26 and 45 years (63.9%). The study also found that more than half of the patients were from Kabwe District (60.7%). Other districts with significant number of cases included Kapiri Mposhi 19 (10.4%), Chibombo 12 (6.6%), Chisamba 10 (5.5%), Mumbwa 7 (3.8%) and Mkushi 7 (3.8%). Furthermore, the analysis established that most of the patients had RR-TB (89.6%). 9.3% had MDR-TB, 0.5% had IR-TB and 0.5% had XDR-TB. RR-TB was present in 93.8% of new cases and 88.9% of relapse cases. MDR-TB was present in 6.2% of new cases and 10% of relapse cases. With regard to outcomes of DR-TB, the investigation revealed that 16.9% of the patients had been declared cured, 45.9% had completed treatment, 6% were lost to follow up and 21.3% had died. Risk factors for mortality on multivariate analysis included age 36-45 years (adjusted odds ratio [aOR] 0.253, 95% CI [0.70-0.908] p = 0.035) and male gender (aOR 0.261, 95% CI [0.107-0.638] p = 0.003).

CONCLUSION

The research has shown beyond doubt that the burden of DR-TB in Central Province is high. The study recommends putting measures in place that will help improve surveillance, early detection, early initiation of treatment and proper follow up of patients.

Community-based directly observed therapy is effective and results in better treatment outcomes for patients with multi-drug resistant tuberculosis in Uganda

BACKGROUND

Health facility-based directly observed therapy (HF DOT) is the main strategy for the management of patients with drug-resistant tuberculosis (DR TB) in Uganda, however, this still yields sub-optimal treatment outcomes. We set out to assess the effectiveness of community-based directly observed therapy (CB DOT) for the treatment of DR TB in Uganda.

METHODS

Using a previously developed patient-centered model for CB DOT, we assigned community health workers (CHWs) as primary caregivers to patients diagnosed with DR TB. CHWs administered daily DOT to patients in their homes. Once a month, patients received travel vouchers to attend clinic visits for treatment monitoring. We assessed the effectiveness of this model using a quasi-experimental pre and post-study. From December 2020 to March 2022, we enrolled adult DR-TB patients on the CB DOT model. We collected retrospective data from patients who had received care using the HF DOT model during the year before the study started. The adjusted effect of CB DOT versus HF DOT on DR TB treatment success was estimated using modified Poisson regression model with robust cluster variance estimator.

RESULTS

We analyzed data from 264 DR TB patients (152 HF DOT, 112 CB DOT). The majority were males (67.8%) with a median age of 36 years (IQR 29 to 44 years). Baseline characteristics were similar across the comparison groups, except for educational level, regimen type, and organizational unit with age being borderline. The treatment success rate in the CB DOT group was 12% higher than that in the HF DOT (adjusted prevalence ratio (aPR)= 1.12 [95%CI 1.01, 1.24], P-value=0.03). Males were less likely to achieve treatment success compared to their female counterparts (aPR=0.87 [95% CI 0.78, 0.98], P-value=0.02). A total of 126 (47.7%) of 264 patients reported at least one adverse event. The HF DOT group had a higher proportion of patients with at least one adverse event compared to the CB DOT group (90/152 [59.2%] versus 36/112 [32.1], P-value<0.01). The model was acceptable among patients (93.6%) and health workers (94.1%).

CONCLUSIONS

CB DOT for DR-TB care is effective and results in better treatment outcomes than HF DOT. The cost-effectiveness of this model of care should be further evaluated.

Bedaquiline Resistance and Molecular Characterization of Rifampicin-Resistant Mycobacterium Tuberculosis Isolates in Zhejiang, China

Purpose

This study aimed to determine the prevalence and molecular characterization of bedaquiline (BDQ) resistance among rifampicin-resistant tuberculosis (RR-TB) isolates collected from Zhejiang, China.

Patients and Methods

A total of 245 RR-TB isolates were collected from 19 municipal TB hospitals in Zhejiang province, China between January and December 2021. Microplate assays were used to determine the minimum inhibitory concentrations (MIC) of BDQ. Whole-genome sequencing (WGS) was performed on isolates with MIC values for BDQ ≥ 0.25 μg/mL.

Results

Five (2.04%) BDQ-resistant strains were isolated from 245 tuberculosis patients. The resistance rate of BDQ was not correlated to the sex, age, treatment history, or occupation of patients. Four BDQ-resistant isolates and three BDQ-sensitive isolates were found to carry Rv0678 mutations, and one BDQ-resistant strain carried both Rv0678 and pepQ mutations. No mutations within the atpE and Rv1979c genes were observed.

Conclusion

BDQ demonstrated strong in vitro antibacterial activity against RR-TB isolates, and the Rv0678 gene was identified as the primary mechanism contributing to BDQ resistance among RR-TB isolates from Zhejiang, China. Furthermore, in addition to the four currently known resistance-associated genes (atpE, Rv0678, Rv1979c, and pepQ), other mechanisms of resistance to BDQ may exist that need further study.

A machine learning approach to explore individual risk factors for tuberculosis treatment non-adherence in Mukono district

Despite the availability and implementation of well-known efficacious interventions for tuberculosis treatment by the Ministry of Health, Uganda (MoH), treatment non-adherence persists. Moreover, identifying a specific tuberculosis patient at risk of treatment non-adherence is still a challenge. Thus, this retrospective study, based on a record review of 838 tuberculosis patients enrolled in six health facilities, presents, and discusses a machine learning approach to explore the individual risk factors predictive of tuberculosis treatment non-adherence in the Mukono district, Uganda. Five classification machine learning algorithms, logistic regression (LR), artificial neural networks (ANN), support vector machines (SVM), random forest (RF), and AdaBoost were trained, and evaluated by computing their accuracy, F1 score, precision, recall, and the area under the receiver operating curve (AUC) through the aid of a confusion matrix. Of the five developed and evaluated algorithms, SVM (91.28%) had the highest accuracy (AdaBoost, 91.05% performed better than SVM when AUC is considered as evaluation parameter). Looking at all five evaluation parameters globally, AdaBoost is quite on par with SVM. Individual risk factors predictive of non-adherence included tuberculosis type, GeneXpert results, sub-country, antiretroviral status, contacts below 5 years, health facility ownership, sputum test results at 2 months, treatment supporter, cotrimoxazole preventive therapy (CPT) dapsone status, risk group, patient age, gender, middle and upper arm circumference, referral, positive sputum test at 5 and 6 months. Therefore, machine learning techniques, specifically classification types, can identify patient factors predictive of treatment non-adherence and accurately differentiate between adherent and non-adherent patients. Thus, tuberculosis program management should consider adopting the classification machine learning techniques evaluated in this study as a screening tool for identifying and targeting suited interventions to these patients.

Frequency of HIV serodifferent couples within TB-affected households in a setting with a high burden of HIV-associated TB

INTRODUCTION

Strong epidemiological links between human immunodeficiency virus (HIV) and tuberculosis (TB) may make household TB contact investigation an efficient strategy for HIV screening and finding individuals in serodifferent partnerships at risk of HIV and linking them to HIV prevention services. We aimed to compare the proportions of HIV serodifferent couples in TB-affected households and in the general population of Kampala, Uganda.

METHODS

We included data from a cross-sectional trial of HIV counselling and testing (HCT) in the context of home-based TB evaluation in Kampala, Uganda in 2016-2017. After obtaining consent, community health workers visited the homes of participants with TB to screen contacts for TB and offer HCT to household members ≥ 15 years. We defined index participants and their spouses or parents as couples. Couples were classified as serodifferent if confirmed by self-reported HIV status or by HIV testing results. We used a two-sample test of proportions to compare the frequency of HIV serodifference among couples in the study to its prevalence among couples in Kampala in the 2011 Uganda AIDS Indicator Survey (UAIS).

RESULTS

We included 323 index TB participants and 507 household contacts aged ≥ 18 years. Most index participants (55%) were male, while most (68%) adult contacts were female. There was ≥ 1 couple in 115/323 (35.6%) households, with most couples (98/115, 85.2%) including the index participant and spouse. The proportion of households with HIV-serodifferent couples was 18/323 (5.6%), giving a number-needed-to-screen of 18 households. The proportion of HIV serodifference among couples identified in the trial was significantly higher than among couples in the UAIS (15.7% vs. 8%, p = 0.039). The 18 serodifferent couples included 14 (77.8%) where the index participant was living with HIV and the spouse was HIV-negative, and 4 (22.2%) where the index partner was HIV-negative, while the spouse was living with HIV.

CONCLUSIONS

The frequency of HIV serodifference among couples identified in TB-affected households was higher than in the general population. TB household contact investigation may be an efficient strategy for identifying people with substantial exposure to HIV and linking them to HIV prevention services.

The differences in drug resistance between drug-resistant tuberculosis patients with and without diabetes mellitus in northeast China: a retrospective study

BACKGROUND

Diabetes mellitus (DM) and drug-resistant tuberculosis (DR-TB) are serious global public health problems. This study aimed to explore the differences in drug resistance between DR-TB patients with and without DM. Risk factors for developing multidrug-resistant tuberculosis (MDR-TB) were also investigated among DR-TB patients.

METHODS

The patient's basic demographic,　clinical characteristics, and drug susceptibility testing (DST) data were collected from the Chinese Disease Control Information System. Descriptive statistics were used to estimate the frequency and proportion of included variables. Categorical variables were compared using the Chi-square test or Fisher's exact test. Chi-square tests for trends were used to determine changes and trends in MDR-TB and pre-extensively drug-resistantTB (pre-XDR-TB) patterns over time. Univariate and multivariate logistic regression analysis was used to explore the risk factors of MDR-TB.

RESULTS

Compared with DR-TB patients with DM, DR-TB patients without DM had significantly higher rates of mono-resistant streptomycin (SM) and any resistance to kanamycin (KM), but significantly lower rates of any resistance to protionamide (PTO) and mono-resistance to levofloxacin (LFX), and pre-XDR-TB (P<0.05). The proportion of resistance to other anti-TB drugs was not statistically different between the DR-TB with and without DM. Among DR-TB patients without and with DM, the proportion of patients with MDR-TB and pre-XDR-TB patterns showed a significant downward trend from 2016 to 2021 (P<0.05). Among DR-TB patients without DM, male, previously treated DR-TB cases, and immigration were risk factors for MDR-TB (P<0.05). In DR-TB patients with DM, a negative sputum smear is a risk factor for MDR-TB (P<0.05).

CONCLUSION

There was no statistical difference in resistance patterns between DR-TB with and without DM, except in arbitrary resistance to PTO and KM, mono-resistant SM and LFX, and pre-XDR-TB. Great progress has been made in the prevention and control of MDR-TB and pre-XDR-TB. However, DR-TB patients with and without DM differ in their risk factors for developing MDR-TB.

Early culture conversion is a poor marker of treatment outcome among people with HIV and drug-resistant TB

OBJECTIVE

Our objective was to determine associations between early (≤2 months) culture conversion (ECC) among people with HIV and drug-resistant tuberculosis (DRTB) in Uganda.

METHODS

This was a countrywide retrospective cohort of people with bacteriologically confirmed DRTB and a positive baseline culture at 16 centres in Uganda between 2013 and 2019. Data were abstracted from treatment files and unit DRTB registers. Monthly sputum cultures were performed using the Lowenstein-Jensen solid medium.

RESULTS

We included 664 people with DRTB and a positive baseline culture, of whom 353 (53.4%) also had HIV. Among those living with HIV, 225 (63.7%) were male and 331 (94.3%) were on antiretroviral therapy. The median month of culture conversion was 2 (interquartile range [IQR] 1-3). ECC was observed among 226 people living with HIV (64.0%; 95% confidence interval [CI] 58.9-68.9). A DRTB treatment regimen of six or more drugs was associated with ECC among people living with HIV (adjusted odds ratio [aOR]  3.82; 95% CI 1.06-13.82; p = 0.041). Cure and overall treatment success was observed among 232 (65.7%) and 269 (76.2%) people living with HIV, respectively. However, ECC was not associated with cure (crude odds ratio [OR]  0.97; 95% CI 0.61-1.54; p = 0.901), death (OR 1.12; 95% CI 0.61-2.29; p = 0.610), or overall treatment success (OR 1.29; 95% CI 0.78-2.13; p = 0.326).

CONCLUSION

The majority of people living with HIV and DRTB achieve ECC. However, ECC does not predict cure, death, or treatment success. Moreover, it may require six or more drugs to achieve ECC. ECC is not an excellent indicator of the effectiveness of DRTB regimens among people living with HIV.

Gender and Drug-Resistant Tuberculosis in Nigeria

We conducted a retrospective study of 2555 DR-TB patients admitted to treatment between 2010 and 2016 in six geopolitical zones in Nigeria. We characterized the gender distribution of DR-TB cases and the association between demographics and clinical data, such as age, treatment category, number of previous TB treatment cycles, and geopolitical zone, with gender. The independent effects of being a male or female DR-TB patient were determined using bivariate and multivariate analyzes with statistical significance of p < 0.05 and a 95% confidence interval. Records from a total of 2555 DR-TB patients were examined for the study. A majority were male (66.9%), largest age-group was 30-39 years old (35.8%), most had MDR-TB (61.4%), were HIV-negative (76.6%), and previously treated for TB (77.1%). The southwest treatment zone had the highest proportion of DR-TB patients (36.9%), and most DR-TB diagnoses occurred in 2016 (36.9%). On bivariate analysis, age, HIV status, treatment zone, and clinical patient group in DR-TB were significantly associated with male gender. On multivariate analysis, males aged 20-29 years (AOR: 0.19, 95% CI: 0.33-0.59, p = 0.001) and HIV-positive males (AOR: 0.44, 95% CI: 0.33-0.59, p = 0.001) had lower likelihood of MDR-TB as males in the south-south treatment zone (AOR: 1.88, 95% CI: 1.23-2.85, p = 0.03), and being male and aged ≥60 years (AOR: 2.19, 95% CI: 1.05-4.54, p = 0.036) increased the probability of DR-TB. The older male population from south-southern Nigeria and women of childbearing age had lower incidence of DR-TB than men of the same age. Tailored interventions to reduce HIV and DR-TB prevalence in the general population, particularly among women of childbearing potential, and treatment support for young and older men are relevant strategies to reduce DR-TB in Nigeria.

Predictors of death among TB/HIV co-infected patients on tuberculosis treatment in Sichuan, China: A retrospective cohort study

Mycobacterium tuberculosis is the most common opportunistic infection among patients with human immunodeficiency virus (HIV) infection, and it is also the leading cause of death, causing approximately one-third of acquired immune deficiency syndrome deaths worldwide. China is on the World Health Organization's global list of 30 high-tuberculosis (TB) burden countries. The objective of this study was to evaluate the mortality rate, survival probabilities, and factors associated with death among patients with TB/HIV co-infection undergoing TB treatment in Sichuan, China. A retrospective cohort study was conducted using the Chinese National TB Surveillance System data of TB/HIV co-infected patients enrolled in TB treatment from January 2020 to December 2020. We calculated the mortality rate and survival probabilities using the Kaplan-Meier estimator, and a Cox proportional hazard model was conducted to identify independent risk factors for TB/HIV co-infection mortality. Hazard ratios and their respective 95% confidence intervals were also reported in this study. Of 828 TB/HIV co-infected patients, 44 (5.31%) died during TB treatment, and the crude mortality rate was 7.76 per 1000 person-months. More than half of the deaths (n = 23) occurred in the first 3 months of TB treatment. Overall survival probabilities were 97.20%, 95.16%, and 91.75% at 3rd, 6th, and 12th month respectively. The independent risk factors for mortality among TB/HIV co-infected patients were having extra-pulmonary TB and pulmonary TB co-infection, history of antiretroviral therapy interruption, and baseline cluster of differentiation 4 T-lymphocyte counts <200 cells/μL at the time of HIV diagnosis. Antiretroviral therapy is important for the survival of TB/HIV co-infected patients, and it is recommended to help prolong life by restoring immune function and preventing extra-pulmonary TB.

Drug Resistance Patterns and Trends in Patients with Suspected Drug-Resistant Tuberculosis in Dalian, China: A Retrospective Study

Purpose

The emergence of drug-resistant tuberculosis (DR-TB) represents a threat to the control of tuberculosis. This study aimed to estimate the patterns and trends of DR-TB in patients with suspected DR-TB. In addition, risk factors for multidrug-resistant tuberculosis (MDR-TB) were identified among suspected DR-TB patients in Dalian, China.

Patients and Methods

A total of 5661 patients with suspected DR-TB from Jan 1, 2013 to Dec 31, 2020 were included in the final analysis. The resistance pattern of all resistant strains was determined by drug susceptibility testing (DST) using the conventional Lowenstein-Jensen Proportion Method (LJ). DR-TB trends were estimated from 2013 to 2020. During the research period, the chi-square test was employed to analyze the significance of linear drug-resistance trends across time. Bivariate and multivariate logistic regression were performed to assess factors associated with MDR-TB.

Results

From 2013 to 2020, the resistance rates of rifampicin (RFP) and isoniazid (INH) decreased significantly, whereas the resistance rates of ethambutol (EMB) and streptomycin (SM) increased in patients with suspected DR-TB. From 2013 to 2020, the prevalence of DR-TB decreased in all patients from 34.71% to 28.01% with an average annual decrease of 3.02%. Among new cases, from 2013 to 2020, the prevalence of DR-TB (from 26.67% to 24.75%), RFP-resistant TB (RR-TB) (from 15.09% to 3.00%) and MDR-TB (from 6.08% to 2.62%) showed a significant downward trend. Among patients with a previous treatment history, DR-TB (from 54.70% to 37.50%), RR-TB (from 44.16% to 11.49%) and MDR-TB (from 26.90% to 10.34%) showed a significant downward trend from 2013 to 2020. Males (AOR 1.28, 95% CI 1.035–1.585), patients 45 to 64 years of age (AOR 1.75, 95% CI 1.342–2.284), patients 65 years and older (AOR 1.65, 95% CI 1.293–2.104), rural residents (AOR 1.24, 95% CI 1.014–1.519) and a previous treatment history (AOR 3.94, 95% CI 3.275–4.741) were risk factors for MDR-TB.

Conclusion

The prevalence of DR-TB, RR-TB and MDR-TB was significantly reduced from 2013 to 2020. Considerable progress has been made in the prevention and treatment of DR-TB during this period. However, the increasing rate of drug resistance in EMB and SM should be taken seriously. Suspected DR-TB patients who are male, older than 45 years of age, live in rural areas, and have a history of TB treatment should be given priority by health care providers.

Genetic and hormonal mechanisms underlying sex-specific immune responses in tuberculosis

Tuberculosis (TB), the world's deadliest bacterial infection, afflicts more human males than females, with a male/female (M/F) ratio of 1.7. Sex disparities in TB prevalence, pathophysiology, and clinical manifestations are widely reported, but the underlying biological mechanisms remain largely undefined. This review assesses epidemiological data on sex disparity in TB, as well as possible underlying hormonal and genetic mechanisms that might differentially modulate innate and adaptive immune responses in males and females, leading to sex differences in disease susceptibility. We consider whether this sex disparity can be extended to the efficacy of vaccines and discuss novel animal models which may offer mechanistic insights. A better understanding of the biological factors underpinning sex-related immune responses in TB may enable sex-specific personalized therapies for TB.