Prevalence of subclinical pulmonary tuberculosis in adults in community settings: an individual participant data meta-analysis.

BACKGROUND: Subclinical pulmonary tuberculosis, which presents without recognisable symptoms, is frequently detected in community screening. However, the disease category is poorly clinically defined. We explored the prevalence of subclinical pulmonary tuberculosis according to different case definitions. METHODS: We did a one-stage individual participant data meta-analysis of nationally representative surveys that were conducted in countries with high incidence of tuberculosis between 2007 and 2020, that reported the prevalence of pulmonary tuberculosis based on chest x-ray and symptom screening in participants aged 15 years and older. Screening and diagnostic criteria were standardised across the surveys, and tuberculosis was defined by positive Mycobacterium tuberculosis sputum culture. We estimated proportions of subclinical tuberculosis for three case definitions: no persistent cough (ie, duration ≥2 weeks), no cough at all, and no symptoms (ie, absence of cough, fever, chest pain, night sweats, and weight loss), both unadjusted and adjusted for false-negative chest x-rays and uninterpretable culture results. FINDINGS: We identified 34 surveys, of which 31 were eligible. Individual participant data were obtained and included for 12 surveys (620 682 participants) across eight countries in Africa and four in Asia. Data on 602 863 participants were analysed, of whom 1944 had tuberculosis. The unadjusted proportion of subclinical tuberculosis was 59·1% (n=1149/1944; 95% CI 55·8-62·3) for no persistent cough and 39·8% (773/1944; 36·6-43·0) for no cough of any duration. The adjusted proportions were 82·8% (95% CI 78·6-86·6) for no persistent cough and 62·5% (56·6-68·7) for no cough at all. In a subset of four surveys, the proportion of participants with tuberculosis but without any symptoms was 20·3% (n=111/547; 95% CI 15·5-25·1) before adjustment and 27·7% (95% CI 21·0-36·4) after adjustment. Tuberculosis without cough, irrespective of its duration, was more frequent among women (no persistent cough: adjusted odds ratio 0·79, 95% CI 0·63-0·97; no cough: adjusted odds ratio 0·76, 95% CI 0·62-0·93). Among participants with tuberculosis, 29·1% (95% CI 25·2-33·3) of those without persistent cough and 23·1% (18·8-27·4) of those without any cough had positive smear examinations. INTERPRETATION: The majority of people in the community who have pulmonary tuberculosis do not report cough, a quarter report no tuberculosis-suggestive symptoms at all, and a quarter of those not reporting any cough have positive sputum smears, suggesting infectiousness. In high-incidence settings, subclinical tuberculosis could contribute considerably to the tuberculosis burden and to Mycobacterium tuberculosis transmission. FUNDING: Mr Willem Bakhuys Roozeboom Foundation.

Enhanced active case finding of drug-resistant tuberculosis in Namibia: a protocol for the hotspots, hospitals, and households (H3TB) study.

INTRODUCTION: Namibia is a high tuberculosis (TB)-burden country with an estimated incidence of 460/100 000 (around 12 000 cases) per year. Approximately 4.5% of new cases and 7.9% of previously treated TB cases are multidrug resistant (MDR) and 47% of patients with MDR-TB are HIV coinfected. Published data suggest a clustering of MDR-TB transmission in specific areas. Identifying transmission clusters is key to implementing high-yield and cost-effective interventions. This includes knowing the yield of finding TB cases in high-transmission zones (eg, community hotspots, hospitals or households) to deliver community-based interventions. We aim to identify such transmission zones for enhanced case finding and evaluate the effectiveness of this approach. METHODS AND ANALYSIS: H3TB is an observational cross-sectional study evaluating MDR-TB active case finding strategies. Sputum samples from MDR-TB cases in three regions of Namibia will be evaluated by whole genome sequencing (WGS) in addition to routine sputum investigations (Xpert MTB/RIF, culture and drug susceptibility testing). We will collect information on household contacts, use of community spaces and geographical map intersections between participants, synthesising these data to identify transmission hotspots. We will look at the feasibility, acceptability, yield and cost of case finding strategies in these hotspots, and in households of patients with MDR-TB and visitors of hospitalised patients with MDR-TB. A compartmental transmission dynamic model will be constructed to evaluate the impact and cost-effectiveness of the strategies if scaled. ETHICS AND DISSEMINATION: Ethics approval was obtained. Participants will give informed consent. H3TB will capitalise on a partnership with the Ministry of Health and Social Services to follow up individuals diagnosed with MDR-TB and integrate WGS data with innovative contact network mapping, to allow enhanced case finding. Study data will contribute towards a systems approach to TB control. Equally important, it will serve as a role model for similar studies in other high-incidence settings.

Tobacco smoking clusters in households affected by tuberculosis in an individual participant data meta-analysis of national tuberculosis prevalence surveys: Time for household-wide interventions?

Tuberculosis (TB) and non-communicable diseases (NCD) share predisposing risk factors. TB-associated NCD might cluster within households affected with TB requiring shared prevention and care strategies. We conducted an individual participant data meta-analysis of national TB prevalence surveys to determine whether NCD cluster in members of households with TB. We identified eligible surveys that reported at least one NCD or NCD risk factor through the archive maintained by the World Health Organization and searching in Medline and Embase from 1 January 2000 to 10 August 2021, which was updated on 23 March 2023. We compared the prevalence of NCD and their risk factors between people who do not have TB living in households with at least one person with TB (members of households with TB), and members of households without TB. We included 16 surveys (n = 740,815) from Asia and Africa. In a multivariable model adjusted for age and gender, the odds of smoking was higher among members of households with TB (adjusted odds ratio (aOR) 1.23; 95% CI: 1.11-1.38), compared with members of households without TB. The analysis did not find a significant difference in the prevalence of alcohol drinking, diabetes, hypertension, or BMI between members of households with and without TB. Studies evaluating household-wide interventions for smoking to reduce its dual impact on TB and NCD may be warranted. Systematically screening for NCD using objective diagnostic methods is needed to understand the actual burden of NCD and inform comprehensive interventions.

Bedaquiline Resistance after Effective Treatment of Multidrug-Resistant Tuberculosis, Namibia.

Bedaquiline is currently a key drug for treating multidrug-resistant or rifampin-resistant tuberculosis. We report and discuss the unusual development of resistance to bedaquiline in a teenager in Namibia, despite an optimal background regimen and adherence. The report highlights the risk for bedaquiline resistance development and the need for rapid drug-resistance testing.

Implementation of targeted next-generation sequencing for the diagnosis of drug-resistant tuberculosis in low-resource settings: a programmatic model, challenges, and initial outcomes.

Targeted next-generation sequencing (tNGS) from clinical specimens has the potential to become a comprehensive tool for routine drug-resistance (DR) prediction of Mycobacterium tuberculosis complex strains (MTBC), the causative agent of tuberculosis (TB). However, TB mainly affects low- and middle-income countries, in which the implementation of new technologies have specific needs and challenges. We propose a model for programmatic implementation of tNGS in settings with no or low previous sequencing capacity/experience. We highlight the major challenges and considerations for a successful implementation. This model has been applied to build NGS capacity in Namibia, an upper middle-income country located in Southern Africa and suffering from a high-burden of TB and TB-HIV, and we describe herein the outcomes of this process.

Association of diabetes, smoking, and alcohol use with subclinical-to-symptomatic spectrum of tuberculosis in 16 countries: an individual participant data meta-analysis of national tuberculosis prevalence surveys.

Background: Non-communicable diseases (NCDs) and NCD risk factors, such as smoking, increase the risk for tuberculosis (TB). Data are scarce on the risk of prevalent TB associated with these factors in the context of population-wide systematic screening and on the association between NCDs and NCD risk factors with different manifestations of TB, where ∼50% being asymptomatic but bacteriologically positive (subclinical). We did an individual participant data (IPD) meta-analysis of national and sub-national TB prevalence surveys to synthesise the evidence on the risk of symptomatic and subclinical TB in people with NCDs or risk factors, which could help countries to plan screening activities. Methods: In this systematic review and IPD meta-analysis, we identified eligible prevalence surveys in low-income and middle-income countries that reported at least one NCD (e.g., diabetes) or NCD risk factor (e.g., smoking, alcohol use) through the archive maintained by the World Health Organization and by searching in Medline and Embase from January 1, 2000 to August 10, 2021. The search was updated on March 23, 2023. We performed a one-stage meta-analysis using multivariable multinomial models. We estimated the proportion of and the odds ratio for subclinical and symptomatic TB compared to people without TB for current smoking, alcohol use, and self-reported diabetes, adjusted for age and gender. Subclinical TB was defined as microbiologically confirmed TB without symptoms of current cough, fever, night sweats, or weight loss and symptomatic TB with at least one of these symptoms. We assessed heterogeneity using forest plots and I2 statistic. Missing variables were imputed through multi-level multiple imputation. This study is registered with PROSPERO (CRD42021272679). Findings: We obtained IPD from 16 national surveys out of 21 national and five sub-national surveys identified (five in Asia and 11 in Africa, N = 740,815). Across surveys, 15.1%-56.7% of TB were subclinical (median: 38.1%). In the multivariable model, current smoking was associated with both subclinical (OR 1.67, 95% CI 1.27-2.40) and symptomatic TB (OR 1.49, 95% CI 1.34-1.66). Self-reported diabetes was associated with symptomatic TB (OR 1.67, 95% CI 1.17-2.40) but not with subclinical TB (OR 0.92, 95% CI 0.55-1.55). For alcohol drinking ≥ twice per week vs no alcohol drinking, the estimates were imprecise (OR 1.59, 95% CI 0.70-3.62) for subclinical TB and OR 1.43, 95% CI 0.59-3.46 for symptomatic TB). For the association between current smoking and symptomatic TB, I2 was high (76.5% (95% CI 62.0-85.4), while the direction of the point estimates was consistent except for three surveys with wide CIs. Interpretation: Our findings suggest that current smokers are more likely to have both symptomatic and subclinical TB. These individuals can, therefore, be prioritised for intensified screening, such as the use of chest X-ray in the context of community-based screening. People with self-reported diabetes are also more likely to have symptomatic TB, but the association is unclear for subclinical TB. Funding: None.

Case-Finding Strategies for Drug-Resistant Tuberculosis: Protocol for a Scoping Review.

BACKGROUND: Transmission of drug-resistant tuberculosis (DR-TB) is ongoing. Finding individuals with DR-TB and initiating treatment as early as possible is important to improve patient clinical outcomes and to break the chain of transmission to control the pandemic. To our knowledge systematic reviews assessing effectiveness, cost-effectiveness, acceptability, and feasibility of different case-finding strategies for DR-TB to inform research, policy, and practice have not been conducted, and it is unknown whether enough research exists to conduct such reviews. It is unknown whether case-finding strategies are similar for DR-TB and drug-susceptible TB and whether we can draw on findings from drug-susceptible reviews to inform decisions on case-finding strategies for DR-TB. OBJECTIVE: This protocol aims to describe the available literature on case-finding for DR-TB and to describe case-finding strategies. METHODS: We will screen systematic reviews, trials, qualitative studies, diagnostic test accuracy studies, and other primary research that specifically sought to improve DR-TB case detection. We will exclude studies that invited individuals seeking care for TB symptoms, those including individuals already diagnosed with TB, or laboratory-based studies. We will search the academic databases including MEDLINE, Embase, The Cochrane Library, Africa-Wide Information, CINAHL, Epistemonikos, and PROSPERO with no language or date restrictions. We will screen titles, abstracts, and full-text articles in duplicate. Data extraction and analyses will be performed using Excel (Microsoft Corp). RESULTS: We will provide a narrative report with supporting figures or tables to summarize the data. A systems-based logic model, developed from a synthesis of case-finding strategies for drug-susceptible TB, will be used as a framework to describe different strategies, resulting pathways, and enhancements of pathways. The search will be conducted at the end of 2021. Title and abstract screening, full text screening, and data extraction will be undertaken from January to June 2022. Thereafter, analysis will be conducted, and results compiled. CONCLUSIONS: This scoping review will chart existing literature on case-finding for DR-TB-this will help determine whether primary studies on effectiveness, cost-effectiveness, acceptability, and feasibility of different case-finding strategies for DR-TB exist and will help formulate potential questions for a systematic review. We will also describe case-finding strategies for DR-TB and how they fit into a model of case-finding pathways for drug-susceptible TB. This review has some limitations. One limitation is the diverse, inconsistent use of intervention terminology within the literature, which may result in missing relevant studies. Poor reporting of intervention strategies may also cause misunderstanding and misclassification of interventions. Lastly, case-finding strategies for DR-TB may not fit into a model developed from strategies for drug-susceptible TB. Nevertheless, such a situation will provide an opportunity to refine the model for future research. The review will guide further research to inform decisions on case-finding policies and practices for DR-TB. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/40009.

Drug-resistant tuberculosis: advances in diagnosis and management.

PURPOSE OF REVIEW: Diagnosis and treatment of drug-resistant tuberculosis (DR-TB) is undergoing substantial changes, owing availability of new diagnostic tools and drugs, coupled with global underdiagnosis and undertreatment. Recent developments are reviewed. RECENT FINDINGS: Molecular diagnostics, for Mycobacterium tuberculosis complex detection and prediction of drug resistance, implemented in the last decade, accelerated TB diagnosis with improved case detection. Nevertheless, access and coverage of drug-resistance testing remain insufficient. Genome sequencing-technologies, based on targeted next-generation sequencing show early potential to mitigate some of the challenges in the future. The recommendation to use an all oral, bedaquiline based regimen for treatment of multidrug-resistant/rifampicin-resistant TB is major advancement in DR-TB care. TB regimen using new and repurposed TB drugs demonstrate in recent clinical trials like, NIX-TB, ZeNIX and TB PRACTECAL considerable treatment success, shorten treatment duration and reduce toxicity. Their optimal use is threatened by the rapid occurrence and spread of strains, resistant to new drugs. Children benefit only very slowly from the progress. SUMMARY: There is notable progress in improved diagnosis and treatment of drug-resistant TB, but complicated by the COVID-19 pandemic the majority of TB patients worldwide don't have (yet) access to the advances.

Predictors of loss to follow-up of tuberculosis cases under the DOTS programme in Namibia.

BACKGROUND: In Namibia, one out of every 25 cases of tuberculosis (TB) is "lost to follow-up" (LTFU). This has impacted negatively on national efforts to end the disease by 2035. The aim of this study was to determine the trends and predictors of LTFU under the directly observed treatment short-course (DOTS) programme in Namibia. METHODS: The study involved a retrospective longitudinal analysis of a nationwide cohort of TB cases registered under the DOTS programme in Namibia from 2006 to 2015. The trends and predictors of LTFU among cases in the National Electronic TB Register of the National TB and Leprosy Program were respectively determined by interrupted time series and multivariate logistic regression analyses using R-Studio software. RESULTS: Out of 104 203 TB cases, 3775 (3.6%) were LTFU. A quarter (26%) of cases with poor outcomes were due to LTFU. The annual decline in cases of LTFU was significant between the first (2005-2010) and second (2010-2015) medium-term plan period for TB programme implementation (p=0.002). The independent predictors of LTFU were male sex (p=0.004), 15-24 years age group (p=0.03), provider of treatment (p<0.001), intensive phase (p=0.047) and living in border/transit regions (p<0.001). HIV co-infection and TB regimen were not significant predictors of LTFU. CONCLUSIONS: There were declining trends in LTFU in Namibia. DOTS programmes should integrate socioeconomic interventions for young and middle-aged adult male TB cases to reduce LTFU.

Adverse events and patients' perceived health-related quality of life at the end of multidrug-resistant tuberculosis treatment in Namibia.

PURPOSE: The health-related quality of life (HRQoL) of patients completing multidrug-resistant tuberculosis (MDR-TB) treatment in Namibia and whether the occurrence of adverse events influenced patients' rating of their HRQoL was evaluated. PATIENTS AND METHODS: A cross-sectional analytic survey of patients completing or who recently completed MDR-TB treatment was conducted. The patients rated their HRQoL using the simplified Short Form-™ (SF-8) questionnaire consisting of eight Likert-type questions. Three supplemental questions on the adverse events that the patients may have experienced during their MDR-TB treatment were also included. Scoring of HRQoL ratings was norm-based (mean =50, standard deviation =10) ranging from 20 (worst health) to 80 (best health), rather than the conventional 0-100 scores. We evaluated the internal consistency of the scale items using the Cronbach's alpha, performed descriptive analyses, and analyzed the association between the patients' HRQoL scores and adverse events. RESULTS: Overall, 36 patients (20 males, 56%) aged 17-54 years (median =40 years) responded to the questionnaire. The median (range) HRQoL score for the physical component summary was 58.6 (35.3-60.5), while the median score for the mental component summary was 59.3 (26.6-61.9), indicating not-so-high self-rating of health. There was good internal consistency of the scale scores, with a Cronbach's alpha value of >0.80. In all, 32 (89%) of the 36 patients experienced at least one adverse drug event of any severity during their treatment (median events =3, range 1-6), of which none was life-threatening. The occurrence of adverse events was not related to HRQoL scores. For patients reporting zero to two events, the median (range) HRQoL score was 56.8 (44.4-56.8), while for those reporting three or more events, the median score was 55.2 (38.6-56.8); P=0.34 for difference between these scores. CONCLUSION: Patients completing treatment for MDR-TB in Namibia tended to score moderately low on their HRQoL, using the generic SF-8 questionnaire. The occurrence of adverse events did not lead to lower HRQoL scores upon treatment completion.

Comparing amikacin and kanamycin-induced hearing loss in multidrug-resistant tuberculosis treatment under programmatic conditions in a Namibian retrospective cohort.

BACKGROUND: Amikacin and kanamycin are mainly used for treating multidrug-resistant tuberculosis (MDR-TB), especially in developing countries where the burden of MDR-TB is highest. Their protracted use in MDR-TB treatment is known to cause dose-dependent irreversible hearing loss, requiring hearing aids, cochlear implants or rehabilitation. Therapeutic drug monitoring and regular audiological assessments may help to prevent or detect the onset of hearing loss, but these services are not always available or affordable in many developing countries. We aimed to compare the cumulative incidence of hearing loss among patients treated for MDR-TB with amikacin or kanamycin-based regimens, and to identify the most-at-risk patients, based on the real-life clinical practice experiences in Namibia. METHODS: We conducted a retrospective cohort study of patients treated with amikacin or kanamycin-based regimens in four public sector MDR-TB treatment sites in Namibia between June 2004 and March 2014. Patients were audiologically assessed as part of clinical care. The study outcome was the occurrence of any hearing loss. Data were manually extracted from patients' treatment records. We compared proportions using the Chi-square test; applied stratified analysis and logistic regression to study the risk of hearing loss and to identify the most-at-risk patients through effect-modification analysis. A P-value < 0.05 was statistically significant. RESULTS: All 353 patients had normal baseline hearing, 46 % were HIV co-infected. Cumulative incidence of any hearing loss was 58 %, which was mostly bilateral (83 %), and mild (32 %), moderate (23 %), moderate-severe (16 %), severe (10 %), or profound (15 %). Patients using amikacin had a greater risk of developing the more severe forms of hearing loss than those using kanamycin (adjusted odds ratio (OR) = 4.0, 95 % CI: 1.5-10.8). Patients co-infected with HIV (OR = 3.4, 95 % CI: 1.1-10.6), males (OR = 4.5, 95 %1.5-13.4) and those with lower baseline body weight (40-59 kg, OR = 2.8, 95 % CI: 1.1-6.8), were most-at-risk of developing hearing loss. CONCLUSION: Amikacin use in the long-term MDR-TB treatment led to a higher risk of occurrence of the more severe forms of hearing loss compared to kanamycin use. Males, patients with low baseline body weight and those co-infected with HIV were most-at-risk. MDR-TB treatment programmes should consider replacing amikacin with kanamycin and strengthen the routine renal, serum therapeutic drug levels and audiometric monitoring in the most-at-risk patients treated with aminoglycosides.

Occurrence and clinical management of moderate-to-severe adverse events during drug-resistant tuberculosis treatment: a retrospective cohort study.

OBJECTIVES: To determine the incidence of symptomatic moderate-to-severe adverse events during treatment of drug-resistant tuberculosis, and to compare their risk and outcomes by patients' human immunodeficiency virus (HIV) co-infection status. METHODS: We conducted a retrospective cohort analysis of patients treated for drug-resistant tuberculosis between January 2008 and February 2010. Routinely, clinicians monitored and managed patients' response to treatment until its completion. Any symptomatic adverse event observed by the clinician or reported by the patient was recorded in the standard patient treatment booklet of the National Tuberculosis and Leprosy Programme. There were 18 symptomatic adverse events routinely monitored. Depending on the nature of the medical intervention needed, each was graded as mild, moderate or severe. Data were extracted from the patient treatment booklet using a structured form, then descriptive, bivariate and Cox proportional hazard analysis performed, stratified by patients' HIV infection status. Statistical associations were done at the 5% level of significance and reported with 95% confidence intervals. RESULTS: Fifty seven (57) patients with drug-resistant tuberculosis were identified, 31 (53%) of whom were HIV co-infected. The cumulative incidence of moderate-to-severe adverse events was 46 events in 100 patients. HIV co-infected patients experienced more moderate-to-severe adverse events compared with the HIV uninfected patients (median 3 versus 1 events, p = 0.01). They had a four-fold increase in the cumulative hazard of moderate-to-severe adverse events compared with the HIV uninfected patients (HR = 4.0, 95% CI 1.5 - 10.5). Moderate-to-severe adverse events were the main determinant of a clinician's decision to reduce the dose or to stop the suspected offending medicine (RR = 3.8, 95% 1.2-11.8). CONCLUSIONS: Moderate-to-severe adverse events are common during drug-resistant tuberculosis therapy. They are more likely to occur and to persist in HIV co-infected patients than in HIV uninfected patients. Clinicians should employ various strategies for preventing drug-induced patient discomfort and harm, such as reducing the dose or stopping the suspected offending medicine. Managers of tuberculosis control programmes should strengthen pharmacovigilance systems. We recommend a more powered study for conclusive risk-factor analysis.

Adverse events during treatment of drug-resistant tuberculosis: a comparison between patients with or without human immunodeficiency virus co-infection.

INTRODUCTION: In settings such as Namibia with a high prevalence of human immunodeficiency virus (HIV) and drug-resistant (DR) tuberculosis (TB) co-infection, interactions and adverse events associated with second-line anti-TB and antiretroviral medicines pose a unique challenge in the treatment of both infections. OBJECTIVE: The main objective of this study was to compare the absolute risks and risk factors for commonly observed adverse events (occurring in >20 % of patients) during DR-TB treatment in HIV-infected and HIV-uninfected patients. METHODS: This was a retrospective cohort analysis of patients treated for DR-TB between January 2008 and February 2010 at the Kondja DR-TB ward in Walvis Bay, Namibia. Data were anonymously collected from patients' treatment records, using a structured form. The data were then analyzed using descriptive statistics, while 2 × 2 contingency tables stratified by HIV status were employed to examine specific risk factor and adverse event relationships, using Epi Info 3.4.3 statistical software. Eighteen adverse events were studied but, because of the small sample size of patients, only the four most frequent ones (occurring in >20 % of patients) were included in the risk factor analysis. The risk factors were a treatment period of <4 weeks; treatment with any highly active antiretroviral therapy (HAART) regimen; specific treatment with a zidovudine (AZT)-based HAART regimen, a cycloserine-based DR-TB regimen or an amikacin-based DR-TB regimen; female gender; baseline body weight ≤ 45 kg; and age 30 ≥ years. RESULTS: Of the 57 DR-TB patients who were included in the analysis, 31 (53 %) were co-infected with HIV. When stratified by HIV status, DR-TB patients had similar exposure to specific DR-TB medicines and comparable demographic and clinical characteristics, except for age, as HIV-infected patients were on average 6.5 years older than HIV-uninfected patients (P = 0.007). Of the 18 studied adverse events, tinnitus (40 %), joint pain (26 %), hearing loss (23 %) and nausea (21 %) were the four most commonly observed events. Only for abdominal pain was there a statistically significant difference in the risk of occurrence between HIV-infected patients and HIV-uninfected patients (26 versus 4 %, P = 0.02). The risk ratios (RRs) for the association between treatment with a cycloserine-based DR-TB regimen and occurrence of joint pain did not differ much between HIV-infected and HIV-uninfected patients (RR 4.3 in HIV-infected patients, P = 0.03; RR 5 in HIV-uninfected patients, P = 0.08). Similarly, although some differences in the RRs were observed between the two HIV status groups, the differences were not statistically significant for tinnitus, hearing loss or nausea. In some instances, HIV status appeared to modify the effect of the association of some of the risk factors and adverse event occurrence, but the wide and overlapping confidence intervals were inconclusive. CONCLUSION: Generally, the absolute risks and risk factors for adverse events were similar between HIV-infected and HIV-uninfected patients treated for DR-TB in our Namibian cohort of 57 patients. Although our findings of comparable adverse event risks between DR-TB and DR-TB/HIV co-infected patients are encouraging, they are inconclusive because of the low statistical power of our study. We recommend a prospective study with a larger sample size that would increase the power and therefore the confidence in the results.

The burden of adverse events during treatment of drug-resistant tuberculosis in Namibia.

OBJECTIVE: Namibia faces a dual burden of HIV/AIDS and tuberculosis (TB). In 2010, HIV prevalence was 18.8%, the TB case notification rate was 634 cases per 100,000 population and the TB/HIV co-infection rate was 58%. There were 372 cases of drug-resistant TB (DR-TB) in 2009. The objective of this study was to assess the prevalence, profile and outcome of adverse events (AEs) associated with treatment of DR-TB and to explore possible influences of HIV disease on the occurrence of adverse events. METHODS: This was a cross-sectional descriptive study. After ethical approval, data were collected from treatment records of all patients treated for DR-TB at the study facility between January 2008 and February 2010 using a structured data collection form. RESULTS: A total of 141 adverse events of varying severity were experienced in 90% (53/59) of patients.The TB/HIV co-infection rate was 53% (n=31). The prevalence of gastrointestinal tract adverse events (abdominal pains, constipation, diarrhea, nausea and vomiting) was 64%, tinnitus 45%, joint pain 28%and decreased hearing 25%. Abdominal pains, rash, nausea, decreased hearing and joint pain were more common in HIV infected than in HIV uninfected patients. CONCLUSIONS: Adverse events of varying severity are common during treatment of DR-TB, particularly in the intensive phase of therapy. Some adverse events were more prevalent in DR-TB patients co-infected with HIV. The study concludes that the characteristics and risk factors of serious adverse events should be further examined.