Project description:Preventing the progression of a drug-resistant tuberculosis (DR-TB) infection to disease is an important pillar of the DR-TB elimination strategy. International guidelines have recently proposed fluoroquinolones for tuberculosis preventive therapy (TPT) in DR-TB contacts, although the available evidence is low quality. The pooled data from small observational studies suggest that a fluoroquinolone-based TPT is safe, effective and cost-effective as a preventive treatment in DR-TB contacts. Three clinical trials are currently ongoing to generate higher quality evidence on the efficacy of levofloxacin and delamanid as a DR-TB preventive therapy. Additional evidence is also needed, regarding TPT treatment in fluoroquinolone-resistant-TB contacts, patient and health care worker perceptions on DR-TB preventive therapy for contacts, and the service delivery models to increase DR-TPT access. This state-of-the-art review presents the current literature on TPT for contacts of DR-TB cases, focusing on the available evidence and international guidelines.
Project description:PurposeNon-adherence to tuberculosis therapy can lead to drug resistance, prolonged infectiousness, and death; therefore, understanding what causes treatment default is important. Pakistan has one of the highest burdens of tuberculosis in the world, yet there have been no qualitative studies in Pakistan that have specifically examined why default occurs. We conducted a mixed methods study at a tuberculosis clinic in Karachi to understand why patients with drug-susceptible tuberculosis default from treatment, and to identify factors associated with default. Patients attending this clinic pick up medications weekly and undergo family-supported directly observed therapy.MethodsIn-depth interviews were administered to 21 patients who had defaulted. We also compared patients who defaulted with those who were cured, had completed, or had failed treatment in 2013.ResultsQualitative analyses showed the most common reasons for default were the financial burden of treatment, and medication side effects and beliefs. The influence of finances on other causes of default was also prominent, as was concern about the effect of treatment on family members. In quantitative analysis, of 2120 patients, 301 (14.2%) defaulted. Univariate analysis found that male gender (OR: 1.34, 95% CI: 1.04-1.71), being 35-59 years of age (OR: 1.54, 95% CI: 1.14-2.08), or being 60 years of age or older (OR: 1.84, 95% CI: 1.17-2.88) were associated with default. After adjusting for gender, disease site, and patient category, being 35-59 years of age (aOR: 1.49, 95% CI: 1.10-2.03) or 60 years of age or older (aOR: 1.76, 95% CI: 1.12-2.77) were associated with default.ConclusionsIn multivariate analysis age was the only variable associated with default. This lack of identifiable risk factors and our qualitative findings imply that default is complex and often due to extrinsic and medication-related factors. More tolerable medications, improved side effect management, and innovative cost-reduction measures are needed to reduce default from tuberculosis treatment.
Project description:Childhood injuries, an important public health issue, globally affects more than 95% of children living in low-and middle-income countries. The objective of this study is to describe the epidemiology of childhood unintentional injuries in Karachi, Pakistan with a specific focus on those occurring within the home environment.This was a secondary analysis of a childhood unintentional injury surveillance database setup in the emergency department of the Aga Khan Hospital, Karachi, Pakistan for 3 months. The data was collected by interviewing caretakers of children under 12 years of age presenting with an unintentional injury to the emergency departments of the four major tertiary care hospitals of Karachi, Pakistan.The surveillance included 566 injured children of which 409 (72%) injuries had taken place at/around home. Of 409 children, 66% were males and mostly between 5 and 11 years of age. Injuries commonly occurred during play time (51%). Fall (59%), dog bites (11%) and burns (9%) were the commonest mechanisms of injury. The majority of the children (78%) were directly discharged from the emergency room with predicted short term disability (42%). There were 2 deaths in the emergency department both due to falls.Childhood injury surveillance system provides valuable in-depth information on child injuries. The majority of these unintentional childhood injuries occur at home; with falls, dog bites and burns being the most common types of unintentional childhood home injuries. Specific surveillance systems for child injuries can provide new and valuable information for countries like Pakistan.
Project description:BACKGROUND:In Asia, over 50% of patients with symptoms of tuberculosis (TB) access health care from private providers. These patients are usually not notified to the National TB Control Programs, which contributes to low notification rates in many countries. METHODS:From January 1, 2011 to December 31, 2012, Karachi's Indus Hospital - a private sector partner to the National TB Programme - engaged 80 private family clinics in its catchment area in active case finding using health worker incentives to increase notification of TB disease. The costs incurred were estimated from the perspective of patients, health facility and the program providing TB services. A Markov decision tree model was developed to calculate the cost-effectiveness of the active case finding as compared to case detection through the routine passive TB centers. Pakistan has a large private health sector, which can be mobilized for TB screening using an incentivized active case finding strategy. Currently, TB screening is largely performed in specialist public TB centers through passive case finding. Active and passive case finding strategies are assumed to operate independently from each other. RESULTS:The incentive-based active case finding program costed USD 223 per patient treated. In contrast, the center based non-incentive arm was 23.4% cheaper, costing USD 171 per patient treated. Cost-effectiveness analysis showed that the incentive-based active case finding program was more effective and less expensive per DALY averted when compared to the baseline passive case finding as it averts an additional 0.01966 DALYs and saved 15.74 US$ per patient treated. CONCLUSION:Both screening strategies appear to be cost-effective in an urban Pakistan context. Incentive driven active case findings of TB in the private sector costs less and averts more DALYs per health seeker than passive case finding, when both alternatives are compared to a common baseline situation of no screening.
Project description:Tuberculosis, caused by Mycobacterium tuberculosis, is a high-burden disease in Pakistan, with multi-drug (MDR) and extensive-drug (XDR) resistance, complicating infection control. Whole genome sequencing (WGS) of M. tuberculosis is being used to infer lineages (strain-types), drug resistance mutations, and transmission patterns-all informing infection control and clinical decision making. Here we analyse WGS data on 535 M. tuberculosis isolates sourced across Pakistan between years 2003 and 2020, to understand the circulating strain-types and mutations related to 12 anti-TB drugs, as well as identify transmission clusters. Most isolates belonged to lineage 3 (n = 397; 74.2%) strain-types, and were MDR (n = 328; 61.3%) and (pre-)XDR (n = 113; 21.1%). By inferring close genomic relatedness between isolates (< 10-SNPs difference), there was evidence of M. tuberculosis transmission, with 55 clusters formed consisting of a total of 169 isolates. Three clusters consist of M. tuberculosis that are similar to isolates found outside of Pakistan. A genome-wide association analysis comparing 'transmitted' and 'non-transmitted' isolate groups, revealed the nusG gene as most significantly associated with a potential transmissible phenotype (P = 5.8 × 10-10). Overall, our study provides important insights into M. tuberculosis genetic diversity and transmission in Pakistan, including providing information on circulating drug resistance mutations for monitoring activities and clinical decision making.
Project description:Pakistan is one of the five highest tuberculosis burden countries globally. We estimated prevalence of adult bacteriologically confirmed pulmonary tuberculosis and annual risk of Mycobacterium tuberculosis (M. tuberculosis) infection in children aged 2-4 years in Karachi, Pakistan. The survey design enabled exploration of tuberculosis burden by whether the population had previously been exposed to widespread tuberculosis active case-finding (ACF) activities or not. We conducted a concurrent adult pulmonary tuberculosis prevalence survey and a child M. tuberculosis infection survey using interferon gamma release assays in four districts (Korangi, South, West and Central). A cluster-based unequal probability random sampling method was employed with the a priori plan to oversample Korangi district which had been the focus of tuberculosis ACF activities since 2011. We defined Korangi district as the 'prior ACF' zone and remaining districts as the 'no prior ACF' zone. Between March 2018 and May 2019, 34,962 adults (78·5% of those eligible) and 1,505 children (59·9%) participated. Overall estimated prevalence of bacteriologically confirmed pulmonary tuberculosis was 387 cases per 100,000 population (95% CI 276-498) with a prevalence of 421 cases [95% CI 276-567] per 100,000 in the 'no prior ACF' and 279 cases [95% CI 155-403] per 100,000 in the 'prior ACF' zone. We estimated the annual risk of M. tuberculosis infection in children to be 1·1% (95% CI 0·7-1·5) in the 'no prior ACF' zone and 0·6% (95% CI 0·3-1·1) in the 'prior ACF' zone. We observed consistent differences in the population distribution of tuberculosis between the 'prior ACF' and 'no prior' ACF zones with a trend towards lower estimates of burden and M. tuberculosis transmission in the 'prior ACF' zone. A plausible explanation is that intensive ACF activities that have been ongoing in Korangi district for the preceding years have noticeably reduced the burden of tuberculosis and transmission.
Project description:In South Africa, roughly half of the drug-resistant TB cases diagnosed are reported to have been started on treatment. We determined the proportion of persons diagnosed with rifampicin resistant (RR-) TB who initiated treatment in Johannesburg after the introduction of decentralized RR-TB care in 2011.We retrospectively matched adult patients diagnosed with laboratory-confirmed RR-TB in Johannesburg from 07/2011-06/2012 with records of patients initiating RR-TB treatment at one of the city's four public sector treatment sites (one centralized, three decentralized). Patients were followed from date of diagnosis until the earliest of RR-TB treatment initiation, death, or 6 months' follow-up. We report diagnostic methods and outcomes, proportions initiating treatment, and median time from diagnosis to treatment initiation.594 patients were enrolled (median age 34 (IQR 29-42), 287 (48.3%) female). Diagnosis was by GenoType MTBDRplus (Hain-Life-Science) line probe assay (LPA) (281, 47.3%), Xpert MTB/RIF (Cepheid) (258, 43.4%), or phenotypic drug susceptibility testing (DST) (30, 5.1%) with 25 (4.2%) missing a diagnosis method. 320 patients (53.8%) had multi-drug resistant TB, 158 (26.6%) rifampicin resistant TB by Xpert MTB/RIF, 102 (17.2%) rifampicin mono-resistance, and 14 (2.4%) extensively drug-resistant TB. 256/594 (43.0%) patients initiated treatment, representing 70.7% of those who were referred for treatment (362/594). 338/594 patients (57.0%) did not initiate treatment, including 104 (17.5%) who died before treatment was started. The median time from sputum collection to treatment initiation was 33 days (IQR 12-52).Despite decentralized RR-TB treatment, fewer than half the patients diagnosed in Johannesburg initiated appropriate treatment. Offering treatment at decentralized sites alone is not sufficient; improvements in linking patients diagnosed with RR-TB to effective treatment is essential.
Project description:Setting: Ten hospitals managing drug-resistant tuberculosis (TB) in Pakistan. Objective: To assess the implementation of TB infection control (IC) practices and reasons for non-adherence to guidelines. Design: This was a descriptive study conducted between April and October 2016 with three components: 1) non-participant observation of service delivery areas (SDAs) (n = 82) in hospitals (n = 10) using structured checklists; 2) exit interviews with 100 patients (10 per hospital); and 3) interviews with 100 health-care workers (HCWs, 10/hospital). Results: Of the 82 SDAs, posters were displayed in 34 (41%), mechanical ventilation was implemented in 79% and functional ultraviolet germicidal irradiation (UVGI) was available in only 26%. Patient interviews showed 50-65% adherence to triage and use of personal protective measures. Key reasons for non-adherence were lack of adequate supplies, discomfort using N-95 masks, a lack of knowledge or training, perceived non-cooperation by patients, poor maintenance of mechanical ventilators and UVGI due to unstable electricity supply, a lack of clarity in roles (no-one designated in charge) and staff shortages and subsequent workloads. Adherence to natural ventilation usage was poor for reasons related to climate and privacy. Conclusion: Implementation of TBIC measures in hospitals was suboptimal. Urgent measures need to be put in place, including retraining of HCWs, addressing weaknesses in mask and poster supplies and constant supervision and monitoring.
Project description:Tuberculosis (TB) control is especially difficult in settings of high HIV prevalence; HIV co-infection erodes host immunity and increases risk of progression to active TB. Studies have demonstrated that a 6-month (or longer) course of monotherapy with isoniazid [isoniazid preventive therapy (IPT)] can reduce this risk. The World Health Organization endorses IPT for symptom-free individuals with HIV/TB co-infection and has recommended expanding IPT to entire communities (community-wide IPT). Although previous reviews have not found a statistically significant elevated risk of isoniazid-resistant TB among individuals previously treated with IPT, community-wide IPT programs may nonetheless generate substantial selective pressure and increase the burden of drug-resistant TB (DRTB). We developed mathematical models to identify the conditions under which community-wide IPT interventions could increase the burden of isoniazid-resistant Mycobacterium tuberculosis, even when we assumed that IPT does not select for resistance among those treated with IPT. We found that in models that included any mechanism of interstrain competition (such as partial immunity conferred by a previous M. tuberculosis infection), community-wide IPT interventions conferred an indirect benefit to drug-resistant strains through selective suppression of drug-sensitive infections. This result suggests that the absence of an observed elevation in the risk of DRTB among those receiving IPT in small-scale studies of limited duration does not imply that the selective pressure imposed by community-wide IPT will not be substantial. Community-wide IPT may play an important role in TB control in these settings, and its rollout should be accompanied by interventions to detect and treat drug-resistant disease.
Project description:Active tuberculosis (TB) must be excluded before initiating isoniazid preventive therapy (IPT) in persons infected with human immunodeficiency virus (HIV), but currently used screening strategies have poor sensitivity and specificity and high patient attrition rates. Liquid TB culture is now recommended for the detection of Mycobacterium tuberculosis in individuals suspected of having TB. This study compared the efficacy, effectiveness, and speed of the microscopic observation drug susceptibility (MODS) assay with currently used strategies for TB screening before IPT in HIV-infected persons.A total of 471 HIV-infected IPT candidates at 3 hospitals in Lima, Peru, were enrolled in a prospective comparison of TB screening strategies, including laboratory, clinical, and radiographic assessments.Of 435 patients who provided 2 sputum samples, M. tuberculosis was detected in 27 (6.2%) by MODS culture, 22 (5.1%) by Lowenstein-Jensen culture, and 7 (1.6%) by smear. Of patients with any positive microbiological test result, a MODS culture was positive in 96% by 14 days and 100% by 21 days. The MODS culture simultaneously detected multidrug-resistant TB in 2 patients. Screening strategies involving combinations of clinical assessment, chest radiograph, and sputum smear were less effective than 2 liquid TB cultures in accurately diagnosing and excluding TB (P<.01). Screening strategies that included nonculture tests had poor sensitivity and specificity.MODS culture identified and reliably excluded cases of pulmonary TB more accurately than other screening strategies, while providing results significantly faster than Lowenstein-Jensen culture. Streamlining of the ruling out of TB through the use of liquid culture-based strategies could help facilitate the massive up-scaling of IPT required to reduce HIV and TB morbidity and mortality.