Tuberculosis case-finding in Cambodia: analysis of case notification data, 2000 to 2013

Progress towards the 2020 milestones of the end TB strategy in Cambodia: estimates of age and sex specific TB incidence and mortality from the Global Burden of Disease Study 2019

BACKGROUND

Cambodia was recently removed from the World Health Organization's (WHO's) top 30 high tuberculosis (TB) burden countries. However, Cambodia's TB burden remains substantial, and the country is on the WHO's new global TB watchlist. We aimed to examine the levels and trends in the fatal and non-fatal TB burden in Cambodia from 1990 to 2019, assessing progress towards the WHO End TB interim milestones, which aim to reduce TB incidence rate by 20% and TB deaths by 35% from 2015 to 2020.

METHODS

We leveraged the Global Burden of Disease 2019 (GBD 2019) analytical framework to compute age- and sex-specific TB mortality and incidence by HIV status in Cambodia. We enumerated TB mortality utilizing a Bayesian hierarchical Cause of Death Ensemble modeling platform. We analyzed all available data sources, including prevalence surveys, population-based tuberculin surveys, and TB cause-specific mortality, to produce internally consistent estimates of incidence and mortality using a compartmental meta-regression tool (DisMod-MR 2.1). We further estimated the fraction of tuberculosis mortality among individuals without HIV coinfection attributable to the independent effects of alcohol use, smoking, and diabetes.

RESULTS

In 2019, there were 6500 (95% uncertainty interval 4830-8680) deaths due to all-form TB and 50.0 (43.8-57.8) thousand all-form TB incident cases in Cambodia. The corresponding age-standardized rates were 53.3 (39.9-69.4) per 100,000 population for mortality and 330.5 (289.0-378.6) per 100,000 population for incidence. From 2015 to 2019, the number of all-form TB deaths decreased by 11.8% (2.3-21.1), while the age-standardized all-form TB incidence rate decreased by 11.1% (6.3-15.6). Among individuals without HIV coinfection in 2019, alcohol use accounted for 28.1% (18.2-37.9) of TB deaths, smoking accounted for 27.0% (20.2-33.3), and diabetes accounted for 12.5% (7.1-19.0). Removing the combined effects of these risk factors would reduce all-form TB deaths by 54.2% (44.2-62.2).

DISCUSSION

Despite significant progress in reducing TB morbidity and mortality since 1990, Cambodia is not on track to achieve the 2020 WHO End TB interim milestones. Existing programs in Cambodia can benefit from liaising with risk factor control initiatives to accelerate progress toward eliminating TB in Cambodia.

Perceptions and Acceptability of Digital Interventions Among Tuberculosis Patients in Cambodia: Qualitative Study of Video-Based Directly Observed Therapy

Background

Despite the development of effective drugs for treatment, tuberculosis remains one of the leading causes of death from an infectious disease worldwide. One of the greatest challenges to tuberculosis control is patient adherence to treatment. Recent research has shown that video-based directly observed therapy is a feasible and effective approach to supporting treatment adherence in high-income settings. However, few studies have explored the potential for such a solution in a low- or middle-income country setting. Globally, these countries’ rapidly rising rate of mobile penetration suggests that the potential for translation of these results may be high.

Objective

We sought to examine patient perceptions related to the use of mobile health, and specifically video-based directly observed therapy, in a previously unstudied patient demographic: patients with tuberculosis in a low-income country setting (Cambodia).

Methods

We conducted a cross-sectional qualitative study in urban and periurban areas in Cambodia, consisting of 6 focus groups with tuberculosis patients who were receiving treatment (standard directly observed therapy) through a nongovernmental organization.

Results

Familiarity with mobile technology and apps was widespread in this population, and overall willingness to consider a mobile app for video-based directly observed therapy was high. However, we identified potential challenges. First, patients very much valued their frequent in-person interactions with their health care provider, which may be reduced with the video-based directly observed therapy intervention. Second, there may be technical issues to address, including how to make the app suitable for illiterate participants.

Conclusions

While video-based directly observed therapy is a promising technology, even in country settings where mobile penetration is reportedly almost universal, it should be introduced with caution. However, the results were generally promising and yielded important insights that not only will be translated into the further adaptation of key features of video-based directly observed therapy for tuberculosis patients in Cambodia, but also can inform the future design and successful implementation of video-based directly observed therapy interventions in low- and middle-income settings more generally.

Epidemiology of tuberculosis in Papua New Guinea: analysis of case notification and treatment-outcome data, 2008-2016

Papua New Guinea has strengthened its surveillance system for tuberculosis (TB) under the National TB Program. This paper provides an overview of TB surveillance data at the national and subnational levels from 2008 to 2016. TB case notification has consistently increased since 2008 with 6184 cases (93 per 100 000 population) in 2008 to 28 598 (359 per 100 000 population) in 2014 and has stabilized since 2014 with 28 244 cases (333 per 100 000 population) in 2016. The population-screening rate for TB rose from 0.1% in 2008 to 0.4% in 2016. Notified cases were dominated by extra-pulmonary TB (EP-TB, 42.4% of all cases in 2016). The proportion of pulmonary TB cases with no sputum test results was high with a national average of 26.6%. The regional variation of case notifications was significant: the Southern Region had the highest number and rate of notified TB cases. Of the nationally reported cases, 26.7% occurred in children. Treatment success rates remained low at 73% for bacteriologically confirmed TB and 64% for all forms of TB in 2016, far below the global target of 90%. For all forms of TB, 19% of patients were lost to follow-up from treatment. An analysis of TB data from the national surveillance system has highlighted critical areas for improvement. A low population-screening rate, a high proportion of pulmonary TB cases without sputum test results and a low treatment success rate suggest areas for improvement in the National TB Program. Our additional subnational analysis helps identify geographical and programmatic areas that need strengthening and should be further promoted to guide the programme's direction in Papua New Guinea.

Trends in Tuberculosis Case Notification and Treatment Success, Haiti, 2010-2015

Since the 2010 earthquake, tuberculosis (TB) control has been a major priority for health sector response and recovery efforts in Haiti. The goal of this study was to analyze trends in TB case notification in Haiti from the aggregate data reported by the National TB Control Program to understand the effects of such efforts. A total of 95,745 TB patients were registered for treatment in Haiti between 2010 and 2015. Three regions, the West, Artibonite, and North departments accounted for 68% of the TB cases notified during the period. Patients in the 15–34 age groups represented 53% (50,560) of all cases. Case notification rates of all forms of TB increased from 142.7/100,000 in 2010 to 153.4 in 2015, peaking at 163.4 cases/100,000 in 2013. Case notification for smear-positive pulmonary TB increased from 85.5 cases/100,000 to 105.7 cases/100,000, whereas treatment success rates remained stable at 79–80% during the period. Active TB case finding efforts in high-risk communities and the introduction of new diagnostics have contributed to increasing TB case notification trends in Haiti from 2010 to 2015. Targeted interventions and novel strategies are being implemented to reach high-risk populations and underserved communities.

Tuberculosis active case finding in Cambodia: a pragmatic, cost-effectiveness comparison of three implementation models

BACKGROUND

Globally, almost 40% of tuberculosis (TB) patients remain undiagnosed, and those that are diagnosed often experience prolonged delays before initiating correct treatment, leading to ongoing transmission. While there is a push for active case finding (ACF) to improve early detection and treatment of TB, there is extremely limited evidence about the relative cost-effectiveness of different ACF implementation models. Cambodia presents a unique opportunity for addressing this gap in evidence as ACF has been implemented using different models, but no comparisons have been conducted. The objective of our study is to contribute to knowledge and methodology on comparing cost-effectiveness of alternative ACF implementation models from the health service perspective, using programmatic data, in order to inform national policy and practice.

METHODS

We retrospectively compared three distinct ACF implementation models - door to door symptom screening in urban slums, checking contacts of TB patients, and door to door symptom screening focusing on rural populations aged above 55 - in terms of the number of new bacteriologically-positive pulmonary TB cases diagnosed and the cost of implementation assuming activities are conducted by the national TB program of Cambodia. We calculated the cost per additional case detected using the alternative ACF models.

RESULTS

Our analysis, which is the first of its kind for TB, revealed that the ACF model based on door to door screening in poor urban areas of Phnom Penh was the most cost-effective (249 USD per case detected, 737 cases diagnosed), followed by the model based on testing contacts of TB patients (308 USD per case detected, 807 cases diagnosed), and symptomatic screening of older rural populations (316 USD per case detected, 397 cases diagnosed).

CONCLUSIONS

Our study provides new evidence on the relative effectiveness and economics of three implementation models for enhanced TB case finding, in line with calls for data from 'routine conditions' to be included in disease control program strategic planning. Such cost-effectiveness comparisons are essential to inform resource allocation decisions of national policy makers in resource constraint settings. We applied a novel, pragmatic methodological approach, which was designed to provide results that are directly relevant to policy makers, costing the interventions from Cambodia's national TB program's perspective and using case finding data from implementation activities, rather than experimental settings.

Examining the quality of childhood tuberculosis diagnosis in Cambodia: a cross-sectional study

BACKGROUND

Cambodia is one of the 22 countries with the highest TB burden. While childhood TB is estimated to make up 10-20% of total TB cases in high-burden settings, this proportion ranges from 1.3 to 39.4% throughout Cambodia's provinces, suggesting potential under- and over-diagnosis of childhood TB, subnationally. The proportion of case notifications classified as extrapulmonary TB out of total TB case notifications in children is 87%, greatly exceeding the expected global range of 20-30%. There is a gap in the literature on how childhood TB is diagnosed in resource-poor settings, and the quality of diagnoses. The study's aim is to quantitatively assess the quality of clinician performance and availability of diagnostic tools, for diagnosing childhood TB in high-burden Operational Districts in Cambodia.

METHODS

Between August and September of 2015, a cross-sectional study was conducted at referral hospitals and villages in 24 high-burden Operational Districts. 40 clinicians, and 104 parents whose child was recently diagnosed with TB were interviewed. Questionnaires assessed availability of diagnostic tools, and clinician knowledge and practice during a clinical examination. Descriptive statistics were calculated to provide cross-sectional data.

RESULTS

Availability of advanced diagnostic tools was low. Only 27.5% of clinicians had Xpert machines available at their facility, and 5% had equipment to perform gastric aspiration. 77.5% of clinicians reported that they had a chest X-ray at their facility, but only 34.6% of parents reported that the clinician conducted a chest X-ray. 72.5% of clinicians could name 5 out of 7 main TB screening criteria; however, parent data suggests that clinicians may not be applying knowledge to practice. The mean number of examinations/tests the clinician conducted during the clinical assessment of the child was 1.64. Of the parents whose child had an enlarged lymph node, 60.22% described lymph node characteristics that were not suggestive of TB.

CONCLUSION

Limited availability of diagnostic tools and suboptimal clinician performance highlight where resources should be allocated to improve quality of diagnoses. Further research needs to be done in low burden Operational Districts to determine the capacity of clinicians and health facilities for diagnosing childhood TB, where cases are likely being missed.

Mitigating Financial Burden of Tuberculosis through Active Case Finding Targeting Household and Neighbourhood Contacts in Cambodia

Background

Despite free TB services available in public health facilities, TB patients often face severe financial burden due to TB. WHO set a new global target that no TB-affected families experience catastrophic costs due to TB. To monitor the progress and strategize the optimal approach to achieve the target, there is a great need to assess baseline cost data, explore potential proxy indicators for catastrophic costs, and understand what intervention mitigates financial burden. In Cambodia, nationwide active case finding (ACF) targeting household and neighbourhood contacts was implemented alongside routine passive case finding (PCF). We analyzed household cost data from ACF and PCF to determine the financial benefit of ACF, update the baseline cost data, and explore whether any dissaving patterns can be a proxy for catastrophic costs in Cambodia.

Methods

In this cross-sectional comparative study, structured interviews were carried out with 108 ACF patients and 100 PCF patients. Direct and indirect costs, costs before and during treatment, costs as percentage of annual household income and dissaving patterns were compared between the two groups.

Results

The median total costs were lower by 17% in ACF than in PCF ($240.7 [IQR 65.5–594.6] vs $290.5 [IQR 113.6–813.4], p = 0.104). The median costs before treatment were significantly lower in ACF than in PCF ($5.1 [IQR 1.5–25.8] vs $22.4 [IQR 4.4–70.8], p<0.001). Indirect costs constituted the largest portion of total costs (72.3% in ACF and 61.5% in PCF). Total costs were equivalent to 11.3% and 18.6% of annual household income in ACF and PCF, respectively. ACF patients were less likely to dissave to afford TB-related expenses. Costs as percentage of annual household income were significantly associated with an occurrence of selling property (p = 0.02 for ACF, p = 0.005 for PCF).

Conclusions

TB-affected households face severe financial hardship in Cambodia. ACF has the great potential to mitigate the costs incurred particularly before treatment. Social protection schemes that can replace lost income are critically needed to compensate for the most devastating costs in TB. An occurrence of selling household property can be a useful proxy for catastrophic cost in Cambodia.

Epidemiology and control of tuberculosis in the Western Pacific Region: update with 2013 case notification data

INTRODUCTION

Since the year 2000, tuberculosis (TB) prevalence in the World Health Organization (WHO) Western Pacific Region decreased 36%. However, there were an estimated 1.6 million TB cases in the Region in 2013. This study describes a regional analysis using the WHO global TB database data from 2000 to 2013.

METHODS

TB surveillance data are annually collected from 36 countries and areas in the Western Pacific Region using a web-based system. TB case notifications, treatment outcomes and information on TB/HIV coinfection are analysed descriptively. Stratified analysis of the TB data by age, sex and countries and areas were conducted.

RESULTS

Countries and areas in the Western Pacific Region notified 1.3 million new and relapse TB cases in 2013. TB notification rate increased in the early 2000s, stabilized for several years and declined recently. Country-specific TB notification rates declined over time for all age groups in most countries. TB treatment success rates remain high in the Region with 16 countries reaching or maintaining 85% (or higher) in 2013. HIV testing among TB cases has increased gradually with approximately 11 000 HIV-positive TB cases diagnosed each year since 2009.

DISCUSSION

The results suggest that true TB incidence is possibly declining. Treatment success rates have remained high for six of seven high-burden countries. TB surveillance data analysis is an important source of programmatic and epidemiological information. Careful interpretation of these findings can provide useful insight for programmatic decision-making. While the TB burden remains immense, national TB programmes must evolve and adapt to build upon previous efforts.