Vineet K. Chadha

The Tuberculosis Cascade of Care in India’s Public Sector: A Systematic Review and Meta-analysis

Background India has 23% of the global burden of active tuberculosis (TB) patients and 27% of the world’s “missing” patients, which includes those who may not have received effective TB care and could potentially spread TB to others. The “cascade of care” is a useful model for visualizing deficiencies in case detection and retention in care, in order to prioritize interventions. Methods and Findings The care cascade constructed in this paper focuses on the Revised National TB Control Programme (RNTCP), which treats about half of India’s TB patients. We define the TB cascade as including the following patient populations: total prevalent active TB patients in India, TB patients who reach and undergo evaluation at RNTCP diagnostic facilities, patients successfully diagnosed with TB, patients who start treatment, patients retained to treatment completion, and patients who achieve 1-y recurrence-free survival. We estimate each step of the cascade for 2013 using data from two World Health Organization (WHO) reports (2014–2015), one WHO dataset (2015), and three RNTCP reports (2014–2016). In addition, we conduct three targeted systematic reviews of the scientific literature to identify 39 unique articles published from 2000–2015 that provide additional data on five indicators that help estimate different steps of the TB cascade. We construct separate care cascades for the overall population of patients with active TB and for patients with specific forms of TB—including new smear-positive, new smear-negative, retreatment smear-positive, and multidrug-resistant (MDR) TB. The WHO estimated that there were 2,700,000 (95%CI: 1,800,000–3,800,000) prevalent TB patients in India in 2013. Of these patients, we estimate that 1,938,027 (72%) TB patients were evaluated at RNTCP facilities; 1,629,906 (60%) were successfully diagnosed; 1,417,838 (53%) got registered for treatment; 1,221,764 (45%) completed treatment; and 1,049,237 (95%CI: 1,008,775–1,083,243), or 39%, of 2,700,000 TB patients achieved the optimal outcome of 1-y recurrence-free survival. The separate cascades for different forms of TB highlight different patterns of patient attrition. Pretreatment loss to follow-up of diagnosed patients and post-treatment TB recurrence were major points of attrition in the new smear-positive TB cascade. In the new smear-negative and MDR TB cascades, a substantial proportion of patients who were evaluated at RNTCP diagnostic facilities were not successfully diagnosed. Retreatment smear-positive and MDR TB patients had poorer treatment outcomes than the general TB population. Limitations of our analysis include the lack of available data on the cascade of care in the private sector and substantial uncertainty regarding the 1-y period prevalence of TB in India. Conclusions Increasing case detection is critical to improving outcomes in India’s TB cascade of care, especially for smear-negative and MDR TB patients. For new smear-positive patients, pretreatment loss to follow-up and post-treatment TB recurrence are considerable points of attrition that may contribute to ongoing TB transmission. Future multisite studies providing more accurate information on key steps in the public sector TB cascade and extension of this analysis to private sector patients may help to better target interventions and resources for TB control in India.

Feasibility of achieving the 2025 WHO global tuberculosis targets in South Africa, China, and India: a combined analysis of 11 mathematical models.

Summary Background The post-2015 End TB Strategy proposes targets of 50% reduction in tuberculosis incidence and 75% reduction in mortality from tuberculosis by 2025. We aimed to assess whether these targets are feasible in three high-burden countries with contrasting epidemiology and previous programmatic achievements. Methods 11 independently developed mathematical models of tuberculosis transmission projected the epidemiological impact of currently available tuberculosis interventions for prevention, diagnosis, and treatment in China, India, and South Africa. Models were calibrated with data on tuberculosis incidence and mortality in 2012. Representatives from national tuberculosis programmes and the advocacy community provided distinct country-specific intervention scenarios, which included screening for symptoms, active case finding, and preventive therapy. Findings Aggressive scale-up of any single intervention scenario could not achieve the post-2015 End TB Strategy targets in any country. However, the models projected that, in the South Africa national tuberculosis programme scenario, a combination of continuous isoniazid preventive therapy for individuals on antiretroviral therapy, expanded facility-based screening for symptoms of tuberculosis at health centres, and improved tuberculosis care could achieve a 55% reduction in incidence (range 31–62%) and a 72% reduction in mortality (range 64–82%) compared with 2015 levels. For India, and particularly for China, full scale-up of all interventions in tuberculosis-programme performance fell short of the 2025 targets, despite preventing a cumulative 3·4 million cases. The advocacy scenarios illustrated the high impact of detecting and treating latent tuberculosis. Interpretation Major reductions in tuberculosis burden seem possible with current interventions. However, additional interventions, adapted to country-specific tuberculosis epidemiology and health systems, are needed to reach the post-2015 End TB Strategy targets at country level. Funding Bill and Melinda Gates Foundation

Prevalence of Pulmonary Tuberculosis among Adults in a Rural Sub-District of South India

Background We conducted a survey to estimate point prevalence of bacteriologically positive pulmonary TB (PTB) in a rural area in South India, implementing TB program DOTS strategy since 2002. Methods Survey was conducted among persons ≥15 years of age in fifteen clusters selected by simple random sampling; each consisting of 5–12 villages. Persons having symptoms suggestive of PTB or history of anti-TB treatment (ATT) were eligible for sputum examination by smear microscopy for Acid Fast Bacilli and culture for Mycobacterium tuberculosis; two sputum samples were collected from each eligible person. Persons with one or both sputum specimen positive on microscopy and/or culture were labeled suffering from PTB. Prevalence was estimated after imputing missing values to correct for bias introduced by incompleteness of data. In six clusters, registered persons were also screened by X-ray chest. Persons with any abnormal shadow on X-ray were eligible for sputum examination in addition to those with symptoms and ATT. Multiplication factor calculated as ratio of prevalence while using both screening tools to prevalence using symptoms screening alone was applied to entire study population to estimate prevalence corrected for non-screening by X-ray. Results Of 71,874 residents ≥15 years of age, 63,362 (88.2%) were screened for symptoms and ATT. Of them, 5120 (8.1%) - 4681 (7.4%) with symptoms and an additional 439 (0.7%) with ATT were eligible for sputum examination. Spot specimen were collected from 4850 (94.7%) and early morning sputum specimens from 4719 (92.2%). Using symptom screening alone, prevalence of smear, culture and bacteriologically positive PTB in persons ≥15 years of age was 83 (CI: 57–109), 152 (CI: 108–197) and 196 (CI :145–246) per 100,000 population respectively. Prevalence corrected for non-screening by X-ray was 108 (CI: 82–134), 198 (CI: 153–243) and 254 (CI: 204–301) respectively. Conclusion Observed prevalence suggests further strengthening of TB control program.

Prevalence of Pulmonary Tuberculosis - A Baseline Survey In Central India

Background The present study provides an estimate of the prevalence of bacteriologially positive pulmonary tuberculosis in Jabalpur, a district in central India. Methodology/Principal Findings A community based cross-sectional survey was undertaken in Jabalpur District of the central Indian state of Madhya Pradesh. A stratified cluster sampling design was adopted to select the sample. All eligible individuals were questioned for pulmonary symptoms suggestive of TB disease. Two sputum samples were collected from all eligible individuals and were examined by Ziehl-Neelsen smear microscopy and solid media culture methods. Of the 99,918 individuals eligible for screening, 95,071 (95.1%) individuals were screened. Of these, 7,916 (8.3%) were found to have symptoms and sputum was collected from 7,533 (95.2%) individuals. Overall prevalence of bacteriologically positive PTB was found to be 255.3 per 100,000 population (95% C.I: 195.3–315.4). Prevalence was significantly higher (p<0.001) amongst males (355.8; 95% C.I: 304.4–413.4) compared with females (109.0; 95% C.I: 81.2–143.3). Prevalence was also significantly higher in rural areas (348.9; 95% C.I: 292.6–412.8) as compared to the urban (153.9; 95% C.I: 123.2–190.1). Conclusions/Significance The TB situation in Jabalpur district, central India, is observed to be comparable to the TB situation at the national level (255.3 versus 249). There is however, a need to maintain and further strengthen TB control measures on a sustained and long term basis in the area to have a significant impact on the disease prevalence in the community.

Tuberculin sensitivity among children vaccinated with BCG under universal immunization programme.

A tuberculin survey was conducted among 45988 children with BCG scar and 54227 children without BCG scar between 1–9 years of age and residing in selected rural areas of three defined zones of India. About 45–60% of the BCG-vaccinated children elicited reactions <5 mm in size and about 70–80% had reactions <10 mm. Therefore, in the majority of children (showing tuberculin reaction of <10 mm), BCG-induced tuberculin sensitivity does not interfere with interpretation of tuberculin test. The study also revealed that a proportion of reactions among BCG vaccinated children in 5–9 mm, 10–14 mm and 15–19 mm range may be attributable to BCG vaccination. Therefore, reactions between 10–14 mm and especially 15–19 mm among the vaccinated children must be interpreted carefully. However, 19 mm was observed as the upper limit for BCG induced tuberculin sensitivity and all reactions > 20 mm in size may be considered to be due to infection with tubercle bacilli, irrespective of the BCG vaccination status.

Cost-effectiveness and resource implications of aggressive action on tuberculosis in China, India, and South Africa: a combined analysis of nine models.

BACKGROUND The post-2015 End TB Strategy sets global targets of reducing tuberculosis incidence by 50% and mortality by 75% by 2025. We aimed to assess resource requirements and cost-effectiveness of strategies to achieve these targets in China, India, and South Africa. METHODS We examined intervention scenarios developed in consultation with country stakeholders, which scaled up existing interventions to high but feasible coverage by 2025. Nine independent modelling groups collaborated to estimate policy outcomes, and we estimated the cost of each scenario by synthesising service use estimates, empirical cost data, and expert opinion on implementation strategies. We estimated health effects (ie, disability-adjusted life-years averted) and resource implications for 2016-35, including patient-incurred costs. To assess resource requirements and cost-effectiveness, we compared scenarios with a base case representing continued current practice. FINDINGS Incremental tuberculosis service costs differed by scenario and country, and in some cases they more than doubled existing funding needs. In general, expansion of tuberculosis services substantially reduced patient-incurred costs and, in India and China, produced net cost savings for most interventions under a societal perspective. In all three countries, expansion of access to care produced substantial health gains. Compared with current practice and conventional cost-effectiveness thresholds, most intervention approaches seemed highly cost-effective. INTERPRETATION Expansion of tuberculosis services seems cost-effective for high-burden countries and could generate substantial health and economic benefits for patients, although substantial new funding would be required. Further work to determine the optimal intervention mix for each country is necessary. FUNDING Bill & Melinda Gates Foundation.

Impact of awareness drives and community-based active tuberculosis case finding in Odisha, India.

Indias Revised National Tuberculosis Control programme employs passive case detection. The new sputum smear-positive case detection rate is less than 70% in Odisha State. During April-June 2012, active case finding (ACF) was conducted through awareness drives and field-based tuberculosis (TB) screening in select communities with the lowest case detection rates. During the campaign, 240 sputum smear-positive TB cases were detected. The number of smear-positive cases detected increased by 11% relative to April-June 2011 in intervention communities compared to an 0.8% increase in non-intervention communities. ACF brought TB services closer to the community and increased TB case detection.

What are the reasons for poor uptake of HIV testing among patients with TB in an Eastern India District

Background National policy in India recommends HIV testing of all patients with TB. In West Bengal state, only 28% of patients with TB were tested for HIV between April-June, 2010. We conducted a cross-sectional survey to understand patient, provider and health system related factors associated with low uptake of HIV testing among patients with TB. Methods We reviewed TB and HIV program records to assess the HIV testing status of patients registered for anti-TB treatment from July-September 2010 in South-24-Parganas district, West Bengal, assessed availability of HIV testing kits and interviewed a random sample of patients with TB and providers. Results Among 1633 patients with TB with unknown HIV status at the time of diagnosis, 435 (26%) were tested for HIV within the intensive phase of TB treatment. Patients diagnosed with and treated for TB at facilities with co-located HIV testing services were more likely to get tested for HIV than at facilities without [RR = 1.27, (95% CI 1.20–3.35)]. Among 169 patients interviewed, 67 reported they were referred for HIV testing, among whom 47 were tested. During interviews, providers attributed the low proportion of patients with TB being referred and tested for HIV to inadequate knowledge among providers about the national policy, belief that patients will not test for HIV even if they are referred, shortage of HIV testing kits, and inadequate supervision by both programs. Discussion In West Bengal, poor uptake of HIV testing among patients with TB was associated with absence of HIV testing services at sites providing TB care services and to poor referral practices among providers. Comprehensive strategies to change providers’ beliefs and practices, decentralization of HIV testing to all TB care centers, and improved HIV test kit supply chain management may increase the proportion of patients with TB who are tested for HIV.

Tobacco smoking: a major risk factor for pulmonary tuberculosis – evidence from a cross-sectional study in central India

BACKGROUND This paper provides information on the association of tobacco smoking and alcohol consumption with pulmonary TB (PTB) in central India. METHODS A community based cross-sectional TB prevalence survey was conducted in Jabalpur district of the central Indian state of Madhya Pradesh. The information on tobacco smoking and alcohol consumption was collected from individuals aged ≥15 years. Using logistic regression analysis, the risk factors for PTB were identified. RESULTS A total of 94 559 individuals provided information on tobacco smoking and alcohol consumption. Persons aged 35-54 years and 55 years and above had, respectively, a 2.19 (95% CI 1.57-3.07) and a 3.26 (95% CI 2.23-4.77) times higher risk of developing PTB compared to persons aged below 35 years. Males had a 2.35 (95% CI 1.66-3.32) times higher risk than females. Tribals (indigenous population) had a 2.32 (95% CI 1.68-3.21) times higher risk than non-tribal population. The adjusted prevalence odds ratio for mild, moderate and heavy tobacco smokers were 2.28, 2.51 and 2.74 respectively as compared to non-smokers. Alcohol consumption was not found to be a risk factor on multivariate analysis. CONCLUSION Tobacco smoking is significantly associated with PTB in this central Indian district. Smoking cessation services need to be integrated into the activities of the TB control programme.

Relationship of nutritional status with tuberculin sensitivity

ObjectiveTo estimate the prevalence of under- nutrition among school children and to find out the relationship between nutritional status and tuberculin sensitivity.MethodsA cross sectional study was carried out among 3335 children between 5–8 years of age attending 60 schools in Bangalore city selected by stratified random sampling. The nutritional anthropometric indices were calculated using reference median as recommended by World Health Organization, classified according to standard deviation units termed as Z-scores. The nutritional status of the children was assessed by Weight for age, Height for age and Bio-mass-index (BMI).ResultsDepending upon the method for classifying nutritional status, the prevalence of under-nutrition (including mild and severe under-nutrition) varied between 14.9–29.8%. The prevalence of severe under-nutrition varied from 2.9–6.7%. The frequency distributions of reaction sizes were found to be similar among children classified by nutritional status. The differences in proportions of significant reactions (=10mm) and mean tuberculin reaction sizes between children classified by nutritional status were not found to be statistically significant.ConclusionTuberculin sensitivity was not influenced by nutritional status among apparently healthy school children.