Evaluation of TB Case Finding through Systematic Contact Investigation, Chhattisgarh, India

Prevalence of latent tuberculosis infection in household contacts of pulmonary tuberculosis, time to treat

Treatment of latent pulmonary tuberculosis (TB) in household contacts has been included in the National Tuberculosis Elimination Program to achieve the target of TB elimination by the Government of India by 2025. However, there are no clear estimates of the prevalence of latent TB among the contacts that could suggest the impact of this intervention. The study was conducted to determine the prevalence of and factors predicting latent TB among household contacts with pulmonary TB. All microbiologically confirmed pulmonary TB patients registered between January 2020 and July 2021 and their household contacts were enrolled. All contacts underwent Mantoux testing to determine the prevalence of latent TB. All symptomatic patients also underwent chest radiographs and sputum examinations to diagnose active pulmonary TB. Thereafter, different demographic and clinical factors were evaluated to find predictors of latent TB using a logistic regression model. A total of 118 pulmonary TB cases and their 330 household contacts were enrolled. The prevalence of latent TB and active TB among the contacts was found to be 26.36% and 3.03%, respectively. The female gender of index TB cases was independently associated with a high proportion of latent TB cases in the family (adjusted odds ratio 2.32; 95% confidence interval 1.07-5.05; p=0.03). Neither the higher sputum smear positivity nor the severity of the chest radiograph of index TB cases had any association with the number of contacts being diagnosed as latent TB or active TB. The results showed a significant prevalence of latent TB among household contacts with pulmonary TB. The severity of the disease in the index patient had no association with the prevalence of latent TB.

Changing patterns of household transmission of tuberculosis in an eastern state of India: The impact of COVID19 pandemic

BACKGROUND

The COVID-19 Pandemic has affected many components of the Tuberculosis (TB) control program. Due to lockdown and restrictions, people, including TB patients, might have spent more time in the household. There might be an increased TB transmission among the household contacts (HHC). The current study was conducted to measure the household transmission of TB and also find out the relationship with several clinico-social factors.

METHODS

Contact tracing data of West Bengal, India, was extracted from Nikshay portal of Central TB Division, Government of India. The anonymized data was divided into two parts, firstly before the lockdown initiation in India and secondly during the lockdown. A modified Poisson regression model was developed to determine the statistical association between clinico-social variables and the pandemic with household-level secondary TB cases.

RESULTS

There was a 30% reduction in daily TB case notification, but the proportion of HHC screened was 4% higher during the pandemic than the pre-pandemic period. The secondary attack rate of household TB disease transmission was 34% lower during the pandemic period. Index TB patients aged under ten years, microbiologically positive, Drug-Resistant TB, having three or more HHCs, treatment delay more than seven days, notified from the private sector, and diagnosis during the pre-pandemic period was found to be independently associated with a higher risk of having a secondary TB case at household.

CONCLUSION

The risk of household TB transmission was significantly lower during the pandemic period compared to the pre-pandemic period, which may be due to better infection prevention and control practices.

The impact of chest radiography and Xpert MTB/RIF testing among household contacts in Chennai, India

Tuberculosis prevalence surveys have demonstrated the benefit of screening with chest x-ray (CXR) and sensitive diagnostic tests compared to symptoms and smear microscopy. However, in programmatic practice there is little evidence on the yield of different algorithms. We implemented contact tracing in Chennai, India for adult sputum-positive TB patients registered from January 2015 to March 2016. Patients with symptoms or abnormal X-ray findings further underwent testing using Xpert MTB/RIF (Xpert) and smear microscopy. A retrospective cohort study was done to summarize the key findings. We verbally screened 5553 contacts for symptoms, CXR through private sector collaboration, Xpert, and smear microscopy. Overall, 1312 (23.6%) contacts screened positive. CXR alone identified 531 (40.5%) of them, 679 (51.8%) were symptom-positive only, while 102 (7.8%) were positive on both the symptom and CXR screen. Overall, 35 bacteriologically positive cases were identified (0.7%). A standard approach of symptoms screening followed by microscopy identified only 9 (25.7%) of the total number of bacteriologically positive cases, whereas the combination of a CRX screening followed by microscopy identified 13 (37.1%) of the cases. The algorithm of symptoms screening followed by Xpert testing, detected 20 cases, whereas the combination of symptoms and CXR followed by Xpert increased this number to 35 (75% increase compared to symptoms and Xpert). Optimal use of more sensitive screening tests, better diagnostic tests, and novel private sector engagement can improve diagnostic yield in a programmatic setting.

Low Tuberculosis (TB) Case Detection: A Health Facility-Based Study of Possible Obstacles in Kaffa Zone, Southwest District of Ethiopia

Background

In Ethiopia, the national TB case detection rate is becoming improved; still some districts are not able to meet their case detection targets which leads to ongoing spread of TB infections to family members and communities. This study was intended to assess possible obstacles contributing to low TB case detection in Kaffa zone, Southwest Ethiopia.

Methods

A cross-sectional descriptive study involving qualitative and quantitative data was conducted from Mar. to Sep. 2019. Sociodemographic characteristics and data on duration of cough, whether sputum smear microscopy was requested or not, and data on TB knowledge and health care-seeking practice were collected from outpatients. Health care delivery barrier for TB case detection was also explored by using in-depth interview and FGD of health staff.

Results

From 802 outpatients with coughing for 2 or more weeks of duration, 334 (41.6%) of them were not requested to have TB microscopic diagnosis. Of these, 11/324 (3.4%) of them were positive for TB after sputum smear microscopy. Only 24.2% of the outpatients were aware as they have had health education on TB disease. Twenty-eight percent of patients perceived that TB was due to exposure to cold air, and 13.5% could not mention any sign or symptom of TB. Amazingly, 54.2% of them did not have any information as current TB diagnosis and treatment is free. Thirty-five percent of the patients were taking antibiotics before visiting the health facility. The interrupted supply of TB diagnostic reagents, frequent electricity interruption, shortage of trained TB care providers, weak health information system, and weak active case finding practice were explored as the factors contributing to low TB case detection.

Conclusion

Interrupted functioning of diagnostic centers, shortage of trained care providers, limited active TB case finding practice, weak health information system, and inadequate knowledge and health care-seeking practice of the patients were identified as contributors for low TB case detection. Thus, improving functioning of diagnostic centers, active TB case finding activities, and expanding health education on TB disease will help to improve TB case detection in the districts.

Identification of subclinical tuberculosis in household contacts using exposure scores and contact investigations

Background

The goal of tuberculosis elimination put forward in the End TB Strategy prioritizes diagnosis and treatment of incipient and subclinical TB, recently defined by key stakeholders as “asymptomatic, early pre-clinical disease during which pathology evolves”. Regarded as indicative of a high risk of TB progression, considerable efforts have been made to identify these cases through exploration of biomarkers. The present study aimed to evaluate simple scoring systems for TB exposure as screening tools for subclinical TB, the only identifiable of the incipient and subclinical disease states, in a contact investigation (CI) setting of low HIV-prevalence.

Methods

Nested within a large prospective study in household contacts (HHCs) of smear positive pulmonary TB cases in South-India conducted 2010–2012, we assessed 1) the association between the Tuberculosis Contact Score (TCS) and the Infectivity Score, with established tools for Mycobacterium tuberculosis (Mtb) infection, corrected for established TB risk factors, and 2) the capability of the TB exposure scores to identify subclinical TB defined by Mtb-culture positivity in sputum or gastric aspirate (subjects < 5 years) specimen.

Results

Of 525 HHCs, 29 were Mtb-culture positive and 96.6% of these asymptomatic. The TCS and the Infectivity Score associated with positive Tuberculin Skin Test and QuantiFeron TB-Gold In-tube assay (QFT) results in multivariate analyses (TCS: OR_TST 1.16, 95% CI: 1.01, 1.33; OR_QFT 1.33 95% CI: 1.16, 1.51. Infectivity Score: OR_TST 1.39, 95% CI: 1.10, 1.76; OR_QFT 1.41 95% CI: 1.16, 1.71). The Infectivity Score showed a moderate capability to identify subclinical TB (AUC of 0.61, 95% CI: 0.52, 0.70).

Conclusions

Although our results did not identify an easily applicable screening tool for subclinical TB, the present study indicates that focusing on TB-related symptoms in CI settings may be of limited value for early identification of HHCs with high risk for TB progression.

Active case finding of tuberculosis among household contacts of newly diagnosed tuberculosis patients: A community-based study from southern Haryana

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Validation and Clinical Application of Interferon-Gamma Release Assay for Diagnosis of Latent Tuberculosis Infection in Children

BACKGROUND

India has the highest tuberculosis (TB) burden, accounting for one-fifth of the global incidence and two-third of the cases in Southeast Asia with an estimated 1.9 million new cases every year. Identifying and treating latent TB infection (LTBI) can reduce the risk of development of active disease by up to 90%, thereby decreasing a major burden to the prevalence of the disease, and thus reducing potential sources in future.

AIM

Early diagnosis of LTBI by tuberculin skin test (TST) and a newer interferon-gamma release assay (IGRA).

MATERIALS AND METHODS

Seventy-seven clinically asymptomatic household contacts (≤18 years) of confirmed pulmonary TB patients were enrolled to compare the performance of TST and IGRA to diagnose LTBI. At baseline, all participants underwent testing for IGRA and TST.

RESULTS

TST showed positivity of 22%, while IGRA demonstrated positivity of 40% in the diagnosis of latent TB. Kappa value at 95% confidence interval was 0.4753, indicates a moderate agreement between the two tests. This indicates that IGRA is a better predictor of latent TB. Maximum positive percentage was in the age group of 16-18 years in both the tests followed by 1-5 years.

AIM

Early diagnosis of LTBI by tuberculin skin test (TST) and a newer interferon-gamma release assay (IGRA).

The Implementation of Early Detection in Tuberculosis Contact Investigation to Improve Case Finding

The early detection of Tuberculosis (TB) among TB contacts is a strategy to find TB cases in earlier stage and to stop the transmission. This study aimed to assess the implementation of early detection in TB contact investigation to improve TB case finding. This was an operational research study conducted in Badung District, Bali, Indonesia. The samples were TB contacts, identified in the period July through September (third quarter) 2017. Contacts were household members who were living and sharing a room at least for 3 months with infectious TB patients and were not previously diagnosed with TB. Data were collected through face-to-face interview using structured questionnaires and registration reviews using a checklist. We visited 124 TB patients and successfully identified 498 contacts, thus the ratio of contacts to cases is 4:1. All TB contacts were invited to participate in TB screening and evaluation program. A total of 100 (20.1%) contacts have attended at least one examination session and 41 contacts have completed all sessions. Ten TB cases were found among the contacts, of which four of them were adults (three bacteriologically confirmed and one clinically confirmed) and six were children (aged under 15 years). The positivity rate among children was higher (46.2%) compared with adults (14.3%). The positivity rate of confirmed TB among contacts with any TB symptoms was 43.8% and that without symptoms was 12.0%. The contribution of early detection in TB contact investigation to improve TB case finding was 8.1% through all TB patients. The early detection in TB contact investigation yielded additional notified cases, especially among children. A comprehensive education, covering cognitive and psychological aspect, is needed to encourage TB contacts to completely participate in early detection program until their diagnosis is confirmed.

Improving detection of tuberculosis among household contacts of index tuberculosis patients by an integrated approach in Myanmar: a cross-sectional study

Background

Contact tracing for tuberculosis (TB) is a recommended measure to improve the case detection rate; however, actual implementation in Myanmar is limited and low detection rates have been reported. Household contacts of a known index TB case are at high risk of infection, thus a more strategic action for contact tracing is required to achieve the goal of the World Health Organization End TB Strategy. This study aimed to assess TB case detection rates among household contacts by an integrated approach and identify risk factors for TB.

Methods

A cross-sectional study was conducted in Mandalay City, Myanmar. Household contacts of index TB cases who had been receiving treatment for at least 3 months were prospectively investigated by an integrated approach which included modification of screening methods and active facilitation of screening investigations as follows. Initial chest x-ray (CXR) was performed for all contacts at the responsible facilities followed by sputum specimen collection for those aged ≥15 years and gene Xpert MTB/RIF examination. Transportation of all household contacts to health facilities and transportation of sputum samples for smear and gene Xpert MTB/RIF examination at centers were arranged by the research team to ensure that all household contacts received all investigations. Risk factors for TB among household contacts were identified by multiple logistic regression models.

Results

Of 174 household contacts, 115 were ≥ 15 years and 59 were < 15 years. The percentage of TB cases detected among the household contacts was 13.8%. There were 14 (12.2%) positive TB cases among the 115 contacts aged ≥15 years while 10 (16.9%) of those aged < 15 years had clinical signs and symptoms of TB with an abnormal CXR. Risk factors among household contacts for TB were being a caretaker of an index case, active and passive smoking, and drinking alcohol.

Conclusions

The integrated approach of TB contact tracing by special arrangement for CXR, sputum and gene Xpert MTB/RIF examination yielded a high TB detection rate in a high TB prevalence area. Logistic and financial administration is needed to strengthen contact tracing. Further research on high-risk household contacts should be considered for increasing TB detection rates.

Operational research within a Global Fund supported tuberculosis project in India: why, how and its contribution towards change in policy and practice

BACKGROUND

The Global Fund encourages operational research (OR) in all its grants; however very few reports describe this aspect. In India, Project Axshya was supported by a Global Fund grant to improve the reach and visibility of the government Tuberculosis (TB) services among marginalised and vulnerable communities. OR was incorporated to build research capacity of professionals working with the national TB programme and to generate evidence to inform policies and practices.

OBJECTIVES

To describe how Project Axshya facilitated building OR capacity within the country, helped in addressing several TB control priority research questions, documented project activities and their outcomes, and influenced policy and practice.

METHODS

From September 2010 to September 2016, three key OR-related activities were implemented. First, practical output-oriented modular training courses were conducted (n = 3) to build research capacity of personnel involved in the TB programme, co-facilitated by The Union, in collaboration with the national TB programme, WHO country office and CDC, Atlanta. Second, two large-scale Knowledge, Attitude and Practice (KAP) surveys were conducted at baseline and mid-project to assess the changes pertaining to TB knowledge, attitudes and practices among the general population, TB patients and health care providers over the project period. Third, studies were conducted to describe the project's core activities and outcomes.

RESULTS

In the training courses, 44 participant teams were supported to develop research protocols on topics of national priority, resulting in 28 peer-reviewed scientific publications. The KAP surveys and description of project activities resulted in 14 peer-reviewed publications. Of the published papers at least 12 have influenced change in policy or practice.

CONCLUSIONS

OR within a Global Fund supported TB project has resulted in building OR capacity, facilitating research in areas of national priority and influencing policy and practice. We believe this experience will provide guidance for undertaking OR in Global Fund projects.

Tuberculosis preventive treatment: the next chapter of tuberculosis elimination in India

The End TB Strategy envisions a world free of tuberculosis—zero deaths, disease and suffering due to tuberculosis by 2035. This requires reducing the global tuberculosis incidence from >1250 cases per million people to <100 cases per million people within the next two decades. Expanding testing and treatment of tuberculosis infection is critical to achieving this goal. In high-burden countries, like India, the implementation of tuberculosis preventive treatment (TPT) remains a low priority. In this analysis article, we explore potential challenges and solutions of implementing TPT in India. The next chapter in tuberculosis elimination in India will require cost-effective and sustainable interventions aimed at tuberculosis infection. This will require constant innovation, locally driven solutions to address the diverse and dynamic tuberculosis epidemiology and persistent programme monitoring and evaluation. As new tools, regimens and approaches emerge, midcourse adjustments to policy and practice must be adopted. The development and implementation of new tools and strategies will call for close collaboration between local, national and international partners—both public and private—national health authorities, non-governmental organisations, research community and the diagnostic and pharmaceutical industry. Leading by example, India can contribute to global knowledge through operational research and programmatic implementation for combating tuberculosis infection.

Stakeholder perspectives for optimization of tuberculosis contact investigation in a high-burden setting

Introduction

Optimal tuberculosis contact investigation impacts TB prevention, timely case finding and linkage to care, however data on routine implementation in high burden contexts is limited.

Materials and methods

In a multi-method qualitative study based on individual interviews with TB patients, facility observations and focus group discussions with health workers (HWs) in 13 public health facilities, and key informant interviews with governmental and non-governmental experts, we describe TB contact investigation in the context of an urban setting in Kenya and identify opportunities for optimization.

Results

Invitation of TB patients to bring close contacts by HWs was key for all patient decisions that led to contact screening in addition to patients’ understanding of TB transmission and desire to avoid contacts suffering from TB. Sub-optimal HW enquiry of TB patients and contacts presenting at the facility were missed opportunities which stemmed from lack of standardized operational procedures, documentation tools and HW training. Stakeholders proposed provision of fast tracked and holistic health packages for contacts seeking TB screening, and sustainable government led funding for the requisite infrastructure and workforce.

Conclusion

TB contact invitation by HWs leading to contact screening occurs in this context. Stakeholder perspectives inform the design of an operational framework for optimized delivery.

Isoniazid Preventive Therapy among Children Living with Tuberculosis Patients: Is It Working? A Mixed-Method Study from Bhopal, India

OBJECTIVE

We assessed uptake of isoniazid preventive therapy (IPT) among child contacts of smear-positive tuberculosis (TB) patients and its implementation challenges from healthcare providers' and parents' perspectives in Bhopal, India.

METHODS

A mixed-method study design: quantitative phase (review of programme records and house-to-house survey of smear-positive TB patients) followed by qualitative phase (interviews of healthcare providers and parents).

RESULTS

Of 59 child contacts (<6 years) of 129 index patients, 51 were contacted. Among them, 19 of 51 (37%) were screened for TB and one had TB. Only 11 of 50 (22%) children were started and 10 of 50 (20%) completed IPT. Content analysis of interviews revealed lack of awareness, risk perception among parents, cumbersome screening process, isoniazid stock-outs, inadequate knowledge among healthcare providers and poor programmatic monitoring as main barriers to IPT implementation.

CONCLUSION

National TB programme should counsel parents, train healthcare providers, simplify screening procedures, ensure regular drug supply and introduce an indicator to strengthen monitoring and uptake of IPT.

Household Contact Screening and Yield of Tuberculosis Cases-A Clinic Based Study in Chennai, South India

Background

Contact investigation is an active case finding strategy to increase detection of Tuberculosis (TB) and a key component of TB control programs. The household contacts are at a higher risk of exposure than members of the general population. The information on the value and yield of household contact screening and the approaches used in high incidence settings like India is limited.

Objective

To evaluate the yield of active case finding in household contacts of newly diagnosed smear positive TB patients and the factors associated with increased yield.

Method

Retrospective record review of the household contacts of newly diagnosed sputum smear positive patients (index case) enrolled in a clinical trial at National Institute of Research in Tuberculosis, Chennai during the period 2007–2014. A sequential screening algorithm with chest x-ray followed by symptom screen was employed to identify presumptive TB patients.

Results

643 household contacts of 280 index TB patients were identified out of which 544 (85%) consented for screening. 71/544 (13%) patients had an abnormal chest radiograph and out of them 70% were symptomatic. A total of 29/544 (5.3%) contacts were found to have TB among whom 23/29 (79%) were sputum smear positive. The number needed to screen (NNS) to identify a new TB case among all household contacts was 19 and among those with an abnormal CXR was 02. Age group > 44 years, male gender and siblings of the index case was associated with abnormal chest radiograph whereas age group between 15–44 was significantly associated with developing TB disease among household contacts.

Conclusion

Active screening among household contacts is an effective way to improve TB case detection. The yield for new TB cases among contacts with abnormal x-ray was high in this study and the use of Chest X-rays in combination with symptom screen is recommended.

Targeted Echocardiographic Screening for Latent Rheumatic Heart Disease in Northern Uganda: Evaluating Familial Risk Following Identification of an Index Case

Background

Echocardiographic screening for detection of latent RHD has shown potential as a strategy to decrease the burden of disease. However, further research is needed to determine optimal implementation strategies. RHD results from a complex interplay between environment and host susceptibility. Family members share both and relatives of children with latent RHD may represent a high-risk group. The objective of this study was to use echocardiographic family screening to determine the relative risk of RHD among first-degree relatives of children with latent RHD compared to the risk in first-degree relatives of healthy peers.

Methodology/Principal Findings

Previous school-based screening data were used to identify RHD positive children and RHD negative peers. All first-degree relatives ≥ 5 years were invited for echocardiography screening (2012 World Heart Federation Criteria). Sixty RHD positive cases (30 borderline/30 definite RHD) and 67 RHD negative cases were recruited. A total of 455/667 (68%) family members were screened. Definite RHD was more common in childhood siblings of RHD positive compared to RHD negative (p = 0.05). Children with any RHD were 4.5 times as likely to have a sibling with definite RHD, a risk that increased to 5.6 times when considering only cases with definite RHD. Mothers of RHD positive and RHD negative cases had an unexpectedly high rate of latent RHD (9.3%).

Conclusions/Significance

Siblings of RHD positive cases with RHD are more likely to have definite RHD and the relative risk is highest if the index case has definite RHD. Future screening programs should consider implementation of sibling screening following detection of an RHD positive child. Larger screening studies of adults are needed, as data on prevalence of latent RHD outside of childhood are sparse. Future studies should prioritize implementation research to answer questions of how RHD screening can best be integrated into existing healthcare structures, ensuring practical and sustainable screening programs.

Rheumatic heart disease (RHD) affects at least 33 million people, most of who live in low-resource environments. RHD is a cumulative process and there exists a latent period between early valve damage and presentation with symptoms. Echocardiographic screening (ultrasound of the heart) has proven highly sensitive for latent RHD detection, but implementation research is needed to effectively develop sustainable public health strategies. Critical to this research is determining whom to screen. As family members have both a shared environment and shared genetic susceptibility, they may represent a high-risk group that could be targeted once a case of RHD is identified. We conducted an echocardiographic family screening study to determine the risk of RHD in families with and without an RHD positive child and found that siblings of children with latent RHD are more likely to have latent RHD themselves. Our data suggest that siblings may represent a particularly high-risk group that could be targeted for echocardiographic screening. Future studies are needed to answer questions of how RHD screening can best be integrated into existing healthcare structures, ensuring practical and sustainable RHD screening programs.