Tuberculosis contact investigation in low- and middle-income countries: standardized definitions and indicators

Finding and treating both tuberculosis disease and latent infection during population-wide active case finding for tuberculosis elimination

In recognition of the high rates of undetected tuberculosis in the community, the World Health Organization (WHO) encourages targeted active case finding (ACF) among "high-risk" populations. While this strategy has led to increased case detection in these populations, the epidemic impact of these interventions has not been demonstrated. Historical data suggest that population-wide (untargeted) ACF can interrupt transmission in high-incidence settings, but implementation remains lacking, despite recent advances in screening tools. The reservoir of latent infection-affecting up to a quarter of the global population -complicates elimination efforts by acting as a pool from which future tuberculosis cases may emerge, even after all active cases have been treated. A holistic case finding strategy that addresses both active disease and latent infection is likely to be the optimal approach for rapidly achieving sustainable progress toward TB elimination in a durable way, but safety and cost effectiveness have not been demonstrated. Sensitive, symptom-agnostic community screening, combined with effective tuberculosis treatment and prevention, should eliminate all infectious cases in the community, whilst identifying and treating people with latent infection will also eliminate tomorrow's tuberculosis cases. If real strides toward global tuberculosis elimination are to be made, bold strategies are required using the best available tools and a long horizon for cost-benefit assessment.

LTBI-negative close contacts of tuberculosis are more likely to develop the disease: enlightenment and lessons from a cluster outbreak

Background

Tuberculosis (TB) prevention and control among groups living together, such as students, workers, older adults in nursing homes, and prisoners, present many challenges due to their particular age and environmental factors, which can make them more susceptible to TB clusters with significant societal impact. This study aimed to evaluate a TB cluster outbreak epidemic in a university and provide suggestions for improving TB control strategies for groups living together.

Methods

Pulmonary TB screening and close-contact investigation were conducted using acid-fast staining, sputum culture, GeneXpert testing, tuberculin skin testing (TST), interferon-gamma release assay (IGRA), and chest computed tomography (CT). GraphPad Prism 9.5.1 was utilized for data analysis. Collected epidemic data were comprehensively analyzed by rate comparison.

Results

The TB cluster outbreak epidemic was identified with an index case confirmed positive. The initial screening was conducted on potential close contacts of the index case, and the TST's positive rate (diameter ≥ 5 mm) and strong positive rate (diameter ≥ 15 mm) among these close contacts were 65.60% (21/32) and 34.40% (11/32), respectively. Moreover, the latent TB infection (LTBI) rate (diameter ≥ 10 mm) was 43.75% (14/32), and the IGRA's positive rate was 9.30% (3/32). Chest CT scans did not reveal any abnormalities. Surprisingly, 5 of the close contacts developed active TB in the second screening, accompanied by changes from negative to positive TST and/or IGRA results, after 3 months of follow-up. Accordingly, we expanded the screening scope to include another 28 general contacts. We found that the positive rate (78.00%, 25/32), strong positive rate (50.00%, 16/32), and LTBI rate (62.50%, 20/32) of the 32 close contacts were significantly higher than those of the additional general contacts (28.00%, 8/28; 14.3%, 4/28; 25.00%, 7/28), as indicated by p < 0.05.

Conclusion

In the event of an epidemic TB outbreak, it is essential to rapidly identify the source of infection and initiate timely screening of close contacts. The initial screening should be focused on individuals without LTBI, who are at higher risk of developing TB. In purified protein derivative-negative individuals living in groups, additional vaccination or revaccination with Bacille Calmette-Guérin may help prevent cluster outbreaks of TB.

Tuberculosis contact investigation in African Portuguese-speaking countries at End TB Strategy era: a scoping review

OBJECTIVES

The contact investigation of tuberculosis (TB) index case is one of the critical elements pointed by the WHO to reach the end of the TB epidemic. The scoping review aimed to map out the recommended and the adopted processes applied to active contact investigation of TB index case in African Portuguese-speaking countries (PALOP).

DESIGN

Scoping review.

DATA SOURCES

We searched B-on, Cochrane Library, PubMed, Web of Science, Scopus, WHOLIS, IRIS, OKR, each country's Ministry of Health websites, WHO, Global Fund, World Bank and bibliographic reference lists from February to May 2020.

ELIGIBILITY CRITERIA

All available literature on TB contact investigation in each country part of PALOP (Angola, Cape Verde, Guinea-Bissau, Mozambique and Sao Tome and Principe) published from 1 January 2010 to 31 January2020.

DATA EXTRACTION AND SYNTHESIS

A data-charting form was developed to extract data on documents' characteristics and variables pertinent to the TB contact investigation process. Before qualitative analysis, we thematically synthesised findings and converted them into appropriate text units.

RESULTS

Fifteen documents were included in the scoping review. The recommended processes for TB contact investigation were identified only for Cape Verde and Mozambique. It included clinical evaluation, counselling and testing for HIV, chest radiography, tuberculin skin test, sputum smear microscopy or Xpert MTB/RIF. The adopted processes were detected only in research studies from Angola, Guinea-Bissau and Mozambique. Therefore, they cannot be assumed as adopted within the scope of the national programmes of the respective countries.

CONCLUSION

This review highlights the scarcity of references on TB contact investigation in PALOP at the End TB Strategy era. Furthermore, it is well clear the importance of an information system that provides actual data for assessing the real impact of such interventions in controlling the disease in African Portuguese-speaking countries.

Theory-Informed Design of a Tailored Strategy for Implementing Household TB Contact Investigation in Uganda

Since 2012, the World Health Organization has recommended household contact investigation as an evidence-based intervention to find and treat individuals with active tuberculosis (TB), the most common infectious cause of death worldwide after COVID-19. Unfortunately, uptake of this recommendation has been suboptimal in low- and middle-income countries, where the majority of affected individuals reside, and little is known about how to effectively deliver this service. Therefore, we undertook a systematic process to design a novel, theory-informed implementation strategy to promote uptake of contact investigation in Uganda, using the COM-B (Capability-Opportunity-Motivation-Behavior) model and the Behavior Change Wheel (BCW) framework. We systematically engaged national, clinic-, and community-based stakeholders and collectively re-examined the results of our own formative, parallel mixed-methods studies. We identified three core behaviors within contact investigation that we wished to change, and multiple antecedents (i.e., barriers and facilitators) of those behaviors. The BCW framework helped identify multiple intervention functions targeted to these antecedents, as well as several policies that could potentially enhance the effectiveness of those interventions. Finally, we identified multiple behavior change techniques and policies that we incorporated into a multi-component implementation strategy, which we compared to usual care in a household cluster-randomized trial. We introduced some components in both arms, including those designed to facilitate initial uptake of contact investigation, with improvement relative to historical controls. Other components that we introduced to facilitate completion of TB evaluation—home-based TB-HIV evaluation and follow-up text messaging—returned negative results due to implementation failures. In summary, the Behavior Change Wheel framework provided a feasible and transparent approach to designing a theory-informed implementation strategy. Future studies should explore the use of experimental methods such as micro-randomized trials to identify the most active components of implementation strategies, as well as more creative and entrepreneurial methods such as human-centered design to better adapt the forms and fit of implementation strategies to end users.

The yield of tuberculosis contact investigation in low- and middle-income settings: a systematic review and meta-analysis

Background

Contact investigation, the systematic evaluation of individuals in close contact with an infectious tuberculosis (TB) patient, is a key active case-finding strategy for global TB control. Better estimates of the yield of contact investigation can guide strategies to reduce the number of underreported and underdiagnosed TB cases, approximately three million cases per year globally. A systematic review (Prospero ID # CRD42019133380) and meta-analysis was conducted to update and enhance the estimates of the yield of TB contact investigation in low- and middle-income countries (LMIC). Pubmed, Web of Science, Embase and the WHO Global Index Medicus were searched for peer-reviewed studies (published between January 2006–April 2019); studies reporting the number of active TB or latent tuberculosis infection (LTBI) found through contact investigation were included. Pooled data were meta-analyzed using a random effects model and risk of bias was assessed.

Results

Of 1,644 unique citations obtained from database searches, 110 studies met eligibility criteria for descriptive data synthesis and 95 for meta-analysis. The pooled yields of contact investigation activities for different outcomes were: secondary cases of all active TB (defined as those bacteriologically confirmed or clinically diagnosed) 2.87% (2.61–3.14, I² 97.79%), bacteriologically confirmed active TB 2.04% (1.77–2.31, I² 98.06%), and LTBI 43.83% (38.11–49.55, I² 99.36%). Yields are interpreted as the percent of contacts screened who are diagnosed with active TB as a result of TB contact investigation activities. Pooled estimates were substantially heterogenous (I² ≥ 75%).

Conclusions

This study provides methodologically rigorous and up-to-date estimates for the yield of TB contact investigation activities in low- and middle-income countries (LMIC). While the data are heterogenous, these findings can inform strategic and programmatic planning for scale up of TB contact investigation activities.

The effectiveness of contact investigation among contacts of tuberculosis patients: a systematic review and meta-analysis

BACKGROUND

We aimed to evaluate the effectiveness of contact investigation in comparison to passive case-detection alone and estimated the yield of co-prevalent and incident tuberculosis (TB), and latent tuberculosis infection (LTBI) among contacts of patients with TB.

METHODS

A systematic search was undertaken of studies published between January 1, 2011 and October 1, 2019 in the English language. The proportion of contacts diagnosed with co-prevalent TB, incident TB and/or LTBI was estimated. Evaluation of the effectiveness of contact investigation included randomised trials, while the yield of contact investigation (co-prevalent and incident TB and LTBI) was assessed in non-randomised studies.

RESULTS

Data were extracted from 244 studies, of which 187 studies measured the proportion of contacts diagnosed with TB disease and 135 studies measured LTBI prevalence. Individual randomised trials demonstrated that contact investigation increased TB case notification (RR 2.5 [95% CI: 2.0-3.2]), TB case detection (OR 1.34 [95% CI: 0.43-4.24]) and decreased mortality (RR 0.6 [95% CI: 0.4-0.8]) and population TB prevalence (risk ratio 0.82 [95% CI: 0.64-1.04]).The overall pooled prevalence of TB was 3.6% (95% CI: 3.3-4.0%; I²=98.9%, 181 studies). The pooled prevalence of microbiologically-confirmed TB was 3.2% (95% CI: 2.6-3.7%; I²=99.5%, 106 studies). The pooled incidence of TB was highest in the first year after exposure to index patients (2.0%, 95% CI: 1.1-3.3%; I²=96.2%, 14 studies) and substantially lower five years after exposure to index patient (0.5%, 95% CI: 0.3-0.9%; 1 study). The pooled prevalence of LTBI among contacts was 42.4% (95% CI: 38.5-46.4%; I²=99.8%, 135 studies).

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis found that contact investigation was effective in high-burden settings. The higher pooled prevalence estimates of microbiologically-confirmed TB compared to previous reviews suggests newer rapid molecular diagnostics contribute to increased case detection.

Parallels and Mutual Lessons in Tuberculosis and COVID-19 Transmission, Prevention, and Control

The coronavirus disease (COVID-19) pandemic has had unprecedented negative effects on global health and economies, drawing attention and resources from many other public health services. To minimize negative effects, the parallels, lessons, and resources from existing public health programs need to be identified and used. Often underappreciated synergies relating to COVID-19 are with tuberculosis (TB). COVID-19 and TB share commonalities in transmission and public health response: case finding, contact identification, and evaluation. Data supporting interventions for either disease are, understandably, vastly different, given the diseases' different histories. However, many of the evolving issues affecting these diseases are increasingly similar. As previously done for TB, all aspects of congregate investigations and preventive and therapeutic measures for COVID-19 must be prospectively studied for optimal evidence-based interventions. New attention garnered by the pandemic can ensure that knowledge and investment can benefit both COVID-19 response and traditional public health programs such as TB programs.

Factors associated with household contacts' tuberculosis testing and evaluation

PURPOSE

No research has been done in New York City that shows the demographic characteristics of household contacts testing, evaluation, and treatment of LTBI. The objective of the study was to identify demographic factors associated with household contacts' TB testing, evaluation, and LTBI treatment.

DESIGN AND METHODS

A retrospective analysis of the New York City (NYC) TB registry data that examined the factors (gender, age, country of birth, race/ethnicity, and borough of residence) associated with TB testing, evaluation, and LTBI treatment. The study sample included all household contacts of TB cases identified from 2010 to 2014 (N = 3,008). The data set was chosen when nurses were the primary case managers at chest centers in the department of health. Descriptive and inferential analysis was used to identify factors associated with testing, evaluation, and LTBI treatment.

RESULTS

The demographic characteristics of household contacts associated with testing, evaluation, and LTBI treatment were consistent with those of TB cases in NYC from 2010 to 2014. Those not tested, not fully evaluated, and refusing LTBI treatment were most often aged 18-44 years and were non-US born. Males were significantly more likely than females not to be fully evaluated. Among racial/ethnic groups, Asian and Hispanic persons were at higher risk of not being fully evaluated, and residents of Queens had the highest risk among the five boroughs. In multivariate analyses, age was a significant predictor of behavior, such that the older the person the less likely to get TB testing or to accept LTBI treatment. Non-US country of birth was associated with lower likelihood of being fully evaluated but more likely to accept LTBI treatment when fully evaluated, while Asian or Hispanic race/ethnicity was associated with higher likelihood of both behaviors.

CONCLUSIONS

Findings on age from this study will enable public health agencies and public health nurses to plan for effective strategies that will increase the number of household contacts who accept TB testing and evaluation, as well as the numbers who will accept and complete LTBI treatment.

An e-registry for household contacts exposed to multidrug resistant TB in Mongolia

BACKGROUND

The WHO recommends that individuals exposed to persons with multidrug resistant tuberculosis (MDRTB) should be screened for active TB and followed up for 2 years to detect and treat secondary cases early. Resource prioritisation means this is rarely undertaken and where it is performed it's usually using a paper-based record, without collation of data. Electronic data collection into a web-based registry offers the opportunity for simplified and systematic TB contact surveillance with automatic synthesis of data at local, regional and national level. This pilot study was designed to explore the feasibility of usage of a novel e-registry tool and explore obstacles and facilitating factors to implementation.

METHODS

In parallel with their paper records, seven dispensaries in Ulaanbaatar, Mongolia collected standardized data electronically using Open Data Kit (ODK). Patients with MDRTB and their contacts were recruited during a single clinic visit. Staff and patients were interviewed to gain insights into acceptability and to identify areas for improvement.

RESULTS

Seventy household contacts of 32 MDR-TB index patients were recruited. 7/70 contacts (10%) traced had active TB at the time they were recruited to the e-registry. Paper registry satisfaction was low; 88% of staff preferred the e-registry as it was perceived as faster and more secure. Patients and their contacts were generally supportive of the e-registry; however, a significant minority 10/42 (24%) of index cases who were invited, declined to participate in the e-registry, with data security cited as their top concern.

CONCLUSION

E-registries are a promising tool for MDRTB contact tracing, but their acceptability amongst patients should not be taken for granted.

Experiences and intentions of Ugandan household tuberculosis contacts receiving test results via text message: an exploratory study

BACKGROUND

The World Health Organization (WHO) recommends household contact investigation for tuberculosis (TB) in high-burden countries. However, household contacts who complete evaluation for TB during contact investigation may have difficulty accessing their test results. Use of automated short-messaging services (SMS) to deliver test results could improve TB status awareness and linkage to care. We sought to explore how household contacts experience test results delivered via SMS, and how these experiences influence follow-up intentions.

METHODS

We conducted semi-structured interviews with household contacts who participated in a randomized controlled trial evaluating home sputum collection and delivery of TB results via SMS (Pan-African Clinical Trials Registry #201509000877140). We asked about feelings, beliefs, decisions, and behaviors in response to the SMS results. We analyzed the content and emerging themes in relation to the Theory of Planned Behavior.

RESULTS

We interviewed and achieved thematic saturation with ten household contacts. Nine received TB-negative results and one a TB-positive result. Household contacts reported relief upon receiving SMS confirming their TB status, but also said they lacked confidence in the results delivered by SMS. Some worried that negative results were incorrect until they spoke to a lay health worker (LHW). Household contacts said their long-term intentions to request help or seek care were influenced by perceived consequences of not observing the LHW's instructions related to the SMS and follow-up procedures; beliefs about the curability of TB; anticipated support from LHWs; and perceived barriers to responding to an SMS request for further evaluation.

CONCLUSION

Household contacts experienced relief when they received results. However, they were less confident about results delivered via SMS than results delivered by LHWs. Delivery of results by SMS should complement continued interaction with LHWs, not replace them.

Levofloxacin versus placebo for the treatment of latent tuberculosis among contacts of patients with multidrug-resistant tuberculosis (the VQUIN MDR trial): a protocol for a randomised controlled trial

INTRODUCTION

Treatment of latent tuberculosis infection (LTBI) plays a substantial role in the prevention of drug-susceptible tuberculosis (TB). However, clinical trials to evaluate the efficacy of preventive therapy for presumed multidrug-resistant (MDR) LTBI are lacking. This trial aims to evaluate the efficacy of the antibiotic levofloxacin in preventing the development of active TB among latently infected contacts of index patients with MDR-TB.

METHODS AND ANALYSIS

A double-blind placebo-controlled parallel group randomised controlled trial will be conducted in 10 provinces of Vietnam. Household contacts living with patients with bacteriologically confirmed rifampicin-resistant or MDR-TB will be eligible for recruitment if they have a positive tuberculin skin test or are known to be immunosuppressed, and do not have active TB. Participants will be randomised to receive either levofloxacin or placebo tablets once per day for 6 months. Screening for incident TB will be performed at 6 months intervals. The primary study outcome is the incidence of bacteriologically confirmed TB within 30 months after randomisation. Analysis will be by intention to treat, using Poisson regression.

ETHICS

Ethical approval from the University of Sydney Human Research Ethics Committee was obtained on 29 April 2015 (2014/929), and from the Vietnam Ministry of Health Institutional Review Board on 30 September 2015 (4040/QD-BYT).

DISSEMINATION

Findings of the study will be published in peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12616000215426.

House-hold contact tuberculosis screening adherence and associated factors among tuberculosis patients attending at health facilities in Gondar town, northwest, Ethiopia

BACKGROUND

Contacting patients with tuberculosis have a substantial risk of developing the disease. Household contact screening has recently been recommended as a strategy to enhance case detection in high-burden countries. But there is no enough information in Gondar town regarding household contact screening practice among TB patients.

METHODS

An institution-based cross-sectional study was conducted from March 1 to 30, 2019 on 404 tuberculosis patients attending at health facilities in Gondar Town. Epi-Info version 7 for data entry and SPSS version 20 for data analysis were used. Descriptive statistics were carried out to illustrate the means, standard deviations, and frequencies. Bivariable and multivariable logistic regression analyses were used to identify significantly associated variables with the dependent variable.

RESULTS

From 412 study populations, 404 were completed the study with 98.06% response rate. The overall household contact TB screening adherence was 47.5% (95% CI: 43.1, 52.5). In the multivariable analysis, having certificate and above educational level (AOR = 2.83, 95% CI:1.40,5.67), having sufficient knowledge about TB (AOR = 8.26, 95% CI:4.34,15.71), being satisfied with health care service (AOR = 3.26, 95% CI:1.58,6.76), health education given by health care workers (AOR = 2.60, 95% CI:1.54,4.40),and having HIV/AIDS co-infection (AOR = 3.54, 95% CI:1.70,7.39), were factors associated with household contact TB screening adherence.

CONCLUSION

Compared to other previous studies, the current finding was high but it was low as compared with WHO and Ethiopian Ministry of Health recommendations (all persons having TB contact should be screened). Educational status, knowledge on TB, satisfaction with delivered health care service, health education given by HCWs about TB and HIV/AIDS co-infection were factors associated with household contact TB screening practice. Thus, strengthening household TB contact screening and educational programs regarding the risk of getting TB infection from household contacts is crucial.

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.

'Something so hard': a mixed-methods study of home sputum collection for tuberculosis contact investigation in Uganda

BACKGROUND

Home sputum collection could facilitate prompt evaluation and diagnosis of tuberculosis (TB) among contacts of patients with active TB. We analyzed barriers to home-based collection as part of an enhanced intervention for household TB contact investigation in Kampala, Uganda.

DESIGN

We conducted a convergent mixed-methods study to describe the outcomes of home sputum collection in 91 contacts and examine their context through 19 nested contact interviews and two focus group discussions with lay health workers (LHWs).

RESULTS

LHWs collected sputum from 35 (39%) contacts. Contacts reporting cough were more likely to provide sputum than those with other symptoms or risk factors (53% vs. 15%, RR 3.6, 95%CI 1.5-2.8, P < 0.001). Males were more likely than females to provide sputum (54% vs. 32%, RR 1.7, 95%CI 1.0-2.8, P = 0.05). Contacts said support from the index patient and the convenience of the home visit facilitated collection. Missing containers and difficulty producing sputum spontaneously impeded collection. Women identified stigma as a barrier. LHWs emphasized difficulty in procuring sputum and discomfort pressing contacts to produce sputum.

CONCLUSIONS

Home sputum collection by LHWs entails different challenges from sputum collection in clinical settings. More research is needed to develop interventions to mitigate stigma and increase success of home-based collection.

Home-based tuberculosis contact investigation in Uganda: a household randomised trial

Introduction

The World Health Organization (WHO) recommends household tuberculosis (TB) contact investigation in low-income countries, but most contacts do not complete a full clinical and laboratory evaluation.

Methods

We performed a randomised trial of home-based, SMS-facilitated, household TB contact investigation in Kampala, Uganda. Community health workers (CHWs) visited homes of index patients with pulmonary TB to screen household contacts for TB. Entire households were randomly allocated to clinic (standard-of-care) or home (intervention) evaluation. In the intervention arm, CHWs offered HIV testing to adults; collected sputum from symptomatic contacts and persons living with HIV (PLWHs) if ≥5 years; and transported sputum for microbiologic testing. CHWs referred PLWHs, children <5 years, and anyone unable to complete sputum testing to clinic. Sputum testing results and/or follow-up instructions were returned by automated SMS texts. The primary outcome was completion of a full TB evaluation within 14 days; secondary outcomes were TB and HIV diagnoses and treatments among screened contacts.

Results

There were 471 contacts of 190 index patients allocated to the intervention and 448 contacts of 182 index patients allocated to the standard-of-care. CHWs identified 190/471 (40%) intervention and 213/448 (48%) standard-of-care contacts requiring TB evaluation. In the intervention arm, CHWs obtained sputum from 35/91 (39%) of sputum-eligible contacts and SMSs were sent to 95/190 (50%). Completion of TB evaluation in the intervention and standard-of-care arms at 14 days (14% versus 15%; difference −1%, 95% CI −9% to 7%, p=0.81) and yields of confirmed TB (1.5% versus 1.1%, p=0.62) and new HIV (2.0% versus 1.8%, p=0.90) diagnoses were similar.

Conclusions

Home-based, SMS-facilitated evaluation did not improve completion or yield of household TB contact investigation, likely due to challenges delivering the intervention components.

In a household randomised trial in Kampala, Uganda, home-based, SMS-facilitated evaluation did not improve completion or yield of household TB contact investigation. Future studies will evaluate user-centred design to improve intervention delivery.http://bit.ly/2xwLpDu

Evaluation of facility and community-based active household tuberculosis contact investigation in Ethiopia: a cross-sectional study

BACKGROUND

No established strategy for household tuberculosis (TB) contact investigation (HTCI) exists in Ethiopia. We implemented integrated, active HTCI model into two hospitals and surrounding community health services to determine yield of active HTCI of all forms of TB and explore factors associated with active TB diagnosis in household contacts (HHCs).

METHODS

Case managers obtained HHC information from index cases at TB/DOTS clinic and liaised with health extension workers (HEWs) who screened HHCs for TB at household and referred contacts under five and presumptive cases for diagnostic investigation.

RESULTS

From 363 all forms TB index cases, 1509 (99%) HHCs were screened and 809 (54%) referred, yielding 19 (1.3%) all forms TB cases. HTCI of sputum smear-positive pulmonary TB (SS + PTB) index cases produced yield of 4.3%. HHCs with active TB were more likely to be malnourished (OR: 3.39, 95%CI: 1.19-9.64), live in households with SS + PTB index case (OR: 7.43, 95%CI: 1.64-33.73) or TB history (OR: 4.18, 95%CI: 1.51-11.55).

CONCLUSION

Active HTCI of all forms of TB cases produced comparable or higher yield than reported elsewhere. HTCI contributes to improved and timely case detection of Tuberculosis among population who may not seek health care due to minimal symptoms or access issues. Active HTCI can successfully be implemented through integrated approach with existing community TB programs for better coordination and efficiency. Referral criteria should include factors significantly associated with active disease.

Diabetes screen during tuberculosis contact investigations highlights opportunity for new diabetes diagnosis and reveals metabolic differences between ethnic groups

Type 2 diabetes (T2D) is a prevalent risk factor for tuberculosis (TB), but most studies on TB-T2D have focused on TB patients, been limited to one community, and shown a variable impact of T2D on TB risk or treatment outcomes. We conducted a cross-sectional assessment of sociodemographic and metabolic factors in adult TB contacts with T2D (versus no T2D), from the Texas-Mexico border to study Hispanics, and in Cape Town to study South African Coloured ethnicities. The prevalence of T2D was 30.2% in Texas-Mexico and 17.4% in South Africa, with new diagnosis in 34.4% and 43.9%, respectively. Contacts with T2D differed between ethnicities, with higher smoking, hormonal contraceptive use and cholesterol levels in South Africa, and higher obesity in Texas-Mexico (p < 0.05). PCA analysis revealed striking differences between ethnicities in the relationships between factors defining T2D and dyslipidemias. Our findings suggest that screening for new T2D in adult TB contacts is effective to identify new T2D patients at risk for TB. Furthermore, studies aimed at predicting individual TB risk in T2D patients, should take into account the heterogeneity in dyslipidemias that are likely to modify the estimates of TB risk or adverse treatment outcomes that are generally attributed to T2D alone.

Characteristics and management of bone and joint tuberculosis in native and migrant population in Shanghai during 2011 to 2015

Background

China had the third highest burden of tuberculosis population in the world. Bone and joint tuberculosis was a major part and its characteristics were rarely discussed before. This study was designed to review the characteristics and management of bone and joint tuberculosis among native and migrant population in Shanghai, China during 2011–2015.

Methods

A retrospective analysis of the patient clinical records on their demographic information, clinical features and treatment was conducted from three tertiary referral hospitals. Analysis of continuous variables included calculation of the median value with interquartile range. Categorical variables were displayed as percentages and compared using the Fisher’s exact test and chi-square test. All continuous variables were compared using Student’s unpaired t-test and Mann Whitney U test.

Results

One hundred fifteen patients with bone and joint tuberculosis were involved in this study. Native people were generally older (p = 0.003) and had more comorbidities like hypertension (40.74% vs. 16.39%, p = 0.004), diabetes mellitus (38.89% vs. 13.11%, p = 0.001), and cancer (31.48% vs. 14.75%, p = 0.032) than migrants. Migrant patients generally experienced a longer period of uncomfortable feelings before going to doctor than native people (p = 0.007). Spine was a major infection site in comparison with other peripheral joints. Radiological evaluation displayed increased osteolytic reaction in migrant patients compared with native people (p = 0.031). The mean time for anti-tuberculosis treatment was significantly longer in native Shanghai patients (8.96 months vs. 7.94 months, p = 0.003). The curative ratio displayed a significant difference between native and migrant patients (88.24%vs.75.93%, p = 0.009).

Conclusion

Bone and joint tuberculosis exhibited a poorer outcome in migrant people, who also had longer period of manifestation, more severe osteolytic reaction from CT scan and higher recurrent rate than native people. The surgical treatment in addition to anti-tuberculosis drug therapy had great implications for bone and joint tuberculosis recovery.

Social determinants of tuberculosis evaluation among household contacts: a secondary analysis

Setting: Seven public sector tuberculosis (TB) units and surrounding communities in Kampala, Uganda. Objective: To evaluate the influence of household-level socio-economic characteristics on completion of TB evaluation during household contact investigation. Design: A cross-sectional study nested within the control arm of a randomized, controlled trial evaluating home-based sputum collection and short messaging service communications. We used generalized estimating equations to estimate the association between completion of TB evaluation and socio-economic determinants. Results: Of 116 household contacts referred to clinics for TB evaluation, 32 (28%) completed evaluation. Completing evaluation was strongly clustered by household. Controlling for individual symptoms, contacts from households earning below-median income (adjusted risk ratio [aRR] 0.28, 95%CI 0.09-0.88, P = 0.029) and contacts from households in which the head of household had no more than primary-level education (aRR 0.40, 95%CI 0.18-0.89, P = 0.025) were significantly less likely to complete evaluation for TB. Conclusion: Socio-economic factors such as low income and education increase the risk that household contacts of TB patients will experience barriers to completing TB evaluation themselves. Further research is needed to identify specific mechanisms by which these underlying social determinants modify the capability and motivation of contacts to complete contact investigation.

Integrating home HIV counselling and testing into household TB contact investigation: a mixed-methods study

Setting: Community health workers (CHWs) increasingly deliver community-based human immunodeficiency virus (HIV) counselling and testing (HCT) services. Less is known about how this strategy performs when integrated with household tuberculosis (TB) contact investigations. Objective: We conducted a prospective mixed-methods study to evaluate the feasibility and quality of CHW-facilitated, home-based HCT among household TB contacts. Design: CHWs visited households of consenting TB patients to screen household contacts for TB and HIV. They performed HIV testing using a serial enzyme-linked immunosorbent assay rapid-antibody testing algorithm. Laboratory technicians at health facilities re-tested the samples and coordinated quarterly HIV panel testing for CHWs. We conducted focus group discussions (FGDs) with CHWs on their experiences in carrying out home-based HCT. Results: Of 114 household contacts who consented to and underwent HIV testing by CHWs, 5 (4%) tested positive, 108 (95%) tested negative, and 1 (1%) had indeterminate results; 110 (96%) samples had adequate volume for re-testing. Overall agreement between CHWs and laboratory technicians was 99.1% (κ = 0.90, 95%CI 0.71-1.00, P < 0.0001). In FGDs, CHWs described context-specific social challenges to performing HCT in a household setting, but said that their confidence grew with experience. Conclusion: Home-based HCT by CHWs was feasible among household TB contacts and produced high-quality results. Strategies to address social challenges are required to optimize yield.

Comparison of the yield of tuberculosis among contacts of multidrug-resistant and drug-sensitive tuberculosis patients in Ethiopia using GeneXpert as a primary diagnostic test

OBJECTIVES

This study compared the yield of tuberculosis (TB) among contacts of multidrug-resistant tuberculosis (MDR-TB) index cases with that in drug-sensitive TB (DS-TB) index cases in a program setting.

METHODS

A comparative cross-sectional study was conducted among contacts of sputum smear-positive new DS-TB index cases and MDR-TB index cases. After contacts were screened, GeneXpert was used for the diagnosis of TB.

RESULTS

The study included 111 MDR-TB and 119 DS-TB index cases. A total of 340 and 393 contacts of MDR-TB and DS-TB index cases, respectively, were traced, of whom 331 among MDR-TB contacts and 353 among DS-TB contacts were screened. There were 20 (6%) presumptive TB cases for MDR-TB contacts and 41 (11%) for DS-TB contacts. The prevalence of TB among MDR-TB contacts was 2.7% and among DS-TB contacts was 4.0%. The majority of the MDR-TB contacts diagnosed with TB had MDR-TB; the reverse was true for DS-TB.

CONCLUSIONS

The yield of TB among contacts of MDR-TB and DS-TB patients using GeneXpert was high as compared to the population-level prevalence. The likelihood of diagnosing rifampicin-resistant TB among contacts of MDR-TB index cases was higher in comparison with contacts of DS-TB index cases. The use of GeneXpert in DS-TB contact investigation has the added advantage of diagnosing rifampicin-resistant TB cases when compared to the use of the nationally recommended acid-fast bacillus (AFB) microscopy for DS-TB contact investigation.

Intensity of exposure to pulmonary tuberculosis determines risk of tuberculosis infection and disease

Household contacts of pulmonary tuberculosis (TB) patients are at increased risk of TB infection and disease. However, their risk in relation to the intensity of exposure remains unknown.We studied smear-positive TB cases and their household contacts in Vitória, Brazil. We collected clinical, demographic and radiographic information from TB cases, and obtained tuberculin skin test (TST) and QuantiFERON-TB Gold (QFT) results from household contacts. We measured intensity of exposure using a proximity score and sleep location in relation to the TB index case and defined infection by TST ≥10 mm or QFT ≥0.35 UI·mL-1 We ascertained secondary TB cases by reviewing local and nationwide case registries.We included 160 TB index cases and 894 household contacts. 464 (65%) had TB infection and 23 (2.6%) developed TB disease. Risk of TB infection and disease increased with more intense exposures. In an adjusted analysis, the proximity score was associated with TB disease (OR 1.61, 95% CI 1.25-2.08; p<0.000); however, its diagnostic performance was only moderate.Intensity of exposure increased risk of TB infection and disease among household contacts; however, its diagnostic performance was still suboptimal. A biomarker to target preventive therapy is urgently needed in this at-risk population.

Drop-out from the tuberculosis contact investigation cascade in a routine public health setting in urban Uganda: A prospective, multi-center study

SETTING

Seven public tuberculosis (TB) units in Kampala, Uganda, where Uganda's national TB program recently introduced household contact investigation, as recommended by 2012 guidelines from WHO.

OBJECTIVE

To apply a cascade analysis to implementation of household contact investigation in a programmatic setting.

DESIGN

Prospective, multi-center observational study.

METHODS

We constructed a cascade for household contact investigation to describe the proportions of: 1) index patient households recruited; 2) index patient households visited; 3) contacts screened for TB; and 4) contacts completing evaluation for, and diagnosed with, active TB.

RESULTS

338 (33%) of 1022 consecutive index TB patients were eligible for contact investigation. Lay health workers scheduled home visits for 207 (61%) index patients and completed 104 (50%). Among 287 eligible contacts, they screened 256 (89%) for symptoms or risk factors for TB. 131 (51%) had an indication for further TB evaluation. These included 59 (45%) with symptoms alone, 58 (44%) children <5, and 14 (11%) with HIV. Among 131 contacts found to be symptomatic or at risk, 26 (20%) contacts completed evaluation, including five (19%) diagnosed with and treated for active TB, for an overall yield of 1.7%. The cumulative conditional probability of completing the entire cascade was 5%.

CONCLUSION

Major opportunities exist for improving the effectiveness and yield of TB contact investigation by increasing the proportion of index households completing screening visits by lay health workers and the proportion of at-risk contacts completing TB evaluation.

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.