Tuberculosis contact tracing yield and associated factors in Uganda

The yield of tuberculosis contact investigation in São Paulo, Brazil: a community-based cross-sectional study

The strategy of tuberculosis (TB) contact investigation is essential for enhancing disease detection. We conducted a cross-sectional study to evaluate the yield of contact investigation for new TB cases, estimate the prevalence of TB, and identify characteristics of index cases associated with infection among contacts of new cases notified between 2010 and 2020 in São Paulo, Brazil. Out of 186466 index TB cases, 131055 (70.3%) underwent contact investigation. A total of 652286 contacts were screened, of which 451704 (69.2%) were examined. Of these, 12243 were diagnosed with active TB (yield of 1.9%), resulting in a number needed to screen of 53 and a number needed to test of 37 to identify one new TB case. The weighted prevalence for the total contacts screened was 2.8% (95% confidence interval [CI]: 2.7%-2.9%), suggesting underreporting of 6021 (95% CI: 5269-6673) cases. The likelihood of TB diagnosis was higher among contacts of cases identified through active case-finding, abnormal chest X-ray, pulmonary TB, or drug resistance, as well as among children, adults, women, individuals in socially vulnerable situations, and those with underlying clinical conditions. The study highlights significant TB underreporting among contacts, recommending strengthened contact investigation to promptly identify and treat new cases.

Routine tuberculosis contact investigation yield and preventive treatment cascade in central Ethiopia

Introduction

There is a global gap between tuberculosis incident cases and the notified cases. Active household contact investigation is one of the strategies to narrow this gap. It has the advantage of giving early diagnosis and preventive treatment to vulnerable and eligible groups. This study assessed the practice of contact investigation and tuberculosis preventive treatment adherence in central Ethiopia.

Method

A cross-sectional study covering all registered bacteriologically confirmed pulmonary tuberculosis patients and their close contacts was conducted in central Ethiopia from January 1, 2022, to December 30, 2022.

Result

A total of 1372 household contacts were declared by the index cases. From these 79.44 % (1090) contacts received a one-time tuberculosis screening giving a total of four (0.36 %) active TB cases. Among 484 household contacts of drug-resistant tuberculosis index cases, 5.53 % (14) had presumptive tuberculosis and 0.79 % (2) had active tuberculosis. While among 837 household contacts of drug-susceptible tuberculosis index cases presumptive TB cases were 1.91 % (16) and active TB cases were 0.23 % (2). Of the 142 eligible under 15 children 81.69 % (116) had started tuberculosis preventive treatment and 84.48 % (98) completed the treatment. On multivariable logistic regression, the associated factor for tuberculosis preventive treatment non-adherence was age 2-5 years (aOR, 0.02, 95 % CI (0.002-0.20) and age 5-15 years (aOR, 0.04,95 % CI (0.002-0 0.95)) P=<0.05).

Conclusion

There was low contact screening practice in the DR-TB index cases as compared to national and global targets. The yield of routine contact investigation was low and it indicates the quality of screening. Tuberculosis preventive treatment initiation and completion rates were also low as compared to those of many other countries and global achievements which need further improvement, especially for completion. Alternative mechanisms should be planned to increase the yield of tuberculosis screening and tuberculosis preventive treatment adherence.

The yield of tuberculosis contact investigation on relapsed TB patients and analysis of associated risk factors: Singapore's experience

The yield of contact investigation on relapsed tuberculosis (TB) cases can guide strategies and resource allocation in the TB control programme. We conducted a retrospective cohort study to review the yield of contact investigation in relapsed TB cases and identify factors associated with TB infection (TBI) among close contacts of relapsed TB cases notified between 2018 and 2022 in Singapore. TB infection positivity was higher among contacts of relapsed cases which were culture-positive for Mycobacterium tuberculosis complex compared to those who were only polymerase chain reaction (PCR)-positive (14.8% vs. 12.3%). On multivariate analysis, after adjusting for age and gender of the index, gender, and existing comorbidities of contacts, factors independently associated with TBI were culture and smear positivity of the index (AOR 1.41, 95%CI 1.02-1.94), higher odds with every 10 years of increase in age compared to contacts below aged 30, contacts who were not Singapore residents (AOR 2.09, 95%CI 1.46-2.97), and household contacts (AOR 2.19, 95%CI 1.44-3.34). Although the yield of screening was higher for those who were culture-positive compared to only PCR-positive relapsed cases, contact tracing for only PCR-positive cases may still be important in a country with moderate TB incidence, should resources allow.

Facilitators and barriers to tuberculosis active case findings in low- and middle-income countries: a systematic review of qualitative research

BACKGROUND

Tuberculosis (TB) is an ancient infection and a major public health problem in many low- and middle-income countries (LMICs). Active case finding (ACF) programs have been established to effectively reduce TB in endemic global communities. However, there is little information about the evidence-based benefits of active case finding at both the individual and community levels. Accurately identifying the facilitators and barriers to TB-ACF provides information that can be used in planning and design as the world aims to end the global TB epidemic by 2035. Therefore, this study aimed to identify the facilitators and barriers to tuberculosis ACF in LMICs.

METHODS

A systematic search was performed using recognized databases such as PubMed, Google Scholar, SCOPUS, HINARI, and other reference databases. Relevant studies that assessed or reported the ACF of TB conducted in LMICs were included in this study. The Joanna Briggs Institute's (JBI) Critical Appraisal Tool was used to assess the quality of the selected studies. The Statement of Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) was used to strengthen the protocol for this systematic review. The Confidence of Evidence Review Quality (CERQual) approach was also used to assess the reliability of the review findings.

RESULTS

From 228 search results, a total of 23 studies were included in the final review. Tuberculosis ACF results were generated under two main themes: barriers and facilitators in LMICs, and two sub-themes of the barriers (healthcare-related and non-healthcare-related barriers). Finally, barriers to active TB case finding were found to be related to (1) the healthcare workers' experience, knowledge, and skills in detecting TB-ACF, (2) distance and time; (3) availability and workload of ACF healthcare workers; (4) barriers related to a lack of resources such as diagnostic equipment, reagents, and consumables at TB-ACF; (5) the stigma associated with TB-ACF detection; (6) the lack of training of existing and new healthcare professionals to detect TB-ACF; (7) communication strategies and language limitations associated with TB ACF; and (8) poor or no community awareness of tuberculosis. Stigma was the most patient-related obstacle to detecting active TB cases in LMICs.

CONCLUSION

This review found that surveillance, monitoring, health worker training, integration into health systems, and long-term funding of health facilities were key to the sustainability of ACF in LMICs. Understanding the elimination of the identified barriers is critical to ensuring a maximum tuberculosis control strategy through ACF.