Effect of Community Active Case Finding Strategies for Detection of Tuberculosis in Cambodia

Summary

Tuberculosis (TB) is a highly stigmatized disease, and approximately one-third of the Cambodian population living with TB are undetected. Therefore, it is vital to find these missing cases and promptly link them to care to reduce disease progression and interrupt further transmission. The integration of community-based, peer-driven intervention in TB active case finding (ACF) is relatively novel. In partnership with KHANA, the National Center for Tuberculosis and Leprosy Control (CENAT), and the Cambodia Anti-Tuberculosis Association (CATA), we will conduct a pragmatic cluster randomized controlled trial comparing 1) the ACF with the seed-and-recruit model; 2) ACF targeting household and neighborhood contacts; 3) ACF targeting the older population using mobile screening units; and 4) passive case finding (PCF) approach. The primary outcome will be the case notification rate in the intervention and control districts during the study period. We will also determine additionality, comparing the yield in each arm with its respective historical baseline and the cumulative yield over the implementation period. The secondary outcomes include the number needed to screen to detect one TB case, cost-effectiveness (direct and indirect costs per TB case notified), and the treatment outcome of all people with TB in this study. The project will be carried out over two years in eight operational districts (province name in parenthesis) - Koh Soutin (Kampong Cham), Stong (Kampong Thom), Kanchreach (Prey Veng), Choeung Prey (Kampong Cham), Dambae (Thbong Khmum), Boribo (Kampong Chhnang), Ponhea Leu (Kandal), and Phnom Srouch (Kampong Speu) - in Cambodia. The selection was also based on the number of health centers to increase comparability and generalizability of study findings. This study will randomize currently underserved operational districts (without active intervention at least in the past six months from the implementation date) to receive the interventions (ACF) and PCF as the control. The results from this proposal will enable a nationwide scale-up of an effective intervention that is contextualized and complies with the principles set by the national TB program to find undiagnosed cases and control TB in Cambodia. Also, this project will complement existing ACF programs in Cambodia by expanding ACF to other operational districts that are currently not served by the Global Fund, its implementing partners, and other organizations. Findings from this trial could also potentially inform active case finding strategies in other countries with a high TB burden.

Conditions

• Tuberculosis

Interventions

OTHER

ACF with a seed-and-recruit model

The intervention will take place for 12 months. In the intervention clusters, potential seeds - TB survivors, people living with HIV, and household contacts of people with TB - will be approached by the research team. Seeds will be trained and act as recruiters in the community to refer presumptive TB cases to the attached health centers. The research team will work with staff at the health centers to facilitate screening and enrollment of recruits who are diagnosed with TB to care. New people with TB who have the potential to be a recruiter will be invited and trained to recruit their peers in the community who may have TB for TB screening. Seeds will be trained to identify people who may have TB and equipped with health promotion skills to impart knowledge and practices about TB. We will follow-up all people with TB referred by seeds for six months from the treatment initiation.

OTHER

ACF targeting household and neighborhood contacts

In this arm, community health volunteers will recruit household contacts of people with TB and TB survivors diagnosed during the preceding two years. Immediate neighbors (10 nearest households) of the index cases (people with TB) who are symptomatic will also be invited by the community health volunteers to the screening session. Next nearest households within the same village will be approached if the number of presumptive TB cases in the 10 nearest households is low. The one-off screening session will be held at the nearest health center on specific days. Presumptive TB cases will be screened for symptoms on-site, and chest x-ray (CXR) will be taken. Sputum samples from presumptive TB cases with abnormal (CXR) will be collected for GeneXpert testing. Test results will be communicated to the newly diagnosed people with TB, and they will be referred to the health centers for treatment and follow-up.

OTHER

ACF targeting the older population using mobile screening units

The outreach team will conduct training and sensitization of the target population of the activities. The schedule of a one-off screening session will be made known to the communities in the districts before the screening day. Each person who visits the screening session will be screened. Demographic information and presence of TB symptoms will be collected at registration by a trained staff. A chest x-ray will then be performed on-site for all persons exhibiting TB symptoms and all elderly aged 55 and above regardless of symptoms. When CXR findings are abnormal, sputum samples will be collected for GeneXpert testing on-site as well. Test results will be communicated to the participants on the spot or via phone calls, and people with TB will be referred for treatment and follow-up at the health center where screening is conducted or a center of their choice. Should the health center of their choice do not fall within the selected sites, follow-up will be conducted via phone calls.

OTHER

Passive case finding

Passive case finding (PCF) strategy is a default setup in the national health system. PCF relies on the self-presentation of presumptive TB cases to the health centers to be diagnosed with TB.

Sponsors & Collaborators

• KHANA Center for Population Health Research

  collaborator OTHER

• National University of Singapore

  lead OTHER

Principal Investigators

• Siyan Yi, PhD · National University of Singapore

• Alvin Teo, MPH · National University of Singapore

Study Design

Allocation

RANDOMIZED

Purpose

SCREENING

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-12-16

Primary Completion

2021-11-30

Completion

2022-01-31

Countries

• Cambodia

Study Locations