Population-wide active case finding and prevention for tuberculosis and leprosy elimination in Kiribati: the PEARL study protocol

Abstract

IntroductionPopulation-wide interventions offer a pathway to tuberculosis (TB) and leprosy elimination, but ‘real-world’ implementation in a high-burden setting using a combined approach has not been demonstrated. This implementation study aims to demonstrate the feasibility and evaluate the effect of population-wide screening, treatment and prevention on TB and leprosy incidence rates, as well as TB transmission.Methods and analysisA non-randomised ‘screen-and-treat’ intervention conducted in the Pacific atoll of South Tarawa, Kiribati. Households are enumerated and all residents ≥3 years, as well as children <3 years with recent household exposure to TB or leprosy, invited for screening. Participants are screened using tuberculin skin testing, signs and symptoms of TB or leprosy, digital chest X-ray with computer-aided detection and sputum testing (Xpert MTB/RIF Ultra). Those diagnosed with disease are referred to the National TB and Leprosy Programme for management. Participants with TB infection are offered TB preventive treatment and those without TB disease or infection, or leprosy, are offered leprosy prophylaxis. The primary study outcome is the difference in the annual TB case notification rate before and after the intervention; a similar outcome is included for leprosy. The effect on TB transmission will be measured by comparing the estimated annual risk of TB infection in primary school children before and after the intervention, as a co-primary outcome used for power calculations. Comparison of TB and leprosy case notification rates in South Tarawa (the intervention group) and the rest of Kiribati (the control group) before, during and after the intervention is a secondary outcome.Ethics and disseminationApproval was obtained from the University of Sydney Human Research Ethics Committee (project no. 2021/127) and the Kiribati Ministry of Health and Medical Services (MHMS). Findings will be shared with the MHMS and local communities, published in peer-reviewed journals and presented at international conferences.

Evaluation of a population-wide, systematic screening initiative for tuberculosis on Daru island, Western Province, Papua New Guinea

“…Small island settings in the Pacific, where the population is geographically isolated and defined, provide a unique opportunity for population-wide screening. Such interventions are increasingly implemented as part of the effort to eliminate TB, in combination with TB infection testing and preventive treatment [ 25 , 26 ]. Given the high burden of TB and the paucity of evidence on systematic TB screening in PNG, all future TB screening projects should incorporate a well-designed evaluation to add to the evidence base and inform screening strategies [ 27 ].…”

Effectiveness of population-wide screening and mass drug administration for leprosy control in Kiribati: the COMBINE protocol

“…Leprosy treatment will be provided by the NLP according to Kiribati national guidelines. Further details of the leprosy screening, diagnosis and treatment eligibility criteria are available in the PEARL study protocol 17…”

“…The safety of treatments for TB are discussed in the PEARL study protocol 17. SDR is very safe, and has been used in Kiribati18 19 and elsewhere12 26–28 with little or no recorded side-effects.…”

“…The COMBINE study is designed to inform programmatic strategies towards leprosy elimination in the Pacific and elsewhere. We aim to assess the effectiveness, feasibility, efficiency and cost of a programme of leprosy screening and mass rifamycin-based chemoprophylaxis delivered in combination with a TB screening, treatment and prevention initiative in Kiribati 17. We will provide evidence for practicable means of integrating leprosy control with other communicable disease programmes that can be used to effectively accelerate leprosy prevention and care in endemic regions.…”

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

“…WHO currently recommends screening of identified high-risk populations, such as people living with HIV, recent household contacts and other groups, such as people initiating immunosuppressive treatment considered to be at high risk of tuberculosis disease progression ( 14 ). Whether additional groups can be identified who will benefit from LTBI-linked ACF in high-incidence settings remains under evaluation ( 10 , 39 ). Three studies in the Asia-Pacific are currently underway to investigate this evidence gap including a randomized controlled trial and “real-life” implementation study, explored below.…”