The study will determine the effect of community-wide screening and treatment for leprosy, combined with PEP for household contacts and once-off mass chemoprophylaxis of the whole population of South Tarawa/Betio on the leprosy new case detection rate.
The COMBINE study: Defining the impact of combined community-wide screening and mass chemoprophylaxis for leprosy in Kiribati: a prospective community implementation study
Project coordination
Partners
- Ministry of Health and Medical Services, Kiribati
- The University of Otago
- The University of Sydney
- Centenary Institute
Project summary
Leprosy and tuberculosis are both spread by the respiratory route and transmission is greatly increased where there is crowding and poor economic conditions. In Kiribati the mean number of cases of leprosy reported annually over the period 2015-2019 was >1,500/1,000,000 people and for tuberculosis 4,680/1,000,000 people. The leprosy control programme in Kiribati currently includes examining the household contacts (HHC) of leprosy patients and giving them a single dose of rifampicin (SDR) as preventative therapy if they do not have leprosy. Mathematical modelling of leprosy transmission in Kiribati demonstrated that the most rapid control strategy would be to combine SDR for HHCs and mass SDR chemoprophylaxis to the community, but this has proved difficult to implement.
The COMBINE project provides a platform to screen a large population for both leprosy and tuberculosis and offer specific mass chemoprophylaxis as preventative measures for leprosy and latent tuberculosis. The tuberculosis component is building on previous studies on tuberculosis that have shown that active case finding in the community through screening and treatment substantially reduces the number of new cases of tuberculosis in succeeding years. Offering treatment for latent tuberculosis as well as screening may help reduce the incidence of tuberculosis. A combined leprosy and tuberculosis (TB) control programme will provide a model to improve delivery of treatment and preventative programmes for both conditions.
In this project, the research group aims to determine the effectiveness, operational constraints, interactions between the occurrence of leprosy and TB, and cost benefits of combined screening, treatment, and prophylaxis for leprosy and TB.
The project will be undertaken in the main population centres of Kiribati, South Tarawa and the adjacent islet of Betio, which are the epicentres of leprosy and tuberculous in Kiribati. Screening for leprosy will be by clinical examination done at the same time as chest x-rays, sputum sampling for PCR testing, and tuberculin skin tests to identify both active and latent tuberculosis. Those with suspicious skin lesions will be referred to the Skin clinic for diagnosis and treatment. Those with active tuberculosis will be treated for this according to WHO treatment guidelines and those with latent tuberculosis treated with 12 weeks of rifapentine and isoniazid. These treatments are also effective regimens to prevent the development of leprosy. All others will receive SDR as prophylaxis for leprosy.
At the end of the study the research group will be able to identify how effective the screening was been in detecting new cases, whether the number of cases has fallen compared with baseline, the acceptability of the rifampicin chemoprophylaxis, the steps needed to implement this effectively, and the costs involved. In addition, a detailed understanding of local spread of both leprosy and tuberculosis will be achieved through GPS mapping of the cases of leprosy, active tuberculosis and latent tuberculosis. This information will help other centres with high rates of leprosy and tuberculosis plan the best interventions for both conditions within their environments.
(The tuberculosis component is funded by a National Health and Medical Research Council grant from the Australian Government.)
Co-financer: Turing Foundation