Yaws is a skin disease caused by T. pallidum pertenue bacteria and is one of the neglected tropical diseases (NTDs) targeted for eradication by 2030. In Indonesia, 74 out of 514 districts are considered endemic for yaws. But in September 2022, five yaws suspected cases were reported from Gunung Kidul, a non-endemic district, and Fakfak, an endemic district with a history of total community treatment (TCT).
Yaws cases are rarely found in non-endemic areas or endemic area where TCT with Azithromycin was introduced. To prevent the spread of yaws and validate rumours in pre-elimination settings, a joint investigation team was deployed to diagnose and treat affected individuals and understand the epidemiology of yaws in the population and area. The team consisted of members of the National Expert Committee for Yaws and Leprosy, the national NTD programme, and the NTD focal person in WHO Indonesia. The investigation result will inform the development of effective control and elimination strategies for the disease. This is in line with WHO’s guideline on yaws eradication.
The team performed clinical evaluations by visiting patients and performing a thorough physical examination to assess the presence of signs and symptoms consistent with yaws, such as skin lesions and joint swelling. Interviews were conducted, and blood samples were taken for rapid diagnostic tests (RDT). Each positive test was followed by other antibody tests, such as the rapid plasma reagin (RPR) test or the Venereal Disease Research Laboratory (VDRL) test, which can detect antibodies in the blood that are produced in response to T. pallidum pertenue infections. The team also visited the patients’ homes and traced contacts among household members and neighbours.
In Fakfak, the suspected case was concluded as not indigenous since the patient just moved to the district. The four suspected cases from Gunung Kidul were tested with RDT and RPR. All had positive RDT results, and one case had a reactive RPR test. Azithromycin was administered to all cases and the ulcers were healed within two weeks. The report was submitted to province and district health offices.
“Efforts to achieve yaws eradication should be started by securing commitments from local authorities to perform adequate surveillance and re-mapping of suspected, probable, and confirmed cases; as well as to review TCT implementation and conduct yaws serological surveys,” said Dr Tri Yunis Miko Wahyono, member of the National Expert Committee.
This investigation is part of Indonesia’s commitment to contribute to regional and global targets. It improved the ability of district health offices in detecting cases, providing adequate treatment, and responding to suspected yaws cases. In addition, case investigations can be used as supporting data to decide initiation of TCT in an area and to prevent contagion in the community.
The investigation team recommended the national NTD Programme to intensify programme sensitization or refresher training for health workers in non-endemic areas, strengthen the surveillance system by implementing active case finding, and increase access to more sensitive diagnostics for screening and diagnosis purposes.
Responding to these recommendations, the national NTD Programme has organized a national virtual workshop on yaws eradication for health workers in the last week of March 2023. WHO continues to support the programme by procuring Dual Path Platform Syphilis Screen and Confirm assay, the recommended diagnostic kit for detecting and differentiating both past and present yaws infection. In addition, the introduction of polymerase chain reaction (PCR) technology to confirm yaws by detecting the DNA in the skin lesions and to monitor azithromycin resistance is planned in July 2023. This will support the eradication of the disease, a global target that needs collective action.
Written by Achmad Naufal Azhari, National Professional Officer for Neglected Tropical Diseases, and Aulia Salmaddiina, National Consultant, WHO Indonesia