Acknowledgements

HorizonsA follow up survey, which will measure the impact of the September 2012 campaign, is ongoing.

Yaws eradication strategy to be put in place elsewhere in the world.

Once validated, new point-of-care dual treponemal/non-treponemal assays will aid in the diagnosis of yaws.

AimDocument active yaws prevalence among Aka <15 years old living in the Districts of Bétou and Enyellé in September 2012, establishing a baseline at the beginning of the elimination process.

MethodsUniversal screening of children <15 presenting for

treatment with azithromycin: - Reporting of skin lesions followed by examination.- Performed by 1 of 3 physicians trained on the clinical

forms of yaws. - Children with suspicious lesions had serologic

confirmation using a syphilis rapid diagnostic test (RDT) after obtaining informed consent from a parent.

Children with suspicious lesions and a positive RDT were considered confirmed cases of active yaws.

Prevalence = (# of confirmed cases/# of children screened)

Results6215 children under 15 were screened for active yaws.

485 (7.8%) had suspicious lesions, of whom 480 (99.0%) accepted confirmatory testing. 183 children (38.1% of all who were tested) were RDT-positive.

There were no significant differences in the rate of clinical suspicion, nor in the rate of RDT-positivity among the three clinicians.

Yaws by age and sex

58.5% of confirmed cases were among boys.

Spatial distribution of yaws

Prevalence in the District of Bétou: 2.0%Prevalence in the District of Enyellé: 3.8%

Prevalence in villages accessible by road/boat: 2.3%Prevalence in villages accessible only by foot : 7.5%

ConclusionsThe spatial distribution of active yaws among <15s was heterogeneous, certain areas warrant closer follow-up and surveillance.

Yaws prevalence was higher in the most difficult to access areas, illustrating the old adage that “where the road ends, yaws begins”. - As the eradication process begins around the world,

priority needs to be given to the most isolated areas.

The imperfect sensitivity of the syphilis RDT for the confirmation of active yaws may have led to overestimations of yaws prevalence, but it remains the most practical tool available. More sensitive and specific point-of-care tests for treponemal diseases are needed.

Reliable surveys can be successfully carried out even in the most inhospitable environments.

Prevalence of yaws among the Aka, Districts of Bétou and Enyellé, Republic of Congo

Coldiron ME 1, Obvala D 2, Mouniaman-Nara I 3, Pena J 3, Blondel C 3, Porten K 1

1Epicentre, Paris, 2Ministry of Public Health and Population, Brazzaville, Congo, 3Médecins sans Frontières, Paris

Circle size is proportional to the number of persons treated at each site, with the largest circle representing 500 persons treated. Green signifies a prevalence <5%; yellow a prevalence of 5-10%; and red a prevalence of >10%.

The AkaSometimes referred to as pygmies, the Aka are isolated and vulnerable, living a nomadic lifestyle in the most inaccessible parts of the jungle.

Hunter-gatherers, they have historically been exploited by their bantu neighbours. Photo: Lam Duc Hien, MSF

10-14y: 27%1-4 y: 25%

5-9y: 48%

Distribution of cases of active yaws by age group, Districts of Bétou and Enyellé, 2012

Number of confirmed yaws cases with the given clinical characteristics, Districts of Bétou and Enyellé, 2012

0 20 40 60 80 100

Hyperkeratosis

Primary lesion

Plaques

Generalized eruption

Plantar/Palmar macules

Ulcers

Papillomata

Plantar HyperkeratosisUlcers

Plaque

Mixed forms Sabre tibia (tertiary)

Background: YawsYaws is an endemic treponematosis with a natural history similar to syphilis, but primarily affecting skin, bone, and cartilage. • Transmission by direct contact with cutaneous lesions• Primary, secondary, latent and late (tertiary) forms• Children <15 years represent 75% of cases• 10% of untreated cases develop late lesions• Communities affected by yaws generally have little access to health care

Advances in Treatment :Single-dose oral azithromycin non-inferior to injectablebenzathine benzylpenicillin � Morges strategy for yaws eradication by 2020• Initial focus: total community treatment (TCT) with azithromycin in areas affected by yaws – by treating all persons cures latent cases• In Congo in September 2012, MSF-OCP implemented the first-ever TCT, carrying out a yaws prevalence survey at the same time.

Clinical manifestations of yaws

PapillomataPeriosteitis

Plantar HyperkeratosisUlcers

Plaque

Mixed forms Sabre tibia (tertiary) Gangosa (tertiary)

Mucocutaneous

Photo credits: Lam Duc Hien, Thomas Vandamme, BenoîtFinck, WHO Handbook on endemic treponematoses

Yaws and syphilisSerologic testing strategies for yaws are similar to those used for syphilis. Given the high similarity of the causative organisms, syphilis assays are used for yaws testing. The SD Bioline syphilis 3.0 is a treponemal antibody immunochromatographic assay designed for point-of-use testing. Like all treponemal tests, once positive, the test remains positive for life, even after effective treatment (unlike non-treponemal assays like the RPR).

Special thanks to Drs Emmanuel Berceot and Thomas Vandamme for their participation in the study, as well as the entire yaws team in Bétou.