Diagnosis is by blood examination using Treponema palliidum haemagglutination assay (TPHA) test & Rapid Plasma Reagin (RPR) test.
Treatment of Yaws
Control of Yaws
The control of Yaws is based on the following principles:
Survey of Yaws
A clinical survey of all the families in endemic areas is made. The survey should cover not less than 95% of the total population. During the survey, persons suffering from Yaws and their contacts are listed.
Yaws Treatment is based on the following observations:
- Treatment with a single injection of long acting penicillin will cure infection.
- The simultaneous treatment of all clinical cases and their likely contacts in the community will stop further transmission in the community.
The WHO has recommended three treatment policies
- Total Mass Treatment
In areas where Yaws is hyper–endemic (i.e. there is more than 10% prevalence of clinically active Yaws cases), a great part of the population is at risk. The entire population including those who have got infected by it, should be given penicillin in the doses mentioned above.
- Juvenile Mass Treatment
In meso–endemic communities (where there is anywhere between 5 to 10% prevalence), treatment is given to all cases and to all children under 15 years of age and other obvious contacts of infectious cases.
- Selective Mass Treatment
In hypo–endemic areas or areas of low prevalence (where there is less than 5% incidence of the disease), treatment is continued to those afflicted by it, members of their household and other obvious contacts of infectious cases.
It is unlikely that a single round of survey and treatment will cover the entire population. In order to halt transmission in its tracks, it is necessary to find out and treat the missed cases as well as new cases. Re–surveys should be undertaken every six to 12 months. Several such follow–ups may be needed before eradication is achieved.
With decline of Yaws to very low levels, emphasis has shifted to “Surveillance and containment” – a technique which has proved highly successful in the eradication of smallpox. The surveillance and containment measures would be concentrated on affected villages, households and other contacts of known Yaws cases. The measures comprise epidemiological investigation of cases to identify probable source(s) of infection and contacts of each known case, so as to discover previously unknown cases and prevent new ones, treatment of cases, prophylactic treatment of contacts with BPG and monthly follow–ups of households with confirmed cases for at least three to four months after treatment of the last active case to assure an interruption in further transmission of the disease.
In a disease like Yaws, dealing with the social and economic conditions of life is as important as focusing on the biological cause. Recrudescence of the disease is apt to occur unless environmental improvement of personal and domestic hygiene, adequate water supply, liberal use of soap, better housing conditions and improvement of the quality of life is achieved.
Resurgence of Yaws
Research has shown that treponemes may persist in lymph glands following treatment and apparent cure. Further, such treponemes are viable and are capable of infecting laboratory animals. This has given cause for concern. It indicates the persistence of infection in the individual and in the population, notwithstanding community–wide penicillin treatment. There has been a resurgence of Yaws especially in West Africa. Small, focal clinical outbreaks (as in Nigeria and Thailand) or wider recrudescence (as in Haiti) have occurred following mass campaigns. It emphasizes the need for periodic assessment of the situation by epidemiological and serological studies.
To determine whether or not Yaws has really been brought under control, serological studies are needed. Ideally, if no Yaws antibodies were found among children born since the Yaws mass campaign was completed, it would mean that the campaign had been totally successful. The actual sample of the population to be tested may be as low as 1 or 2%.