Epidemiologically, Yaws is not as vulnerable to eradication as is smallpox. Listed below are the reasons for it:
Cases of Yaws (untreated) are contagious for months or even years after initial onset.
- Latent cases occur frequently, and the treponemes persist in CSF and lymph nodes even after apparent cure.
- Immunity acquired is only partial, not long lasting as in the case of smallpox.
- The disease is not fatal.
- Accurate diagnosis of Yaws by non–medical personnel is a problem.
- There is no vaccine against Yaws.
Studies in eastern Nigeria, the Philippines and Thailand have shown that the transmission of infection continues to take place in the child population at large. As things stand, available health services have been reporting only isolated clinical cases. The question remains whether Yaws could be eradicated globally using the current resources and tools, and whether elimination of the last few cases is worth the expense. It is clear that Yaws is no longer perceived as an important public health problem even in endemic areas. Consequently, “Yaws control countries” must consider their own epidemiological situation and resources and decide between effective control and eradication.