Situation and trends
Endemic treponematoses are a group of chronic bacterial infections caused by treponemes. These infections are:
- Yaws (also known as framboesia or pian) caused by Treponema pallidum subspecies Pertenue, the most common of these infections. Transmission occurs mainly in poor communities in warm, humid tropical regions of Africa, Asia, Latin America and the Pacific.
- Endemic syphilis (also known as bejel) caused by T. pallidum subspecies endemicum. Transmission occurs principally in the Sahel region of Africa and the Arabian Peninsula.
- Pinta caused by T. carateum. Transmission occurs only in the American region.
A review of the historic documents from 1950 to 2016 shows that 99 countries and territories are endemic for yaws; 22 are endemic for bejel and 19 are endemic for pinta.
Since 1990, formal reporting of data on endemic treponematoses to WHO is not mandatory and the availability of data is therefore limited. Only 15 of the 99 endemic countries and territories have recent data on yaws based on the routine surveillance system; however, these data may indicate only the presence of the disease and not its full extent. Papua New Guinea and the Solomon Islands each report more than 10 000 cases per year. Ecuador and India appear to have interrupted transmission. There are no recent data reported on the number of cases of bejel and pinta.