Yaws (Endemic treponematosis)
Yaws is a highly contagious skin infection characterized by skin lumps that eventually ulcerate if untreated; it may even disfigure bones and cause destructive lumps around the nose and mouth. It is caused by a subspecies of Treponema pallidum, the same bacteria which causes syphilis. In areas in Maguindanao where cases of yaws have been identified in the 1970s, locals have called the disease “bakataw.”
Last Updated: September 26, 2023

Yaws is caused by Treponema pallidum subspecies pertenue. The bacteria is spread through close skin contact—sexual or not—most commonly between children living in conditions of poor hygiene.

During the earlier stages of yaws, which begin several weeks after getting infected, signs and symptoms include: • an initial red lump that grows in size and ulcerates • several other lumps all over the body similar to the first lump • swollen lymph nodes near the lump or all over the body • fever • a feeling of general discomfort • bone and joint pain Five to 10 years later, destructive lesions may develop; they include the following: • permanent curving of the legs • painless lumps within and around joints • rubbery lumps (called gummata) in bones and on the skin • bony growths on and around the nose • mutilating facial ulcers, particularly around the nose

Diagnosis of yaws is usually made based on an individual’s medical history and physical examination. Since the bacteria causing yaws is the same species as the one causing syphilis, laboratory testing for the two are also the same. This involves testing the blood to look for antibodies against the bacteria or to look for the bacteria itself. Yaws is highly curable. It is treated with antibiotic medications, usually azithromycin (which is given once as an oral dose). Individuals are then examined four weeks after treatment to find out if the antibiotic had cleared the infection. If treatment with azithromycin fails, a single injection of penicillin is usually given. Close contacts of individuals with yaws should also receive treatment

There is currently no vaccine for yaws. To help reduce the spread of the infection, adequate health education and improvement in personal hygiene are necessary. In areas where yaws is prevalent, a community approach involving mass treatment is advised to help decrease the amount of cases and help stop the spread of the disease; this is done by giving oral azithromycin (an antibiotic) to at least 90% of the population.
Last Updated: September 26, 2023