What is yaws?

• Yaws is a skin infection caused by the bacteria Treponema pallidum pertenue. 
• Treponema pertenue is not found in New Zealand. 
• Until 1961 yaws was common in the Pacific islands. 
• Between 1959 and 1961 people from Fiji, Samoa, Tonga, the Cook Islands and Tokelau Islands were given injections of penicillin as part of a special World Health Organization (WHO) campaign to stop the disease. 
• Yaws has not come back in these islands but people who were born before the WHO campaign may still have signs of past infection in their blood and this can be picked up on a blood test. 
• Today, yaws is still seen occasionally in Indonesia, Papua New Guinea and the Solomon Islands.

How do I know if I have yaws?

Yaws is not a sexually transmitted infection but is spread by skin-to-skin contact from skin sores. This usually happens during childhood. These skin sores may be found on the legs, arms, nose, mouth and soles of the feet. The sores heal, leaving a special scar.

How is yaws diagnosed?

People who have been infected in the past with yaws produce an antibody in their blood to the bacteria which causes yaws. This antibody is identical to the antibody produced to the bacteria which causes syphilis.

What is syphilis?

• Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum pallidum. 
• It can cause a painless sore in the genital area followed by a rash covering the body as well as sometimes on the palms of the hands and soles of the feet. 
• Syphilis is more serious than yaws because it can be transmitted to sexual partners. It can also lead to long term damage to organs like the brain and heart. 
• In pregnant women it can affect the development of a baby in the mother’s uterus. 
• Both syphilis and yaws can be treated easily with penicillin injections. 
• Some Pacific islands which have high rates of syphilis include the Marshall Islands, Papua New Guinea, Fiji and Tahiti.

How is syphilis diagnosed?

•  When applying for residency into New Zealand and most other countries you are required to have a blood test for syphilis. 
• If you attend a sexual health clinic your blood will also be tested for syphilis. 
• This test will be positive if you have been infected in the past with either of the treponemes (types of bacteria) which cause yaws or syphilis. Both these infections make the same antibody. 
• It is impossible to tell from the blood test whether the person has yaws or the more serious syphilis infection.

How can the doctor tell the difference between syphilis and yaws?

• The doctor will ask questions about past sexual contacts, genital symptoms and skin symptoms, eg, sore and rashes. 
• A person with a past history of yaws will often remember skin problems as a child, sores or ulcers that did not heal quickly, sore bones and joints, and sores around the mouth which healed with scarring. 
• Any South Pacific Islander born before 1960 may recall seeing yaws as a child in their community. 
• Those born after 1960 with a positive treponemal blood test must be assumed to have syphilis until proven otherwise. 
• The doctor may also need to test other members of the family to help decide between syphilis or yaws and whether they should also be treated.

How is yaws or syphilis treated?

• Penicillin injections are the best treatment for syphilis and yaws, but other types of antibiotic tablets can sometimes be given. 
• People with a positive treponemal blood test but no history suggesting yaws will generally be treated as having syphilis. 
• It is better to treat someone than to wait for the possible damaging complications of long term syphilis. 
• Follow-up blood tests are usually taken after treatment and will be arranged by the clinic or your doctor.

Where to go for assessment?

Sexual health clinics specialise in the treatment of syphilis and yaws and have experience in how to manage these conditions - treatment is free and confidential. Your family doctor is able to contact the specialist doctors at these clinics for advice. You can attend these clinics for advice by telephoning a clinic in your area for an appointment.

Original material provided by Auckland Sexual Health Service. Reviewed by everybody, July 2008.