“Why do you think that?” asked the Microbiologist.
“Well, they have a funny skin lump and I had read recently that syphilis can mimic any other type of infection and that it’s making a comeback and so I did the test and it’s positive!”
The Microbiologist groaned to himself.
“Let me have a look at the results as well” he said.
To the Microbiologists surprise the patient did have positive syphilis serology.
“Where is the patient from?” the Microbiologist asked.
“What do you mean? They live locally” answered the GP.
“I mean where were they born? Have they lived abroad?”
“Oh, I don’t know. Why does it matter?”
“Can you give them a call and find out then call me back. This could be Yaws, Pinta or Bejel” replied the Microbiologist.
“Sorry my what? …Your's a pint of what…and a bagel? What did you say? This line is really bad” said the GP getting increasingly confused.
“Find out where they have been and call me back and then I’ll explain further” answered the Microbiologist.
Yaws, Pinta or Bejel are treponemal infections which are non-venereal (i.e. not spread through sexual contact) as opposed to syphilis which is also a treponemal infection but is venereal. They are caused by spirochete bacteria from the Treponema species:
- Yaws = Treponema pallidum subspecies pertenue
- Pinta = Treponema carateum
- Bejel = Treponema pallidum subspecies endemicum
I have tried to find out the origins of the names of these infections but no one seems to know for sure. Yaws is from the Carib for “sore”, Pinta is from the Spanish for “spot” and Bejel is thought to be from the Arabic word bajal which I think means rustic or rural (maybe describing the fact that this infection is more common in people from rural areas). But am I completely wrong? Does anyone know any more? Let me know…
How do Yaws, Pinta or Bejel present?
Yaws is an aggressive and highly infectious disease. The primary lesion, known as a “mother yaw”, is a painless papilloma on the face or legs (occasionally arms). This papilloma gets bigger over weeks or months becoming either ulcerated or framboesial (looking like a raspberry!). As the primary lesion starts to heal secondary lesions start to appear in the form of macules, papules and papilloma with associated inflammation of the bones (periostitis) causing “saber shins” (curved shin bones) and inflammation of the fingers (polydactylitis). Lesions tend to heal spontaneously but relapses are common. Primary and secondary yaws is known as “early yaws” which can last up to 5 years.
Late yaws occurs more than 5 years after the initial infection and affects 10-20% of those infected. It is characterised by destruction of skin and bone which whilst rarely fatal can be very disabling and socially stigmatising. Yaws does not affect any other body organs, unlike syphilis.
The primary lesion of Pinta is usually an itchy and scaly red papule with associated regional lymphadenopathy, most commonly on the arms or legs. The primary lesions often disappear spontaneously but 3-12 months later secondary lesions appear as papules or plaques of varying sizes in various areas of the body, including the face, arms and legs. These secondary lesions often go through various colour changes from blue to purple to brown before becoming pale and depigmented.
The primary lesions of Bejel are usually tiny painless papules that often are not noticed by the patient. Secondary lesions typically appear as the primary lesions start to heal, after a few months, and usually take the form of painless patches on the mucous membranes, and more papules on the rest of the body. The skin lesions can resemble those of venereal syphilis (Treponema pallidum subspecies pallidum). Late features similar to syphilis with collapse of the nasal septum and painful lesions on the soles of the feet can occur but neurological or cardiovascular disease does not occur as it could in syphilis. Mortality from Bejel is very rare.
Syphilis on the other hand presents as either primary at the point of inoculation with a chancre (painless swelling or punched out ulcer with regional lymphadenopathy) or secondary with spread from the primary site usually with a rash plus lymphadenopathy (raised mucous patches and condylomata lata - highly infectious painless wart-like lesions on warm moist sites e.g. genitals and perineal skin). Symptoms can also present 20-40 years after the initial infection, called tertiary syphilis, with gummatous, cardiovascular or neurological disease.
Yaws primarily affects children under the age of 10 years in the tropics including West Africa (especially Ghana and Cameroon), Latin America, the Caribbean, East Asia (especially Indonesia, Papua New Guinea and Timor Leste) and the South Pacific Islands (including the Solomon Islands and Vanuatu). Yaws is transmitted through direct contact with the highly infective primary and secondary skin lesions.
Pinta is not very infectious and it is not known for sure how it is transmitted, though it is likely to be through direct contact with infected lesions. Black flies and other biting insects are also suspected to play a role in spreading the bacterium. Pinta is only found in isolated rural areas of the American tropics including Brazil, Peru, Venezuela, Central America and Cuba, and usually affects older children and adults.
Bejel is spread by contact with infected secretions, including eating utensils used by a person with primary Bejel which have been inadequately cleaned. Lesions are infectious until they have completely disappeared. It predominantly infects children aged 2-15 years in Eastern Europe and the Middle East.
Congenital transmission does not occur with any of the non-venereal treponemal infections.
Syphilis is primarily a sexually transmitted disease but it can also be acquired through direct contact with a chancre or other infected secretions. Syphilis can be acquired congenitally. Syphilis can be found Worldwide.
How are Yaws, Pinta or Bejel diagnosed?
The diagnosis of a non-venereal treponemal infection is initially based on clinical suspicion, either due to the presence of a classical skin lesion or travel to or living in an endemic country. In the UK the main reason for considering the diagnosis of a non-venereal treponemal infection is a positive treponemal blood test in a patient who has had the blood test done to look for syphilis; further clinical suspicion is added if the patient has travelled to or lived in an endemic country. The treponemal blood tests include T. pallidum enzyme immunoassay (EIA), T. pallidum particle agglutination assay (TPPA), T. pallidum haemagglutination assay (TPHA), and T. pallidum IgG or IgM immunoblot. These treponemal blood tests do not distinguish between the different treponemal infections (Syphilis, Yaws, Pinta or Bejel) and remain positive for life and so a positive test in these patients is unable to say which treponemal infection the patient has had. These patients also have raised non-treponemal tests such as the Rapid Plasma Reagin tests (RPR) which can also make you think the patient might have syphilis.
Traditionally infection would be confirmed through the observation of spirochete bacteria in fluid or tissue from skin lesions using dark ground microscopy or immunoflourescent antibody. These observations combined with the travel history to give the likely bacterium. Now, in the UK most laboratories no longer have the equipment or expertise to do dark ground microscopy and so the main stay of diagnosis is PCR on infected fluid or tissue which is able to distinguish the different diseases.
How are Yaws, Pinta or Bejel treated?
The easy thing about managing the non-venereal treponemal infections is that the treatment is the same whichever bacterium is causing the disease. Yep really after all that the treatment is the same! But Microbiologists do like to grow and identify these things!! The treatment is either a single dose of IM Benzathine Penicillin G (<10 years old 1.2 million units, >10 years 2.4 million units) OR a single oral dose of Azithromycin (30mg/kg max. 2g). Note: Penicillin resistance can occasionally occur but Azithromycin resistance has not been yet been seen.
All patients should have repeat RPR tests done at 6 and 12 months. If the RPR does not drop more than 2 fold or goes up at 12 months then the patient should be retreated.
“Yours a pint of what…and a bagel? This line is really bad”
Meanwhile the GP called their patient then redialled straight back to the Duty Microbiologist. “Sorry that line was terrible, I thought you wanted a pint of ale and a bagel!” said the GP chuckling away… “I did call the patient though and they were originally from Brazil, does that help?”
The Microbiologist explained his clinical suspicion to the GP, who nodded knowingly but had never thought of Yaws, Pinta or Bejel as possible diagnoses. On further questioning of the GP by the Microbiologist, it turned out that the patient’s skin lesion had a bluish colour to it. Finally a biopsy of the lesion was arranged through the local dermatology department and the diagnosis was confirmed as Pinta by PCR. The patient was given a dose of oral Azithromycin and had follow up blood tests at 6 and 12 months. By 12 months the RPR had dropped considerably and the GP was able to reassure patient that they had been cured.
The Microbiologist put the phone down and muttered “a pint of ale and a bagel” …we don’t make everything up!