1942
An endemic treponematosis.
Caused by Treponema pallidum subspecies pertenue.
Affects children and adults in poor rural areas of tropical countries.
Affects children in rural areas of the tropics where rainfall and humididity are high and poor hygiene favors person to person transmission.
Affects the skin and long bones of children in poor rural  communities in the tropics.
Not associated with a zoonotic reservoir.
Affects mainly skin, bones and cartilage.
Chronic infectious disease caused by a gram-negative bacteria closely related to nonvenereal endemic treponematoses bejel and pints, and T palladium subspecies palladium, the causative agent of syphilis.
Disproportionately affects economically disadvantaged populations.
Causes disfiguring skin and bone lesions.
Has primary, secondary and tertiary stages.
Unless treated early, can become a chronic relapsing disease.
Can lead to deforming bone lesions.
Transmission of T palladian pertenue occurs by direct contact of minor abrasions of an uninfected person with contagious skin lesions of an infected person.
Median time to inoculation and appearance of primary yaws lesions is 21 days with the range of 9-90 days.
Primary lesions manifest is a papule, papilloma, or ulcer of the skin ranging in diameter from 2 to 5 cm.
Yaws lesions most commonly involves the skin of the lower leg and ankle.
Less frequently involves the arm, hand, or buttocks.
The primary lesion resolves over the course of 3-6 months.
If not treated the lesion can spread hematogenously and by lymphatic dissemination to lead to secondary yaws characterized by contagious, superficial scaling of the skin and plaques of the palms and soles associated with arthralgias and malaise.
Untreated chronic relapsing disease may manifest as periostitis, ulcerations of the pallate and nasopharynx, deformities of long bones of the extremities and dactylitis.
Penicillin drug of choice to endemic treponematoses.
WHO recommends one injection of long-acting benzathine benzylpenicillin at a dose of 1.2 MU for adults and 0.6 MU for children.
Oral phenoxymethylpenicillin 50mg/kg/d in 4 doses for 7-10 days is effective therapy.
A sinle oral dose of azithromycin 30mg/kg is non-inferior to benzathine benzylpenicillin (Mitja O et al).
Presently treatment of all eligible members of the community with oral azithromycin and active surveillance and targeted treatment at 6 month intervals.
Three rounds of mass ministration of azithromycin at six month intervals compared to one round of administration of azithromycin resulted in a reduction in the community prevalence of yaws.