YAWS

YAWS

framboesia, frambesia tropica, parangi, paru, buba, pian, bouba, endemic treponema, endemic treponematoses.

Yaws is a chronical contagious, nonvenereal, treponemal infection in humans

Etiology

Family Spirochaetaceae Genus Treponema Species Treponema

pertenue

Treponema pertenue is morphologically identical to Treponema pallidum.

Epidemiology

The major route of infection is through direct person-to-person contact.

The treponemes associated with yaws are primarily present in the epidermis. The ulcerative skin lesions present early in the disease are teeming with spirochetes, which can be transmitted via direct skin-to-skin contact and via breaks in the skin from trauma, bites, or excoriations.

No sex predilection exists. Yaws predominantly affects children younger than 15

years. Peak incidence occurs in children aged 6-10 years.

The disease occurs primarily in warm, humid, tropical areas of Africa, Asia, South America, and Oceania, among poor rural populations where conditions of overcrowding and poor sanitation prevail.

Clinical manifestations

In most patients, yaws remains limited to the skin, but early bone and joint involvement can occur. Although yaws lesions disappear spontaneously, secondary bacterial infections and scarring are common complications. In contrast to venereal syphilis, cardiovascular and neurological abnormalities almost never occur in patients with yaws.

Clinical manifestations

The incubation period is 2-6 weeks.1. The prodromal period:Headache;weakness;chill;fever (39 °C);Arthralgia, muscle and joint pains in

night time.

The primary lesion occurs 2 weeks to 6 months after inoculation.

It begins as a papule that typically becomes a large papilloma.

This may persist for several months and then resolve spontaneously, often with scarring.

During this stage, the treponeme may disseminate by means of the bloodstream or the lymphatics or topically through excoriation by the individual.

Secondary disease can involve multiple cutaneous lesions, including macules, papules, nodules, hyperkeratoses, and ulcerations.

Lymphadenitis with swollen and tender lymph nodes may occur proximal to lesions.

Periosteal infection and destruction of cartilage occur later in the course of the disease.

Clinical manifestations

The initial lesions characteristically resolve spontaneously by 6 months but then recur after a latent period.

Relapses often occur for up to 5 years, after which they diminish in severity and frequency.

Clinical manifestations

Approximately 10% of untreated patients develop late disease, including periosteal lesions that damage bone.

Deformities are also observed, including saber shins caused by chronic periosteal infection of the tibia and gangosa as well as destruction of the cartilage in the nose.

Other late-stage manifestations include hyperkeratosis of the palms and soles and gummas of the skull, sternum tibia, and other bones.

Gangosa

Laboratory diagnostic

Nontreponemal test (eg, rapid plasma reagent [RPR], VDRL) results are positive in all stages, except very early lesions.

Confirmatory treponemal tests (eg, Treponema pallidum hemagglutination [TPHA], microhemagglutination Treponema pallidum [MHA-TP], fluorescent treponema antibody absorption [FTA-ABS]) are not practical in remote areas.

Laboratory diagnostic

Results of dark-field examination of early lesions will be positive.

Biopsy of late lesions may be needed to show characteristic histopathology.

Histologic Findings: Typical histopathology of early yaws shows papillomatous epidermal hyperplasia, focal spongiosis, and intraepidermal microabscesses.

Treponemes are found in the epidermidis.

Treatment

Drug Category: Antibiotics - Penicillin G benzathine (Bicillin LA); Tetracycline (Sumycin) and Erythromycin can be used in patients allergic to penicillin.

Prevention:

No vaccines for the disease are available.