Yaws

Yaws belongs to a group of chronic bacterial infections (endemic treponematoses, nonvenereal spirochetal diseases) caused by treponemes. Other diseases belonging to this group are bejel (endemic syphilis) and pinta. Yaws is the most common of all and occurs primarily in the warm, humid and tropical areas of Africa, Central and South America, the Caribbean, Indian peninsula and the equatorial islands of South-East Asia.

In India, literature on yaws is rather scanty. Reports suggest that yaws was non-existent in India till 1887 when the cases were first noticed among tea plantation labourers in Assam. From Assam, yaws later spread to the states of Orissa, Chattishgarh, Madhya Pradesh and other areas.

In India, the disease is mostly known by the name of the tribes affected most in any region. Thus for example, the disease is called ‘Madia Roga’ and ‘Gondi Roga’ in Bastar area of Chattishgarh and Sironcha area of Maharashtra respectively and ‘Koya rogam’ in Andhra Pradesh and Orissa. Some synonyms of yaws are based on its clinical features e.g. it is called ‘Domaru Khahu’ in Assam which indicates a fig like eruption. ‘Chakawar’ is a term used for chronic ulcers so commonly seen in Central India and part of Uttar Pradesh.

The disease was reported from the communities living in hilly and forested areas in the tribal inhabitied districts in states of Chattishgarh, Orissa, Andhra Pradesh and Maharashtra. Madhya Pradesh, Tamilnadu, Assam, Jharkhandr, Uttar Pradesh and Gujarat are other states from where cases had been reported earlier.

The disease has been eliminated from India in 2006. This disease primarily affects tribal population living in remote, hilly and forest areas having difficult terrain. It is responsible not only for great deal of misery to the affected people but also contributes significantly to the economic strain of the already impoverished segments of our society.

Symptoms

• Yaws is characterized by a primary skin lesion (Early Yaws) which usually occurs in children and adolescents in endemic situation.
• These lesions may persist for 3-6 months and heal spontaneously, often leaving a scar.
• Nocturnal bone pain and tenderness of the tibia and other long bones due to periostitis are common.
• Usually after 5 years of onset of illness, destructive lesions of the skin, bone and cartilage (late yaws) may appear which are non-infectious but may make a person disabled.
• Yaws simulates the lesions of scabies, impetigo, skin tuberculosis, tinea versicolor, tropical ulcer, leprosy and psoriasis. It may also accompany these diseases.

Causal agent and transmission

The organism responsible for yaws is Treponema pallidum subspecies pertenue. It is morphologically and immunologically identical to T. pallidum (the organism that causes venereal syphilis).

Yaws is transmitted by direct (person-to-person) contact with the exudates and serum from infectious lesions.

Treatment

Treatment is same for cases and contacts. Penicillin (Injection Benzathine Pencillin) is the drug of choice. Though reaction to penicillin in tribal areas is rare but intradermal skin test to detect penicillin hypersensitivity should be performed in every case. In patients allergic to penicillin, alternate drugs such as Tetracycline and Erythromycin may be used.

Related Resources

1. YAWS elimination: India’s success story leads the way for global eradication
2. YAWS Eradication Programme Guidelines for Medical Officers

Source : National Centre for Disease Control