While the decay of custom has been hastened by the introduction of new diseases, it has not been accompanied by any attempt to eradicate the old.
Chief among indigenous diseases (if diseases introduced before contact with foreigners may be called indigenous) is yaws, called by the Fijians thoko, or by its Malayo-Polynesian name—tona, and by various dialectic modifications of that word, which is also used in Tonga, Samoa, Tahiti, and many other Polynesian islands.
The disease is but little known to the medical profession in Europe, either in practice or in medical literature. Its medical designation is Frambœsia, so called from the strawberry-like eruptions that accompany it. By the French it is called "Le Pian." In Great Britain it is now extinct, but in the Hebrides and in the south-west counties of Scotland it was met with under the name of "sibbens," or "sivvens," as late as the beginning of the nineteenth century.
THE SYMPTOMS
It is common throughout Africa, Malaysia and Polynesia. Being contagious, it was carried by means of the slave traffic from Africa to tropical America and the West Indian Islands. From the east coast of Africa and Madagascar, about 340 years ago, the Dutch or Portuguese traders carried it to Ceylon, where it still bears the name of "Parangi Lede" or "Foreigners' evil." Hamilton noticed it in Timor in 1791, saying "it seldom terminates fatally and only seizes them once in their lives."[99] Crawfurd, who wrote in 1811-1817, noticed it in Java.
Dr. Martin, the able editor of Mariner's Account of the Tonga Islands, writing in 1810, was the first to recognize the identity of tona with yaws, though he never saw the disease. But the existence of tona was recognized by Captain Cook and numerous other visitors to the South Seas during the last and the beginning of the present century, though they were not aware of its real nature.
The premonitory symptoms of yaws are, as a rule, insignificant and obscure; the appearance of one of the sores is generally the earliest indication that a child is infected, but adults have noticed pains in the limbs, fever, restlessness, or languor. The first sore, called the tina-ni-thoko, or mother-yaw, is usually a large one about half-an-inch to an inch in extent, and is often surrounded by a group of smaller sores. It generally appears on the site of some wound or scratch, more often about the lips. Those that follow are generally developed upon some part of the body where the skin is delicate, such as the neck, the groin, or the axillæ, or in parts where the true skin joins the mucous membrane. Doubtless the lips of children are first infected owing to the child's habit of putting the hands to the mouth, the hand being the part most likely to come in contact with the virus of another child.
After an uncertain interval a crop of pabules, or in some cases blebs, begin to appear, the face and the parts already mentioned being their favourite point of appearance. If the eruption begins with blebs the case is spoken of as thoko se ni niu (cocoanut flower thoko, from the resemblance of the eruption to a spray of the unexpanded flowers of the palm).
In the next stage a soft warty excrescence, which is the matrix of the sore, pushes its way through the true skin by forcing it aside rather than breaking down its substance. On reaching the surface the granulations which form this out-growth exude a fluid which is highly contagious. It forms in time a crust or scab, the reddish appearance of which is very characteristic of the yaws eruption. If this be removed by means of oil or a poultice, the granulated surface of the sore beneath it has that resemblance to a raspberry or mulberry which has given the name of Frambœsia to the disease. In
some cases the crust assumes a curvilinear outline, recalling the appearance of the well-known Pharaoh's serpent. These are especially seen about the corners of the mouth, the neck and the axillæ, and constitute the thoko ndina or true yaws. In other cases they retain a circular shape on all parts of the body, and are then called thoko mbulewa or button or limpet yaws. During the healing process they become converted into annular or horse-shoe patterns, the centre receding before the periphery.