A.—4A

The reason given by the Samoans for not having brought their young children for the first injection was that they think three crops of frambcesial rash should come out before any treatment is given, and also fear of the effects of injecting a young baby. This belief is gradually dying down, but it will probably be some time before the Samoan realizes that his children should come on the first signs of the disease. The underdosing of the primary cases, although it did not cure the babies, had a marked beneficial effect both on the individual cases and in encouraging the populace to bring their children early, because the cases that we were allowed to inject on the first malaga were so ill that their parents brought them for injection as a last hope, and they all survived and were comparatively healthy, in spite of some secondary rash at the time of the second malaga, which seems to show that the injected children probably derived considerable benefit, although not cured. Types 1 to 3 are practically limited to children in the first decade of life. Types 4, 5, 7, and 8 are rarely seen above fifteen years, while type 9 is usually not active after fifteen years of age, although permanent results are carried throughout life. Types 1 to 9 do not materially differ from the types of lesion described by Spittel* as due to yaws. Type 10 we believe to be a yaws condition. It commences by the skin on dorsum of the hands and feet becoming dry and turning a slaty-blue colour. The superficial epidermis is then shed in large, thin flakes, leaving a tight atrophic skin below. This continues for some months, the proximal border gradually spreading up the foot and hand till it reaches well above' the wrist and ankle ; at the same time all the pigment is extracted from the skin first affected, so that the dorsum of the hand or foot will be leucodermatous while the ankle and wrist are a slaty-grey. The condition usually starts in the third or fourth decade of life, and may continue for many years. In the old standing cases the process may extend half-way up the leg or forearm. On receiving injections all exfoliation and cracking stop, the slaty colour of the skin disappears, and the whole of the skin becomes more supple and healthy. The leucodermatous patches remain permanently. There seems to bo no tendency to recurrence, as is shown by cases that have been injected three years ago without recurrence. Type 11 : Probably many conditions are grouped under this heading, but they all affect either the soles of the feet or the palms of the hands—usually of adults. Generally the condition shows as a thickening of the skin, which is either punched out in what might be described as worm-eaten holes, or may simply have deep and painful cracks ; or the skin may peel off in large, irregular flakes, with occasionally small deep-seated water-blisters in it. The condition is worst in the wet season, and we think that moisture is probably a necessity, if not the only cause, in many of the cases. It shows a great tendency to relapse every year at the same season, and does this in spite of all treatment. The reason for having so many apparent cures was that the first malaga was held in the wet season, while the second was just at the end of the following dry season. The injections seem to always give considerable temporary relief. Type 12 : In this type there is very marked increase in the horny layers of the skin, usually seen in young adolescents in Samoa. The condition is not common and does not appear to be influenced by the season of the year : we believe that it is probably due to yaws. The effect of N.A.B. injections are variable, but usually cause considerable improvement. Type 6 : A large proportion of these cases received treatment with potassium iodide as well as injections, but in cases treated medicinally at their homes it is always uncertain whether the medicines prescribed are taken as directed, or even whether they are taken at all, so that no more mention will be made of this additional treatment. The figures given in the above table show that the percentage of relapses in the earlier stages of the disease is much greater after only two doses than after three doses of novarsenobillon, and probably four injections would give still better results ; but there is always the danger that if we make the cure too complete we may remove the immunity that an attack of the disease conveys against a second infection. At the present time some 51,000 injections have been given on the three-injection system without causing a single case to become reinfected with yaws, so that it may be fairly safely assumed that we are not removing the immunity conveyed by an attack of the disease. If the cases were completely cured and all immunity lost, it would seriously affect our campaign, for at present the primary and secondary stages of the disease are entirely confined to the children amongst the Samoans, and a cure that allowed of reinfection of adults would soon tend to loose favour, however good it might be, for large areas of the population can receive treatment for the condition only once or twice in the year at the most. When the medical service has expanded sufficiently to allow us to have Native medical practitioners in every district of Samoa, so that cases can receive immediate treatment, then complete cure will be safe and will be the ideal treatment. But at the present time we endeavour to keep an immune adult population, by merely treating cases sufficiently to cure the infective primary and secondary rashes, which may also prevent the occurrence of the disabling tertiary conditions. This we. hope will allow a large proportion of the present children to reach adult life without becoming infected, and so gradually exterminate the disease without risking a serious epidemic of yaws amongst the adult population before we have the personnel to control it. The immunity which an attack of yaws gives the Samoans in preventing their infection with syphilis, as stated by Parhamf seems to be very great, as we have never seen a case of syphilis in

*R. L. Spittel, F.R.C.S. : " Frambcesia Tropica," pp. 3-44 ; London, 1923. Parham, J. C.: " Relation between Syphillis and Yaws." American Journal of Tropical Medicine, Vol. 11, p. 347, July, 1922.

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