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The incidence of yaws in the New Hebrides
58 TRANSACTIONSOF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE. Vol. 49. No. 1. January 1955. THE
INCIDENCE
OF YAWS IN THE
NEW HEBRIDES
BY
A. R. M I L L S , M.R.e.s., L.I~.Ca',, D.T.M. & H. British Service Medical Officer, New Hebrides. South Pacific Health Service.
T h i s investigation was m a d e d u r i n g the course of tours in t h e rural areas of the N e w Ilebrides, the islands being visited d u r i n g the period f r o m A u g u s t , 1952, to D e c e m b e r , 1953. T h e study was m a d e clinically and single-handed. T h e r e are no figures for the incidence of yaws in the g r o u p previous to this report. LAMBERT (1924) stated that " Yaws is the m o s t prevalent disease," and all observers have agreed t h a t it is very c o m m o n . Geography.
The New Hebrides, including the Banks and Torres islands, lie in the South Pacific between latitude 13 ° and 21°S and longitude 166 ° and 171°E. They have an area of roughly 5,700 square miles (4,847 sq. kin.). The group comprises 12 major islands, 18 lesser islands and about 30 small islands and islets distributed round their coasts. They are dispersed in the form of a " Y " of which the southern islands form the tail. Approximately 40 islands are inhabited. The largest island in the group is Espiritu Santo with an area of 1,500 square miles and mountains over 6,000 feet high (1,800 m.). Most of the islands are of the " high " volcanic type, with incomplete fringing coral reefs. There are three active volcanoes in the group. Vegetation is varied but is mostly evergreen bush. On the populated islands are coconut, coffee and cocoa plantations as well as many native gardens where yam, taro, manioc, etc., are grown. Climate.
The climate of the New Hebrides is tropical with two fairly well-defined seasons, that of the E.N.E. trade winds from about April to November, and the hot or doldrum season from December to March. At Vila, situated near the centre of the group, the average annual rainfall is 81 in. (2,057 mm.) and the temperature ranges from a maximum of 94°F. (34.4°C.) to a minimum night temperature in the cool season, of 56°F. (13.3°C.). In the southern portion of the group, the annual rainfall averages 55 in. (1,397 mm.), while in the north it rises to 160 in. (4,064 mm.). The monthly average relative humidity varies between 77 per cent. and 89 per cent. The Inhabitants.
T h e people of the N e w H e b r i d e s are m o s t l y Melanesians, b u t there is also admixture of Polynesian blood, especially in the east and south. T h e y vary f r o m well-built, light b r o w n w a v y - h a i r e d in the marginal Polynesian g r o u p s to small n u m b e r s of people of p y g m y type in central Malekula and Espiritu Santo. M o s t of the inhabitants are dark b r o w n with woolly hair, rather heavy features and b r o a d noses. T h e y are of g o o d physique. T h e n o n - i n d i g e n o u s peoples are F r e n c h , British, I n d o - C h i n e s e , Chinese and other Pacific islanders. T h e estimate of the p o p u l a t i o n for 1953 has been m a d e f r o m District Agents reports, personal observations and other sources. T h e r e is no accurate census of the N e w Hebrides.
A. R. M I L L S
59
Mode of life. The indigenous inhabitants live in reed or cane huts, the floor of which may be earth, coral chips or stone blocks. Sleeping mats are laid on the floor. Some huts are very primitive being of ridge-tent shape with" no walls, whereas others are quite elaborate with high walls, thick thatch and windows. The huts are commonly overcrowded. The people are keen gardeners and their diet is largely vegetable. Taro, manioc, yam and bananas are the commonest articles of diet. Breadfruit, coconut and other nuts, sea-food, pig, chicken, pigeon and a large variety of fruits make up a satisfactory and varied diet. Malnutrition is almost never seen. Villages are often small. T h e largest has a population of 600, but many Melanesians live in a collection of only a dozen people inhabiting two or three huts. These work their gardens, fish or cut copra. There is no general system of excretal disposal. Some villages have closets over the reef in the inter-tidal zone, and a few have earth closets. Where these do not exist, the neighbouring bush is used. Domestic animals run about the villages, but pigs may be kept behind a barrier. Children sit in close bodily contact with adults for hours at a stretch. In spite of the lack of hygiene, there is a relative absence of flies in some parts of the group. This may be due partly to the siting of a village open to the winds, and partly to the efficiency of scavengers such as crabs, ants, rats, etc. Anopheles farauti, the only anopheline species present in the group, is found on all but a few marginal islands. Malaria, tuberculosis and yaws are the commonest diseases.
YAWS
The data presented here were gathered during visits at various times to islands and villages. On arriving in a village I would get together as many persons as possible of all ages and both sexes. After explaining my purpose, I examined them and treated them on the spot. Often, only a short time would be available in any one place, and the reluctance of the Melanesians to accept strangers would mean that much time would be spent in persuading the people to come forward. Questioning, in pidgin English, about past illnesses is time consuming and fruitless, so all data are from direct observations. As MARPLES (1953) found in Samoa, the New Hebrideans are indifferent to yaws, and even if they were interested, it would take time to find out what was meant by " long time too much," or " long time little bit." Treatment was given by the single injection method of PAM (procaine penicillin C in oil with 2 per cent. aluminium monostearate). A scaled dosage of up to 1.2 m. units for an adult was given to infectious subjects and certain contacts. Out of the 792 patients seen, 477 were t r e a t e d - 219 in the Banks and Torres and 258 on Futuna. The results of treatment proved to be strikingly good where a follow-up was possible, as on the latter island.
Classification of lesions. In this survey lesions are classified as Infective or Non-infective, using Harding's : Infective lesions : " All primary and secondary lesions in which spirochaetes may be
(1949) criteria
60
I N C I D E N C E OF YAWS
I N T H E N E W HEBRIDES
e x p e c t e d to exist on t h e surface, i n c l u d i n g t h e p r i m a r y lesions, s e c o n d a r y f r a m b o e s i o m a t a , c o n d y l o m a t a a n d p s e u d o g r a n u l o m a t o u s e r u p t i o n s of t h e sole." Non-infective : " A l l d r y s e c o n d a r y lesions o f soft skin, ulcers, b o n e a n d j o i n t lesions a n d all n o n - g r a n u l o m a t o u s lesions o f t h e p a l m s a n d soles." T h e f r e q u e n c y o f lesions seen i n t h e g r o u p a c c o r d i n g to t h e t e r m i n o l o g y a p p r o v e d b y W H O (1953), b a s e d o n d a t a f r o m 283 cases, is as follows : Total (1) Initial lesions (2) Multiple papillomata (3) " Wet crab " yaws (4) Other early skin lesions (5) Hyperkeratosis (6a) G u m m a t a and ulcers (6b) Gangosa (rhinopharyngitis mutilans) (7) Bone and joint lesions (8) Latent yaws (9) Other manifestations : (a) juxta articular nodules - - not seen (b) bursitis ....
8
151 55 13 42 7 1 17
Percentage 2.8 51.2 19.6 4.6 13 2.5 0.3 6 ?
Geographical distribution : Group of islands
Population 1953
Number examined
Torres Banks Northern District Central District No. 2 Central District No. 1 Southern District Non-native
185 1839 6986 18417 6580 8131 4089
53 502 134 262 323 318 nil
13 193 10 8 58 147 --
24 204 20 -5 110 --
46227
1592
429
363
Yaws
Inactive
Non-inactive
Total 37 397 30 8
63 257 792
S e x distribution : S h o w e d little variation. O f 361 cases of i n f e c t i v e y a w s 183 of t h e s u b j e c t s w e r e m a l e a n d 178 female. I n 347 cases o f n o n - i n f e c t i v e yaws, 188 were in m a l e s a n d 159 in females. A g e distribution : T h e s e figures give t h e p e r c e n t a g e of cases o c c u r r i n g in t h e a g e - g r o u p s :
Age in years 1-5 6-10 11 - 15 16 - 20 21 - 30 31 - 40 41 - 50 51 - 60 61 - 70 70 plus
Infective yaws. (number in sample, 329)
Non-infective yaws. (number in sample, 340)
44 15 13 9 12 6
9 4 8 9 18 21 21 5 3 2
1
nil nil nil
A. R. MILLS
61
It can be seen from the Table that there is a great variation in the incidence, but the remote areas, e.g. Banks, Torres and F u t u n a resemble each other closely. In the Banks and Torres 78 per cent. of those examined had yaws and 70 per cent. in Futuna. In the Northern District, parts of Santo, Tontouba, Aoba and Maewo were visited. Almost all the subjects in this group came from Maewo, the most remote island. Central District No. 2 consists of Pentecost, Malekula, Ambrym, Paama, Lopevi and Epi, 196 people in this group were seen at Melsissi on Pentecost, a good mission station where there were no overt cases. Bush areas of this District have not been surveyed. Central District No. 1 includes Efate and its neighbouring islands and islets. T h e incidence is low because this part of the group is the most accessible and has the best medical services. T h e Southern District consists of Erromanga, Tanna, Futuna, Aniwa and Aneityum. T h e rural areas are heavily infected. T h u s yaws in the New Hebrides follows the familiar pattern. It is a rural disease and is rarely seen amongst the inhabitants of Vila or Santo, or even in areas where efficient clinics exist. T h e majority of infective cases occur in children, and non-infective cases in adults. SUMMARY
OF CONTENTS
(1) General information is given about the geography, climate and inhabitants of the New Itebrides. (2) T h e method of investigation is described. T h e type and n u m b e r of cases of yaws seen throughout the group are tabulated : 1,592 of the indigenous races were examined and of these 429 had infective yaws and 363 non-infective yaws. Therefore, of the population examined, 50 per cent. were infected with yaws. REFERENCES ASH, J. E. & SPITZ, S. (1945). Pathology of Tropical Diseases. Philadelphia and London Saunders Co. HACKETT,C. J. (1953). Trans. R. Soc. trop. Med. Hyg., 47, 318. HARDINC, R. D. (1949). Ibid., 40, 206. LAMBERT, S. M. (1924). Health Survey of the New Hebrides. Suva. MARPLES, M. J. (1950). Trans. R. Soc. trop. Med. Hyg., 44, 319. - & BACON, D. F. (1953). Ibid., 47, 141. WORLD HEALTHOI~GANIZATION(1953). Monograph series, No. 15.
: W. B.
INCIDENCE
OF YAWS IN THE
NEW HEBRIDES
BY
A. R. M I L L S , M.R.e.s., L.I~.Ca',, D.T.M. & H. British Service Medical Officer, New Hebrides. South Pacific Health Service.
T h i s investigation was m a d e d u r i n g the course of tours in t h e rural areas of the N e w Ilebrides, the islands being visited d u r i n g the period f r o m A u g u s t , 1952, to D e c e m b e r , 1953. T h e study was m a d e clinically and single-handed. T h e r e are no figures for the incidence of yaws in the g r o u p previous to this report. LAMBERT (1924) stated that " Yaws is the m o s t prevalent disease," and all observers have agreed t h a t it is very c o m m o n . Geography.
The New Hebrides, including the Banks and Torres islands, lie in the South Pacific between latitude 13 ° and 21°S and longitude 166 ° and 171°E. They have an area of roughly 5,700 square miles (4,847 sq. kin.). The group comprises 12 major islands, 18 lesser islands and about 30 small islands and islets distributed round their coasts. They are dispersed in the form of a " Y " of which the southern islands form the tail. Approximately 40 islands are inhabited. The largest island in the group is Espiritu Santo with an area of 1,500 square miles and mountains over 6,000 feet high (1,800 m.). Most of the islands are of the " high " volcanic type, with incomplete fringing coral reefs. There are three active volcanoes in the group. Vegetation is varied but is mostly evergreen bush. On the populated islands are coconut, coffee and cocoa plantations as well as many native gardens where yam, taro, manioc, etc., are grown. Climate.
The climate of the New Hebrides is tropical with two fairly well-defined seasons, that of the E.N.E. trade winds from about April to November, and the hot or doldrum season from December to March. At Vila, situated near the centre of the group, the average annual rainfall is 81 in. (2,057 mm.) and the temperature ranges from a maximum of 94°F. (34.4°C.) to a minimum night temperature in the cool season, of 56°F. (13.3°C.). In the southern portion of the group, the annual rainfall averages 55 in. (1,397 mm.), while in the north it rises to 160 in. (4,064 mm.). The monthly average relative humidity varies between 77 per cent. and 89 per cent. The Inhabitants.
T h e people of the N e w H e b r i d e s are m o s t l y Melanesians, b u t there is also admixture of Polynesian blood, especially in the east and south. T h e y vary f r o m well-built, light b r o w n w a v y - h a i r e d in the marginal Polynesian g r o u p s to small n u m b e r s of people of p y g m y type in central Malekula and Espiritu Santo. M o s t of the inhabitants are dark b r o w n with woolly hair, rather heavy features and b r o a d noses. T h e y are of g o o d physique. T h e n o n - i n d i g e n o u s peoples are F r e n c h , British, I n d o - C h i n e s e , Chinese and other Pacific islanders. T h e estimate of the p o p u l a t i o n for 1953 has been m a d e f r o m District Agents reports, personal observations and other sources. T h e r e is no accurate census of the N e w Hebrides.
A. R. M I L L S
59
Mode of life. The indigenous inhabitants live in reed or cane huts, the floor of which may be earth, coral chips or stone blocks. Sleeping mats are laid on the floor. Some huts are very primitive being of ridge-tent shape with" no walls, whereas others are quite elaborate with high walls, thick thatch and windows. The huts are commonly overcrowded. The people are keen gardeners and their diet is largely vegetable. Taro, manioc, yam and bananas are the commonest articles of diet. Breadfruit, coconut and other nuts, sea-food, pig, chicken, pigeon and a large variety of fruits make up a satisfactory and varied diet. Malnutrition is almost never seen. Villages are often small. T h e largest has a population of 600, but many Melanesians live in a collection of only a dozen people inhabiting two or three huts. These work their gardens, fish or cut copra. There is no general system of excretal disposal. Some villages have closets over the reef in the inter-tidal zone, and a few have earth closets. Where these do not exist, the neighbouring bush is used. Domestic animals run about the villages, but pigs may be kept behind a barrier. Children sit in close bodily contact with adults for hours at a stretch. In spite of the lack of hygiene, there is a relative absence of flies in some parts of the group. This may be due partly to the siting of a village open to the winds, and partly to the efficiency of scavengers such as crabs, ants, rats, etc. Anopheles farauti, the only anopheline species present in the group, is found on all but a few marginal islands. Malaria, tuberculosis and yaws are the commonest diseases.
YAWS
The data presented here were gathered during visits at various times to islands and villages. On arriving in a village I would get together as many persons as possible of all ages and both sexes. After explaining my purpose, I examined them and treated them on the spot. Often, only a short time would be available in any one place, and the reluctance of the Melanesians to accept strangers would mean that much time would be spent in persuading the people to come forward. Questioning, in pidgin English, about past illnesses is time consuming and fruitless, so all data are from direct observations. As MARPLES (1953) found in Samoa, the New Hebrideans are indifferent to yaws, and even if they were interested, it would take time to find out what was meant by " long time too much," or " long time little bit." Treatment was given by the single injection method of PAM (procaine penicillin C in oil with 2 per cent. aluminium monostearate). A scaled dosage of up to 1.2 m. units for an adult was given to infectious subjects and certain contacts. Out of the 792 patients seen, 477 were t r e a t e d - 219 in the Banks and Torres and 258 on Futuna. The results of treatment proved to be strikingly good where a follow-up was possible, as on the latter island.
Classification of lesions. In this survey lesions are classified as Infective or Non-infective, using Harding's : Infective lesions : " All primary and secondary lesions in which spirochaetes may be
(1949) criteria
60
I N C I D E N C E OF YAWS
I N T H E N E W HEBRIDES
e x p e c t e d to exist on t h e surface, i n c l u d i n g t h e p r i m a r y lesions, s e c o n d a r y f r a m b o e s i o m a t a , c o n d y l o m a t a a n d p s e u d o g r a n u l o m a t o u s e r u p t i o n s of t h e sole." Non-infective : " A l l d r y s e c o n d a r y lesions o f soft skin, ulcers, b o n e a n d j o i n t lesions a n d all n o n - g r a n u l o m a t o u s lesions o f t h e p a l m s a n d soles." T h e f r e q u e n c y o f lesions seen i n t h e g r o u p a c c o r d i n g to t h e t e r m i n o l o g y a p p r o v e d b y W H O (1953), b a s e d o n d a t a f r o m 283 cases, is as follows : Total (1) Initial lesions (2) Multiple papillomata (3) " Wet crab " yaws (4) Other early skin lesions (5) Hyperkeratosis (6a) G u m m a t a and ulcers (6b) Gangosa (rhinopharyngitis mutilans) (7) Bone and joint lesions (8) Latent yaws (9) Other manifestations : (a) juxta articular nodules - - not seen (b) bursitis ....
8
151 55 13 42 7 1 17
Percentage 2.8 51.2 19.6 4.6 13 2.5 0.3 6 ?
Geographical distribution : Group of islands
Population 1953
Number examined
Torres Banks Northern District Central District No. 2 Central District No. 1 Southern District Non-native
185 1839 6986 18417 6580 8131 4089
53 502 134 262 323 318 nil
13 193 10 8 58 147 --
24 204 20 -5 110 --
46227
1592
429
363
Yaws
Inactive
Non-inactive
Total 37 397 30 8
63 257 792
S e x distribution : S h o w e d little variation. O f 361 cases of i n f e c t i v e y a w s 183 of t h e s u b j e c t s w e r e m a l e a n d 178 female. I n 347 cases o f n o n - i n f e c t i v e yaws, 188 were in m a l e s a n d 159 in females. A g e distribution : T h e s e figures give t h e p e r c e n t a g e of cases o c c u r r i n g in t h e a g e - g r o u p s :
Age in years 1-5 6-10 11 - 15 16 - 20 21 - 30 31 - 40 41 - 50 51 - 60 61 - 70 70 plus
Infective yaws. (number in sample, 329)
Non-infective yaws. (number in sample, 340)
44 15 13 9 12 6
9 4 8 9 18 21 21 5 3 2
1
nil nil nil
A. R. MILLS
61
It can be seen from the Table that there is a great variation in the incidence, but the remote areas, e.g. Banks, Torres and F u t u n a resemble each other closely. In the Banks and Torres 78 per cent. of those examined had yaws and 70 per cent. in Futuna. In the Northern District, parts of Santo, Tontouba, Aoba and Maewo were visited. Almost all the subjects in this group came from Maewo, the most remote island. Central District No. 2 consists of Pentecost, Malekula, Ambrym, Paama, Lopevi and Epi, 196 people in this group were seen at Melsissi on Pentecost, a good mission station where there were no overt cases. Bush areas of this District have not been surveyed. Central District No. 1 includes Efate and its neighbouring islands and islets. T h e incidence is low because this part of the group is the most accessible and has the best medical services. T h e Southern District consists of Erromanga, Tanna, Futuna, Aniwa and Aneityum. T h e rural areas are heavily infected. T h u s yaws in the New Hebrides follows the familiar pattern. It is a rural disease and is rarely seen amongst the inhabitants of Vila or Santo, or even in areas where efficient clinics exist. T h e majority of infective cases occur in children, and non-infective cases in adults. SUMMARY
OF CONTENTS
(1) General information is given about the geography, climate and inhabitants of the New Itebrides. (2) T h e method of investigation is described. T h e type and n u m b e r of cases of yaws seen throughout the group are tabulated : 1,592 of the indigenous races were examined and of these 429 had infective yaws and 363 non-infective yaws. Therefore, of the population examined, 50 per cent. were infected with yaws. REFERENCES ASH, J. E. & SPITZ, S. (1945). Pathology of Tropical Diseases. Philadelphia and London Saunders Co. HACKETT,C. J. (1953). Trans. R. Soc. trop. Med. Hyg., 47, 318. HARDINC, R. D. (1949). Ibid., 40, 206. LAMBERT, S. M. (1924). Health Survey of the New Hebrides. Suva. MARPLES, M. J. (1950). Trans. R. Soc. trop. Med. Hyg., 44, 319. - & BACON, D. F. (1953). Ibid., 47, 141. WORLD HEALTHOI~GANIZATION(1953). Monograph series, No. 15.
: W. B.