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The incidence of sicklaemia in West Africa
83 TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL I~DICINE AND HYGIENE. VOI. 40. N o . 1. A u g u s t , 1946.
T H E I N C I D E N C E O F S I C K L A E M I A I N W E S T AFRICA. BY
G. M. FINDLAY,* W. MUIR ROBERTSON, AND
F. J. ZACHARIAS.
Since HERRICK (1910) first described an anaemia associated with sickling of the red cells in a native of the West Indies, the siclding phenomenon has aroused interest in America where it has been recognized as an important factor in the pathology of the negro. Under the term sicklaemia (COOLEY and LEE, 1926) are included those cases of anaemia with periodic haemolytic crises and those, more numerous, which without clinical symptoms exhibit sickling of the red cells in ~itro, whenever the oxygen tension is reduced--the sickling trait. In West Africa, the ancestral home of most American negroes, sicklaemia has received scant attention apart from record of individual cases by RUSSELL and TAYLOR (1932), SMITH (1934) and REID (1936), and the fuller and more recent studies of EVANS (1944 and 1945). The present communication deals with the incidence of sicklaemia in the British West African Colonies. INCIDENCE OF SICKLINC. As the majority of investigations were made under field conditions, the technique employed was simple. After cleaning the skin, a drop of blood was • Our thanks are due to Brigadier J. B. A. WI~MO~, D.D.M.S.,West African Command, for permission to publish these results. Dr. A. H. CHENNA~D and Dr. W . J. McCLINTOCK, of the Colonial Medical Service, very kindly placed patients at our disposal, while Miss D. BARNTULL and Mr. A. Y. KPSOLO gave us m u c h help and assistance.
84
SICKLAEMIA
placed on a slide, covered with a clean cover glass and ringed with vaseline. Ringed preparations, which must be protected from the depredations of ants, were kept at room temperature and examined after 24 hours. In all 5,500 Africans were examined of whom 12-4 per cent. showed the sickling trait. Just over half the totalnumber, were natives of the Gold Coast and French Togo, the remainder came from Gambia, Sierra Leone and Nigeria, where southern tribes, pagans from the Plateau and Hausas were examined. Siclding was found in all tribes and no significant specific tribal differences were noted. The sex incidence of sickling was approximately equal, 11.2 per cent. in males, 12.6 per cent. in females. Differences were noted in relation to age (see table). Although the numbers from the two extremes of life were small, they suggest that the expectation of life in sicklers may be less than in normal persons. The incidence of sicklaemia in relation to certain physiological and patho. logical conditions was investigated.
1. Pregnancy. R~ID (1936) pointed out that a sickling crisis in the later months of pregnancy was often fatal. Of 455 pregnant women examined in Accra, seventy-seven, or 16.9 per cent., sickled. I~ID (1944) found thirteen sicklers among 100 pregnant women in the Gold Coast.
2. Sterility. Of sixty-one women who either had never conceived or had failed to produce a viable foetus, thirteen, or 21-3 per cent., sickled.
3. Lunacy. Of seventy-six lunatics of both sexes, aged 35 to 60 years, five, or 6"5 per cent., sickle& This rate is comparable with that in old people without mental disease.
4. General Morbidity. Among 296 hospital patients not suffering from mental disease, pneumonia o r ulcers, forty-seven, or 15-8 per cent., sickled. 5. Pneumonia.
The incidence o f aickling in Africans with pneumonia was investigated to determine if the jaundice seen in negroes with pneumonia can be correlated with sicklaemia. In South Africa, GF.LF~D and Lpwm (1942) found jaundice in 10 per cent. of negroes with, pneumonia. Among 1,240 consecutive cases o f
O. M. FINDLAY, W. MUIR ROBERTSON AND F. J. ZACHARIAS
8~
pneumonia in West African soldiers, sixty-five, or 5-9. per cent., had jaundice. Of these 1,240 pneumonia patients, 125 sickled, and of the 125 sicklers twelve (9-6 :per cent.) had jaundice. Among the 1,115 non-sickling pneumonia patients, fifty-three, or 4.7 per cent., had jaundice. The difference in the incidence of jaundice in sicklers and non-sicklers is not statistically significant. 6. Ulcers.
The association between sickle cell anaemia and leg ulcers was described by HEm~ICK (1910). Later observers have estimated that in America ulcers of the leg occur at one time or another in the history of 40 per cent. of negroes with sickle cell anaemia. DIGGS et al. (1933) could not determine any correlation between the siclding trait and the presence among American negroes of active ulceration or old scars on the legs. In West Africa, of 103 patients with tropical ulcers of the leg, twelve, or 11-6 per cent., exhibited sicklaemia. S I C K L I N G I N RACES OTHER T H A N THE N E G R O .
From time to time sicklaemia has been described in whites in whom, so it is alleged, there is no negro ancestry. All cases have come from the Mediterranean area or America. In the former, since Roman times there has been a large infiltration of negroes, while in America negro ancestry may be vehemently denied but is not easily excluded. DIGGS et al. (1933) examined 309 whites from Memphis, SYDENSTRICKER (1924), 1,000 from the Southern States, and KORI3 and MIYAlVIOTO(1927), 100 from St. Louis ; all were negative. Five hundred and sixty-eight British soldiers and airmen, temporarily stationed in West Africa, were all negative ; 188 Syrians were also negative. T~ta. INCIDENCE OF SICKLING I N RELATION TO AGE (BOTH SEXRS) I N NORMAL AFRICANS.
Group. N e w - b o r n babies (cord blood) I n f a n t s (1 to 5 years) ...... School children (6 to 15 years) Students (16 to 20 years) A d u l t s (21 to 50 years) ... O l d people (60 years a n d over)
... ... ... °°.
Number examined,
Number sickling.
25 243 455 426 1,510 50
29 44 43 192 2
9
Percentage w i t h sictding. 36"0 11"9 9"6 10"9 12"7 4"0
DISCUSSION AND CONCLUSION. Among 5,500 West Africans exarruned, 682, or 12"4 per cent., had sicklaemia. In the United States of America the results of seventeen investigators,
86
SICKLAEMIA
summarized by LEwis (1942), showed that among 11,121 negroes examined, 832 (7.48 per cent.) sickle& Variations were from 4-3 per cent. in Georgia to 15 per cent. in North Carolina. TOMLINSON(1945), among 3,000 examinations in the Panama Canal zone, observed 11"2 per cent. of sicklers. In West Africa, Ev~,~s (1944) found that among 561 African soldiers, 112 (19-9 per cent.) sickled. In Gambians the rate was 28.3 per cent. Conclusions.
Among 5,500 West Africans examined, the incidence of sicklaemia was 12.4 per cent. REFERENCES. T. B. & LEE, P. (1926). Amer. y. Dis. Child., 32, 334. DIcGs, L. W., AHMANN,C. F. & BIBB,J. (1933). Ann. int. Med., 7, 769. EW,NS, W.R. (1944). Trans. R. Soc. trop. Med. Hyg., 37, 281. (1945). Ibid., 39, 207• GELFAND,M. & LEWIS,B. (1942). S. Africa reed. Y., 16, 436. I-~_~ICK, J.B. (1910). Arch. int. Med., 6, 517. LEwis, J . H . (1942). The Biology of the Negro. Chicago, University of Chicago Press. KORB, J. H. &.MIYAMOTO,K. (1927). South reed. y., 20, 912. REID, R. D. (1936). West Africa Med. ft., 9, 15. • (1944). Personal communication. RUSSELL,H. & TAYLOR,C. J. S.O. (1932). Ibid., 5, 68. SMITH , E.C. (1934). Trans. R. Soc. trop. Med. Hyg., 28, 209. SYD~STaICKER,V.P. (1924). ft. Amer. reed. Ass., 83, 12. TOMLINSON,W.J. (1945). Amer. y. Med. Sc., 209, 181. COOLEY,
T H E I N C I D E N C E O F S I C K L A E M I A I N W E S T AFRICA. BY
G. M. FINDLAY,* W. MUIR ROBERTSON, AND
F. J. ZACHARIAS.
Since HERRICK (1910) first described an anaemia associated with sickling of the red cells in a native of the West Indies, the siclding phenomenon has aroused interest in America where it has been recognized as an important factor in the pathology of the negro. Under the term sicklaemia (COOLEY and LEE, 1926) are included those cases of anaemia with periodic haemolytic crises and those, more numerous, which without clinical symptoms exhibit sickling of the red cells in ~itro, whenever the oxygen tension is reduced--the sickling trait. In West Africa, the ancestral home of most American negroes, sicklaemia has received scant attention apart from record of individual cases by RUSSELL and TAYLOR (1932), SMITH (1934) and REID (1936), and the fuller and more recent studies of EVANS (1944 and 1945). The present communication deals with the incidence of sicklaemia in the British West African Colonies. INCIDENCE OF SICKLINC. As the majority of investigations were made under field conditions, the technique employed was simple. After cleaning the skin, a drop of blood was • Our thanks are due to Brigadier J. B. A. WI~MO~, D.D.M.S.,West African Command, for permission to publish these results. Dr. A. H. CHENNA~D and Dr. W . J. McCLINTOCK, of the Colonial Medical Service, very kindly placed patients at our disposal, while Miss D. BARNTULL and Mr. A. Y. KPSOLO gave us m u c h help and assistance.
84
SICKLAEMIA
placed on a slide, covered with a clean cover glass and ringed with vaseline. Ringed preparations, which must be protected from the depredations of ants, were kept at room temperature and examined after 24 hours. In all 5,500 Africans were examined of whom 12-4 per cent. showed the sickling trait. Just over half the totalnumber, were natives of the Gold Coast and French Togo, the remainder came from Gambia, Sierra Leone and Nigeria, where southern tribes, pagans from the Plateau and Hausas were examined. Siclding was found in all tribes and no significant specific tribal differences were noted. The sex incidence of sickling was approximately equal, 11.2 per cent. in males, 12.6 per cent. in females. Differences were noted in relation to age (see table). Although the numbers from the two extremes of life were small, they suggest that the expectation of life in sicklers may be less than in normal persons. The incidence of sicklaemia in relation to certain physiological and patho. logical conditions was investigated.
1. Pregnancy. R~ID (1936) pointed out that a sickling crisis in the later months of pregnancy was often fatal. Of 455 pregnant women examined in Accra, seventy-seven, or 16.9 per cent., sickled. I~ID (1944) found thirteen sicklers among 100 pregnant women in the Gold Coast.
2. Sterility. Of sixty-one women who either had never conceived or had failed to produce a viable foetus, thirteen, or 21-3 per cent., sickled.
3. Lunacy. Of seventy-six lunatics of both sexes, aged 35 to 60 years, five, or 6"5 per cent., sickle& This rate is comparable with that in old people without mental disease.
4. General Morbidity. Among 296 hospital patients not suffering from mental disease, pneumonia o r ulcers, forty-seven, or 15-8 per cent., sickled. 5. Pneumonia.
The incidence o f aickling in Africans with pneumonia was investigated to determine if the jaundice seen in negroes with pneumonia can be correlated with sicklaemia. In South Africa, GF.LF~D and Lpwm (1942) found jaundice in 10 per cent. of negroes with, pneumonia. Among 1,240 consecutive cases o f
O. M. FINDLAY, W. MUIR ROBERTSON AND F. J. ZACHARIAS
8~
pneumonia in West African soldiers, sixty-five, or 5-9. per cent., had jaundice. Of these 1,240 pneumonia patients, 125 sickled, and of the 125 sicklers twelve (9-6 :per cent.) had jaundice. Among the 1,115 non-sickling pneumonia patients, fifty-three, or 4.7 per cent., had jaundice. The difference in the incidence of jaundice in sicklers and non-sicklers is not statistically significant. 6. Ulcers.
The association between sickle cell anaemia and leg ulcers was described by HEm~ICK (1910). Later observers have estimated that in America ulcers of the leg occur at one time or another in the history of 40 per cent. of negroes with sickle cell anaemia. DIGGS et al. (1933) could not determine any correlation between the siclding trait and the presence among American negroes of active ulceration or old scars on the legs. In West Africa, of 103 patients with tropical ulcers of the leg, twelve, or 11-6 per cent., exhibited sicklaemia. S I C K L I N G I N RACES OTHER T H A N THE N E G R O .
From time to time sicklaemia has been described in whites in whom, so it is alleged, there is no negro ancestry. All cases have come from the Mediterranean area or America. In the former, since Roman times there has been a large infiltration of negroes, while in America negro ancestry may be vehemently denied but is not easily excluded. DIGGS et al. (1933) examined 309 whites from Memphis, SYDENSTRICKER (1924), 1,000 from the Southern States, and KORI3 and MIYAlVIOTO(1927), 100 from St. Louis ; all were negative. Five hundred and sixty-eight British soldiers and airmen, temporarily stationed in West Africa, were all negative ; 188 Syrians were also negative. T~ta. INCIDENCE OF SICKLING I N RELATION TO AGE (BOTH SEXRS) I N NORMAL AFRICANS.
Group. N e w - b o r n babies (cord blood) I n f a n t s (1 to 5 years) ...... School children (6 to 15 years) Students (16 to 20 years) A d u l t s (21 to 50 years) ... O l d people (60 years a n d over)
... ... ... °°.
Number examined,
Number sickling.
25 243 455 426 1,510 50
29 44 43 192 2
9
Percentage w i t h sictding. 36"0 11"9 9"6 10"9 12"7 4"0
DISCUSSION AND CONCLUSION. Among 5,500 West Africans exarruned, 682, or 12"4 per cent., had sicklaemia. In the United States of America the results of seventeen investigators,
86
SICKLAEMIA
summarized by LEwis (1942), showed that among 11,121 negroes examined, 832 (7.48 per cent.) sickle& Variations were from 4-3 per cent. in Georgia to 15 per cent. in North Carolina. TOMLINSON(1945), among 3,000 examinations in the Panama Canal zone, observed 11"2 per cent. of sicklers. In West Africa, Ev~,~s (1944) found that among 561 African soldiers, 112 (19-9 per cent.) sickled. In Gambians the rate was 28.3 per cent. Conclusions.
Among 5,500 West Africans examined, the incidence of sicklaemia was 12.4 per cent. REFERENCES. T. B. & LEE, P. (1926). Amer. y. Dis. Child., 32, 334. DIcGs, L. W., AHMANN,C. F. & BIBB,J. (1933). Ann. int. Med., 7, 769. EW,NS, W.R. (1944). Trans. R. Soc. trop. Med. Hyg., 37, 281. (1945). Ibid., 39, 207• GELFAND,M. & LEWIS,B. (1942). S. Africa reed. Y., 16, 436. I-~_~ICK, J.B. (1910). Arch. int. Med., 6, 517. LEwis, J . H . (1942). The Biology of the Negro. Chicago, University of Chicago Press. KORB, J. H. &.MIYAMOTO,K. (1927). South reed. y., 20, 912. REID, R. D. (1936). West Africa Med. ft., 9, 15. • (1944). Personal communication. RUSSELL,H. & TAYLOR,C. J. S.O. (1932). Ibid., 5, 68. SMITH , E.C. (1934). Trans. R. Soc. trop. Med. Hyg., 28, 209. SYD~STaICKER,V.P. (1924). ft. Amer. reed. Ass., 83, 12. TOMLINSON,W.J. (1945). Amer. y. Med. Sc., 209, 181. COOLEY,