Chronic splenomegaly in West Africa (with special reference to Nigeria): an enquiry into the contribution of syphilis as a factor in its causation; with some observations on the commoner signs of this diease among West African negroes
Manuwa, Samuel Layinka Ayodeji
1. Of 1000 consecutive cases that were treated at the African Hospital, Calabar, West Africa, 260 had enlarged spleens, and 71, enlarged livers. 67 of the latter ere associated with enlarged spleens, leaving 4 which were not so associated. It is considered that the cases are in every way representative of the condition as it occurs in Nigeria and the coastal belt of West Africa.2. The cases were principally examined in order to find out what part syphilis plays in the production of splenomegaly in West Africa. Those cases who did not show enlarged spleens among the total number examined were used as controls. The various criteria necessary for such an investigation are discussed.3. The spleen rate was found to show 2 waves: a primary one during the age periods 0 to 20 years, and a secondary wave from 31 to 60 years. The liver rate showed a corresponding primary wave between 0 to 20 years. This was followed by a slight decline from 21 to 40 years, and then a secondary rise from 41 to 60.4. The general clinical features presented by 207 in-patient cases as a whole are discussed, and a list given of the diseases for which they were primarily admitted. Only a few of the cases were admitted for conditions pointing directly to a splenic or hepatic condition.5. Those diseases which may produce splenic enlargement and which occurred in the series are discussed. Syphilis was the commonest, followed closely by malaria. It is pointed out that owing to the method of classification, the figures for syphilis are too low. For example, many of the cases of chronic ulcerations were of syphilitic origin, though they were often recorded simply as "ulcers".6. Many of the commoner diseases, especially those of the blood, which cause splenic enlargement did not occur among the series: they are rare in Nigeria.7. It is pointed out that malaria, yaws, and syphilis are the three diseases to which attention would have to be principally concentrated in the present enquiry. It was recognised that the investigation of the syphilis factor would be attended with some difficulty because any of its tertiary lesions and its serological reactions are identical with those of yaws, a disease which is endemic in Nigeria. The comparative incidence of the three diseases in the country is discussed. Their order of frequency in the area served by the Calabar Hospital is stated to be yaws, syphilis, and malaria in the proportion 1 : 1.3 : 2.8. It is considered however that these figures given for malaria are too high while those for syphilis are low.8. The results of a single examination of the blood for malaria and microfilaria are noted. The malaria parasite rate among cases who showed splenic enlargement (referred to as the "spleens") as well as the controls who showed no such enlargement referred to as the "others") showed a rise between 0 to 10 years of age followed by a steady decline from 11 to 60 years. This rise corresponded to the primary wave of the spleen and liver rates. The secondary wave in the spleen and liver rates however had no counterpart in the malaria parasite rate. The "spleens" showed a higher malaria parasite rate than the "others".9. It is emphasised that the malaria parasite rate was no indication of chronic malarial infection, the incidence of which could be more accurately assessed by taking into consideration the history of previous attacks among the cases, at least during the last 12 months. It is pointed out however that this could not be done because of the inability of most natives to give accurate history of their illnesses.10. Filarial and intestinal protozoal infection was not a factor in the cases of splenomegaly examined.11.Actual and differential blood counts of 33 spleen cases were done and the averages recorded. It was observed that these showed not much difference from what can be regarded as the West African normal and that the only value they have in the present enquiry was to show that only 'a single case of blood disease (von Jaksch's anaemia) occurred.12. The examination of spleen, liver, and gland punctures for parasites showed negative results.13. Five cases of jaundice occurred, of which one at least was of definitely syphilitic origin.14. In order to eliminate the yaws factor from the figures obtained for clinical syphilis, a careful investigation was made into the history of the former disease in every case. No person was regarded as syphilitic where there was any posibility of the yaws factor operating. The number who gave a history of yaws was found to be approximately equal among both the "spleens" and the "others" (controls) i.e., 11.1 and 12.7 per cent respectively. The disease cannot therefore be recorded as being a factor in the production of splenomegaly..15, The cases who showed physical signs of syphilis among the spleens and controls are recorded. The former showed a consistently higher incidence of the disease as clinically observed at each age period and among the cases as a whole.16. The commoner signs of the disease as seen among the cases are considered in some detail, their relative diagnostic importance being discussed. Adenopathy was found to be of little or no value. Nocturnal bone and joint aches were one of the commonest symptoms. A peculiar type of depigmentation of the skin of the lower extremities which is sometimes accompanied by loss of one or more digits is described. It is pointed out that this lesion is not of leprotic or yaws, but is most probably of syphilitic, origin. Lesions of the nervous system were uncommon.17. The figures for stigmata of congenital syphilis were low. It is pointed out that this is in accord with similar observations in many parts of Africa where the syphilis rate among the general population is known to be high, and that the probable explanation is that it is due to the high death rate among syphilitic infants.18. A Sachs-Georgi test was done on all the cases. The technique is described and the value of the test discussed with special reference to yaws, syphilis, and malaria. It is pointed out that the initial figures obtained represented the combined yaws and syphilis rate, and that the correct assessment of the rate for the latter disease was made by eliminating the yaws factor. This was done by finding out the number of serum-positives among those who had never contracted yaws. The "spleens" were found to have a combined yaws and syphilis rate of 71.5 per cent while the real syphilis rate was 60.3 per cent. The corresponding figures among the "others" were lower, being 54.3 and 41.5 per cent respectively. The combined yaws and syphilis rate among the total 1,000 cases examined was 58.8 per cent, while the real syphilis rate was 46.5 per cent. It is pointed out that the former rate approximates those for other parts of Nigeria, and for the general Calabar community.19. There was a marked disproportion between the serological and clinical figures especially in children of 0 to 10 and 11 to 20 years old among both classes of patients, more particularly among the "spleens". The possible reasons for this are 'discussed. It is pointed out that the high seismological figures during these age periods represent not only the rate of congenital syphilis but also that of the disease acquired very early in childhood. It is further pointed out that the clinical figures among these children are low because in collecting them, several cases in whom the sole lesion observed was enlarged spleen were not included and that many of such cases were possibly congenital syphilitics or subjects of the early acquired disease. It is considered therefore that an enlarged spleen may often be the only sign of congenital or early acquired. syphilis among West African children.20. The syphilis and malaria parasite rates are compared with the incidence of enlarged spleen and liver in each group. It is shown that enlarged spleen was found to associate more commonly with signs of syphilis than with those of malaria as parasitologically observed during the age period 0 to 10 years. This holds true as an index of chronic malarial infection only for this age period alone, as the figures for malaria parasite at the other age periods are an imperfect guide to the part that this disease plays. Though it is recognised that malaria is a considerable factor in the production of splenomegaly, yet it is suggested that the 2 waves which occurred in the spleen and liver rates during the age period 0 to 20 and 31 to 60 were partly of syphilitic origin; the primary wave being in part due to congenital and possibly early acquired syphilis, and the secondary being in part a tertiary manifestation of the sexually acquired disease or a late manifestation of "syphilis hereditaria tarda".21. It is pointed out that owing to the primitive state of civilisation, to ignorance regarding the mode of spread and to lack of effective native treatment, syphilis is very prevalent in Africa. The theory is propounded that where the universally prevalent syphilitic taint does not give rise primarily to a syphilitic splenomegaly, its presence probably forms a. basis on which enlargement of the native spleen in malaria develops more easily or in a more exaggerated degree than in an individual whose constitution is not originally thus burdened. The incidence of enlarged spleen in each age group among the cases described is analysed in the light of this theory.22. The effect of quinine and antisyphilitic treatment on the size of the enlarged spleen in 180 cases is recorded. These were grouped according as to whether the syphilitic factor was or was not operating in the production of the splenomegaly according to the serum reaction of the cases. The syphilitics showed a readier response to specific treatment than to quinine, while the non-syphilitics were more rapidly influenced with quinine than with antisyphilitic treatment. It is pointed out that, though by reason of the smallness of the numbers examined no dogmatic conclusions can be drawn from the results obtained, yet these suggest that the syphilitic element was present in an appreciable number of cases. It is urged that as 22.7 per cent of the cases treated showed some response during the short space of 6 weeks to combined quinine and antisyphilitic treatment, cases of chronic splenomegaly should first be given the benefit of such treatment before the decision is arrived at to perform splenectomy.23. An abstact of 10 cases records is given to illustrate the types of splenomegaly that might have been diagnosed as of purely malarial origin while they were really in part syphilitic. The post-mortem notes are given of 2 cases which were fatal and included a case of chronic polyorrhomenitis. It is pointed out that as this condition is sometimes met with in cases on whom splenectomyis performed, it may not be so very rare.24. A short list of the possibilities in the practical diagnosis of splenomegaly as seen in West Africa is given. Syphilis is given a prominent place because the results of the present investigation suggest that the influence of this disease ranks probably almost as high as that of malaria in the production of the condition.25. The respect to which this work constitutes a contribution to our knowledge is indicated.