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Sporogony in Plasmodium falciparum apparently unaffected by sulforthomidine (Fanasil)
CORRESPONDENCE
357
excess of normal and that this excess was mostly accounted for by the presence of large amounts of gamma globulin. T h e mean values and the ranges are shown in the table where they are compared with values obtained from apparently healthy people. T h e outstanding findings in this study are the low albumin values encountered and the high globulin values, particularly those for the gamma fraction. This was particularly surprising in view of the absence of malaria, filariasis, leishmaniasis and other infections known to be responsible in many tropical and sub-tropical communities for increase in the globulin fraction and the plasma proteins. F r o m this it is to be presumed that either the diet of the Tristan da Cunha Islanders is deficient in protein or infections other than those already mentioned are responsible for these abnormal protein values. Concerning the diet, this is in fact deficient in protein, particularly in view of the high calorie requirements of the Islanders. With regard to other infections, it was shown by THACKER (1963) that the following were present among the considerable proportion of the c o m m u n i t y - 72.2% were infected with Trichuris trichiura and 23% with Ascaris lumbricoides, 78"9% had significantly high toxoplasma antibodies in the serum. I n addition it is known that the Islanders suffered from upper respiratory infections from time to time both before they left their island and after arrival in Britain. While in Tristan da Cunha such outbreaks of respiratory infection occurred after the visit of ships and their personnel to the Island. In this connex/on however, it must be noted that such upper respiratory infection among them is unlikely to have been more common than it is among persons in Britain who do not exhibit the protein changes here recorded. Of the infections known to be common among the Islanders it is suggested that those with soil-transmitted helminths and toxoplasmosis are most likely to be responsible for the raised gamma globulin values. Disintegration of invading larvae of soil-transmitted helminths in the tissues is perhaps most likely to provoke gamma globulin response. T h e low albumin values appear to highlight the need for further attention to be given to their nutritional status as well as to control of infection and perhaps particularly soil-transmitted helminthic infections among them. We are, etc. A. W. WOODRUFF L. E. PETTITT Hospital for Tropical Diseases, London, INT.W.1. 22 ffanuary, 1965. REFERENCES BLACK, J. A., THACKER, C. K. M., LEWIS, H. E. & THOULD, A. K. (1963). Brit. reed. J., 2, 1018. HARRISON, G. A. (1947). Chemical Methods in Clinical Medicine. London: Churchill. RICKETS, W. E., STERLING, K., KIRSNER, J. B. & PALMER, W. L. (1949). Gastroenterology, 13, 205. TAYLOR, H. L., MICKLESON, O. & KEYS, A. (1949). ft. din. Invest., 28, 273. THACKER, C. K. M. (1963). Trans. R. Soc. trop. Med. Hyg., 57, 10. WOODRUFF, A. W. (1963). Contribution to symposium on medical problems presented by the Tristan da Cunha community. Ibid., 57, 23.
SPOROGONY IN Plasmodium falciparum APPARENTLY UNAFFECTED BY SULFORTHOMIDINE
(FANASIL) SiR,mSulforthomidine (Fanasil, Roche), previously known as sulphorthodimethoxine, is a long-acting sulphonamide recommended for therapeutic use in weekly doses. Recently this drug has been shown to be an effective suppressant and also a potent schizontocide against East African strains of Plasmodium falciparum (LAING, 1964, 1965). In these trials neither the production nor the morphology of gametocytes appeared to be affected
358
CORRESPONDENCE
although it was possible that, like proguanil and pyrimethamine, the drug might render gametocytes incapable of development in the mosquito host. Such an effect was clearly shown to be possessed by sulphamezathine (FINDLAY et al., 1946). T o investigate any sporontocidal action, a male African aged 37 was given 1.0 g. of sulforthomidine 7 days after the onset of an acute attack of P. falciparum malaria; symptoms subsided and asexual parasites could not be found after 48 hours. 200 laboratorybred Anopheles gambiae were fed on him 5 days atter treatment, when gametocytes estimated at 50 per c.mm. were present in the peripheral blood. A second dose of 1-0 g. of sulforthomidine was given 2 days later and 200 mosquitoes were fed 2 days after that when parasitaemia was still at the same level. Both batches of mosquitoes were dissected after intervals oi 14 days, with the following results : - 1st batch--12 of 64 surviving mosquitoes had sporozoites in the salivary glands; 1 other had normally developing o6cysts. 2nd batch--20 of 61 surviving mosquitoes had sporozoites in the salivary glands; 4 others had normally developing o6cysts. Sulforthomidine, therefore, would appear to have no sporontocidal action against
P. falciparum. I am, etc., A. B. G. LAING,
Malariologist. East African Institute of Malaria and Vector Borne Diseases, Amani, Tanzania. 21 April, 1965. REFERENCES FINDLAY, G. M., MAEGRAITH, B. G., MARKSON, J. L. & HOLDEN, J. R. (1946). trop. reed. Parasit., 40, 358. LAING, A. B. G. (1964). Brit. reed. ft., 2, 1439. (1965). Ibid., 1, 905.
Ann.
357
excess of normal and that this excess was mostly accounted for by the presence of large amounts of gamma globulin. T h e mean values and the ranges are shown in the table where they are compared with values obtained from apparently healthy people. T h e outstanding findings in this study are the low albumin values encountered and the high globulin values, particularly those for the gamma fraction. This was particularly surprising in view of the absence of malaria, filariasis, leishmaniasis and other infections known to be responsible in many tropical and sub-tropical communities for increase in the globulin fraction and the plasma proteins. F r o m this it is to be presumed that either the diet of the Tristan da Cunha Islanders is deficient in protein or infections other than those already mentioned are responsible for these abnormal protein values. Concerning the diet, this is in fact deficient in protein, particularly in view of the high calorie requirements of the Islanders. With regard to other infections, it was shown by THACKER (1963) that the following were present among the considerable proportion of the c o m m u n i t y - 72.2% were infected with Trichuris trichiura and 23% with Ascaris lumbricoides, 78"9% had significantly high toxoplasma antibodies in the serum. I n addition it is known that the Islanders suffered from upper respiratory infections from time to time both before they left their island and after arrival in Britain. While in Tristan da Cunha such outbreaks of respiratory infection occurred after the visit of ships and their personnel to the Island. In this connex/on however, it must be noted that such upper respiratory infection among them is unlikely to have been more common than it is among persons in Britain who do not exhibit the protein changes here recorded. Of the infections known to be common among the Islanders it is suggested that those with soil-transmitted helminths and toxoplasmosis are most likely to be responsible for the raised gamma globulin values. Disintegration of invading larvae of soil-transmitted helminths in the tissues is perhaps most likely to provoke gamma globulin response. T h e low albumin values appear to highlight the need for further attention to be given to their nutritional status as well as to control of infection and perhaps particularly soil-transmitted helminthic infections among them. We are, etc. A. W. WOODRUFF L. E. PETTITT Hospital for Tropical Diseases, London, INT.W.1. 22 ffanuary, 1965. REFERENCES BLACK, J. A., THACKER, C. K. M., LEWIS, H. E. & THOULD, A. K. (1963). Brit. reed. J., 2, 1018. HARRISON, G. A. (1947). Chemical Methods in Clinical Medicine. London: Churchill. RICKETS, W. E., STERLING, K., KIRSNER, J. B. & PALMER, W. L. (1949). Gastroenterology, 13, 205. TAYLOR, H. L., MICKLESON, O. & KEYS, A. (1949). ft. din. Invest., 28, 273. THACKER, C. K. M. (1963). Trans. R. Soc. trop. Med. Hyg., 57, 10. WOODRUFF, A. W. (1963). Contribution to symposium on medical problems presented by the Tristan da Cunha community. Ibid., 57, 23.
SPOROGONY IN Plasmodium falciparum APPARENTLY UNAFFECTED BY SULFORTHOMIDINE
(FANASIL) SiR,mSulforthomidine (Fanasil, Roche), previously known as sulphorthodimethoxine, is a long-acting sulphonamide recommended for therapeutic use in weekly doses. Recently this drug has been shown to be an effective suppressant and also a potent schizontocide against East African strains of Plasmodium falciparum (LAING, 1964, 1965). In these trials neither the production nor the morphology of gametocytes appeared to be affected
358
CORRESPONDENCE
although it was possible that, like proguanil and pyrimethamine, the drug might render gametocytes incapable of development in the mosquito host. Such an effect was clearly shown to be possessed by sulphamezathine (FINDLAY et al., 1946). T o investigate any sporontocidal action, a male African aged 37 was given 1.0 g. of sulforthomidine 7 days after the onset of an acute attack of P. falciparum malaria; symptoms subsided and asexual parasites could not be found after 48 hours. 200 laboratorybred Anopheles gambiae were fed on him 5 days atter treatment, when gametocytes estimated at 50 per c.mm. were present in the peripheral blood. A second dose of 1-0 g. of sulforthomidine was given 2 days later and 200 mosquitoes were fed 2 days after that when parasitaemia was still at the same level. Both batches of mosquitoes were dissected after intervals oi 14 days, with the following results : - 1st batch--12 of 64 surviving mosquitoes had sporozoites in the salivary glands; 1 other had normally developing o6cysts. 2nd batch--20 of 61 surviving mosquitoes had sporozoites in the salivary glands; 4 others had normally developing o6cysts. Sulforthomidine, therefore, would appear to have no sporontocidal action against
P. falciparum. I am, etc., A. B. G. LAING,
Malariologist. East African Institute of Malaria and Vector Borne Diseases, Amani, Tanzania. 21 April, 1965. REFERENCES FINDLAY, G. M., MAEGRAITH, B. G., MARKSON, J. L. & HOLDEN, J. R. (1946). trop. reed. Parasit., 40, 358. LAING, A. B. G. (1964). Brit. reed. ft., 2, 1439. (1965). Ibid., 1, 905.
Ann.