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Mortality rates of South African Bantu and Caucasian children
404
CORRESPONDENCE
challenge infection. Although none of the monkeys receiving only the irradiated larvae ever exhibited microfilaraemia, no effort was made to determine the fate of these worms. Since it is essential that the fate of living immunizing larvae be determined if such a vaccine is to be of practical use in man or animals, we have recently completed a similar study using D. immitis in its natural host, the dog. Freshly obtained infective stage larvae dissected from experimentally infected mosquitoes were exposed to 20 K. rads from a cobalt source and known numbers were introduced subcutaneously into the medial surface of the thigh of 9 beagles either 1 or 2 times. 5 dogs were euthanized at time-intervals ranging from 15 to 137 days following the inoculations. Larvae were found in subcutaneous tissues of the inoculated leg, abdomen and chest, as well as in the dorsal fascia of the lumbar and thoracic regions of the body. Larvae recovered which had developed beyond the 3rd stage were all females. The largest of the recovered worms measured approximately 6.3 mm. and was found 87 days post-inoculation. Compared to normal larvae in this stage of development, they were smaller and less well differentiated. No worms were found later than this date; none were found in the hearts of dogs euthanized at times when normal, non-irradiated worms would have reached tile heart (ORIHEL, 1961). T h e remaining 4 dogs were challenged with 200 normal infective-stage •larvae. No larvae were found after 31 days in one; after 140 days 7 adult worms were found in the heart of another, and the third dog which produced a patent infection was found to harbour 6 worms. No microfilaraemia has been detected ill tile fourth dog after one year.* Compared to the 33-40% recovered from the 200 larvae inoculated into positive control dogs, no more than 4% have been recovered in the immunized dogs. Since it appears that the immunity elicited by the irradiated larvae was relative rather than absolute, we are continuing our studies using greater numbers of irradiated larvae to see if these inzreased doses may produce better protection. Physiological, pathological, parasitological and serological studies accompanying these experiments are being carried out and will be reported in detail at a later date. We are, etc., MARY F. GUEST MINe M. WONG M. M. J. LAVOIPIERRE National Center for Primate Biology, 22 February, 1971 University of California, Davis, California, 95616. *This dog has since been euthanized and a single adult female was found in the hearL REFERENCES ORIHEL, T. C. (1961). ft. Parasit., 47, 251. WONG, M. M., FREDERICKS,H. J. & RAMACHANDRAN, C. P. (1969). Bull. Wld Hhh Org., 40, 493.
MORTALITY RATES OF SOUTH AFRICAN BANTU AND CAUCASIAN CHILDREN
SIR,--In the interesting and useful paper by RICHARDSON(1970) on mortality rates of South African Bantu and Caucasian preschool children in urban and rural areas of South Africa, it is concluded that mortality rates 'for the South African B a n t u g r o u p s studied, though well below those reported for relatively under-developed countries are still far higher than figures for Caucasians.' The author uses 1951 and 1954, 1-4 years mortalities in Jamaica and Guyana respectively for comparison with her recent South African figures (dates not given) and then draws the conclusion quoted above. More recent 1-4 year mortality rates for many countries, including Jamaica and Guyana are readily available. However, they are more commonly expressed as deaths aged 1-4 years per 1000 population, in that age group than per 1000 live births. Recalculating the 'Bantu general' population, rural area, we find that out of 1000 live births 879 have survived to their third birthday (the middle of the 1-4 period). 55"0 have died between 1 and under 5 years, given a 1-4 mortality rate of 62"6. This rate is 11% higher than that calculated per 1000 births (55.0). The equivalent rate for the urban 'Bantu general' population is 47.4. Both these rates compare very unfavourably (even if we allow for underrecording) with figures given for such countries as Guatemala (23.9 in 1963), the Philippines (8.8 in 1963) (AYKROYD,1968), Guyana (5.8 in 1960 and45.2 in 1893)and Jamaica (4.8 in 1965)
CORRESPONDENCE
405
(CooK, 1969; ASHCROFTet al., 1968). However, Haiti is an example of a country w k h a higher 1-4 mortality (265) than South African 'Bantu' populations (BEGHIN, 1969). Considering that per caput national income and per caput G D P are much higher for South Africa than all the other countries mentioned above (UNITED NATIONS , 1969) these 'Bantu general' mortality rates are extraordinarily high. BENGOA(1970) has very recently set out 1-4 mortality rates for 13 of the less affluent countries for 1950-52, 1960-62 and 1966; all are well below the 'Bantu general' rates given. T h e contention made that mortalities for the South African Bantu groups studied were 'well below those reported for relatively (sic) under-developed countries' appears to be misleading. I am, etc., J. MICHAEL GURNEY,
23 February, 1971
Caribbean F o o d and Nutrition Institute, University of the West Indies, Mona P.O. Box 140, Kingston 7.
REFERENCES ASHCROFT, M. T., BELL, RUTH, NICHOLSON, C. C. & PEMBERTON, S. (1968). Trans. R. Soc.
trop. Med. Hyg., 62, 607. AYKROYD, W. R. (1968). TurkishJ. Pedlar., 10, 50. BEGHIN, I. (1969). Les Probl&nes de sant~ et de nutrition en Haiti, un essai d'interpretation. Brussels : Acad6mie royale des sciences d'outre-Mer. BENGOA, J. M. (1970). W H O Chronicle, 24, 552. COOK, R. (1969). ,7. trop. Pedlar., 1~, 109. RICHARDSON, BARBARAD. (1970). Trans. R. Soc. trop. Med. Hyg., 64, 921. UNITED NATIONS (1969). Statistical Year Book 1968 (Twentieth Issue). New York: Statistical Office of the United Nations. AURAL INFESTATIONBY THYSANURA
SIR,--I report here the occurrence of aural infestation by a silverfish. As far as I can ascertain this site of infestation in man has not previously been reported. T h e insect was removed alive by Surgeon Lieut. Hopkin from the ear of a patient in Muharraq in the Persian Gulf. Symptoms were tinnitus and otalgia for two days. After removal a small haematoma was seen on the tympanic membrane and the adjacent wall of the external auditory meatus. T h e insect was a member of the family Lepismatidae. Further identification was not possible because of the damage caused to it during removal from the ear. Silverfish are commonly found in warm, moist environments in kitchens, bathrooms and store-rooms where they feed on food particles, dead insects, moulds and other organic debris. At least 18 species of Collembola have been reported in intimate association with man, often causing a pruritic dermatitis. SCOTTet al. (1962) noted a case of infestation, without dermatitis, of the heads and pubic areas of a Texas family by Orchesella albosa. I am, Sir, Yours faithfully, N. R. H. BURGESS, Lecturer in Medical Entomology, Royal A r m y Medical College, Millbank, 5 March, 1971 London, S.W.1. REFERENCE SCOTT, H. G., WISEMAN, J. S. & STOJANOVICH, C. J. (1962). Ann. ent. Soc. Am., 53, 428. DRUGS AFFECTINGFOETALHAEMOGLOBINSYNTHESIS
SIR,--In the January issue of the Transactions (1971, 65, 78) we reported that the administration to hamsters of prolactin and perphenazine induced the synthesis of foetal haemoglobin or a haemoglobin which behaved electrophoretically like it.
CORRESPONDENCE
challenge infection. Although none of the monkeys receiving only the irradiated larvae ever exhibited microfilaraemia, no effort was made to determine the fate of these worms. Since it is essential that the fate of living immunizing larvae be determined if such a vaccine is to be of practical use in man or animals, we have recently completed a similar study using D. immitis in its natural host, the dog. Freshly obtained infective stage larvae dissected from experimentally infected mosquitoes were exposed to 20 K. rads from a cobalt source and known numbers were introduced subcutaneously into the medial surface of the thigh of 9 beagles either 1 or 2 times. 5 dogs were euthanized at time-intervals ranging from 15 to 137 days following the inoculations. Larvae were found in subcutaneous tissues of the inoculated leg, abdomen and chest, as well as in the dorsal fascia of the lumbar and thoracic regions of the body. Larvae recovered which had developed beyond the 3rd stage were all females. The largest of the recovered worms measured approximately 6.3 mm. and was found 87 days post-inoculation. Compared to normal larvae in this stage of development, they were smaller and less well differentiated. No worms were found later than this date; none were found in the hearts of dogs euthanized at times when normal, non-irradiated worms would have reached tile heart (ORIHEL, 1961). T h e remaining 4 dogs were challenged with 200 normal infective-stage •larvae. No larvae were found after 31 days in one; after 140 days 7 adult worms were found in the heart of another, and the third dog which produced a patent infection was found to harbour 6 worms. No microfilaraemia has been detected ill tile fourth dog after one year.* Compared to the 33-40% recovered from the 200 larvae inoculated into positive control dogs, no more than 4% have been recovered in the immunized dogs. Since it appears that the immunity elicited by the irradiated larvae was relative rather than absolute, we are continuing our studies using greater numbers of irradiated larvae to see if these inzreased doses may produce better protection. Physiological, pathological, parasitological and serological studies accompanying these experiments are being carried out and will be reported in detail at a later date. We are, etc., MARY F. GUEST MINe M. WONG M. M. J. LAVOIPIERRE National Center for Primate Biology, 22 February, 1971 University of California, Davis, California, 95616. *This dog has since been euthanized and a single adult female was found in the hearL REFERENCES ORIHEL, T. C. (1961). ft. Parasit., 47, 251. WONG, M. M., FREDERICKS,H. J. & RAMACHANDRAN, C. P. (1969). Bull. Wld Hhh Org., 40, 493.
MORTALITY RATES OF SOUTH AFRICAN BANTU AND CAUCASIAN CHILDREN
SIR,--In the interesting and useful paper by RICHARDSON(1970) on mortality rates of South African Bantu and Caucasian preschool children in urban and rural areas of South Africa, it is concluded that mortality rates 'for the South African B a n t u g r o u p s studied, though well below those reported for relatively under-developed countries are still far higher than figures for Caucasians.' The author uses 1951 and 1954, 1-4 years mortalities in Jamaica and Guyana respectively for comparison with her recent South African figures (dates not given) and then draws the conclusion quoted above. More recent 1-4 year mortality rates for many countries, including Jamaica and Guyana are readily available. However, they are more commonly expressed as deaths aged 1-4 years per 1000 population, in that age group than per 1000 live births. Recalculating the 'Bantu general' population, rural area, we find that out of 1000 live births 879 have survived to their third birthday (the middle of the 1-4 period). 55"0 have died between 1 and under 5 years, given a 1-4 mortality rate of 62"6. This rate is 11% higher than that calculated per 1000 births (55.0). The equivalent rate for the urban 'Bantu general' population is 47.4. Both these rates compare very unfavourably (even if we allow for underrecording) with figures given for such countries as Guatemala (23.9 in 1963), the Philippines (8.8 in 1963) (AYKROYD,1968), Guyana (5.8 in 1960 and45.2 in 1893)and Jamaica (4.8 in 1965)
CORRESPONDENCE
405
(CooK, 1969; ASHCROFTet al., 1968). However, Haiti is an example of a country w k h a higher 1-4 mortality (265) than South African 'Bantu' populations (BEGHIN, 1969). Considering that per caput national income and per caput G D P are much higher for South Africa than all the other countries mentioned above (UNITED NATIONS , 1969) these 'Bantu general' mortality rates are extraordinarily high. BENGOA(1970) has very recently set out 1-4 mortality rates for 13 of the less affluent countries for 1950-52, 1960-62 and 1966; all are well below the 'Bantu general' rates given. T h e contention made that mortalities for the South African Bantu groups studied were 'well below those reported for relatively (sic) under-developed countries' appears to be misleading. I am, etc., J. MICHAEL GURNEY,
23 February, 1971
Caribbean F o o d and Nutrition Institute, University of the West Indies, Mona P.O. Box 140, Kingston 7.
REFERENCES ASHCROFT, M. T., BELL, RUTH, NICHOLSON, C. C. & PEMBERTON, S. (1968). Trans. R. Soc.
trop. Med. Hyg., 62, 607. AYKROYD, W. R. (1968). TurkishJ. Pedlar., 10, 50. BEGHIN, I. (1969). Les Probl&nes de sant~ et de nutrition en Haiti, un essai d'interpretation. Brussels : Acad6mie royale des sciences d'outre-Mer. BENGOA, J. M. (1970). W H O Chronicle, 24, 552. COOK, R. (1969). ,7. trop. Pedlar., 1~, 109. RICHARDSON, BARBARAD. (1970). Trans. R. Soc. trop. Med. Hyg., 64, 921. UNITED NATIONS (1969). Statistical Year Book 1968 (Twentieth Issue). New York: Statistical Office of the United Nations. AURAL INFESTATIONBY THYSANURA
SIR,--I report here the occurrence of aural infestation by a silverfish. As far as I can ascertain this site of infestation in man has not previously been reported. T h e insect was removed alive by Surgeon Lieut. Hopkin from the ear of a patient in Muharraq in the Persian Gulf. Symptoms were tinnitus and otalgia for two days. After removal a small haematoma was seen on the tympanic membrane and the adjacent wall of the external auditory meatus. T h e insect was a member of the family Lepismatidae. Further identification was not possible because of the damage caused to it during removal from the ear. Silverfish are commonly found in warm, moist environments in kitchens, bathrooms and store-rooms where they feed on food particles, dead insects, moulds and other organic debris. At least 18 species of Collembola have been reported in intimate association with man, often causing a pruritic dermatitis. SCOTTet al. (1962) noted a case of infestation, without dermatitis, of the heads and pubic areas of a Texas family by Orchesella albosa. I am, Sir, Yours faithfully, N. R. H. BURGESS, Lecturer in Medical Entomology, Royal A r m y Medical College, Millbank, 5 March, 1971 London, S.W.1. REFERENCE SCOTT, H. G., WISEMAN, J. S. & STOJANOVICH, C. J. (1962). Ann. ent. Soc. Am., 53, 428. DRUGS AFFECTINGFOETALHAEMOGLOBINSYNTHESIS
SIR,--In the January issue of the Transactions (1971, 65, 78) we reported that the administration to hamsters of prolactin and perphenazine induced the synthesis of foetal haemoglobin or a haemoglobin which behaved electrophoretically like it.