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Use of the weight-for-height (Nabarro) chart to screen young children for wasting
664
TRANSACTKW
DF THE
ROYALSOCIETY OFTROPICAL MEDICINE
AND HYGIENE (1986) 80
Correspondence to the Editor
Cerastes vipera envenoming-a report of seven cases Cerastes vitma XV) of the Viwridae is found in
sandy areasof Africa and the Sind; and Negev deserts. CV is the smallest poisonous snake in Israel; its maximal length is about 30 cm. It is active at night and usually spends the day buried in the sand (MOORE et al., 1980). The venom contains phospholipidase proteinase and transaminase activities (MOHAMEDet al., 1969a; LABIB et al., 1981a)and shows a procoagulant activity probably due to activation at multiple sites in the blood coagulation cascade.At higher venom concentrations, fibrinogenolytic activity is present (BOFFA et al., 1972; LABIB er al., 1981b). The chemistry
of
CV venom and its effects on laboratory animals have been known for several years (LABIB et al., 198 lb; MOHAMED et al., 1969b, 1977).
Our medical centre is located in the Negev desert of Israel. In a retrospective chart review of all admissions for snake bites during the years 1980-1981, 42 cases were attributed to poisonous snakes, seven of which were positively identified as CV bites. Of these seven, five were snake collectors. all of whom suffered finaer bites while handling the snakes. The remaining tko were victims of an accidental encounter. The patients ranged from age 16 to 34 years. In six the envenoming resulted in a minor local swelling and a small haematoma. Only one patient demonstrated minor abnormalities in his coagulation profile (prolonged prothrombin time and low fibrinogen); this was not associated with clinical evidence of bleeding. Complete blood count, urinalysis, renal and liver &tnction tests as well as ECG were normal in all patients. One subject, a 20-year-old snake collector with previously known hypersensitivity to Hymenoptera venom, had been bitten several times in the past by various snakes including viperideas. He developed stridor and bronchospasmthree hours after CV bite which responded to corticosteroids and bronchodilators. This patient had a normal coagulation profile. Fasciotomy and antibiotics were necessary because of several local reaction with secondary infection. Other patients did not require therapy and were discharged from hospital within three days. Desnite auite broad distribution of CV, only two documented cases of human victims have -been reported (ZIMMERMAN et al., 1981), both with only mild coagulation disturbances and without systemic signs. The group reported here had a remarkably uneventful clinical course, excluding the patients with known hypersensitivity. - The absence‘of systemic manifestations and coagulopathy in the published cases may be explained by assuming a low dose of venom per body-weight of the victim, or due to the high incidence of “dry bite”, namely a bite with little or no iniection of venom. We conclude that CV envenoming, while possibly danaerous in a child. is relativelv harmless in an adult and&e use of antivenin is not justified unless there is bleeding or laboratory evidence of worsening haemostatic failure.
N. A. A. A.
BEN-BARUCH PORATH KLEINER-BAUMGARTEN
KEYNAN
Dept. of Medicine “B”, Soroka University Hospital and Fadty of Health Sciences, Ben Guriun University of the Negev, Ber Skeva, Israel
References
Boffa, M. C., Josso,F. & Boffa, G. A. (1972). The action of Viperu aspis venom on blood clotting factors and platelets. Thrombosis et Diathesis Haemorrhagica, 27, 8-18. Labib, R. S., Awad, E. R. & Farag, N. W. (1981a).Proteases of Cerastescerastes(Egyptian sand viper) and Cerustes vipera (Sahara sand viper) snake venoma. Toxicon, 19,
73-83.
Labib, R. S., Azab, N. H. & Farag, N. W. (1981b). Effects of Cerastescenzsres(Egyptian sand viper) and Cerasces vipera (Sahara sand viper) snake venoms on blood coagulation: separation of coagulant and anticoagulant factors and their correlation with arginine esteraseand protease activities. Toxicon, 19, 85-94. Mohamed, A. H., Kamel, A. & Ayobe, M. H. (1969a). A and B activitiesof Egyptian Studies of phospholipase snakevenomsanda scorpiontoxin. Toxicon, 6,293-298. Mohamed, A. H., Kamel, A. 81 Ayobe, M. H. (1%9b). Someenzymatic activities of Egyptian snake venoms and a scorpion venom. Toximn, 7, 185-188. Mohamed, A. H., Saleh, A. M., Abmed, S. & El-Maghraby, M. (1977). Effect of Cerasrestipera snake venom on blood and bone marrow cells. Toxkm, 15, 35-40. Moore, M. G. (Editor). (1980). In: PuisotwusSnakes of the World (1st edit.). Tunbridge Wells, U.K.: Castle House Publications Ltd., p. 83. Zimmerman, J., Mann, G., Kaplan, H. Y. & Sagher U. (1981). Envenoming by Cerasfesviperu-a report of)two cases. Transactions of the Royal Society of Tropical Medicine and Hygiene, 75, 702-705.
Accepted for publication 24th October, 1985.
Use of the weight-for-height (Nabarro) chart to screen young children for wasting CAMPBELLand his colleagues (1985) present interesting data on the nutritional status of children in Tanzania, Zambia and Zaire, which show a low prevalence of wasting among children in the three countries. Such data provide a valuable perspective for evaluating the severity of the famine-related nutritional status of children in surrounding countries. The similaritv of their nutritional status distribution patterns to those of American children on whom the WHO reference curves are based also helus
confirm the validity of maintaining a single growth reference curve for all children. We feel, however, that the authors’ conclusions regarding the ability of the portable measuring chart to assess accurately nutritional status are both incorrect and misleading. To examine the sensitivity of the
TRANSACTIONS OF THE
ROYALSOCIETY OF TROPICALMEDICINEAND HYGIENE(1986)80 CORRESPONDENCE
board to detect the appropriate percentage of median standard weight for height? they compared findings obtained with the chart wtth percentage of median determined with NCHS tables. However, the height measurements they used for the NCHS tables were read simultaneously with the nutritional status decile from the same Nabarro chart. What thev therefore assessedwas the Nabarro chart’s correspondencewith NCHS values rather than accuracv of the board correctly to determine height (i.e., nutritional status). In fact, such correspondence between the Nabarro chart and the NCHS tables could have been assessed without doing a survey. Their study fails to answer the more essential question of whether data generated with that version of the Nabarro chart is asaccurate as data obtained using conventional measurements of height obtained with a standard height board. We recently performed such a comparison during a random survey of 660 children in two regions of Mauritania most severely affected by the 1983-84 drought (BINKIN et al., 1985). We found that although the specificity of the chart was high, its sensitivity was less than 60% when the chart was used in a fashion similar to that employed by CAMPBELL et al. (1985); this sensitivity was increased to 88% only when the chart was used with a fixed footboard and moveable headboard. Although the chart may be useful for rapidly screening individuals for feeding programmes or for following the status of individual children, we feel that it has limited use in populationbased field surveys such as those conducted by Campbell et al. Field surveys are costly and timeconsuming to conduct. The modest additional cost of purchasing and training workers to use a standard height board is well justified by the increased quality of the height data obtained. Additionally, the chart characterizes nutritional status in a categorical rather than continuous fashion. Lack of a continuous variable to express nutritional status seriously limits analysis of the data.,particularly in regard to the use of multivariate statisucal techniques. Thus, although the chart may be useful for screening purposes, we concluded that field surveys on which major policy and resources allocation decisions are to be based should maximize the quality and quantity of information contained by including a more accurate determination of height. NANCY J. BINKIN PHILLIP NIEBURG Division of Nutrition, Center for Health Promotion and Education, Department of Health & Human
Setvices, Centers for Disease Control, Atlanta GA 30333, USA References Binkin, N. J., Goldman, H. W., Brown, B. H. & Nieburg, I’. (1985). The weight-for-height chart: Is it accurate enough for field surveys?Journal of Tropical Pediatrics, 31, 152-157. Campbell, J. L., Cutting, W. A. M., Elton, R. A., Minton
E. J. & Spreng, J. (1985). The portable Nabarro weight-height anthropometric nutrition assessment chart. A field trial in three countries in Africa. Transac-
665
tions of the Royal Society of Tropical Medicine and Hygiene,
79, 409-411.
Accepted for publication 21st December, 1985. Use of the weight-for-height (Nabarco) chart to screen young children for wasting: a reply
Drs. Binkin & Nieburg have made someinteresting observations about our paper (CAMPBELL et al., 1985) based partly on their own surveys in Mauritania (BINKIN et aE., 1985). One important difference between the surveys was that ours was specifically intended to field test the more portable and slim version of the weight-forheight chart. This required genuine mobility since the medical students undertaking the survey had to travel on foot, cycle, motor-cycle, canoeand crowded public transport. On one occasion the plant with weight chart in position was used as a paddle when the proper paddle had fallen into the Zambezi. The addition of a fixed foot board and a moveable head board would clearly limit transportability. Two modifications which increase the accuracy of measurement with somecost to mobility are a small lixed foot board and
TRANSACTKW
DF THE
ROYALSOCIETY OFTROPICAL MEDICINE
AND HYGIENE (1986) 80
Correspondence to the Editor
Cerastes vipera envenoming-a report of seven cases Cerastes vitma XV) of the Viwridae is found in
sandy areasof Africa and the Sind; and Negev deserts. CV is the smallest poisonous snake in Israel; its maximal length is about 30 cm. It is active at night and usually spends the day buried in the sand (MOORE et al., 1980). The venom contains phospholipidase proteinase and transaminase activities (MOHAMEDet al., 1969a; LABIB et al., 1981a)and shows a procoagulant activity probably due to activation at multiple sites in the blood coagulation cascade.At higher venom concentrations, fibrinogenolytic activity is present (BOFFA et al., 1972; LABIB er al., 1981b). The chemistry
of
CV venom and its effects on laboratory animals have been known for several years (LABIB et al., 198 lb; MOHAMED et al., 1969b, 1977).
Our medical centre is located in the Negev desert of Israel. In a retrospective chart review of all admissions for snake bites during the years 1980-1981, 42 cases were attributed to poisonous snakes, seven of which were positively identified as CV bites. Of these seven, five were snake collectors. all of whom suffered finaer bites while handling the snakes. The remaining tko were victims of an accidental encounter. The patients ranged from age 16 to 34 years. In six the envenoming resulted in a minor local swelling and a small haematoma. Only one patient demonstrated minor abnormalities in his coagulation profile (prolonged prothrombin time and low fibrinogen); this was not associated with clinical evidence of bleeding. Complete blood count, urinalysis, renal and liver &tnction tests as well as ECG were normal in all patients. One subject, a 20-year-old snake collector with previously known hypersensitivity to Hymenoptera venom, had been bitten several times in the past by various snakes including viperideas. He developed stridor and bronchospasmthree hours after CV bite which responded to corticosteroids and bronchodilators. This patient had a normal coagulation profile. Fasciotomy and antibiotics were necessary because of several local reaction with secondary infection. Other patients did not require therapy and were discharged from hospital within three days. Desnite auite broad distribution of CV, only two documented cases of human victims have -been reported (ZIMMERMAN et al., 1981), both with only mild coagulation disturbances and without systemic signs. The group reported here had a remarkably uneventful clinical course, excluding the patients with known hypersensitivity. - The absence‘of systemic manifestations and coagulopathy in the published cases may be explained by assuming a low dose of venom per body-weight of the victim, or due to the high incidence of “dry bite”, namely a bite with little or no iniection of venom. We conclude that CV envenoming, while possibly danaerous in a child. is relativelv harmless in an adult and&e use of antivenin is not justified unless there is bleeding or laboratory evidence of worsening haemostatic failure.
N. A. A. A.
BEN-BARUCH PORATH KLEINER-BAUMGARTEN
KEYNAN
Dept. of Medicine “B”, Soroka University Hospital and Fadty of Health Sciences, Ben Guriun University of the Negev, Ber Skeva, Israel
References
Boffa, M. C., Josso,F. & Boffa, G. A. (1972). The action of Viperu aspis venom on blood clotting factors and platelets. Thrombosis et Diathesis Haemorrhagica, 27, 8-18. Labib, R. S., Awad, E. R. & Farag, N. W. (1981a).Proteases of Cerastescerastes(Egyptian sand viper) and Cerustes vipera (Sahara sand viper) snake venoma. Toxicon, 19,
73-83.
Labib, R. S., Azab, N. H. & Farag, N. W. (1981b). Effects of Cerastescenzsres(Egyptian sand viper) and Cerasces vipera (Sahara sand viper) snake venoms on blood coagulation: separation of coagulant and anticoagulant factors and their correlation with arginine esteraseand protease activities. Toxicon, 19, 85-94. Mohamed, A. H., Kamel, A. & Ayobe, M. H. (1969a). A and B activitiesof Egyptian Studies of phospholipase snakevenomsanda scorpiontoxin. Toxicon, 6,293-298. Mohamed, A. H., Kamel, A. 81 Ayobe, M. H. (1%9b). Someenzymatic activities of Egyptian snake venoms and a scorpion venom. Toximn, 7, 185-188. Mohamed, A. H., Saleh, A. M., Abmed, S. & El-Maghraby, M. (1977). Effect of Cerasrestipera snake venom on blood and bone marrow cells. Toxkm, 15, 35-40. Moore, M. G. (Editor). (1980). In: PuisotwusSnakes of the World (1st edit.). Tunbridge Wells, U.K.: Castle House Publications Ltd., p. 83. Zimmerman, J., Mann, G., Kaplan, H. Y. & Sagher U. (1981). Envenoming by Cerasfesviperu-a report of)two cases. Transactions of the Royal Society of Tropical Medicine and Hygiene, 75, 702-705.
Accepted for publication 24th October, 1985.
Use of the weight-for-height (Nabarro) chart to screen young children for wasting CAMPBELLand his colleagues (1985) present interesting data on the nutritional status of children in Tanzania, Zambia and Zaire, which show a low prevalence of wasting among children in the three countries. Such data provide a valuable perspective for evaluating the severity of the famine-related nutritional status of children in surrounding countries. The similaritv of their nutritional status distribution patterns to those of American children on whom the WHO reference curves are based also helus
confirm the validity of maintaining a single growth reference curve for all children. We feel, however, that the authors’ conclusions regarding the ability of the portable measuring chart to assess accurately nutritional status are both incorrect and misleading. To examine the sensitivity of the
TRANSACTIONS OF THE
ROYALSOCIETY OF TROPICALMEDICINEAND HYGIENE(1986)80 CORRESPONDENCE
board to detect the appropriate percentage of median standard weight for height? they compared findings obtained with the chart wtth percentage of median determined with NCHS tables. However, the height measurements they used for the NCHS tables were read simultaneously with the nutritional status decile from the same Nabarro chart. What thev therefore assessedwas the Nabarro chart’s correspondencewith NCHS values rather than accuracv of the board correctly to determine height (i.e., nutritional status). In fact, such correspondence between the Nabarro chart and the NCHS tables could have been assessed without doing a survey. Their study fails to answer the more essential question of whether data generated with that version of the Nabarro chart is asaccurate as data obtained using conventional measurements of height obtained with a standard height board. We recently performed such a comparison during a random survey of 660 children in two regions of Mauritania most severely affected by the 1983-84 drought (BINKIN et al., 1985). We found that although the specificity of the chart was high, its sensitivity was less than 60% when the chart was used in a fashion similar to that employed by CAMPBELL et al. (1985); this sensitivity was increased to 88% only when the chart was used with a fixed footboard and moveable headboard. Although the chart may be useful for rapidly screening individuals for feeding programmes or for following the status of individual children, we feel that it has limited use in populationbased field surveys such as those conducted by Campbell et al. Field surveys are costly and timeconsuming to conduct. The modest additional cost of purchasing and training workers to use a standard height board is well justified by the increased quality of the height data obtained. Additionally, the chart characterizes nutritional status in a categorical rather than continuous fashion. Lack of a continuous variable to express nutritional status seriously limits analysis of the data.,particularly in regard to the use of multivariate statisucal techniques. Thus, although the chart may be useful for screening purposes, we concluded that field surveys on which major policy and resources allocation decisions are to be based should maximize the quality and quantity of information contained by including a more accurate determination of height. NANCY J. BINKIN PHILLIP NIEBURG Division of Nutrition, Center for Health Promotion and Education, Department of Health & Human
Setvices, Centers for Disease Control, Atlanta GA 30333, USA References Binkin, N. J., Goldman, H. W., Brown, B. H. & Nieburg, I’. (1985). The weight-for-height chart: Is it accurate enough for field surveys?Journal of Tropical Pediatrics, 31, 152-157. Campbell, J. L., Cutting, W. A. M., Elton, R. A., Minton
E. J. & Spreng, J. (1985). The portable Nabarro weight-height anthropometric nutrition assessment chart. A field trial in three countries in Africa. Transac-
665
tions of the Royal Society of Tropical Medicine and Hygiene,
79, 409-411.
Accepted for publication 21st December, 1985. Use of the weight-for-height (Nabarco) chart to screen young children for wasting: a reply
Drs. Binkin & Nieburg have made someinteresting observations about our paper (CAMPBELL et al., 1985) based partly on their own surveys in Mauritania (BINKIN et aE., 1985). One important difference between the surveys was that ours was specifically intended to field test the more portable and slim version of the weight-forheight chart. This required genuine mobility since the medical students undertaking the survey had to travel on foot, cycle, motor-cycle, canoeand crowded public transport. On one occasion the plant with weight chart in position was used as a paddle when the proper paddle had fallen into the Zambezi. The addition of a fixed foot board and a moveable head board would clearly limit transportability. Two modifications which increase the accuracy of measurement with somecost to mobility are a small lixed foot board and