The Pattern for Common Anaemia among Saudi Children

Transcription

1 The Pattern for Common Anaemia among Saudi Children by Mohsen Ali Faris El-Hazmi* PhD and Arjumand Sultan Warsy** PhD *Medical Biochemistry Department and WHO Collaborating Centre for Haemoglobinopathies, Thalassaemias and Enzymopathies, College of Medicine and King Khalid Hospital, King Saud University, Riyadh, Saudi Arabia **Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia Summary Anaemia is of frequent occurrence in children in different parts of the world and poses a signi cant health problem. A few isolated reports indicate that anaemia occurs at a high prevalence rate in Saudi Arabia though the actual prevalence in several regions is not known. The aim of the present study was to determine the prevalence of different types of anaemias in Saudi children in different areas of the country. Blood samples were collected from 5381 children less than 14 years of age, and haematological analysis and red cell indices were determined. The results of haematological parameters were used to group the children as anaemic (Hb < 11.2 g/dl) and non-anaemic (Hb > 11.2 g/dl) and the red cell indices were used to classify the anaemia as hypochromic±microcytic, normochromic± normocytic, and normochromic±macrocytic. The overall prevalence of anaemia in Saudi children was 24.8 per cent. The prevalence was highest in the children from the Eastern province (41.3 per cent) and lowest in the central province (16.5 per cent). Within each province differences were obvious in the prevalence of anaemias in the different areas. The majority of the anaemia in the eastern and south-western provinces was hypochromic±microcytic, while in the north-western and central provinces normochromic±normocytic anaemia occurred most frequently. Macrocytic anaemia was not encountered in any of the screened areas of the central province and many areas of the eastern province. However, in north-western and south-western provinces it occurred at a frequency of 0.15±3.4 per cent. The data show that anaemia is a frequent problem in Saudi children living in different parts of Saudi Arabia and emphasizes the need for nutritional and genetic assessment to determine the nutritional contributions to anaemias and hence the correction of nutritional anaemias by proper dietary intervention. Introduction Anaemia is of frequent occurrence in children in some areas of Saudi Arabia as revealed by a few isolated reports. In a study on preschool children, Sebai et al. 1 reported a prevalence of anaemia of 36 per cent in the Tamnia region in south-western Saudi Arabia. In another study, also in south-western province, anaemia was present in 19.6 per cent of the children screened, 2 while in a study conducted on patients in the south-western province, Sejeny and co-workers indicated that in majority of the children anaemia was due to haemolytic abnormalities. 3 In Bedouin infants, Stevens et al. 4 reported 25 per cent hypochromic anaemia of which less than 10 per cent was believed to be due to iron de ciency and the rest due to a-thalassaemia. In a survey of the pattern of anaemia in the eastern province of Saudi Arabia, anaemia was identi ed in 917/1270 (72.27 per cent) cases. 5 Genetic states, nutritional factors, and Correspondence: Professor Dr Mohsen A. F. El-Hazmi, Medical Biochemistry Department and WHO Collaborating Centre for Haemoglobinopathies, Thalassaemias and Enzymopathies, College of Medicine and King Khalid Hospital, PO Box 2925, Riyadh 11461, Saudi Arabia. parasite infestations were implicated as the major causes of anaemia in Saudi Arabia. 1±9 We conducted a comprehensive survey of the Saudi population living in different areas of Saudi Arabia to determine (1) the overall prevalence of anaemia; (2) the prevalence of different types of anaemias; and (3) the prevalence of different types of anaemias in different areas of Saudi Arabia. In this paper we present our ndings in the different areas and show the signi cant differences in the overall prevalence and types of anaemia in 17 areas screened. Materials and Methods This study was conducted in children <14 years, attending outpatient clinics for minor illnesses in 17 different areas of Saudi Arabia in the four provinces 10 shown in the sketch map (Fig. 1). There were a total of 5381 children screened from different areas and the number from each area is presented in Fig. 1. Blood was drawn by venepuncture in tubes containing ethylene diamine tetraacetic acid (EDTA) or heparin; fresh whole blood was used for the preparation of blood smears, Journal of Tropical Pediatrics Vol. 45 August 1999 q Oxford University Press

2 Fig. 1. Areas screened and the total number of children in each area. which were air dried and used for the study of red cell morphology. The estimation of haematological parameters [total haemoglobin (Hb), red blood cell (RBC) count, white blood cell (WBC) count, and haematocrit (packed cell volume; PCV)] and red cell indices [mean cell volume (MCV), mean cell haemoglobin (MCH), and mean cell haemoglobin concentration (MCHC)], was carried out using Coulter Counter ZF6 with a haemoglobinometer attachment. The results obtained were entered on the computers at the Computer Centre, King Saud University, Riyadh and analysed using the Statistical Analysis System (SAS). The normal reference range (mean 6 SD) for haematological parameters was calculated for Saudi children and the value of total Hb, RBC count, and PCV were used to classify each child as anaemic or non-anaemic. In addition, the values of MCV and MCH were used to classify the anaemia as hypochromic±microcytic, normochromic±normocytic, or normochromic±macrocytic according to the de nition of Dacie and Lewis. 11 Results Anaemia was de ned as `total haemoglobin concentration of less than 11.2 g/dl in children less than 14 years of age'. The children were grouped into anaemic and nonanaemic categories and the overall prevalence of anaemia in Saudi Arabia was found to be 24.8 per cent. The children were grouped according to the province and anaemia prevalence was calculated (Table 1). The highest prevalence of anaemia was in the eastern province and the lowest in the central province. The children were further grouped according to each area to which they belonged and the prevalence was calculated in each area. The total anaemia prevalence in each area is presented in Fig. 2. Within each province signi cant differences were seen. The highest prevalence of anaemia was in Al-Qateef in the eastern province and the lowest in Qaseem in the central province. Further grouping was done according to red cell morphology and the anaemia was classi ed as hypochromic±microcytic, normochromic±normocytic, or normochromic±macrocytic. The overall prevalence of these three types of anaemia in the Saudi children was 11 per cent, 13.3 per cent, and 0.45 per cent, respectively. The distribution of these anaemia types was calculated in each area and the results are presented in Table 2. Hypochromic±microcytic anaemia was the most frequent in Al-Qateef, Al-Hafouf, and Jaizan, while normochromic±normocytic anaemia was more frequent in the majority of other areas. No case of macrocytosis was seen in Riyadh, Al-Qaseem, Sulayel, Al-Qateef, Abha, Jaizan, Najran, Majarda, Yanbu, Makkah, or Safra. In the eastern province one child (1/664, i.e per cent), in the north-western province 15/439 (i.e. 3.4 per cent) children, and in the south-western province 222 Journal of Tropical Pediatrics Vol. 45 August 1999

3 Table 1 Total prevalence of anaemia in children and its pathogenesis in the four provinces of Saudi Arabia Prevalence of type of anaemia Total Total No. anaemic HC±MC NC±NC NC±MC investigated No. (%) No. (%) No. (%) No. (%) Central (16.5) 109 (8.5) 103 (8.0) 0 (0) Eastern (41.3) 174 (26.2) 99 (14.9) 1 (0.15) North-western (21.2) 15 (3.4) 63 (14.3) 15 (3.4) South-western (25.3) 298 (9.9) 451 (15.0) 8 (0.27) Total (24.8) 596 (11.0) 716 (13.3) 29 (0.45) HC±MC ˆ hypochromic±microcytic; NC±NC ˆ normochromic±normocytic; NC±MC ˆ normochromic±macrocytic. Fig. 2. Prevalence (%) of anaemia in areas screened. 8/2997 (i.e per cent) had normochromic±macrocytic anaemia (Table 1). Discussion Interest in the investigation of anaemia developed in the Saudi population during the early 1970s soon after it was realized that sickle cell and a-thalassaemia genes occur at a high prevalence in the eastern province population. 6 The rst study which reported a high prevalence of anaemia was in 1981 by Sebai et al. 1 who investigated 257 preschool children in the Tamnia region in south-western Saudi Arabia and reported a prevalence of 36 per cent. In 1985, El-Hazmi 7 screened the plain and low mountainous areas in Tehamat-Aseer in the south-west and found a wide range of anaemia prevalence, from as low as 2 per cent to as high as 50 per cent in the different areas. In the group studied by Sejeny et al., patients in the south-western province were surveyed, 67 per cent of whom were children. Of this group 50.4 per cent had normochromic anaemia, 47.4 per cent had hypochromic anaemia, and 2.2 per cent had macrocytic anaemia. In a more recent investigation, Stevens et al. 4 investigated the pathogenesis of anaemia in 138 Saudi Bedouin children and found that 25 per cent of the Journal of Tropical Pediatrics Vol. 45 August

4 Table 2 Prevalence of anaemias in Saudi children in different regions Prevalence Hypochromic± Normochromic± Normochromic± No. microcytic normocytic macrocytic Province investigated No. (%) No. (%) No. (%) Central Riyadh (13.6) 39 (7.17) 0 (0) Qaseem (6.83) 34 (7.74) 0 (0) Sulayel (1.68) 30 (10.70) 0 (0) Eastern Al-Hafouf (20.1) 28 (9.39) 1 (3.35) Al-Qateef (31.1) 71 (19.39) 0 (0) North-western Makkah (7.38) 20 (13.42) 0 (0) Khaiber (5.32) 25 (13.29) 9 (4.75) Al-Ula (2.94) 18 (17.64) 6 (5.97) South-western Abha (7.94) 102 (23.83) 0 (0) Jaizan (24.14) 140 (23.97) 0 (0) Najran (6.68) 36 (4.81) 0 (0) Qunfuda (5.09) 26 (12.04) 1 (0.46) Al-Baha (8.25) 30 (10.3) 4 (1.37) Bisha (2.80) 47 (13.2) 3 (0.84) Yanbu (14.68) 29 (16.38) 0 (0) Majarda (0) 32 (22.06) 0 (0) Safra (3.8) 9 (17.30) 0 (0) anaemia was hypochromic. At a well baby clinic in Riyadh, Saudi Arabia, Al-Fawaz surveyed 356 infants (6 months to 2 years) and reported an anaemia prevalence of per cent, of which 27.9 per cent were due to iron de ciency. 8 Al Awamy 5 surveyed 1270 individuals in the eastern province (age not mentioned) and reported a prevalence of 72.2 per cent anaemia in this group of individuals. In the Saudi literature only two cases of pernicious anaemia have so far been reported. Both were Saudi males, one from Al-Qaseem 12 and the other from Wadi Al-Dawasir 13 in the central province, and both were diagnosed in Riyadh. This study is the rst detailed and comparative survey of the different areas of Saudi Arabia and shows that anaemia is present in children in each area though the prevalence differs signi cantly. In addition, the pathogenesis of anaemia shows further differences. In some areas, hypochromic±microcytic anaemia is more common while in others, normochromic±normocytic anaemia occurs at a higher prevalence. The estimated average prevalence of anaemia in young children in developed and developing countries is 12 per cent and 51 per cent, respectively. 14 The total prevalence of anaemia in Saudi children was 24.8 per cent, though the prevalence ranged from 16.5 per cent in the central province to 41.3 per cent in the eastern province, which is more than that in developed countries and considerably less than that in developing countries. However, signi cant differences are seen in anaemia prevalence in different areas, where Al-Qateef and Jaizan almost reach the prevalence reported for developing countries, while Qaseem has a prevalence signi cantly lower than that reported in developed countries. The high prevalence of anaemia in the eastern, northwestern, and south-western provinces can be accounted for, to some extent, by the high prevalence of sickle cell gene and a- and b-thalassaemia genes. 15±21 These genes occur at a high though variable prevalence and may be a major factor in anaemia development in Saudi children. In the central province, where the gene frequency is signi cantly low, the anaemia prevalence is also relatively lower, particularly in Qaseem. It is interesting to note that areas such as the eastern province where the gene frequencies for the haemoglobinopathies and thalassaemia are high, the prevalence of anaemia is also high. This is also re ected in the high frequency of hypochromic±microcytic anaemia, which is caused either by thalassaemias or by iron de ciency. Since in this study no attempt was made to identify the underlying pathology, we suggest the involvement of both thalassaemias and iron de ciency in the development of hypochromic±microcytic anaemia. In all provinces, the normochromic±normocytic anaemias also occurred at high prevalence, with the highest prevalence in the north-western and south-western provinces. In earlier studies various possible factors have been implicated in the development of anaemias in Saudis. These include parasite infestations, nutritional de ciencies, and genetic defects of haemoglobin, that is sickle 224 Journal of Tropical Pediatrics Vol. 45 August 1999

5 cell haemoglobin (HbS) and thalassaemias. 1±8 Glucose- 6-phosphate dehydrogenase (G-6-PD) de ciency also occurs at a high though variable frequency, but is not implicated as a cause of anaemia since under steady-state conditions, the G-6-PD-de cient individuals are not anaemic. However, Matbouli and co-workers in a survey of 41 cases of anaemia reported that 22 per cent had haemolytic anaemia and 10 per cent were G-6-PD de cient. 9 No case of macrocytic anaemia was identi ed in the central province amongst the 1281 children screened and in the eastern and south-western provinces the frequency was 0.15 per cent and 0.25 per cent, respectively where only 1/664 and 8/2997 children had macrocytosis. This clearly indicates that vitamin B 12 and folate de ciency are not of common occurrence and this can be related to the dietary habits of the people. This also con rms previous reports that macrocytic anaemia is of rare occurrence. 12,13 However, in the north-western province, several children 15/439 (3.4 per cent) had macrocytosis. This indicates that macrocytosis is not so rare and careful investigation of anaemia must be carried out. A very interesting nding was the wide variation in the prevalence of each type of anaemia in each area within a province. This suggests that there is no speci c pattern common to the Saudi provinces. All types of anaemias exist, with higher prevalence of hypochromic microcytic anaemia in some areas and normochromic± normocytic anaemia in others. Since the treatment is dependent to a large extent on the nature and causes of anaemia, it is necessary that complete differential diagnosis of the anaemia must be made for a successful outcome of the treatment strategy. We are in the process of further studies to determine the factors and their contribution to anaemia in Saudi children in different provinces and this should provide a clear documentation of the pathological mechanisms involved in the development of anaemia in Saudi children. References 1. Sebia ZA, El-Hazmi MAF, Serenius F. Health pro le of preschool children in Tamnia villages, Saudi Arabia. Saudi Med J 1981; 2: 68± El-Hazmi MAF, Sebai ZA. Laboratory tests pro le for preschool children at Tamnia (Asseer province). Saudi Med J 1981; 2: 198± Sejeny SA, Khurshid M, Kamil A, Khan FA. Anaemia survey in the south-western region of Saudi Arabia. Proceedings of the Fourth Saudi Medical Conference. King Faisal University, Dammam, 1980; 124±8. 4. Stevens DW, Wainscoat JS, Ketley N, Timms P, Ayoub D, Shah R. The pathogenesis of hypochromic anaemia in Saudi infants. J Trop Pediatr 1989; 35:301±5. 5. Al-Awamy BH, Ibrahim A, Naeem MA, Ahmed MA. Pattern of anaemia in the eastern province of Saudi Arabia. 8th Saudi Medical Conference, Riyadh, 30 October± 3 November 1983: 15 (Abstract). 6. Lehmann H, Maranjian G, Mourant AE. Distribution of sickle cell haemoglobin in Saudi Arabia. Nature 1963; 198: 492±3. 7. El-Hazmi MAF. The red cell genetics and environmental interactions. A Tehamat-Aseer pro le. Saudi Med J 1985; 6: 101± Al-Fawaz IM. Surveillance for iron de ciency anaemia at well baby clinic in Riyadh, Saudi Arabia. Saudi Med J 1993; 14: 27± Matbouli S, Farani H, Omar A. Haemolytic anaemias: patterns of disease in the western region. Proceedings of The Seventh Saudi Medical Meeting, Damma, Saudi Arabia, 3±6 May 1982: 75 (Abstract). 10. Malaria Control Program. Ministry of Health, Saudi Arabia. Bahr-Al-Allum Press, Riyadh, Dacie JV, Lewis SM. Practical Haematology. Churchill Livingstone, London, Mohamed AE, Madkour MM. Pernicious anaemia in a Saudi male. Saudi Med J 1984; 5: 201± Mohammed AR, Al-Karawi M. A second case of pernicious anaemia in Saudis. Saudi Med J 1986; 7: De Maeyer EM. Preventing and Controlling Iron De ciency Anaemia Through Primary Health Care. World Health Organization, Geneva. 15. El-Hazmi MAF. The distribution and nature of hemoglobinopathies in Arabia. In: Winter WP (ed.), Hemoglobin Variants in Human Populations. CRC Press Inc., Boca Raton, Florida, 1987; 65± El-Hazmi MAF. Haemoglobinopathies, thalassaemias and enzymopathies in Saudi Arabia: the present status. Acta Haematol 1987; 78: 130± El-Hazmi MAF, Jabbar FA, Al-Faleh FZ, Al-Swailem AR, Warsy AS. Pattern for sickle cell, thalassaemia and glucose-6-phosphate dehydrogenase de ciency genes in north-western Saudi Arabia. Hum Hered 1991; 41: 26± El-Hazmi MAF. Haemoglobinopathies, thalassaemias and enzymopathies in Saudi Arabia. Saudi Med J 1992; 13: 488± El-Hazmi MAF. Genetic red cell disorders in Saudi Arabia ± a multifaceted problem. Hemoglobin 1994; 18: 257± El-Hazmi MAF, Warsy AS. Hemoglobinopathies in Arab Countries. In: Teebi AS, Farag TI (eds), Genetic Disorders among Arab Populations, Oxford Monographs on Medical Genetics No 30. Oxford University Press, New York, 1996; 83± El-Hazmi MAF. Haemoglobin disorders: a pattern for thalassaemia and haemoglobinopathies in Arabia. Acta Haematol 1982; 68: 43±51. Journal of Tropical Pediatrics Vol. 45 August