Over two years cord blood from 27 879 babies was screened for glucose-6-phosphate dehydrogenase (G6PD) deficiency. The overall incidence was 3.1% in boys and 1.6% in girls. Sixty nine babies had severe jaundice (bilirubin concentration greater than 380 mmol/l (20 mg/100 ml], and exchange transfusion was performed. Parents were given written and verbal instructions to avoid herbs and drugs that trigger kernicterus, which reduced the incidence of kernicterus and thereby prevented mental retardation. G6PD deficiency is common in all three ethnic groups (Malays, Chinese, and Indians) in Malaysia and screening is recommended.
In this paper, urolithiasis is remarked from the standpoint of descriptive epidemiology, which examines the frequency distribution of a given disease in a population in terms of time, place and personal characteristics with an aim of identifying risk factors or some clues to the etiology. Some descriptive epidemiological features of urolithiasis are summarized. Prevalence rate is around 4% (4-15% in males and 4-8% in females), and incidence rate varies from area to area: 53.2 per 100,000 population in 1975 in Japan, 364 in 1976 in Malaysia, and 540 in 1979 in West Germany. Prevalence and/or incidence rates have, in general, increased in the developed countries since World War II and in the developing countries as well, where upward trends are quite analogous to the trends observed in the nineteenth century in Europe. Recurrence rate, which is much higher in males than in females, ranges from 31% to 75%, depending on the follow-up periods. In the industrialized countries, upper urinary (renal and ureteral) stones account for more than 90% of total stones, which are ordinarily calcium complexes in composition. More common in the developing countries are lower urinary (bladder and urethral) stones, frequently composed of magnesium ammonium phosphate, which indicates a close association with urinary tract infections. Variations in frequency are evident by season and by region within a country. Age and sex differentials in urinary stone formers are substantial: more common in males 30-40 years old in the industrialized countries and in children under 10 years old in the developing countries. Racial differentials are also noted; blacks appear to suffer less frequently than whites. Stone formers experience more frequent episodes of stone formation in their family members, particularly father and brothers, than non-stone formers. These findings on racial differentials and family preponderance suggest the possible relevance of genetic factors in stone formation. Stone formers are more likely to be occupationally sedentary and socially affluent. This observation and differentials by age and sex suggest the probable relevance of lifestyle and environmental factors in stone formation. Epidemiological factors incriminated for stone formation will be discussed in a separate paper.
Data on 1800 term babies, 600 from each of the Chinese, Malay and Indian racial groups, were used to identify the factors affecting birthweight in Singapore. After adjustment for gestation, maternal height and other variables, the mean Indian birthweight was 100 g less than for the Chinese (P less than 0.001), 0.001), while the Malays averaged 33 g less than the Chinese. The shortfall in Indian birthweight is thought to be due, at least partly, to environmental factors.
Matched MeSH terms: Continental Population Groups*
Over an 18 month period, 34,495 livebirths were delivered in the Kuala Lumpur Maternity Hospital. 36 neonates (1.044 per 1000 livebirths) had Down's syndrome. The observed rates of Down's syndrome per 1000 livebirths by single year intervals of maternal age were calculated. By using the discontinuous slope model, our study showed that the incidence of Down's syndrome among the Malaysian liveborns increased markedly when the maternal age exceeded 35 years. This study also suggested that the Malay mothers had increased risk of producing babies with Down's syndrome at a later age than the Chinese and the Indians. However, a larger number of babies in each racial group needs to be studied to confirm this.
126 Malaysian children, 65 boys and 61 girls from higher income families were followed-up regularly from birth to six years of age in the University Hospital, Kuala Lumpur. Their physical growth, development, dietary and illness patterns were measured at each visit. The study confirms the observations of previous studies that boys are, on the average, heavier and taller than girls and that Asians are smaller in size with relatively shorter legs compared with children of European ancestry. These racial differences are due to a combination of genetic and environmental differences. Since there are genetic differences in the size and shape of children, standards applicable to the specific population should be used to obtain the best results when assessing the health of an individual child. The growth charts presented in this paper can be used as standards to monitor the growth of Asian infants and pre-school children.
In order to examine whether erythrocyte membrane handling of sodium is influenced by factors other than hypertension, measurements of red cell sodium transport were studied in one hundred normotensive volunteers. Erythrocyte sodium content was found to increase with increasing age, body weight and mean arterial pressure (MAP). It is also significantly correlated with age, body weight and MAP. Total sodium efflux was found to be reduced and negatively correlated with age and body weight. A reduction in ouabain-sensitive sodium efflux was also observed with increasing age and body weight. In males, the rate of ouabain-sensitive sodium efflux is higher than in females. Race was found to have no effect on erythrocyte electrolyte content and cationic flux rates of subjects. These data suggest that when studies in hypertension are going to be carried out, control subjects carefully matched for age, body weight and sex should be used if confounding results are not to be obtained.
Matched MeSH terms: Continental Population Groups*
Prediction equations for peak expiratory flow rate (PEFR) of Malay, Chinese and Indian children were obtained by analysing 1020 PEFR recordings of children free of respiratory symptoms and illnesses. Boys had significantly higher PEFR than girls. For both sexes the highest levels of PEFR were observed in Malays and the lowest in Indians. The differences between Malay and Chinese boys were not statistically significant but the levels of PEFR for Malay and Chinese boys were significantly higher than those for Indian boys. In girls the differences among the ethnic groups were not statistically significant. Although ethnic differences were observed in boys these differences might not be clinically important. A common prediction equation for each sex should be both practical and accurate. When compared with predicted levels for white American and Australian children the predicted levels of PEFR of Malaysian children were found to be lower; these differences could be clinically important and the use of standards for Western children when assessing Malaysian children might not be appropriate.
Matched MeSH terms: Continental Population Groups*
Apolipoprotein(a) [apo(a)] exhibits a genetic size polymorphism explaining about 40% of the variability in lipoprotein(a) [Lp(a)] concentration in Tyroleans. Lp(a) concentrations and apo(a) phenotypes were determined in 7 ethnic groups (Tyrolean, Icelandic, Hungarian, Malay, Chinese, Indian, Black Sudanese) and the effects of the apo(a) size polymorphism on Lp(a) levels were estimated in each group. Average Lp(a) concentrations were highly significantly different among these populations, with the Chinese (7.0 mg/dl) having the lowest and the Sudanese (46 mg/dl) the highest levels. Apo(a) phenotype and derived apo(a) allele frequencies were also significantly different among the populations. Apo(a) isoform effects on Lp(a) levels were not significantly different among populations. Lp(a) levels were however roughly twice as high in the same phenotypes in the Indians, and several times as high in the Sudanese, compared with Caucasians. The size variation of apo(a) explains from 0.77 (Malays) to only 0.19 (Sudanese) of the total variability in Lp(a) levels. Together these data show (I) that there is considerable heterogeneity of the Lp(a) polymorphism among populations, (II) that differences in apo(a) allele frequencies alone do not explain the differences in Lp(a) levels among populations and (III) that in some populations, e.g. Sudanese Blacks, Lp(a) levels are mainly determined by factors that are different from the apo(a) size polymorphism.
Matched MeSH terms: Continental Population Groups/genetics*
An excess of male over female deaths is characteristic of modern national populations, whereas in some high-mortality societies female mortality exceeds that of males. Among the Semai Senoi, a Malaysian Orang Asli ("aboriginal") population, women experienced higher mortality than males in the decades before 1969. This differential occurred in all age classes older than 15 years so that the sex ratio progressively increased with age. A recent (1987) restudy of the Semai population found that sex-specific differential mortality is much reduced. A comparison of the 1969 and 1987 life tables shows a sharp shift in the sex ratios of mortality for the post-15-year-old age classes (the geometric means of age classes 15-44 were 0.768 in 1969 and 0.997 in 1987) so that male and female expectations of further life at age 15 are now nearly identical. In contrast to the best-known cases of high female mortality (mostly in South Asia), Semai sex differential mortality does not include the childhood ages. The Semai have traditionally been relatively sexually egalitarian, and sex bias in care has not occurred. Analysis of sex-specific causes of death for the pre-1969 population suggests that maternal mortality is the major cause of the excess female deaths. The reduced number of maternal deaths seems largely due to better health care, particularly the availability of hospital services. Interestingly, the reduction in female mortality has occurred simultaneously with increased fertility, and overall mortality has continued at relatively high levels (eO less than 36). Thus, rather than forming a component of a unitary demographic transition, declining sex differences in mortality can be accounted for by a specific factor, better maternal care.
Two hundred and seventy-five Orang Asli volunteers living in nine villages in the Pos Legap Valley of Perak State, peninsular Malaysia, participated in a prospective study designed to characterize the epidemiological, parasitological, and entomological characteristics of Plasmodium falciparum, P. vivax, and P. malariae malaria transmission. Prevalence rates for the three plasmodial species at initiation of the study ranged from 56% in the 0-4-year-old age group to 0% in individuals over the age of 40. Entomological surveys were conducted, enabling us to determine mosquito salivary gland-positive rates and entomological inoculation rates of 1.2 infectious mosquito bites per person per month for P. falciparum, 2.4 for P. vivax, and 0.3 for P. malariae. Cumulative incidence rates over the 16 weeks of the study, following radical cure of all volunteers, were 22.5% for P. falciparum, 12.7% for P. vivax, and 1.5% for P. malariae. The median baseline antibody titer against the immunodominant repetitive B cell epitope of P. falciparum or P. vivax circumsporozoite protein was significantly higher for volunteers who did not become parasitemic. Volunteers were selected for further study if they had evidence of being challenged with P. falciparum sporozoites during the study, based on a two-fold or greater increase in antibody titer against the immunodominant repetitive B cell epitope of the circumsporozoite protein. Resistance to infection was seen in six of 10 individuals who had high (greater than 25 OD units) baseline ELISA titers, compared with only three of 24 individuals who had low baseline ELISA titers (chi 2 P less than 0.02). A similar analysis for P. vivax did not show a significant correlation.
The socioeconomic, social behaviour and dietary pattern of 100 Aborigines and Malays, aged 7 years and above from Kuala Pangsoon, Selangor Malaysia were studied by using pretested questionnaires. The individual's dietary intake was estimated using 24 hour recall for 3 days within one week which was chosen at random. The household's food consumption pattern was evaluated using food frequency questionnaires. There was no difference in the total income per month for both communities, as well as the educational attainment of the head of household and property ownership. The proportion of smokers among the Aborigines and the Malays was almost similar (33%) but the percentage of heavy smokers was higher among Aborigines compared to Malays. One third of the Aborigines regularly consume alcohol. The main energy source for both communities was rice, sugar and cooking oil whilst fish and eggs were the main sources of protein. More than 50% of the Aborigines take tapioca or tapioca leaves at least once a week compared to less than 20% among the Malays. There was no significant different in the intake of energy, protein and carbohydrate between the groups. However, the Aborigines take less fats and iron compared to the Malays. The difference in terms of smoking, drinking habit and dietary intake may determine the distribution of disease in both communities.
Food-borne parasitic zoonoses are emerging as major public health problems in most countries because they are widespread and pose a medical challenge. Not only are they important from an economic standpoint, but they also cause severe sequalae in all those affected. The extent of parasitic zoonoses in Malaysia is considered a "tip of the iceberg" problem. Cases of zoonotic diseases, like porocphaliasis, sarcocystosis, toxoplasmosis, cysticercosis, hydatidosis, echinostomiasis, and gnathostomiasis are traced and documented. An epidemiologic reassessment of methods is suggested to determine the extent of these parasitoses in Malaysia.
There have been changes in the national policy regarding population growth in Malaysia from 1982. This report studies the changes in contraceptive practice among the three racial groups in this country, i.e. Malays, Chinese and Indians, over a 5-year period with an interval of 10 years. This is a retrospective study based on the attendance at the same family planning clinic in an urban setting. The striking change noted is the change in the racial composition of contraceptive usage in the two study periods with a shift from the Chinese being predominant in 1975-1979 to Malays in 1985-1989. There was no change among the numbers of Indians using contraception. The results also reveal a significant trend of change for users of the pill and those undergoing sterilization. There were no significant changes in IUD, condom and injectable usage. The study demonstrates how national policies, level of education and rural urban migration can significantly alter contraceptive practice.
A prospective study was carried out on 50 patients who had their fetal weight estimated by 3 clinicians of different seniority and compared to the ultrasound estimated fetal weights using 3 different formulas. All the patients delivered within 24 hours of their clinical and ultrasound estimates. A wide range of birth-weights (1,800-4,500 g) was estimated among the 3 different races (Malay, Chinese and Indians). The results showed that there was no significant difference in birth-weight estimation amongst the 3 clinicians as well as between the 3 ultrasound formulas used. There was however significant difference between these 2 groups when compared with the actual birthweight with clinical estimation being superior to ultrasound estimation in our population. This level of significance did not extend beyond 4,000 g fetal weight (actual) thus making both clinical and ultrasound estimation of fetal weight equally accurate after 4,000 g. This has important implications for developing countries where there is a lack of technologically advanced ultrasound machines capable of doing sophisticated functions like fetal weight estimations but has experienced clinicians who could perform this function equally well if not better.
The malaria parasite rates and densities were compared in 79 ovalocytic-normocytic pairs of Malayan Aborigines matched for age, sex, proximity of residence to each other, and use of bed nets when sleeping in their jungle settlement in central Peninsular Malaysia. Malaria infection was determined from thick and thin Giemsa-stained blood films collected monthly for a period of six months. Blood films from ovalocytic individuals were found to be positive for malaria less often than in persons with normal red blood cells (P less than 0.05). Malaria infections per 100 person-months at risk were 9.7 in the ovalocytic group compared with 15.19 in the normocytic group. Among individuals parasitemic at any time, heavy infections (greater than or equal to 10,000 parasites/mm3 of blood) with Plasmodium falciparum, P. vivax, and P. malariae were encountered only in normocytic subjects, which comprised approximately 12.5% of the malaria-positive individuals in this group. In an earlier survey of 629 settlers that identified subjects for the above study, the prevalence of ovalocytosis was found to increase significantly with age. The above field observations support the view that ovalocytic individuals might have a survival advantage in the face of malaria. Consideration of the ovalocytic factor is indicated in future evaluations of malaria control measures in areas where ovalocytosis is prevalent.
An enzyme-linked immunosorbent assay using excretory-secretory antigens of the second stage larvae maintained in vitro was used to determine the seroprevalence of Toxocara antibodies in Orang Asli (aborigines) of Peninsular Malaysia. The mean + 3 SD optical density of 30 healthy subjects was used as the cut-off point. Overall prevalence was found to be 31.9%. No significant relationship was found between positive rates with sex and age groups, though children between 0 to 9 years recorded the highest positive rates. Eosinophil counts were found to be closely related to the proportion of positivity to toxocaral infection and mean optical densities. There was some degree of cross-reaction with Trichuris trichuria positive sera.
Spirometry was performed on 614 female subjects ranging in age from 13 to 69 years and comprising all the main races in Malaysia. They were divided into six age categories. Mean forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were 2.51 +/- 0.02 and 2.31 +/- 0.02l, respectively. Both FVC and FEV1 correlated negatively with age. Regression analysis revealed an age-related decline in FVC of 220 ml per decade of life. Multiple stepwise regression of the data for the prediction of an individual's FVC above the age of 20 years gave an equation: FVC(l) = 0.0312 (height)-0.022 (age)-1.64. Predicted FVC values derived from equations based on other populations were considerably higher than the observed mean in this study. Our study, therefore, reemphasizes the need to be cautious when applying formulae derived from one population to another. Grossly erroneous conclusions may be reached unless predicted equations for lung-function tests for a given population group are derived from studies based on the same population group.
The effect of consuming large amounts of cassava leaves on thyroid function and urinary iodine was studied. Twenty volunteers were given 200 gm of boiled cassava leaves twice a day for 12 consecutive days. Thyroid hormones triiodothyronine and thyroxine were significantly lower by 9 days. Urinary iodine excretion was also significantly decreased. Cassava leaves, consumed in large amounts by aborigines, probably caused goitres by decreasing iodine absorption.
Spirometry was performed on 1,999 subjects (1,385 males and 614 females) ranging in age from 13 to 69 years and comprising of all the main races in Malaysia. They were divided into 6 age groups. Mean forced vital capacity (FVC) in the males and females was 3.49 +/- 0.02 L and 2.51 +/- 0.02 L respectively. Both FVC and FEV1 correlated negatively with age. Regression analysis on data between the ages of 20 to 69 years revealed an age-related decline in FVC of about 30 ml per year of life in the males and 22 ml per year in the females. Multiple stepwise regression of the data for the prediction of an individual's FVC above the age of 20 years gave an equation for the males: FVC = 0.0407 (height)-0.0296 (age)-2.343 L and for the females: FVC = 0.031 (height)-0.022 (age)-1.64 L. Predicted FVC values derived from equations based on other populations were considerably higher than the observed mean in this study, re-emphasizing the need to be cautious when applying formulae derived from one population to another. Grossly erroneous conclusions may be reached unless predicted equations for lung-function tests for a given population group are derived from studies based upon the same population group.
A review of gestational trophoblastic disease diagnosed at the Department of Pathology, University Hospital, Kuala Lumpur from January 1989 to December 1990 using established histological criteria showed 25 complete hydatidiform moles (CHM), 11 partial hydatidiform moles (PHM), 1 invasive mole and 2 choriocarcinoma. The ages of the patients with CHM ranged from 21 to 43 years (mean = 28.5 years) and PHM 20 to 33 years (mean = 27.5 years). The invasive mole occurred in a 42-year-old Malay woman. The two patients with choriocarcinoma were both Chinese and 41 and 46-years old respectively. During the same period, 1,062 non-molar abortions and 13,115 births, inclusive of livebirths and stillbirths were recorded at the University Hospital. The incidence rate of hydatidiform moles was thus estimated to be 1:384 pregnancies. PHM constituted 30% of all molar pregnancies. Hydatidiform moles occurred among the Malays, Chinese and Indians at the rate of 2.43, 2.66 and 3.29 per 1,000 pregnancies respectively. It appears that hydatidiform molar pregnancy has the highest prevalence among the Indians, a finding similar to an earlier Singapore study.