Hong Kong Journal of Paediatrics [HK J Paediatr (New Series) 2003;8:70-86]

Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China

CY Yeung ( 楊執庸 ) FRCP(C), FRCP, FRACP

Correspondence to: Prof CY Yeung

Received August 22, 2002

Literature review and author's personal observations have shown that Chinese children are uniquely different, not only in their look but also in many medical and health conditions. Genetic make-up accounts for some of the differences. Traditions and environment exert significant influences also. Many traditional practices produce clinical problems which are not encountered in the west. Infections are different in Chinese; there are much fewer E.coli sepsis in the neonates, and invasive Haemophilus influenzae type-b (Hib) infections in early childhood and infectious mononucleosis syndrome in the adolescents are uncommon. These findings, together with differences in the pattern of many other infectious conditions are highly suggestive of an enhanced herd immunity from a multitude of early antigenic stimulations. As significant number of Chinese people have emigrated to settle in many overseas places in recent years, child care workers should be alerted to some of these unique health features to ensure they can provide the optimal management for these Chinese children.

Keyword : Childhood diseases; Chinese child health; Chinese traditions; Herd immunity

Introduction

"Different race has different face",¹ this saying obviously applies to Chinese children, as they do look different from children of other ethnic origins. In fact, many health problems are different in Chinese children also.^2-6 Genetic conditions account for some of the differences. Well-known examples can be found in the thalassaemia syndromes which are highly prevalent in southern Chinese,^7,8 or cystic fibrosis which is very rare in Chinese,² although it is the most common chronic lung problem in Caucasians.⁹

Traditions usually exert major influences on all kinds of child-care practices in the Chinese culture.^2-6,10-13 Many medical and health problems demonstrate strong cultural characteristics. As improvement in socio-economic conditions and changes in life-style together with trends towards westernization have occurred in many Chinese communities^{2,4,5,10,12,13} in recent years, there are associated significant changes of disease pattern in the children also.^2,4,10,12,13 Such changes appear to occur in children who have migrated to take up residence in overseas places as well.

This paper reviews some of the documentations and the author's personal observations on the differences commonly identified in children of Chinese origin.

Background

Chinese people comprise of five major ethnic groups,¹⁴ viz. Han (漢), Man (Manchurians 滿), Mong (Mongolians 蒙), Hwei (Islamics 回), Zhuang (Tibetans 藏). Han is the majority. There are many other "ethnic minority groups" whose features sometimes draw some similarities to the people of the bordering countries. For example, a small group in south-western China has some Persian features; a few people in the North-west look Russian. Most of the Manchurians, Mongolians and Hweis have integrated into the Han society and have become indistinguishable from the Hans, from whom most of the reports regarded as Chinese are based.

External Features

At birth, the Chinese infant has a broader face, often with depressed nasal bridge (Table 1).^{1,2,5,10,15-24} He does not look "yellow", as his skin pigmentation usually takes days, often weeks to establish. More than one in ten infants have up-slanting eyes. One in four has "low-set ears" by Western standard. The head is usually not as elongated as the Caucasians. This could be due to the supine-sleeping position^2,12,25,26 resulting in flattening of the occiput rather than an oblong shape assumed by the head lying on its sides from the prone-sleeping posture.

Of the many external features as listed in Table 1, particularly note-worthy are the "Mongolian blue spots" which are present in nearly all newborns.¹⁵ These skin patches, many of them can be quite large around the buttocks, persist till 5-6 years old; and such features should not to be mistaken for "child abuse" by the inexperienced. It is interesting also to note that Chinese children born or raised in temperate regions such as North America are generally less pigmented and not as "yellow" as their cousins who live in China.

Child Growth

"Chinese are born small and remain small all through childhood",^27-29 this is a common misconception. Such belief was apparently based on observations made in days when the nutritional status and health care facilities were poor.^{2, 4,10,28,29} Recent studies conducted in more developed Chinese communities, like Hong Kong, have indicated that both the intra-uterine³⁰ and childhood growth grids³¹ are similar if not identical to the National Council of Health Standards (NCHS) curves of U.S.A. These secular changes appear not influenced by previously presumed genetic and ethnic factors as some workers have suggested. ³²

Already Chinese teenagers of Hong Kong in the late 1980s were 4.2 - 6.7 cm taller than those in the late 1960s.³¹ Similar secular growth trends are occurring in various big cities in Mainland China^29,33-35 and Taiwan.³⁶ One study showed that the femur length was shorter,³⁷ and several surveys have shown that Chinese children in certain big cities of North America are shorter and lighter^26,38 than the Caucasian-Americans. These findings could be the result of certain traditional feeding practices which have been found to provide less than optimal dietary intake for the growing Chinese children rather than because of their ethnic endowment.^24,27,39

Psycho-social Features

Up-bringing of children are culturally more regimented and disciplinary,^2,4,40,41 unlike the permissive attitude of the West. Young children are usually well-behaved and more subdued. Like most Orientals, Chinese parents are usually more over-protective.^2,4,40,41 Children are not encouraged to be physically venturous and exploratory. That may explain the much lower incidence of deaths from various accidents including car accidents, despite of a much higher density of both people and motor vehicles in a Chinese community (Hong Kong) as exemplified in Table 2.⁴³

Many reports have indicated more superior cognitive, mathematics and other academic attainments among Chinese immigrant children,^44-46 compared with indigenous children. These findings could be due to the parental attitude and pressure for their children to be high achievers. Such attribute might also be related to the need for survival as the less-privileged ethnic minority in new societies. Of course, a more favorable developmental endowment cannot be excluded.

Housing development in most Chinese urban areas has put much emphasis on nuclear family units in recent years.¹¹ This tends to erode into the traditional "extended-big family structure" in the Chinese culture. Young couples who encounter problems do not have ready access to advice or intervention from their seniors. As emotion or tension escalates, little buffering mechanism is available within the household. This could be an important reason for the increasing frequency of abused children reported nowadays,⁴⁷ although still lower compared with other industrialized countries of the West.

Congenital Abnormalities

Congenital anomalies as listed in Table 3 are some examples quite unique in Chinese.^48-54 Uncommon occurrences of neural-tube defects^50-52 appear to be due to the plentiful vegetables with folic acid in the southern Chinese diet.⁵¹ In a study of supplementing women with folic acid in several northern provinces in China, significant reduction of neural tube disorders has resulted.⁵³ Other conditions like meconium ileus and meconium-plug syndrome from cystic fibrosis^2,5,6,9 are extremely rare occurrences,^5,6 very different from the experience drawn from Europe and North America.

Congenital conditions which are much less common in Chinese also include congenital dislocation of hips (CDH) which was found to be ten times less common compared with the Caucasians,⁵⁴ pulmonary hypoplasia from renal agenesis and congenital hypertrophic pyloric stenosis.^55,56 Strictly speaking, pyloric stenosis is an acquired condition, as most infants only develop symptoms days, sometimes even weeks, after birth. Local experience has indicated its occurrence is on the rise in recent years. If such observation holds true, it may suggest an etiologic relationship to many recently introduced perinatal interventional therapies which may be stressful to the infants, resulting in increased vagal discharges and smooth muscle hypertrophy as a response around the pylorus.

The incidence of congenital heart defects is similar to Caucasians, but the pattern of heart defects is different.^{57, 58} There are more right heart obstructive lesions and less hypoplastic left heart syndrome (Table 4). Cardiovascular defects associated with Chinese children with Down syndrome are also different (Table 4);⁵⁹ the commonest problem is not atrio-ventricular cushion defect as noted in the western literature but ventricular septal defect. Although the frequency of congenital heart block has not been clearly documented, one might suspect that it would be higher, as there are many more young Chinese women with systemic lupus erythematosis.^60,61

Hydrops fetalis due to a-thalassaemia is common.⁷ 4.5% and 4% of a southern Chinese school-age population have been found to be carriers of the a & b thalassaemia genes respectively.⁸ While infants with hydrops fetalis due to α-thalassaemia either die in-utero or soon after birth, children with β-thalassaemia major usually require monthly blood-transfusions and daily chelation therapy to sustain life. 4.42% boys and 0.45% girls⁶² were found to be severely deficient in glucose-6-phosphate dehydrogenase (G-6-P D). Such enzyme defect had accounted for a very high incidence of neonatal jaundice and kernicterus (Figure 1) in the past;^63-66 even in older children haemolytic anaemia often occurs in association with an infection, in particular with hepatitis and typhoid fever, or precipitated by an oxidizing agent. Hare-lips and cleft palate which were noted to be more prevalent in Chinese previously^49,67 have recently been found to be similar in incidence⁶⁷ as in other reports.

The Chinese Neonates

Conditions which are more prevalent in Chinese neonates are shown in Table 5. Many neonatal conditions commonly encountered in Caucasian infants are infrequent occurrences in Chinese (Table 6).^2,5,6 The infant of the diabetic mother (IDM) is one example;^68,69 it is apparently because of the incidence of young diabetics in China which has been found to be the lowest among all population surveys reported so far.^70,71 In the better-developed and westernized communities,^69,71 the incidence of young diabetics however is increasing.

Respiratory distress syndrome (RDS) was an infrequent occurrence in Chinese.^{4,5,12,13,72,73} This observation had intrigued most of the visiting American-physicians in the Vietnam-war-years in the latter part of 60s and early 70s, who thought that the rarity of RDS in the immature infants in Vietnam and in vacation-places like Hong Kong must be due to genetic reasons. Upsurges of infants with RDS in recent years in Hong Kong (Figure 2)^72,73 and other developed Chinese communities have now been noted in many Chinese communities. There is an obvious association with improvement in socio-economic conditions and living standards although increased survival of the immaturely born might have also contributed. Alleviation of many intra-uterine stressful conditions has been proposed as a probable reason for the recent increase of RDS.^12,13,72,73 Many of these conditions would induce fetal adrenal responses enhancing the maturation of the surfactant system.

Many factors have also been suggested to be associated with enhancement of the functions of various fetal and neonatal systems.^2,4,5,12,74 One illustration can be noted in the traditional feeding and eating habit, when personal chop-sticks and table-spoons are dugged into common food dishes. Such practice would promote cross-contamination of both commensals and potential pathogens. It could also increase the chances of sub-clinical or even overt infections in the pregnant mothers; which in turn might induce stress-responses from the fetuses.^4,40 Over-crowded living conditions especially among the less-privileged communities could further re-enforce these stressors. Such stressor-responses would exert some effects on the various fetal systems not only in enhancing surfactant production,^{4,12,13,72,73} but also in advancing other systems including the immune functions.

It is very interesting to note a totally different pattern of etiologies of neonatal sepsis and meningitis recorded in a rapidly developing Chinese community of Hong Kong (Table 7), suggesting differences in certain environmental factors and herd immunity. Earlier experience from a tertiary perinatal centre^74,75 has already showed a scarcity of E.Coli infections; much less than the expected 25% of infants with sepsis (only 7%) developed meningitis. Only <8% of early Group-B Streptococcal sepsis failed to survive.^74-76 Such favorable outcome (compared to results of other centers in that period) was postulated to be due to a more mature defense mechanism. Indeed, in a study conducted in Hong Kong, the cord blood levels of IgG and complements of the Chinese newborn infants were noted to be higher compared to Caucasian reports, they were especially prominent among the immaturely born.⁷⁷ The leucocytes from the Chinese neonates, even among those born early, were found to have more mature (using indigenous adults as standards) phagocytic and candidacidal functions although they are equally immature in their chemotactic activities.⁷⁸ These 'favorable' factors are apparently features of a more mature defense-mechanism than those reported from Caucasians.

A fairly high number of Salmonella meningitis was noted in Chinese (Table 7).⁷⁹ This is probably a reflection of the over-crowded living condition and sub-hygienic environment in the earlier years. Very high prevalence rate of sclerema neonatorum^81,82 has also been reported from many parts of China. Nearly all such reports were from under-developed communities where poor hygiene and inadequate sanitary facilities would have invited a lot of serious infections, in addition to subjecting the infants to cold-exposure due to inappropriate thermal environment. In better-developed communities, like Hong Kong, the condition has practically totally disappeared.

Influences of Traditional Practices

Most childcare practices passed on from generations to generations are based on traditional beliefs, frequently mixed with an element of superstition. "Respect and obey the elders" is regarded as the top virtue in the Chinese culture. Their teachings and practices are usually observed as "biblical truth". Seniors or grannies often dictate the kind of care and treatment for the children, even though sometimes these do not conform to common sense to the parents.

There is a strong traditional belief that the body can go off-balance easily. Many foods, weather changes or disease-states can tip the balance between " Yin and Yang(陰陽)" ;^2-4,74,83,85 many untoward bodily reactions may be induced. By carefully choosing the right kind of practices as described below, homeostasis can be restored and the body can be maintained at its "neutral" or healthy position.^2,4,74,83-86

Many foods are believed to provoke undesirable "Hot(熱)" , "Cold (寒)" or sometimes "Toxic (毒)" (Tables 8 & 9) reactions.^{2,4, 74,83-86} When the body is off-balanced, many ailments or illnesses would occur. Nursing mothers are therefore very careful in their eating habits,⁸⁶ and in the weaning period the kind of foods offered to the infants are also rather restrictive.^{2,4,24,74,83,84} Certain vegetables and fruits would be avoided because of their potential "cooling effects (寒涼) ", many food items are not given to avoid provoking "hot (熱)" or "toxic (毒)" body reactions.

Studies have shown a low caloric and low protein content besides demonstrating certain other inadequacies in the traditional Chinese weaning diet.^{13,24,31,32,39,41,83-85} Such findings have offered explanation to the frequently quoted "growth faltering" of the child around 4-5 month old,²⁴ when weaning would commence. It has also been mis-interpreted as a genetic or racial characteristics.^24,31,32 As infant feeding^33,34 habits have changed in the more developed communities, such "growth faltering" has disappeared now.^29,31,32

The nursing mother⁸⁶ consumes a lot of ginger, which is believed to "do away with the gases" (Kui-Fung 驅風) in the post-partum period. Apart from its effect on seasoning the foods, ginger is known to possess bacterio-static activities. It is usually taken together with hard boiled pork-knuckles and vinegar, which is believed to be bacteriostatic and able to leach the calcium from the bones. She also eats quite a bit of chicken cooked in rice-wine with ginger as well. Apparently such "high-calorie" foods would help to "replenish" her nutritional deprivation from the pregnancy; but their effects on the breast-feeding infant are not well understood.

The newborn infant is often given certain herbal tea to nullify the "undesirable effects of pregnancy (清胎毒)". Some of these herbs (like Chuen-Lien 川蓮, Ngau-huang 牛黃 & Yin-chen 茵陳) have been found to be highly potent in displacing bilirubin from its protein-binding.^87-89 When given to the jaundiced infant, they would generate increased amount of unbound bilirubin enhancing the risk of brain damage (Figure 3).^63-66 In fact, many jaundiced term infants who developed kernicterus had history of such herbal consumption, suggestive of a causal relationship.^64,65 Some herbs, in particular "Chuen-Lien" (Coptis Sinensis), have also been frequently noted to precipitate acute haemolytic jaundice and have been associated with the development of kernicterus in the G-6-P D deficient infants as well.^90,91

Covering the umbilical stump to avoid exposure to the open air (露風) is another very popular traditional practice.^2,4,5,74 Materials used have ranged from unhygienic cloths or herbal powder by the less-privileged to sterile-gauze covering in the more elite. Such practice could enhance bacterial overgrowth even if it does not invite infection.^{4,5,13,24,32,41,66,74} In in-vitro studies, even trace amount of certain pro-inflammatory cytokines such as TNF-a has been shown to enhance bilirubin cytotoxicity.^92,93 Infants in sub-hygienic environment or those with their umbilicus covered, encouraging bacterial overgrowth and potential cytokine response, would therefore be particularly at risk of bilirubin toxicity. It is gratifying to note the drastic disappearance of kernicterus in Chinese term infants over the past 3 decades in many places, like Hong Kong (Figure 1).^12,13,65,66 This is probably related to an aggressive health education program to discourage the incriminate use of herbs and to keep the umbilicus uncovered and properly clean.

Documentation of herbal therapies in China dates back more than 5,000 years.^{2,4,12,13,74,94,95} Usage of herbal medicine is so deep-rooted in Chinese societies that it is impossible to find modern cities with Chinese immigrants without herbal stores in their "China-Towns". Besides therapeutic usage, herbs are often consumed for "body-building" purposes, aiming at restoring or balancing various body functions.

Many beneficial therapeutic effects have been observed with herbs,^94-98 regrettably not many of these observations are scientifically confirmed. Many acclaimed therapeutic effects are often blown out of proportions by the media, generating unnecessary excitements. Many herbs have become suddenly popular "over-night" despite of absence of proper pharmacologic and toxicologic studies. Such folklore beliefs, easy access, off-the-counter availability and scarcity of scientific studies have rendered herbal medicines rather unacceptable to the western-trained doctors. Apparently more research is needed to dig into herbal medicines, which would probably turn out to be a therapeutic "Gold Mine". Indeed of the very small number of laboratory-based studies conducted, we have found some herbs to be therapeutically beneficial.⁹⁷

The presence of acupoints can be easily confirmed by an electronic "acupoint-finder", although the clinical significance is open to questions. This system is however totally alien to western medicine although many beneficial effects have been reported.^99-103 Besides the better-known anaesthetic effects, we have found that acupucture could significantly alleviate the effect of exercise-induced asthma in children with bronchial hyper-reactivities.¹⁰² However, we would not recommend its use for treatment of asthmatic attacks because of its short-lived effects. The National Institute of Health (NIH) of U.S.A. has identified four areas of health problems where acupucture has been approved to be of use, viz. pain-control, anti-emetic especially during chemotherapy, emotional instability problem, and as adjunct for anaesthetics. Apparently more work needs to be done to improve our understanding of this system of "Meridians" with their various topographic acupoints where their electrical potentials would change with disease-conditions.¹⁰⁴

Rubbing lotions and liniments onto the temple-regions are often traditionally done to counter-act fainting spells or motion sickness. Counter-irritants, like moxibustions or mentholatum ointments, are often applied to the abdomen to combat abdominal pains. Scraping the skin with a porcelain spoon to "get rid of undesirable Qi" (scraping "the wind (刮風)" out of the body) is also a common practice. The child with fever may have his back, his nape and his forehead scraped resulting in clusters of linearly arranged bruises (Figure 4), which could be mis-interpreted for "child abuses" to the un-aware.

Being particularly conscious of maintaining the body in homeostasis, regular consumption of certain hard-boiled soups is believed to be able to do away the undesirable body-reactions, like "hot-air accumulations". Some Chinese may regularly take to herbal tea to do so. To resist various ill-effects of the severe winter, many "tonics" are consumed. Popular 'winter tonics' often include "snake-soup or other hard-broiled game meats" to keep warm. To boost the child's resistance to infections, bird's nest soups are often given. Theoretically such prolonged and high temperature treatment could alter most of the potential pathogens, if any. Such pathogens as 'bird flu' or other viruses and bacteriae which may have contaminated the "bird's nest" (which is the gelatinous saliva from the swallow) or the meats of the wild animals could be killed but certain antigenic properties might still be preserved. The presumed "tonic" effects could well be due to the immunizing and boostering properties of these heat-treated antigens. Of course this hypothesis needs to be confirmed or refuted by more research.

Changing Pattern of Childhood Diseases

It is encouraging to note that with advances in socio-economic conditions and health care facilities, the Infant Mortality Rate (IMR) and the Under-5-Mortality Rate have both shown dramatic decline among most developed Chinese communities (Figure 5 & Table 10). Take Hong Kong as an illustration,^11-13,105 the IMR has decreased from around 100 / 1000 live births in the immediate post-World War II years to only 2.9 / 1000 in 2001. The most important contribution to such decline must have been the highly effective immunization programs, as exemplified by the effective eradication of poliomyelitis (Figure 6) and the marked decline in tuberculosis deaths with B.C.G. vaccinations (Figure 7). Together with an efficient sanitary water supply system, most of the potentially fatal and disabling childhood infectious diseases have become nearly eradicated. Deaths from diphtheria, poliomyelitis, pertussis, measles, or diarrhoeal syndromes have nearly disappeared from these places like Hong Kong.

Similarly, bacterial pneumonia which used to cause over 10% fatality among infants born in Hong Kong 50 years ago, only accounted for less than 20 deaths during infancy per 100,000 live-births in recent years (Table 11).^2,73,105 There have also been marked decrease in bacterial and related diseases (Figures 8 & 9)¹⁰⁶ which is mirrored by an increase of viral and non-bacterial disorders (Figure 10). Intestinal worm infestations, though uncommon in the cities, are still highly prevalent in 70⁺% of the children coming from certain rural districts of China,¹⁰⁷ apparently due to unhygienic farming habits, inadequate health education and poverty.

Both the extent and the rate of improvements in the child health statistics in the better-developed Chinese communities have surpassed many highly developed western countries (Tables 10 & 11). The reasons for these achievements are still not fully understood. A slightly lower incidence of low birth weight infants and much less neural tube defects in Chinese infants cannot account for the extent of these improvements. Rarity of sudden infant death syndrome (SIDS),^25,26 which is still the leading 'cause' of post-neonatal deaths in the Western world, appears to be a most intriguing phenomenon Whether herd-immunity or liberal use of anti-microbials may play some role needs further clarification.

Herd Immunity

Classical infectious mononucleosis syndrome^108,109 among the teenagers and invasive Haemophilus influenzae type b (Hib) diseases¹¹⁰ in young children are uncommon, even rarer in the past. These are probably due to an early exposure to these pathogens and to a large number of other potential pathogens^111-116 resulting in multi-potent anti-bodies formation and an enhanced herd immunity (Table 12).^111-115 Such early antigenic exposures and sustained herd immunity may also explain the relatively uncommon findings of hypertrophic tonsils and acute/serous otitis media all through childhood.¹¹⁶ Similarly many young infants who contracted pulmonary tuberculosis tend to develop the post-primary and sputum-positive clinical entity.^2,72,73 This is probably because of repeated early exposures to various organisms due to traditional feeding habits or to the over-crowded living conditions, although having received BCG at birth may also contribute. With improvement in socio-economic conditions, changes in the manifestation of these diseases would probably occur in future also.

Such repeated and early exposures to a multitude of antigens or potential pathogens could be important factors for sustaining a pleuro-potent herd immunity in Chinese children. These antigenic stimuli might have been even more intense in years past, when over-crowded living conditions were common and sanitary conditions were often sub-standard. This concept draws some similarities to the "Hygiene hypothesis"^117-120 for the development of allergies in later life. The hypothesis has suggested that early antigen exposures to a host of antigens and infections could account for an altered immune response resulting in much less allergic diseases in later childhood.

Various improvements and advances in the society through the years would have reduced these early potential antigenic stimulations, which could have altered the herd immunity and accounted for the changes in disease pattern as described above. It may also explain the significant increase in allergic diseases^{12,13,72,73,118,120} such as children with allergic rhinitis and severe asthma necessitating admissions to the hospital in recent years^121,122 as shown in Figure 11. Interestingly, other altered immune conditions, like coeliac disease and chronic inflammatory bowel conditions have remained rare as before.¹²³

Conclusion

Chinese children are different from other ethnic people, not only in their look but also in many medical and health conditions. Genetic disorders account for some differences, most of the other conditions appear to be affected by environmental factors and traditional practices. As there are much movements of Chinese people to take up residence in overseas places in recent years, it is important for child care workers to be alerted to some of the unique features of Chinese children to avoid misunderstanding and even possible mis-management.

References

1. Tsai FJ, Tsai CH, Peng CT, Wu JY, Lien CH, Wang TR. Different race, different face: minor anomalies in Chinese newborn infants. Acta Paediatr 1999;88:323-6.

2. Yeung CY. Chinese children are different. In "Chinese Child Health International" web-site (http:// www.cchi.com.hk); Yeung CY, Ko PYS, Ho F (eds). 2002 Feb.

3. Yeung CY. Child health in the rapidly changing society of Hong Kong. Proc Int Healthcare Conf; Hong Kong. 1988; pp178-182.

4. Yeung CY. Traditional Asian practices and their influences on child health. J Paediatr Obstet Gynae 1991;17:5-12.

5. Yeung CY. Chinese neonates are different. Chapter in Textbook of Neonatology. Hong Kong University Press, November 1996; 877-83.

6. Yeung CY. Neonates are different, especially the Chinese. HK J Paediatr 1992;9:133-4.

7. Todd D, Lai MC, Braga CA, Soo HN. Alpha-thalassaemia in Chinese: cord blood studies. Br J Haematol 1969;16:551-6.

8. Lau YL, Chan LC, Chan A, et al. Prevalence of genotypes of alpha- and beta-thalassaemia carriers in Hong Kong: implications for population screening. N Eng J Med 1997;336:1298-301.

9. Jaffe A, Bush A. Cystic fibrosis: review of the decade. Monaldi Arch Chest Dis 2001;56:240-7.

10. Birch A. Hong Kong: the colony that never was. Hong Kong Sing Cheong Printing Co. Ltd, 1991.

12. Yeung CY. Changing pattern of childhood diseases in Hong Kong - a rapidly developing community. Current Paediatrics 1999;9:209-14.

13. Yeung CY. Changing pattern of neonatal diseases in Hong Kong. Journal of Paediatrics and Obstetrics & Gynaecology 2000 Jan/Feb;5-12.

14. Li SB, Lai JH, Gao SH, et al. STR polymorphisms in five Chinese ethnic groups. Yi Chuan Xue Bao 2000;27:1035-41.

15. Leung AK. Mongolian spots in Chinese children. Int J Dermatol 1988;27:106-8.

16. Li AMC. Yeung CY. Editors: A Clinical Atlas of Chinese Infants. Hong Kong University Press, The University of Hong Kong, Hong Kong, 1996.

17. Wu KH, Tsai FJ, Li TC, Tsai CH, Peng CT, Wang TR. Normal values of inner canthal distance, interpupillary idstance and palpebral fissure length in normal Chinese children in Taiwan. Acta Paediatr Taiwan 2000;41:22-7.

18. Wang YX, He GX, Tong GH, Wang DB, Xu KY. Cerebral asymmetry in a selected Chinese population. Australas Radiol 1999;43:321-4.

19. Ngan P, Hagg U, Yiu C, Merwin D, Wei SH. Cephalometric comparisons of Chinese and Caucasian surgical Class III patients. Int J Adult Orthodon Orthognath Surg 1997;12:177-88.

20. Wang D, Qian G, Zhang M, Farkas LG. Differences in horizontal, neoclassical facial canons in Chinese (Han) and North American Caucasian populations. Aesthetic Plast Surg 1997;21:265-9.

21. Leung AK, Ma KC, Siu TO, Robson WL. Palpebral fissure length. In Chinese newborn infants. Comparison with other ethnic groups. Clin Pediatr (Phila) 1990;29:172-4.

22. Quant JR, Woo GC. Normal values of eye position and head size in Chinese children from Hong Kong. Optom Vis Sci 1993;70:668-71.

23. Lian WB, Lee WR, Ho LY. Penile length of newborns in Singapore. J Pediatr Endocrinol Metab 2000;13:55-62.

24. Field CE, Baber F. Growing up in Hong Kong. Hong Kong University Press, 1974.

26. Yeung CY. Sudden infant death ?A Chinese perspective. JAMA - SEA 1995; p13-14.

27. Yip R, Li Z, Chong WH. Race and birth weight: the Chinese example. Pediatrics 1991;87:688-93.

28. Singh GK, Yu SM. Birthweight differentials among Asian Americans. Am J Public Health 1994;84:1444-9.

29. Shen T, Habicht JP, Chang Y. Effect of economic reforms on child growth in urban and rural areas of China. N Engl J Med 1996;335:400-6.

30. Woo JS, Li DF, Ma HK. Intra-uterine growth standards for Hong Kong Chinese. Austr NZJ Obstet Gynaecol 1986;26:54-8.

31. Tam SYM, Karlberg JPE, Kwan EYW, Tsang AMC, Baber FM, Low LCK. The improvement in growth socioeconomic and health status in Hong Kong Chinese infants: 1967 to 1994. HK J Paediatr 1999;4:3-9.

32. Brooks AA, Johnson MR, Steer PJ, Pawsson ME, Abdalla HI. Birth weight: nature or nurture? Early Hum Devel 1995;42:29-35.

33. Leung SS, Lau JT, Xu YY, et al. Secular changes in standing height, sitting height and sexual maturation of Chinese - the Hong Kong Growth Study, 1993. Ann Hum Biol 1996;23:297-306.

34. Ling JY, King NM. Secular trends in stature and weight in southern Chinese children in Hong Kong. Ann Hum Biol 1987; 14:187-90.

35. Cheng JC, Leung SS, Lau J. Anthropometric measurements and body proportions among Chinese children. Clin Orthop 1996; 323:22-30.

36. Lin WS, Shao LX. The status of physical growth in Chinese children. Coll Antropol 1997;21:101-8.

37. Raman S, Teoh T, Nagaraj S. Growth patterns of the humeral and femur length in a multiethnic population. Int J Gynaecol Obstet 1996;54:143-7.

38. Wang X, Guyer B, Paige DM. Differences in gestational age-specific birthweight among Chinese, Japanese, and white Americans. Int J Epidemiol 1994;23:119-28.

39. Li AMC, Baber FM, Yu A, Leung VS. A pilot study on the weaning diets of Hong Kong children. Bull of HK Med Assoc 1982;34:87-95.

40. Ekblad S. Children's thoughts and attitudes in China and Sweden: impacts of a restrictive versus a permissive environment. Acta Psychiatr Scand 1984;70:578-90.

41. Yeung CY. Influence of some Chinese traditional practices on child health. Acta Pediatrica Sinica 1986;29(Suppl):161-5.

42. Ekblad S. Influence of child-rearing on aggressive behavior in a transcultural perspective. Acta Psychiatr Scand Suppl 1988;344:133-9.

43. Department of Health Annual Reports; 1985, 2001 & 2002; Hong Kong Government Printers.

44. Stevenson HW, Stigler JW, Lee SY, Lucker GW, Kitamura S, Hsu CC. Cognitive performance and academic achievement of Japanese, Chinese, and American children. Child Dev 1985;56:718-34.

45. Stevenson HW, Lee SY, Stigler JW. Mathematics achievement of Chinese, Japanese, and American children. Science 1986;231:693-9.

46. Kwok DC, Lytton H. Perceptions of mathematics ability versus actual mathematics performance: Canadian and Hong Kong Chinese children. Br J Educ Psychol 1996;66(Pt 2):209-22.

47. Annual Report of Association of Protection of Children's Right of Hong Kong; 1999, 2002.

48. Emanuel I, Huang SW, Gutman LT, Yu FC, Lin CC. The incidence of congenital malformations in a Chinese population: the Taipei collaborative study. Teratology 1972;5:159-69.

49. Yi NN, Yeow VK, Lee ST. Epidemiology of cleft lip and palate in Singapore ?a 10-year hospital-based study. Ann Acad Med Singapore 1999;28:655-9.

50. Ghosh A, Woo JS, Poon IM, Ma HK. Neural-tube defects in Hong Kong Chinese. Lancet 1981;2:468-9.

51. Wong W, Chang A. Neural-tube defect and folic acid status in Hong Kong Chinese. Br J Obstet Gynaecol 1993;100:1065.

52. Xiao KZ, Zhang ZY, Su YM, et al. Central nervous system congenital malformations, especially neural tube defects in 29 provinces, metropolitan cities and autonomous regions of China: Chinese Birth Defects Monitoring Program. Int J Epidemiol 1990; 19:978-82.

53. Berry RJ, Li Z. Folic acid alone prevents neural tube defects: evidence from the china study. Epidemiology 2002;13:114-6.

54. Hoaglund FT, Kalamchi A, Poon R, Chow SP, Yau AC. Congenital hip dislocation and dysplasia in Southern Chinese. Int Orthop 1981;4:243-6.

55. Shim WK, Campbell A, Wright SW. 276 cases of pyloric stenosis in Hawaii: II Racial aspects. Hawaii Med J 1970;29:292-5.

56. Lammer EJ, Edmonds LD. Trends in pyloric stenosis incidence, Atlanta, 1968 to 1982. J Med Genet 1987;24:482-7.

57. Lien WP, Chen JJ, Chen JH, et al. Frequency of various congenital heart diseases in Chinese adults: analysis of 926 consecutive patients over 13 years of age. Am J Cardio 1986;57:840-4.

58. Jacobs EG, Leung MP, Karlberg J. Distribution of symptomatic congenital heart disease in Hong Kong. Pediatr Cardiol 2000; 21:148-57.

59. Lo NS, Leung PM, Lau KC, Yeung CY. Congenital cardiovascular malformations in Chinese children with Down's syndrome. Chin Med J (Engl) 1989;102:382-6.

60. Mok CC, Lee KW, Ho CT, Lau CS, Wong RW. A prospective study of survival and prognostic indicators of systemic lupus erythematosus in a southern Chinese population. Rheumatology (Oxford) 2000;39:399-406.

61. Yu A, Wong VC, Lee AK, Hung BK, Ma HK. Systemic lupus erythematosus in pregnancy in Hong Kong Chinese. Asia Oceania J Obstet Gynaecol 1986;12:321-6.

62. Yeung CY, Lee FT. Erythrocyte G6PD assay on Chinese newborn infants with an automated method. HKJ Paediatr 1985;2:46-55.

63. Yeung CY, Field CE. Phenobarbitone therapy in neonatal hyperbilirubinaemia. Lancet 1969;2:135-9.

64. Yeung CY. Neonatal hyperbilirubinemia in Chinese. Trop Geogr Med 1973;25:151-7.

66. Yeung CY. Changing pattern of neonatal jaundice and kernicterus in Chinese neonates. Chin Med J (Engl) 1997;110:448-54.

67. Lam BCC. Changing pattern of congenital malformations in a regional perinatal centre of Hong Kong. Proc of Conference on Perinatal Medicine in the 21st Century. Jan 2002; p15-18.

68. Pan XR, Yang WY, Li GW, Liu J. Prevalence of diabetes and its risk factors in China, 1994. National Diabetes Prevention and Control Cooperative Group. Diabetes Care 1997;20:1664-9.

69. Yang Z, Wang K, Li T, et al. Childhood diabetes in China. Enormous variation by place and ethnic group. Diabetes Care 1998;21:525-9.

70. Fu H, Shen SX, Chen ZW, et al. Shanghai, China, has the lowest confirmed incidence of childhood diabetes in the world. Diabetes Care 1994;17:1206-8.

71. Huen KF, Low LC, Wong GW, et al. Epidemiology of diabetes mellitus in children in Hong Kong: the Hong Kong childhood diabetes register. J Pediatr Endocrinol Metab 2000;13:297-302.

73. Yeung CY. Changing pattern of lower respiratory tract infections in Hong Kong children. Pediatr Pulmonol 2001;Suppl 23:161-4.

74. Yeung CY. Influence of some Chinese traditional practices on child health. Acta Pediatrica Sinaca 1986;29(Suppl):33-9.

75. Tsoi NS, Yeung CY. A retrospective survey on neonatal sepsis in Tsan Yuk Maternity Hospital. Proc of Jubilee Scientific Conference of Department of Paediatrics, University of Hong Kong. Sept 1987; p164.

76. Chan VC, Lee WH. A review of neonatal GBS infection in Queen Elizabeth Hospital. HK J Paediatr (new series) 1999;5:25-9.

77. Tam A, Wong HN, Tang TS, Yeung CY. Cord blood immunoglobulin and complement levels in preterm and term Chinese newborns. HK J Paediatr 1992;9:193-8.

78. Wan T, Yeung C, Tam A. Neutrophil functions of Chinese neonates. J Paediatr Child Health 2000;36:153-8.

79. Low LC, Lam BC, Wong WT, Chan-Lui WY, Yeung CY. Salmonella meningitis in infancy. Aust Paediatr J 1984;20:225-8.

80. Robertson NRC. Infection in the newborn. In: Robertson NRC, editor. Textbook of Neonatology, part II. Edinburgh: Churchill Livingstone, 1992:943-1006.

81. Yao Y, Gong F, Xiong Y, Xiong F, Tang S. Observation on the changes of lipid peroxidation in neonates with sclerema. Hua Xi Yi Ke Da Xue Xue Bao 1997;28:440-1.

82. Hong WL, Pan LY. Neonatal hypothermia and scleroedema. In: Yu VYH, Feng ZK, Tsang RC, Yeung CY, editors. Textbook of Neonatal Medicine - A Chinese Perspective, Hong Kong University Press, 1996:187-92.

83. Choa G. Some ideas concerning food and diet among Hong Kong Chinese. In: Some traditional Chinese ideas and concepts in Hong Kong social life today. Topley M (Ed) Royal Asiatic Society Publication, 1967.

84. Woo J, Leung SS, Ho SC, Lam TH, Janus ED. Dietary intake and practices in the Hong Kong Chinese population. J Epidemiol Community Health 1998;52:631-7.

85. Woo J, Woo KS, Leung SS, et al. The Mediterranean score of dietary habits in Chinese populations in four different geographical areas. Eur J Clin Nutr 2001;55:215-20.

86. Wong HO, Fung H, Rogers MS. Dietary patterns amongst ethnic Chinese pregnant women in Hong Kong. J Obstet Gynaecol Res 1997;23:91-6.

87. Yeung CY, Lee FT, Wong HN. Effect of a popular Chinese herb on neonatal bilirubin protein binding. Biol Neonate 1990;58:98-103.

88. Yeung CY. Effects of drugs and herbs on neonatal jaundice. Sing Paediatric J 1988;39(Suppl):5-9.

89. Yeung CY, Leung CS, Chen YZ. An old traditional herbal remedy for neonatal jaundice with a newly identified risk. J Paediatr Child Health 1993;29:292-4.

90. Yeung CY. Erythrocyte G6PD deficiency and neonatal hyperbilirubinaemia. In "Child Health in the Tropics", 6th Nutricia Symposium, 1985; p71-79.

91. Chan TK. Erythrocyte Glucose-6-phosphate dehydrogenase deficiency in Chinese. HK J Paediatr (new series) 2000;5:1-8.

92. Ngai KC, Yeung CY. Additive effect of tumor necrosis factor-alpha and endotoxin on bilirubin cytotoxicity. Paediatr Res 1999;45:526-30.

93. Yeung CY, Ngai KC. Cytokine- and endotox- in enhanced bilirubin cytotoxicity. J Perinatology 2001;21 Suppl 1:S56-S62.

94. Huang Di Nei Jing: "Shen Nung Bun Zhou Gang Mu"; Shang Wu Publishers, Shanghai 1937.

95. "Ma Huang Duei" Herbal Medicine Notes, Hu Nan Province Archeologic Archives, 1985.

96. Schuster BG. Demonstrating the validity of natural products as anti-infective drugs. J Altern Complement Med 2001;7 Suppl 1:S73-82.

97. Yeung CY, Leung CS, Lee FT. Alleviation of cigarette-induced intra-uterine growth retardation by a Chinese herbal medicine. Early Hum Dev 1989;19:247-51.

98. Lin X, Tu C, Yang C. Study on treatment of eczema by Chinese herbal medicine with anti-type IV allergic activity. Zhongguo Zhong Xi Yi Jie He Za Zhi 2000;20:258-60.

99. Somri M, Vaida SJ, Sabo E, Yassain G, Gankin I, Gaitini LA. Acupuncture versus ondansetron in the prevention of postoperative vomiting. A study of children undergoing dental surgery. Anaesthesia 2001;56:927-32.

100. Kemper KJ, Sarah R, Silver-Highfield E, Xiarhos E, Barnes L, Berde C. On pins and needles? Pediatric pain patients' experience with acupuncture. Pediatrics 2000;105(4 Pt 2):941-7.

101. David J, Townsend S, Sathanathan R, Kriss S, Dore CJ. The effect of acupuncture on patients with rheumatoid arthritis: a randomised, placebo-controlled cross-over study. Rheumatology (Oxford) 1999;38:864-9.

102. Wong VC, Sun JG, Wong W. Traditional Chinese Medicine (Tongue acupuncture) in children with drooling problems. Pediatr Neurol 2001;25:47-54.

103. Chow OK, So SY, Lam WK, Yu DY, Yeung CY. Effect of acupuncture on exercise-induced asthma. Lung 1983;161:321-6.

104. Friedman MJ, Birch S, Tiller WA. Towards the development of a mathematical model for acupuncture meridians. Acupunct Electrother Res 1989;14:217-26.

105. Yeung CY. Paediatrics in Hong Kong - a commontary. J Paediatr Child Health 1987;29:5-7.

107. Li LZ, Bing XZ, Hong T, et al. Epidemiology of human geohelminth infectious (ascaris, trichuris, nectoriasis) in Lushui and Puer Countries in Yunnan, China. Southeast Asian J Trop Med Public Hal 2000;310:448-53.

108. Chan KH, Tam JS, Peiris JS, Seto WH, Ng MH. Epstein-Barr virus (EBV) infection in infancy. J Clin Virol 2001;21:57-62.

109. Yeung CY. Infections mononucleosis syndrome; in "Chinese Child Health International" (http://www.cchi.com.hk) educational web-site. Eds Yeung CY, Ko PYS, Ho FCW, 2001.

110. Lau YL, Yung R, Low L, Sung R, Leung CW, Lee WH. Haemophilus influenzae type b infections in Hong Kong. Pediatr Infect Dis J 1998; 17(9 Suppl):S165-9.

111. Kangro HO, Osman HK, Lau YL, Heath RB. Yeung CY, Ng MH. Seroprevalence of antibodies to human herpe viruses in England and Hong Kong. J Med Virol 1994;43:91-6.

112. Tam AYC, Yeung CY. Theprevalence of "TORCH" antibodies in Chinese newborns. HK J Paediatr 1987;5:241-4.

113. Ulanova M, Hahn-Zoric M, Lau YL, Lucas A, Hanson LA. Expression of Haemophilus influenzae type b idiotype 1 on naturally acquired antibodies. Clin Exp Immunol 1996;105:422-8.

114. Lundin BS, Dahlman-Hoglund A, Pettersson I, Dahlgren UI, Hanson LA, Telemo E. Antibodies given orally in the neonatal period can affect the immune response for two generations: evidence for active maternal influence on the newborn's immune system. Scand J Immunol 1999;50:651-6.

115. Zheng BJ, Ma GZ, Tam JS, et al. The effects of maternal antibodies on neonatal rotavirus infection. Pediatr Infect Dis J 1991;10:865-8.

116. Sung RTY, Yu CW, Chan JTS, et al. How common is acute otitis media in Hong Kong. HKPract 1998;20:114-9.

118. Illi S, von Mutius E, Lau S, et al. Early childhood infectious diseases and the development of asthma up to school age: a birth cohort study. BMJ 2001;322:390-5.

119. Prescott SL, Macaubas C, Smallacombe T, Holt BJ, Sly PD, Holt PG. Development of allergen-specific T-cell memory in atopic and normal children. Lancet 1999;353:196-200.

120. Shirakawa T, Enomoto T, Shimazu S, Hopkin JM. The inverse association between tuberculin responses and topic disorders. Science 1997;275:77-9.

121. Yeung CY. Childhood asthma; a Hong Kong experience. HK J Paediatr 1989;5:1-8.

122. Martinez FD, Holt PG. Role of microbial burden in aetiology of allergy and asthma. Lancet 1999;354 Suppl 2:SII12-15.

123. Karlinger K, Gyorke T, Mako E, Mester A, Tarjan Z. The epidemiology and the pathogenesis of inflammatory bowel disease. Eur J Radiol 2000;35:154-67.