Huey-Jen Jenny Su

Higher temperature and urbanization affect the spatial patterns of dengue fever transmission in subtropical Taiwan

Our study conducted spatial analysis to examine how temperature and other environmental factors might affect dengue fever distributions, and to forecast areas with potential risk for dengue fever endemics with predicted climatic change in Taiwan. Geographic information system (GIS) was used to demonstrate the spatial patterns of all studied variables across 356 townships. Relationships between cumulative incidence of dengue fever, climatic and non-climatic factors were explored. Numbers of months with average temperature higher than 18 degrees C per year and degree of urbanization were found to be associated with increasing risk of dengue fever incidence at township level. With every 1 degrees C increase of monthly average temperature, the total population at risk for dengue fever transmission would increase by 1.95 times (from 3,966,173 to 7,748,267). A highly-suggested warmer trend, with a statistical model, across the Taiwan Island is predicted to result in a sizable increase in population and geographical areas at higher risk for dengue fever epidemics.

Climate, traffic-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan

The prevalence of allergic rhinitis, a common respiratory disorder, may be rapidly increasing. Epidemiological studies, however, indicate little about its association with climatic factors and air pollution. The relationship between traffic-related air pollutants and allergic rhinitis in middle-school students was therefore investigated. In a nationwide survey of middle-school students in Taiwan conducted in 1995/1996, the lifetime prevalence of physician-diagnosed allergic rhinitis and typical symptoms of allergic rhinitis were compared with air-monitoring station data on temperature, relative humidity, sulphur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), carbon monoxide (CO) and particulate matter with a 50% cut-off aerodynamic diameter of 10 µm (PM10). A total of 331,686 nonsmoking children attended schools located within 2 km of 55 stations. Mean (range) annual exposures were: CO 853 (381–1,610) parts per billion (ppb), NOx 35.1 (10.2–72.4) ppb, SO2 7.57 (0.88–21.2) ppb, PM10 69.2 (40.1–116.2) µg·m−3, O3 21.3 (12.4–34.1) ppb, temperature 22.9 (19.6–25.1)°C, and relative humidity 76.2 (64.8–86.2)%. The prevalence of physician-diagnosed allergic rhinitis was 28.6 and 19.5% in males and females, respectively, with prevalence of questionnaire-determined allergic rhinitis 42.4 and 34.0%. After adjustment for age, parental education and history of atopic eczema, physician-diagnosed allergic rhinitis was found to be associated with higher nonsummer (September–May) warmth and traffic-related air pollutants, including CO, NOx and O3. Questionnaire-determined allergic rhinitis correlated only with traffic-related air pollutants. Nonsummer warmth and traffic-related air pollution, probably mediated through exposure to common allergens such as dust mites, are possible risk factors for allergic rhinitis in middle-school-aged children.

Traffic-Related Air Pollution, Climate, and Prevalence of Eczema in Taiwanese School Children

The prevalence of childhood eczema is increasing in many countries. Epidemiological studies, however, say little of its association to outdoor air pollution and climate factors. We conducted a nationwide survey of middle-school students in Taiwan from 1995 to 1996. The 12-month prevalence of eczema was compared with air monitoring station data of temperature, relative humidity, and criteria air pollutants. A total of 317,926 children attended schools located within 2 km of 55 stations. Prevalence rates of recurrent eczema were 2.4 and 2.3% in boys and girls, respectively, with prevalence rates of flexural eczema 1.7% in both sexes. After adjustment for possible confounders, flexural eczema was found to be associated with traffic-related air pollutants, including nitrogen oxides and carbon monoxide. Recurrent eczema was associated with traffic-related air pollution only in girls. There were no associations for the highest monthly means of temperature, whereas the annual means and the lowest monthly means of temperature were negatively related to flexural eczema, but only in girls. The lowest monthly mean relative humidity was positively related to eczema. The results suggest that air pollution and climatic factors, which showed stronger associations in girls than boys, may affect the prevalence of childhood eczema.

Associations between dietary intake and serum polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) levels in Taiwanese.

The study was conducted to correlate the consumption frequency of different food groups (milk, eggs, fish, and others) and the levels of serum polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations of residents living near a municipal waste incinerator. All selected subjects were between 18 and 65 years old and proportionally chosen from each age group based on population distribution. In addition, they had to have lived within a 5-km radius of the incinerator for at least 5 years. Trained interviewers administered a dietary questionnaire interview. Higher serum PCDD/F levels were found in older than in younger subjects, and higher PCDD/F concentrations were found in females than in males. An analysis between the consumption frequency of different foods and serum PCDD/F levels showed that fish might have contributed the highest quantity of measured serum PCDD/Fs. Yet, the regression coefficient of dietary intake and PCDD/F concentration was only 0.017 before and 0.105 after adjusting for the variables of age, gender, and smoking status of the study subjects. The frequency of fish consumption may be the most significant contributor to serum PCDD/F levels. Further research is needed to quantify the association between the consumption of various food groups and their potential contributions to the corresponding serum PCDD/F concentrations.

The association between tumor necrosis factor, HLA-DR alleles, and IgE-mediated asthma in Taiwanese adolescents

Background: Human leukocyte antigen (HLA) DR genes and the tumor necrosis factor (TNF) gene locus are associated with asthma and IgE production. TNFα‐308G/A frequencies between Japanese and Caucasians in the UK have been found to be different. The roles of HLA‐DRB1 and TNF genotypes are unknown in Taiwanese adolescents with IgE‐mediated asthma (I‐asthma).

Fatty Liver and Hepatic Function for Residents with Markedly High Serum PCDD/Fs Levels in Taiwan

This study was designed to examine the associations between serum polychtorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) levels and adverse hepatic-related health outcomes. Residents living in the vicinity of a closed pentachlorophenol (PCP) manufacturing factory (exposure area) and other areas nearby (control area) were identified from prior investigation of serum PCDD/Fs measurements. A total of 85 subjects were recruited for the study, 52 from exposure area and 33 from control, respectively. Average level of serum PCDD/Fs was 80.1 6 50.9 pg WHO-TEQ/g lipid for those residing in exposure area, and 25.5 6 18.2 in control area. Statistically higher odds ratio (ORs) for fatty liver and gamma-glutamyltransferase (GGT) activity was found in subjects with higher serum PCDD/Fs levels and high body mass index (BMI) as compared to those with lower PCDD/Fs levels and less BMI. Data suggest that dioxin exposure and high lipid content affect the prevalence of fatty liver in exposed subjects. Future study should be directed to prevent continuous exposure to environmental PCDD/Fs from the defunct PCP factory, and to characterize prospectively, with a larger study sample size, the potential long-term consequences on hepatic function associated with contaminant exposure.

Roles of genotypes of β2-adrenergic receptor in the relationship between eosinophil counts and lung function in Taiwanese adolescents

To examine the roles of genetic polymorphism of the β2-adrenergic receptor (β2AR) in the relationship between eosinophil (EOS) counts and eosinophil cationic protein (ECP) counts and lung function, we recruited a random sample from the 1996 nationwide survey of asthma prevalence in middle school children. A total of 149 subjects—42 asthmatic children, 38 asthmatics in remission (no reported attack for more than 12 months), and 69 nonasthmatics—completed a physical evaluation, pulmonary function test, and determination of EOS, ECP, and β2AR genotypes at amino acids 16 and 27. Asthmatic children had higher EOS and ECP than did nonasthmatics. No association was found between asthma and β2AR genotypes. Lung function was significantly and inversely correlated with EOS but not with ECP in asthmatic children. By genotype, an inverse correlation between lung function and EOS was found in asthmatic children with Arg16Arg or Gln27Glu. A nonsignificant but similar inverse correlation was found in asthmatic children with Arg16Gly or Gln27Gln. However, a nonsignificant but positive correlation was found in asthmatic children with Gly16Gly. In conclusion, we suggest that EOS is a better clinical indicator of airway inflammation than ECP when children are not having an asthma attack. The association between an increase of EOS and lower lung function can be differentiated by β2AR genotypes at amino acid 16.

A dose-dependent relationship between the severity of visible mold growth and IgE levels of pre-school-aged resident children in Taiwan

UNLABELLED To demonstrate a dose-dependent relationship between severity of indoor visible mold growth and serum total IgE levels of resident children. A total of 97 children (4-7 years old) identified from previously established birth-cohort, with information pertaining to indoor environmental conditions after childs birth, were successfully recruited while sera were concurrently collected for total IgE and specific IgE analysis during clinical visits. Severity of visible mold growth at homes was scaled into three levels accordingly. A statistically significant dose-dependent relationship was found between severity of indoor visible mold growth and total serum IgE levels. The trend sustains after the model was adjusted for resident childs age, gender, pet-keeping history, number of siblings, atopic history of parents, presence of incense burning, and environmental tobacco smoking (ETS) at home. Further analysis of specific IgE to commonly examined fungal allergens did not substantiate the correlation. Rather, resident childs specific IgE to mite allergens, although without statistical significance, seemed to better associate with the ranked severity of indoor mold growth in this study. An adjuvant role of fungal exposure to enhance sensitization in indoor environment is therefore suggested in Taiwanese population with high prevalence of building dampness. PRACTICAL IMPLICATIONS The presence of indoor visible mold growth, potentially resulting in fungal exposure, was not associated directly with changing biomarker levels of allergic response in resident children, rather playing an adjuvant role to enhance sensitization. On the other hand, other allergens, such as mite allergen examined in this study, appeared to support a more plausible etiology for directly triggering the ultimate allergic symptoms and diseases of interest. Evidence as such may derive different priority-setting when designing preventive measures for managing indoor air quality.

Distribution variations of multi allergens at asthmatic children's homes

Increasing asthma prevalence is evident in many countries and childhood asthma has also become one of the most common chronic diseases in children. Exposure to indoor allergens has been be attributed to a significant increase in asthma occurrence. Meanwhile, allergen distribution varies widely among different countries. This brief investigation reports the distribution of common indoor allergens, such as mite (Dermatophagoides pteronyssinus, Der p 1 and Der p 2), cat (Felis domesticus, Fel d 1), and German cockroach allergens (Blattella germanica, Bla g 1) at different sites of asthmatic children in Taiwan. Approximately 40 asthmatic childrens homes participated in this study and the cohort was followed prospectively for approximately 6 months, starting in December until the following May. Dust samples were collected from each childs mattress, and bedroom and living room floors. All samples were analyzed with monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA). Statistical difference of Der p 1 concen trations is observed among those on the mattress, bedroom and living room floor, except for in May. Seasonal variation in Der p 1 levels on the mattress and bedroom floor is also significant (P < 0.025 and 0.001, respectively). Distributional variation seems to be significant for most allergens among sites within homes in most seasons. Therefore, if only one sample is to be taken, the month of May would be a more ideal choice of study period, and detailed sampling across sites appears to be necessary should the true environmental exposure of allergens be desired.

School type, stress and sport-related injuries in middle school students in central Taiwan

Abstract This study was to examine sports injuries in middle school students, and to identify potential factors associated with sports injuries in this population (aged between 12 and 15 years). Sports injuries were measured by self-reported questionnaires during 1995 and 1996 among middle school students in Yun-lin, a county in central Taiwan. A total of 13,764 students responded, accounting for a 86% return rate. Among those who responded 10,893 sports injuries were reported in a 2-year period, giving an injury rate of 532.8/1000 person-year. Male students were approximately three times more likely than female students to experience sports injuries. Students in private schools were at higher risk of sports injuries than in public schools (odds ratio, OR=1.3). Levels of personal stress (OR= 1.5 and 1.2 for having “three or more” and “one or two” stressful life events relative to having no stressful event), higher parental education (OR=1.5 and 1.2 for students whose parents have “college or higher education level” and “senior-high or middle school education” relative to “elementary school or below”), and levels of exercise (OR=1.6 for exercise frequently comparing to rarely exercise) were positively associated with the occurrence of sports injury. With these above findings, we suggest: (1) providing prevention program for sport-related injuries firstly in private schools of this population; and (2) further studies being conducting to confirm the association between exercise level, stress and parental education and the occurrence of sports injuries.