I-Shou Chang

Epidemiologic Features of Kawasaki Disease in Taiwan, 2003–2006

OBJECTIVE. Kawasaki disease is the leading cause of acquired heart disease in children worldwide. This study characterizes the epidemiology of Kawasaki disease in Taiwan between 2003 and 2006. METHODS. Using Taiwans 2003–2006 national health insurance claims, we investigated the epidemiologic features of Kawasaki disease (ICD-9-CM code 446.1) and coronary artery aneurysm formation (International Classification of Diseases, Ninth Revision, Clinical Modification code 414.11) and compared the incidences of these diseases with those occurring between 1996 and 2002 in Taiwan and those reported by other countries. RESULTS. During our 4-year study period, 3877 children and adolescents <20 years of age were hospitalized for Kawasaki disease. Ninety percent of these children were <5 years of age, and the male/female ratio was 1.62:1. The annual incidence of Kawasaki disease was 153 in 100000 children <1 year of age, 111 in children 1 year of age, 58 in children 2 years of age, 30 in children 3 years of age, 19 in children 4 years of age, and 5.2 in children 5 to 9 years of age. The overall incidence was 69 cases per 100000 for children <5 years of age. Kawasaki disease recurred in 1.5% of all cases. Kawasaki disease occurred most frequently in the summer and least frequently in the winter. Coronary artery aneurysm occurred in 7.2% (279 of 3877) of all Kawasaki disease cases. CONCLUSIONS. The overall incidence of Kawasaki disease was 69 in 100000 children <5 years of age between 2003 and 2006 in Taiwan, comparable with the incidence of 66 in 100000 children between 1996 and 2002. Taiwan has the third highest incidence of Kawasaki disease in the world, after Japan and Korea. In Taiwan, it occurs more frequently during the summer.

Epidemiologic features of Kawasaki disease in Taiwan, 1996-2002.

Objective. Kawasaki disease (KD) is the most common acquired heart disease in children worldwide. The incidence of KD varies among different countries, with Asian countries supposedly having higher incidences than Western countries. However, the incidence of KD in Taiwan has not been well investigated. Methods. Since the implementation of Taiwans National Health Insurance (NHI) in 1995, NHI has covered health care for >96% its population. Using the NHI database from 1996 to 2002, we investigated epidemiologic features of KD (International Classification of Diseases, Ninth Revision, code 446.1), the rate of coronary artery aneurysm formation (International Classification of Diseases, Ninth Revision, code 414.11), and the change in incidence during the recent 7 years. We also compared the annual incidences in Taiwan with those reported by other countries. Results. During the 7-year study period, KD occurred most frequently in the summer and least frequently in winter. It is interesting that the highest peak occurred in the summer of 1998 at the same time that Taiwans enterovirus 71 epidemic was occurring. Ninety-one percent of KD cases occurred in children who were <5 years old, and the male-to-female ratio was 1.70:1. Recurrence of KD was found in 1.3% (94 of 7305) of these children, and coronary artery aneurysm was found in 7.3% (536 of 7305). The annual incidence per 100 000 children was 146 in children <1 year old, 98 in 1-year-old children, 51 in 2-year-old children, 28 in 3-year-old children, 19 in 4-year-old children, and 5.3 in 5- to 9-year-old children; the incidence of KD decreased with increased age. The overall incidence was 66 cases per 100 000 children <5 years old from 1996 to 2002 with the annual incidence not differing significantly during the 7-year study period. Conclusions. KD in Taiwan occurs more frequently in boys and in the summer months. During the 7-year study period, the annual KD incidence in Taiwan of 66/100000 in children <5 years old was the second highest in the world after Japan.

HLA-A33 Is Associated With Susceptibility to Enterovirus 71 Infection

OBJECTIVE. Enterovirus 71 has caused large epidemics of disease, resulting in many fatalities and severe sequelae, in Taiwan and some other countries. In this study, host genetic factors were investigated to link susceptibility to and clinical severity of enterovirus 71 infections. METHODS. We enrolled 219 enterovirus 71 case subjects and 97 control children. HLA typing was performed with sequence-specific primers, and polymorphisms of immune-related candidate genes were detected with polymerase chain reaction, followed by automated gene sequencing. RESULTS. Of the 219 enterovirus 71 cases, 26% (56 of 219 cases) were uncomplicated cases, 74% (163 of 219 cases) were complicated cases, 57% (125 of 219 cases) were complicated cases with central nervous system involvement, and 17% (38 of 219 cases) involved cardiopulmonary failure after central nervous system involvement. Univariate analyses showed that tumor necrosis factor α promoter type II (−308 A allele), HLA-A33, and HLA-DR17 were significantly associated with enterovirus 71 susceptibility. Multivariate analysis demonstrated that HLA-A33 was the gene most significantly susceptible to enterovirus 71. HLA-A2 was associated with the development of cardiopulmonary failure. CONCLUSIONS. HLA-A33, which is a common phenotype in Asian populations but is rare in white populations, was most significantly associated with enterovirus 71 infection, compared with the other candidate genes we studied, whereas HLA-A2 was significantly related to cardiopulmonary failure.

Disease burden and epidemiology of herpes zoster in pre-vaccine Taiwan

Herpes zoster, a common disease, has an important impact on the health of adults, particularly the elderly, and the health system. This study evaluated the disease burden and epidemiological characteristics of herpes zoster in Taiwan. Using herpes zoster-related ICD-9-CM codes used on Taiwans National Health Insurance claims, we analyzed overall and age group differences in incidence, complications, utilization of healthcare facilities, lengths of stay, and cost of their medical care in Taiwans population from 2000 to 2005. The overall annual incidence of zoster was 4.97 cases per 1000 people, with women having a significantly higher incidence than men (5.20 per 1000 vs. 4.72 per 1000, p<0.001). The incidence increased stepwise with age, with 5.18 cases per 1000 in people 40-50 years old, 8.36 in those 50-60, 11.09 in those 60-70, and 11.77 in those above 70 years old. The estimated lifetime risk of developing herpes zoster was 32.2%. Zoster-related hospitalizations and medical cost per patient increased with age. In conclusion, about two-thirds of Taiwans zoster cases occur in adults older than 40 years old and about one-third of the population would develop zoster within their lifetime.

Varicella breakthrough infection and vaccine effectiveness in Taiwan.

We performed this nationwide retrospective investigation among the recipients of varicella vaccine to evaluate the breakthrough varicella infection rate, factors associated with breakthrough infection and the vaccine effectiveness. The recipients of these vaccinations were identified through Taiwans National Immunization Information System and data on breakthrough infections among these recipients were collected by using Taiwans National Health Insurance Claims Database. From 2000 to 2007, 1,057,345 persons received varicella vaccinations in Taiwan. Varicella breakthrough infection occurred among 22,640 (2.1%) vaccinees and 170 (0.016%) required hospitalization for varicella disease. Annual breakthrough infection rates ranged from 0.12% to 2.04%. The mean age of vaccination was 1.6 years (median 1.3 years) and the mean age at breakthrough infection was 3.9 years. The mean interval between vaccination and the breakthrough infection was 2.3 years. The rate was significantly lower in regions where free varicella vaccinations were available than in regions where they were not (P<0.001). Varicella breakthrough infection was significantly more likely to occur at 5 and 6 years of age among the vaccinees, who received vaccination between 12 months and 23 months of age (P<0.001). The vaccine effectiveness against varicella was 82.6% and against varicella-related hospitalization was 85.4% from 2000 to 2005.

Epidemiological study of hospitalization associated with respiratory syncytial virus infection in Taiwanese children between 2004 and 2007.

BACKGROUND/PURPOSE Respiratory Syncytial Virus (RSV) is the leading cause of hospitalization in young children. The population-based burden of RSV hospitalization and the effect of potential risk factors on the severity of illness were evaluated in Taiwanese children. METHODS We analyzed the annual population-based incidence, underlying diseases and characteristics of hospitalizations due to RSV in Taiwanese children under 5 years of age from 2004 to 2007 by using Taiwans National Health Insurance database. RESULTS A total of 11,081 children with RSV-associated hospitalization were studied. Average annual population-based hospitalization incidence was 1,077 and 232 per 100,000 children-year in children under 6 months and under 5 years of age, respectively. The peak incidence occurred between 1 and 2 months of age. The male-to-female incidence risk ratio was 1.4:1 (p < 0.001). There was a significant seasonal distribution with consistent peaks in the spring and autumn every year (p < 0.001). A total of 373 patients (3.3%) had repeated RSV infection. The 943 children (8.5%) with underlying diseases were older (p = 0.001), required longer intensive care unit (ICU) stays (p < 0.001), had a higher rate of endotracheal intubation (p < 0.05), and incurred higher medical costs (p < 0.001). A total of 888 patients (8%) required ICU care. Younger age (p < 0.001), prematurity (p < 0.001), cerebral palsy (p < 0.001) and congenital heart disease (p < 0.001) were independent predictors of requiring ICU care. CONCLUSION RSV infection occurs biennially with peaks in spring and fall in Taiwan. Patients with underlying diseases need longer hospital and ICU stays and incur higher medical costs. Younger age, prematurity, congenital heart disease and cerebral palsy are predictors of ICU care.

Epidemiology and impacts of children hospitalized with pneumonia from 1997 to 2004 in Taiwan

Few studies have investigated the epidemiology and disease burden of childhood pneumonia in Taiwan, a middle‐income country.

Epidemiological characteristics of varicella from 2000 to 2008 and the impact of nationwide immunization in Taiwan.

BackgroundVaricella has an important impact on public health. Starting in 2004 in Taiwan, nationwide free varicella vaccinations were given to 1-year-old children.MethodsOur study investigated the epidemiological characteristics of varicella from 2000 to 2008, and assessed the change of varicella epidemiology after the mass varicella immunization. ICD-9-CM codes related to varicella or chickenpox (052, 052.1, 052.2, 052.7, 052.8, 052.9) were analyzed for all young people under 20 years of age through the National Health Insurance database of Taiwan from 2000 to 2008.ResultsCase numbers of varicella or chickenpox significantly declined after the nationwide immunization in 2004. Winter, particularly January, was the epidemic season of varicella. We found a significant post-vaccination decrease in incidence among preschool children, especially 3 to 6 year-old children-- the peak incidence was 66 per thousand for 4 and 5 year-old children before the nationwide immunization (2000 to 2003), and the peak incidence was 23 per thousand for 6 year-old children in 2008 (p < 0.001). Varicella-related hospitalization also significantly decreased in children younger than 6 years after the nationwide immunization.ConclusionThe varicella annual incidence and varicella-related hospitalization markedly declined in preschool children after nationwide varicella immunization in 2004.

Tuberculosis in Children and Adolescents, Taiwan, 1996–2003

Analysis of data from Taiwan’s National Tuberculosis (TB) Registry showed that incidence of TB in persons <20 years of age was 9.61/100,000 person-years, biphasic, and age-relevant, with a major peak in persons slightly >12 years. Aboriginal children were 8.1–17.4× more likely to have TB than non-Aboriginal children.