Chwan-chuen King - Academia.edu (original) (raw)

Papers by Chwan-chuen King

Research paper thumbnail of Early Detection for Cases of Enterovirus- and Influenza-Like Illness through a Newly Established School-Based Syndromic Surveillance System in Taipei, January 2010 ~ August 2011

PLOS ONE, Apr 15, 2015

School children may transmit pathogens with cluster cases occurring on campuses and in families. ... more School children may transmit pathogens with cluster cases occurring on campuses and in families. In response to the 2009 influenza A (H1N1) pandemic, Taipei City Government officials developed a School-based Infectious Disease Syndromic Surveillance System (SID-SSS). Teachers and nurses from preschools to universities in all 12 districts within Taipei are required to daily report cases of symptomatic children or sick leave requests through the SID-SSS. The pre-diagnosis at schools is submitted firstly as common pediatric disease syndrome-groups and re-submitted after confirmation by physicians. We retrieved these data from January 2010 to August 2011 for spatio-temporal analysis and evaluated the temporal trends with cases obtained from both the Emergency Department-based Syndromic Surveillance System (ED-SSS) and the Longitudinal Health Insurance Database 2005 (LHID2005). Through the SID-SSS, enterovirus-like illness (EVI) and influenza-like illness (ILI) were the two most reported syndrome groups (77.6% and 15.8% among a total of 19,334 cases, respectively). The pre-diagnosis judgments made by school teachers and nurses showed high consistency with physicians' clinical diagnoses for EVI (97.8%) and ILI (98.9%). Most importantly, the SID-SSS had better timeliness with earlier peaks of EVI and ILI than those in the ED-SSS. Furthermore, both of the syndrome groups in these two surveillance systems had the best correlation reaching 0.98 and 0.95, respectively (p<0.01). Spatio-temporal analysis observed the patterns of EVI and ILI both diffuse from the northern suburban districts to central Taipei, with ILI spreading faster. This novel system can identify early suspected cases of two important pediatric infections occurring at schools, and

Research paper thumbnail of Surveillance and Epidemiology of Infectious Diseases using Spatial and Temporal Lustering Methods

Integrated series on information systems, Oct 19, 2010

In the control of infectious diseases, epidemiologic information and useful clustering algorithms... more In the control of infectious diseases, epidemiologic information and useful clustering algorithms can be integrated to garner key indicators from huge amounts of daily surveillance information for the need of early intervention. This chapter first introduces the temporal, spatial and spatiotemporal clustering algorithms commonly used in surveillance systems-the key concepts behind the algorithms and the criteria for appropriate use. This description is followed by an introduction to different statistical methods that can be used to analyze the clustering patterns which occur in different epidemics and epidemic stages. Research methods such as flexible analysis of irregular spatial and temporal clusters, adjustment of personal risk factors, and Bayesian approaches to disease mapping and better prediction all will be needed to understand the epidemiologic characteristics of infectious diseases in the future.

Research paper thumbnail of A multitope SARS-CoV-2 vaccine provides long-lasting B cell and T cell immunity against Delta and Omicron variants

Journal of Clinical Investigation, 2022

BACKGROUND. The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrou... more BACKGROUND. The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrough infections due to waning immunity. We report phase I/II trial results of UB-612, a multitope subunit vaccine containing S1-RBD-sFc protein and rationally designed promiscuous peptides representing sarbecovirus conserved helper T cell and cytotoxic T lymphocyte epitopes on the nucleocapsid (N), membrane (M), and spike (S2) proteins. METHOD. We conducted a phase I primary 2-dose (28 days apart) trial of 10, 30, or 100 μg UB-612 in 60 healthy young adults 20 to 55 years old, and 50 of them were boosted with 100 μg of UB-612 approximately 7 to 9 months after the second dose. A separate placebo-controlled and randomized phase II study was conducted with 2 doses of 100 μg of UB-612 (n = 3,875, 18-85 years old). We evaluated interim safety and immunogenicity of phase I until 14 days after the third (booster) dose and of phase II until 28 days after the second dose. RESULTS. No vaccine-related serious adverse events were recorded. The most common solicited adverse events were injection site pain and fatigue, mostly mild and transient. In both trials, UB-612 elicited respective neutralizing antibody titers similar to a panel of human convalescent sera. The most striking findings were long-lasting virus-neutralizing antibodies and broad T cell immunity against SARS-CoV-2 variants of concern (VoCs), including Delta and Omicron, and a strong booster-recalled memory immunity with high cross-reactive neutralizing titers against the Delta and Omicron VoCs. CONCLUSION. UB-612 has presented a favorable safety profile, potent booster effect against VoCs, and long-lasting B and broad T cell immunity that warrants further development for both primary immunization and heterologous boosting of other COVID-19 vaccines.

Research paper thumbnail of Recommendations for protecting against and mitigating the COVID-19 pandemic in long-term care facilities

Journal of Microbiology, Immunology and Infection, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of National retrospective cohort study to identify age-specific fatality risks of comorbidities among hospitalised patients with influenza-like illness in Taiwan

BMJ Open, 2019

ObjectivesThis study aimed to examine comprehensively the prognostic impact of underlying comorbi... more ObjectivesThis study aimed to examine comprehensively the prognostic impact of underlying comorbidities among hospitalised patients with influenza-like illness (ILI) in different age groups and provide recommendations targeting the vulnerable patients.Setting and participantsA retrospective cohort of 83 227 hospitalised cases with ILI were identified from Taiwan’s National Health Insurance Research Database from January 2005 to December 2010. Cases were stratified into three different age groups: paediatric (0–17 years), adult (18–64 years) and elderly (≧65 years), and their age, sex, comorbidity and past healthcare utilisation were analysed for ILI-associated fatality.Main outcome measuresORs for ILI-related fatality in different age groups were performed using multivariable analyses with generalised estimating equation models and adjusted by age, sex and underlying comorbidities.ResultsHospitalised ILI-related fatality significantly increased with comorbidities of cancer with meta...

Research paper thumbnail of Early Detection for Cases of Enterovirus- and Influenza-Like Illness through a Newly Established School-Based Syndromic Surveillance System in Taipei, January 2010 ~ August 2011

PLOS ONE, 2015

School children may transmit pathogens with cluster cases occurring on campuses and in families. ... more School children may transmit pathogens with cluster cases occurring on campuses and in families. In response to the 2009 influenza A (H1N1) pandemic, Taipei City Government officials developed a School-based Infectious Disease Syndromic Surveillance System (SID-SSS). Teachers and nurses from preschools to universities in all 12 districts within Taipei are required to daily report cases of symptomatic children or sick leave requests through the SID-SSS. The pre-diagnosis at schools is submitted firstly as common pediatric disease syndrome-groups and re-submitted after confirmation by physicians. We retrieved these data from January 2010 to August 2011 for spatio-temporal analysis and evaluated the temporal trends with cases obtained from both the Emergency Department-based Syndromic Surveillance System (ED-SSS) and the Longitudinal Health Insurance Database 2005 (LHID2005). Through the SID-SSS, enterovirus-like illness (EVI) and influenza-like illness (ILI) were the two most reported syndrome groups (77.6% and 15.8% among a total of 19,334 cases, respectively). The pre-diagnosis judgments made by school teachers and nurses showed high consistency with physicians' clinical diagnoses for EVI (97.8%) and ILI (98.9%). Most importantly, the SID-SSS had better timeliness with earlier peaks of EVI and ILI than those in the ED-SSS. Furthermore, both of the syndrome groups in these two surveillance systems had the best correlation reaching 0.98 and 0.95, respectively (p<0.01). Spatio-temporal analysis observed the patterns of EVI and ILI both diffuse from the northern suburban districts to central Taipei, with ILI spreading faster. This novel system can identify early suspected cases of two important pediatric infections occurring at schools, and

Research paper thumbnail of Surveillance and Epidemiology of Infectious Diseases using Spatial and Temporal Lustering Methods

Integrated Series in Information Systems, 2010

In the control of infectious diseases, epidemiologic information and useful clustering algorithms... more In the control of infectious diseases, epidemiologic information and useful clustering algorithms can be integrated to garner key indicators from huge amounts of daily surveillance information for the need of early intervention. This chapter first introduces the temporal, spatial and spatiotemporal clustering algorithms commonly used in surveillance systems-the key concepts behind the algorithms and the criteria for appropriate use. This description is followed by an introduction to different statistical methods that can be used to analyze the clustering patterns which occur in different epidemics and epidemic stages. Research methods such as flexible analysis of irregular spatial and temporal clusters, adjustment of personal risk factors, and Bayesian approaches to disease mapping and better prediction all will be needed to understand the epidemiologic characteristics of infectious diseases in the future.

Research paper thumbnail of Probabilistic daily ILI syndromic surveillance with a spatio-temporal bayesian hierarchical model

Background: For daily syndromic surveillance to be effective, an efficient and sensible algorithm... more Background: For daily syndromic surveillance to be effective, an efficient and sensible algorithm would be expected to detect aberrations in influenza illness, and alert public health workers prior to any impending epidemic. This detection or alert surely contains uncertainty, and thus should be evaluated with a proper probabilistic measure. However, traditional monitoring mechanisms simply provide a binary alert, failing to adequately address this uncertainty. Methods and Findings: Based on the Bayesian posterior probability of influenza-like illness (ILI) visits, the intensity of outbreak can be directly assessed. The numbers of daily emergency room ILI visits at five community hospitals in Taipei City during 2006-2007 were collected and fitted with a Bayesian hierarchical model containing meteorological factors such as temperature and vapor pressure, spatial interaction with conditional autoregressive structure, weekend and holiday effects, seasonality factors, and previous ILI visits. The proposed algorithm recommends an alert for action if the posterior probability is larger than 70%. External data from January to February of 2008 were retained for validation. The decision rule detects successfully the peak in the validation period. When comparing the posterior probability evaluation with the modified Cusum method, results show that the proposed method is able to detect the signals 1-2 days prior to the rise of ILI visits. Conclusions: This Bayesian hierarchical model not only constitutes a dynamic surveillance system but also constructs a stochastic evaluation of the need to call for alert. The monitoring mechanism provides earlier detection as well as a complementary tool for current surveillance programs.

Research paper thumbnail of From SARS in 2003 to H1N1 in 2009: Lessons learned from Taiwan in preparation for the next pandemic

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights

Research paper thumbnail of Spatial mapping of temporal risk characteristics to improve environmental health risk identification: A case study of a dengue epidemic in Taiwan

Science of The Total Environment, 2006

Mapping uneven events, such as disease cases or pollutants, is a basic but important procedure fo... more Mapping uneven events, such as disease cases or pollutants, is a basic but important procedure for analyzing regional relationships and variation in public health and environmental agencies. The purpose of mapping is to find out the spatial clustering of uneven events and identify spatial risk areas, which could lead to potential environmental hazards or epidemics. Meanwhile, more hypotheses could be generated through mapping process for further investigations. This paper proposed a novel spatial-temporal approach to focusing on: (1) how often these uneven cases occur, (2) how long these cases persist and (3) how significant cases occur in consecutive periods across the study area. The proposed model was applied to the dengue fever epidemic in Taiwan in 2002 as a case study, which was the worst epidemic in the last 60 years. This approach provides procedures to identify spatial health risk levels with temporal characteristics and assists in generating hypothesis that will be investigated in further detail.

Research paper thumbnail of The Impact of Matching Vaccine Strains and Post-SARS Public Health Efforts on Reducing Influenza-Associated Mortality among the Elderly

PLoS ONE, 2010

Public health administrators do not have effective models to predict excess influenza-associated ... more Public health administrators do not have effective models to predict excess influenza-associated mortality and monitor viral changes associated with it. This study evaluated the effect of matching/mismatching vaccine strains, type/subtype pattern changes in Taiwan's influenza viruses, and the impact of post-SARS (severe acute respiratory syndrome) public health efforts on excess influenza-associated mortalities among the elderly. A negative binomial model was developed to estimate Taiwan's monthly influenza-associated mortality among the elderly. We calculated three winter and annual excess influenzaassociated mortalities [pneumonia and influenza (P&I), respiratory and circulatory, and all-cause] from the 1999-2000 through the 2006-2007 influenza seasons. Obtaining influenza virus sequences from the months/years in which death from P&I was excessive, we investigated molecular variation in vaccine-mismatched influenza viruses by comparing hemagglutinin 1 (HA1) of the circulating and vaccine strains. We found that the higher the isolation rate of A (H3N2) and vaccine-mismatched influenza viruses, the greater the monthly P&I mortality. However, this significant positive association became negative for higher matching of A (H3N2) and public health efforts with post-SARS effect. Mean excess P&I mortality for winters was significantly higher before 2003 than after that year [mean 6 S.D.: 1.4461.35 vs. 0.3561.13, p = 0.04]. Further analysis revealed that vaccine-matched circulating influenza A viruses were significantly associated with lower excess P&I mortality during post-SARS winters (i.e., 2005-2007) than during pre-SARS winters [0.0360.06 vs. 1.5761.27, p = 0.01]. Stratification of these vaccine-matching and post-SARS effect showed substantial trends toward lower elderly excess P&I mortalities in winters with either mismatching vaccines during the post-SARS period or matching vaccines during the pre-SARS period. Importantly, all three excess mortalities were at their highest in May, 2003, when inter-hospital nosocomial infections were peaking. Furthermore, vaccine-mismatched H3N2 viruses circulating in the years with high excess P&I mortality exhibited both a lower amino acid identity percentage of HA1 between vaccine and circulating strains and a higher numbers of variations at epitope B. Our model can help future decision makers to estimate excess P&I mortality effectively, select and test virus strains for antigenic variation, and evaluate public health strategy effectiveness.

Research paper thumbnail of Taipei's Use of a Multi-Channel Mass Risk Communication Program to Rapidly Reverse an Epidemic of Highly Communicable Disease

PLoS ONE, 2009

Background: In September 2007, an outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in ... more Background: In September 2007, an outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in Keelung City and spread to Taipei City. In response to the epidemic, a new crisis management program was implemented and tested in Taipei. Methodology and Principal Findings: Having noticed that transmission surged on weekends during the Keelung epidemic, Taipei City launched a multi-channel mass risk communications program that included short message service (SMS) messages sent directly to approximately 2.2 million Taipei residents on Friday, October 12th, 2007. The public was told to keep symptomatic students from schools and was provided guidelines for preventing the spread of the disease at home. Epidemiological characteristics of Taipei's outbreak were analyzed from 461 sampled AHC cases. Median time from exposure to onset of the disease was 1 day. This was significantly shorter for cases occurring in family clusters than in class clusters (mean6SD: 2.663.2 vs. 4.3964.82 days, p = 0.03), as well as for cases occurring in larger family clusters as opposed to smaller ones (1.261.7 days vs. 3.964.0 days, p,0.01). Taipei's program had a significant impact on patient compliance. Home confinement of symptomatic children increased from 10% to 60% (p,0.05) and helped curb the spread of AHC. Taipei experienced a rapid decrease in AHC cases between the Friday of the SMS announcement and the following Monday, October 15, (0.70% vs. 0.36%). By October 26, AHC cases reduced to 0.01%. The success of this risk communication program in Taipei (as compared to Keelung) is further reflected through rapid improvements in three epidemic indicators: (1) significantly lower crude attack rates (1.95% vs. 14.92%, p,0.001), (2) a short epidemic period of AHC (13 vs. 34 days), and (3) a quick drop in risk level (1,2 weeks) in Taipei districts that border Keelung (the original domestic epicenter). Conclusions and Significance: The timely launch of this systematic, communication-based intervention proved effective at preventing a dangerous spike in AHC and was able to bring this high-risk disease under control. We recommend that public health officials incorporate similar methods into existing guidelines for preventing pandemic influenza and other emerging infectious diseases.

Research paper thumbnail of Risk Factors of Enterovirus 71 Infection and Associated Hand, Foot, and Mouth Disease/Herpangina in Children During an Epidemic in Taiwan

Pediatrics, 2002

Objective. In 1998, an enterovirus 71 (EV71) epidemic in Taiwan was associated with hand, foot, a... more Objective. In 1998, an enterovirus 71 (EV71) epidemic in Taiwan was associated with hand, foot, and mouth disease (HFMD)/herpangina and involved 78 fatal cases. We measured EV71 seroprevalence rates before and after the epidemic and investigated risk factors associated with EV71 infection and illness. Methods. Neutralizing antibodies to EV71 were assayed for 539 people before the epidemic and 4619 people of similar ages after the epidemic. Questionnaires, which were completed during household interviews after the epidemic, solicited demographic variables, exposure history, and clinical manifestations. Results. A total of 129 106 cases of HFMD were reported during the epidemic. Age-specific pre-epidemic EV71 seroprevalence rates were inversely related to age-specific periepidemic mortality rates (r = −0.82) or severe case rates (r = −0.93). Higher postepidemic EV71 seropositive rates among children who were younger than 3 years positively correlated with higher mortality rates in dif...

Research paper thumbnail of Emergence and Evolution of Avian H5N2 Influenza Viruses in Chickens in Taiwan

Journal of Virology, 2014

Sporadic activity by H5N2 influenza viruses has been observed in chickens in Taiwan from 2003 to ... more Sporadic activity by H5N2 influenza viruses has been observed in chickens in Taiwan from 2003 to 2012. The available information suggests that these viruses were generated by reassortment between a Mexican-like H5N2 virus and a local enzootic H6N1 virus. Yet the origin, prevalence, and pathogenicity of these H5N2 viruses have not been fully defined. Following the 2012 highly pathogenic avian influenza (HPAI) outbreaks, surveillance was conducted from December 2012 to July 2013 at a live-poultry wholesale market in Taipei. Our findings showed that H5N2 and H6N1 viruses cocirculated at low levels in chickens in Taiwan. Phylogenetic analyses revealed that all H5N2 viruses had hemagglutinin (HA) and neuraminidase (NA) genes derived from a 1994 Mexican-like virus, while their internal gene complexes were incorporated from the enzootic H6N1 virus lineage by multiple reassortment events. Pathogenicity studies demonstrated heterogeneous results even though all tested viruses had motifs (R-X...

Research paper thumbnail of High rate of hepatitis C virus infection in an isolated community: Persistent hyperendemicity or period-related phenomena?

Journal of Medical Virology, 1997

We investigated underlying risks for hyperendemic hepatitis C virus (HCV) infection among the 185... more We investigated underlying risks for hyperendemic hepatitis C virus (HCV) infection among the 1853 inhabitants of a mountainous village in Eastern Taiwan with high prevalence of HCV and hepatitis B virus (HBV). Among the 80 selected adults, we found that having resided away from the village before 1985 was protective against HCV infection, while residing in the village after 1985 posed little risk for HCV infection to children and young adults < 30 years of age. Among the 559 school children 7 through 14 years of age, anti-HCV prevalence was 1.9%, and the HBV carrier rate was 29%. Following up 270 children 1 year later, we found that new HCV infection occurred in 0.74% and new or repeated HBV infection occurred in 6.5% of the children, indicating distinct transmission patterns between HBV and HCV. Children of anti-HCVpositive mothers were either anti-HCV-negative or were infected by distinct genotypes of HCV from those infecting their mothers; most married couples in whom both were infected, were infected by HCV of discordant genotypes, indicating negligible importance of sexual or vertical HCV transmission. A casecontrol study comparing 13 anti-HCV-positive and 53 anti-HCV-negative children showed that having received parenteral medication in local clinics was a significant risk for HCV infection. Our data indicate that, unlike the case of HBV, HCV transmission by vertical or sexual route, or through casual contact are extremely inefficient, and our data further suggest that HCV hyperendemicity is unlikely to persist as a result of the more stringent practice of parenteral precautions in nearly all aspects of daily life.

Research paper thumbnail of Facing the Global Challenges of Emerging and Re-emerging Infectious Diseases in Taiwan

International Journal of Infectious Diseases, 2008

Research paper thumbnail of Influenza pandemic plan: integrated wild bird/domestic avian/swine/human flu surveillance systems in Taiwan

International Congress Series, 2004

Background: Integrated virological surveillance systems along the transmission chains from animal... more Background: Integrated virological surveillance systems along the transmission chains from animals to humans in areas with large swine/chicken/duck populations and numerous wild migrating birds grasps the frontline timing to detect novel flu viruses. Materials and methods: Animal and human virological surveillance systems have been established to monitor evolutional changes of flu viruses in the same and different hosts/geographical areas over years. Selected sentinel physicians collected specimens from influenza-like patients at local clinics/hospitals in: (a) counties with high populations of swine/avian/wild birds in Taiwan and (b) Kinmen islet-closest to China. Results: Novel animal and human influenza viruses (swine H1N2, avian H5 and H7 and human H3N2 within the lineage of A/Fujian/411/2002) were detected in 2002. However, subtypes of H5, H7 and H9 were not found in human isolates in Taiwan till Oct. 2003. Sentinel physician and school absenteeism surveillance systems were more sensitive than human laboratory and respiratory syndromic surveillance systems. Variation patterns of antigenic sites of HA1 in human versus animal flu A viruses were also quite different. Conclusion: The integrated surveillance is very useful in disease control and understanding conditions for the emergence of novel flu viruses with pandemic potential.

Research paper thumbnail of Human influenza surveillance in areas with animal flu epidemics and China visitors in Taiwan

International Congress Series, 2004

Background: This study investigates the changes in human flu viruses in areas where unique animal... more Background: This study investigates the changes in human flu viruses in areas where unique animal flu viruses or epidemics were isolated in Taiwan and Kinmen islet. Materials and methods: Sentinel physicians obtained throat swabs from patients presenting with flu-like illness and two-step RT-PCR, using five sets of primers for matrix (M) and HA2, to detect all the animal influenza viruses and then typing/subtyping for human flu viruses. Questionnaires included travel history, animal contacts and occupations. Results: One flu B and eight flu A H3N2 isolates were identified in the flu season of 2002-2003, including 1, 2, 2 and 3 H3N2 in Taoyuan, Yilan, Tainan and Kinmen, respectively. Amino acid sequences of HA of human isolates revealed that Pro (P) at position 227 among most of the Kinmen isolates (2/3) replaced Ser (S) in the Taiwanese isolates, including one mutant from Gln (Q) to His (H) at position 156 of the HA gene for five out of eight H3N2 Taiwan isolates. Phylogenetic analysis demonstrated that all of the H3N2 viruses were of human origin (belonging to the lineage of A/Fujian/411/2002), with 80-90% homology in HA, NA and M gene segments of A/Swine/PingTung/Taiwan/199.2/02 (H3N2) and 75-77% homology in HA gene segment of A/Wild Bird/Taiwan/243/02(H3) and A/Mallard Duck/Taiwan/3.3/03 (H3). Conclusions: Residents in Kinmen islet frequently traveling from China need to monitor their flu A viruses that might be different from those obtained on the main Taiwan island.

Research paper thumbnail of Assessment of Intervention Measures for the 2003 SARS Epidemic in Taiwan by Use of a Back-Projection Method

Infection Control & Hospital Epidemiology, 2007

Objectives. To reconstruct the infection curve for the 2003 severe acute respiratory syndrome (SA... more Objectives. To reconstruct the infection curve for the 2003 severe acute respiratory syndrome (SARS) epidemic in Taiwan and to ascertain the temporal changes in the daily number of infections that occurred during the course of the outbreak. Method. Back-projection method. Results. The peaks of the epidemic correspond well with the occurrence of major infection clusters in the hospitals. The overall downward trend of the infection curve after early May corresponds well to the date (May 10) when changes in the review and classification procedure were implemented by the SARS Prevention and Extrication Committee. Conclusion. The major infection control measures taken by the Taiwanese government over the course of the SARS epidemic, particularly those regarding infection control in hospitals, played a crucial role in containing the outbreak.

Research paper thumbnail of Epidemiology of measles in Taiwan: dynamics of transmission and timeliness of reporting during an epidemic in 1988–9

Epidemiology and Infection, 1995

SummaryWe analysed nation-wide reported measles cases during the 1988–9 epidemic and found that l... more SummaryWe analysed nation-wide reported measles cases during the 1988–9 epidemic and found that longer duration and wider spread were two major characteristics of the outbreak. All the 22 county/city index cases were reported with a delay of > 4 days and 64% were aged 5–14 years. This epidemic occurred mainly among 5–14-year-old school-children (59%), infants under 1 year (19%), and pre-school children (18%). The overall attack rate was 0·63 cases per 10000 population, with the highest attack rate (7·4 cases per 10000 population) occurring in infants. Among 280 confirmed cases <15 months of age, 9-month-old infants (42 cases) had a higher risk of measles and peaked at 10 months (49 cases). This epidemic started in March 1988 among 5–9-year-old children in the northern suburban area, then spread to Taipei City and neighbouring counties or cities. It continued to spread from the northern to southern and western areas during the summer vacation and New Year holidays. Multiple log...

Research paper thumbnail of Early Detection for Cases of Enterovirus- and Influenza-Like Illness through a Newly Established School-Based Syndromic Surveillance System in Taipei, January 2010 ~ August 2011

PLOS ONE, Apr 15, 2015

School children may transmit pathogens with cluster cases occurring on campuses and in families. ... more School children may transmit pathogens with cluster cases occurring on campuses and in families. In response to the 2009 influenza A (H1N1) pandemic, Taipei City Government officials developed a School-based Infectious Disease Syndromic Surveillance System (SID-SSS). Teachers and nurses from preschools to universities in all 12 districts within Taipei are required to daily report cases of symptomatic children or sick leave requests through the SID-SSS. The pre-diagnosis at schools is submitted firstly as common pediatric disease syndrome-groups and re-submitted after confirmation by physicians. We retrieved these data from January 2010 to August 2011 for spatio-temporal analysis and evaluated the temporal trends with cases obtained from both the Emergency Department-based Syndromic Surveillance System (ED-SSS) and the Longitudinal Health Insurance Database 2005 (LHID2005). Through the SID-SSS, enterovirus-like illness (EVI) and influenza-like illness (ILI) were the two most reported syndrome groups (77.6% and 15.8% among a total of 19,334 cases, respectively). The pre-diagnosis judgments made by school teachers and nurses showed high consistency with physicians' clinical diagnoses for EVI (97.8%) and ILI (98.9%). Most importantly, the SID-SSS had better timeliness with earlier peaks of EVI and ILI than those in the ED-SSS. Furthermore, both of the syndrome groups in these two surveillance systems had the best correlation reaching 0.98 and 0.95, respectively (p<0.01). Spatio-temporal analysis observed the patterns of EVI and ILI both diffuse from the northern suburban districts to central Taipei, with ILI spreading faster. This novel system can identify early suspected cases of two important pediatric infections occurring at schools, and

Research paper thumbnail of Surveillance and Epidemiology of Infectious Diseases using Spatial and Temporal Lustering Methods

Integrated series on information systems, Oct 19, 2010

In the control of infectious diseases, epidemiologic information and useful clustering algorithms... more In the control of infectious diseases, epidemiologic information and useful clustering algorithms can be integrated to garner key indicators from huge amounts of daily surveillance information for the need of early intervention. This chapter first introduces the temporal, spatial and spatiotemporal clustering algorithms commonly used in surveillance systems-the key concepts behind the algorithms and the criteria for appropriate use. This description is followed by an introduction to different statistical methods that can be used to analyze the clustering patterns which occur in different epidemics and epidemic stages. Research methods such as flexible analysis of irregular spatial and temporal clusters, adjustment of personal risk factors, and Bayesian approaches to disease mapping and better prediction all will be needed to understand the epidemiologic characteristics of infectious diseases in the future.

Research paper thumbnail of A multitope SARS-CoV-2 vaccine provides long-lasting B cell and T cell immunity against Delta and Omicron variants

Journal of Clinical Investigation, 2022

BACKGROUND. The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrou... more BACKGROUND. The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrough infections due to waning immunity. We report phase I/II trial results of UB-612, a multitope subunit vaccine containing S1-RBD-sFc protein and rationally designed promiscuous peptides representing sarbecovirus conserved helper T cell and cytotoxic T lymphocyte epitopes on the nucleocapsid (N), membrane (M), and spike (S2) proteins. METHOD. We conducted a phase I primary 2-dose (28 days apart) trial of 10, 30, or 100 μg UB-612 in 60 healthy young adults 20 to 55 years old, and 50 of them were boosted with 100 μg of UB-612 approximately 7 to 9 months after the second dose. A separate placebo-controlled and randomized phase II study was conducted with 2 doses of 100 μg of UB-612 (n = 3,875, 18-85 years old). We evaluated interim safety and immunogenicity of phase I until 14 days after the third (booster) dose and of phase II until 28 days after the second dose. RESULTS. No vaccine-related serious adverse events were recorded. The most common solicited adverse events were injection site pain and fatigue, mostly mild and transient. In both trials, UB-612 elicited respective neutralizing antibody titers similar to a panel of human convalescent sera. The most striking findings were long-lasting virus-neutralizing antibodies and broad T cell immunity against SARS-CoV-2 variants of concern (VoCs), including Delta and Omicron, and a strong booster-recalled memory immunity with high cross-reactive neutralizing titers against the Delta and Omicron VoCs. CONCLUSION. UB-612 has presented a favorable safety profile, potent booster effect against VoCs, and long-lasting B and broad T cell immunity that warrants further development for both primary immunization and heterologous boosting of other COVID-19 vaccines.

Research paper thumbnail of Recommendations for protecting against and mitigating the COVID-19 pandemic in long-term care facilities

Journal of Microbiology, Immunology and Infection, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of National retrospective cohort study to identify age-specific fatality risks of comorbidities among hospitalised patients with influenza-like illness in Taiwan

BMJ Open, 2019

ObjectivesThis study aimed to examine comprehensively the prognostic impact of underlying comorbi... more ObjectivesThis study aimed to examine comprehensively the prognostic impact of underlying comorbidities among hospitalised patients with influenza-like illness (ILI) in different age groups and provide recommendations targeting the vulnerable patients.Setting and participantsA retrospective cohort of 83 227 hospitalised cases with ILI were identified from Taiwan’s National Health Insurance Research Database from January 2005 to December 2010. Cases were stratified into three different age groups: paediatric (0–17 years), adult (18–64 years) and elderly (≧65 years), and their age, sex, comorbidity and past healthcare utilisation were analysed for ILI-associated fatality.Main outcome measuresORs for ILI-related fatality in different age groups were performed using multivariable analyses with generalised estimating equation models and adjusted by age, sex and underlying comorbidities.ResultsHospitalised ILI-related fatality significantly increased with comorbidities of cancer with meta...

Research paper thumbnail of Early Detection for Cases of Enterovirus- and Influenza-Like Illness through a Newly Established School-Based Syndromic Surveillance System in Taipei, January 2010 ~ August 2011

PLOS ONE, 2015

School children may transmit pathogens with cluster cases occurring on campuses and in families. ... more School children may transmit pathogens with cluster cases occurring on campuses and in families. In response to the 2009 influenza A (H1N1) pandemic, Taipei City Government officials developed a School-based Infectious Disease Syndromic Surveillance System (SID-SSS). Teachers and nurses from preschools to universities in all 12 districts within Taipei are required to daily report cases of symptomatic children or sick leave requests through the SID-SSS. The pre-diagnosis at schools is submitted firstly as common pediatric disease syndrome-groups and re-submitted after confirmation by physicians. We retrieved these data from January 2010 to August 2011 for spatio-temporal analysis and evaluated the temporal trends with cases obtained from both the Emergency Department-based Syndromic Surveillance System (ED-SSS) and the Longitudinal Health Insurance Database 2005 (LHID2005). Through the SID-SSS, enterovirus-like illness (EVI) and influenza-like illness (ILI) were the two most reported syndrome groups (77.6% and 15.8% among a total of 19,334 cases, respectively). The pre-diagnosis judgments made by school teachers and nurses showed high consistency with physicians' clinical diagnoses for EVI (97.8%) and ILI (98.9%). Most importantly, the SID-SSS had better timeliness with earlier peaks of EVI and ILI than those in the ED-SSS. Furthermore, both of the syndrome groups in these two surveillance systems had the best correlation reaching 0.98 and 0.95, respectively (p<0.01). Spatio-temporal analysis observed the patterns of EVI and ILI both diffuse from the northern suburban districts to central Taipei, with ILI spreading faster. This novel system can identify early suspected cases of two important pediatric infections occurring at schools, and

Research paper thumbnail of Surveillance and Epidemiology of Infectious Diseases using Spatial and Temporal Lustering Methods

Integrated Series in Information Systems, 2010

In the control of infectious diseases, epidemiologic information and useful clustering algorithms... more In the control of infectious diseases, epidemiologic information and useful clustering algorithms can be integrated to garner key indicators from huge amounts of daily surveillance information for the need of early intervention. This chapter first introduces the temporal, spatial and spatiotemporal clustering algorithms commonly used in surveillance systems-the key concepts behind the algorithms and the criteria for appropriate use. This description is followed by an introduction to different statistical methods that can be used to analyze the clustering patterns which occur in different epidemics and epidemic stages. Research methods such as flexible analysis of irregular spatial and temporal clusters, adjustment of personal risk factors, and Bayesian approaches to disease mapping and better prediction all will be needed to understand the epidemiologic characteristics of infectious diseases in the future.

Research paper thumbnail of Probabilistic daily ILI syndromic surveillance with a spatio-temporal bayesian hierarchical model

Background: For daily syndromic surveillance to be effective, an efficient and sensible algorithm... more Background: For daily syndromic surveillance to be effective, an efficient and sensible algorithm would be expected to detect aberrations in influenza illness, and alert public health workers prior to any impending epidemic. This detection or alert surely contains uncertainty, and thus should be evaluated with a proper probabilistic measure. However, traditional monitoring mechanisms simply provide a binary alert, failing to adequately address this uncertainty. Methods and Findings: Based on the Bayesian posterior probability of influenza-like illness (ILI) visits, the intensity of outbreak can be directly assessed. The numbers of daily emergency room ILI visits at five community hospitals in Taipei City during 2006-2007 were collected and fitted with a Bayesian hierarchical model containing meteorological factors such as temperature and vapor pressure, spatial interaction with conditional autoregressive structure, weekend and holiday effects, seasonality factors, and previous ILI visits. The proposed algorithm recommends an alert for action if the posterior probability is larger than 70%. External data from January to February of 2008 were retained for validation. The decision rule detects successfully the peak in the validation period. When comparing the posterior probability evaluation with the modified Cusum method, results show that the proposed method is able to detect the signals 1-2 days prior to the rise of ILI visits. Conclusions: This Bayesian hierarchical model not only constitutes a dynamic surveillance system but also constructs a stochastic evaluation of the need to call for alert. The monitoring mechanism provides earlier detection as well as a complementary tool for current surveillance programs.

Research paper thumbnail of From SARS in 2003 to H1N1 in 2009: Lessons learned from Taiwan in preparation for the next pandemic

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights

Research paper thumbnail of Spatial mapping of temporal risk characteristics to improve environmental health risk identification: A case study of a dengue epidemic in Taiwan

Science of The Total Environment, 2006

Mapping uneven events, such as disease cases or pollutants, is a basic but important procedure fo... more Mapping uneven events, such as disease cases or pollutants, is a basic but important procedure for analyzing regional relationships and variation in public health and environmental agencies. The purpose of mapping is to find out the spatial clustering of uneven events and identify spatial risk areas, which could lead to potential environmental hazards or epidemics. Meanwhile, more hypotheses could be generated through mapping process for further investigations. This paper proposed a novel spatial-temporal approach to focusing on: (1) how often these uneven cases occur, (2) how long these cases persist and (3) how significant cases occur in consecutive periods across the study area. The proposed model was applied to the dengue fever epidemic in Taiwan in 2002 as a case study, which was the worst epidemic in the last 60 years. This approach provides procedures to identify spatial health risk levels with temporal characteristics and assists in generating hypothesis that will be investigated in further detail.

Research paper thumbnail of The Impact of Matching Vaccine Strains and Post-SARS Public Health Efforts on Reducing Influenza-Associated Mortality among the Elderly

PLoS ONE, 2010

Public health administrators do not have effective models to predict excess influenza-associated ... more Public health administrators do not have effective models to predict excess influenza-associated mortality and monitor viral changes associated with it. This study evaluated the effect of matching/mismatching vaccine strains, type/subtype pattern changes in Taiwan's influenza viruses, and the impact of post-SARS (severe acute respiratory syndrome) public health efforts on excess influenza-associated mortalities among the elderly. A negative binomial model was developed to estimate Taiwan's monthly influenza-associated mortality among the elderly. We calculated three winter and annual excess influenzaassociated mortalities [pneumonia and influenza (P&I), respiratory and circulatory, and all-cause] from the 1999-2000 through the 2006-2007 influenza seasons. Obtaining influenza virus sequences from the months/years in which death from P&I was excessive, we investigated molecular variation in vaccine-mismatched influenza viruses by comparing hemagglutinin 1 (HA1) of the circulating and vaccine strains. We found that the higher the isolation rate of A (H3N2) and vaccine-mismatched influenza viruses, the greater the monthly P&I mortality. However, this significant positive association became negative for higher matching of A (H3N2) and public health efforts with post-SARS effect. Mean excess P&I mortality for winters was significantly higher before 2003 than after that year [mean 6 S.D.: 1.4461.35 vs. 0.3561.13, p = 0.04]. Further analysis revealed that vaccine-matched circulating influenza A viruses were significantly associated with lower excess P&I mortality during post-SARS winters (i.e., 2005-2007) than during pre-SARS winters [0.0360.06 vs. 1.5761.27, p = 0.01]. Stratification of these vaccine-matching and post-SARS effect showed substantial trends toward lower elderly excess P&I mortalities in winters with either mismatching vaccines during the post-SARS period or matching vaccines during the pre-SARS period. Importantly, all three excess mortalities were at their highest in May, 2003, when inter-hospital nosocomial infections were peaking. Furthermore, vaccine-mismatched H3N2 viruses circulating in the years with high excess P&I mortality exhibited both a lower amino acid identity percentage of HA1 between vaccine and circulating strains and a higher numbers of variations at epitope B. Our model can help future decision makers to estimate excess P&I mortality effectively, select and test virus strains for antigenic variation, and evaluate public health strategy effectiveness.

Research paper thumbnail of Taipei's Use of a Multi-Channel Mass Risk Communication Program to Rapidly Reverse an Epidemic of Highly Communicable Disease

PLoS ONE, 2009

Background: In September 2007, an outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in ... more Background: In September 2007, an outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in Keelung City and spread to Taipei City. In response to the epidemic, a new crisis management program was implemented and tested in Taipei. Methodology and Principal Findings: Having noticed that transmission surged on weekends during the Keelung epidemic, Taipei City launched a multi-channel mass risk communications program that included short message service (SMS) messages sent directly to approximately 2.2 million Taipei residents on Friday, October 12th, 2007. The public was told to keep symptomatic students from schools and was provided guidelines for preventing the spread of the disease at home. Epidemiological characteristics of Taipei's outbreak were analyzed from 461 sampled AHC cases. Median time from exposure to onset of the disease was 1 day. This was significantly shorter for cases occurring in family clusters than in class clusters (mean6SD: 2.663.2 vs. 4.3964.82 days, p = 0.03), as well as for cases occurring in larger family clusters as opposed to smaller ones (1.261.7 days vs. 3.964.0 days, p,0.01). Taipei's program had a significant impact on patient compliance. Home confinement of symptomatic children increased from 10% to 60% (p,0.05) and helped curb the spread of AHC. Taipei experienced a rapid decrease in AHC cases between the Friday of the SMS announcement and the following Monday, October 15, (0.70% vs. 0.36%). By October 26, AHC cases reduced to 0.01%. The success of this risk communication program in Taipei (as compared to Keelung) is further reflected through rapid improvements in three epidemic indicators: (1) significantly lower crude attack rates (1.95% vs. 14.92%, p,0.001), (2) a short epidemic period of AHC (13 vs. 34 days), and (3) a quick drop in risk level (1,2 weeks) in Taipei districts that border Keelung (the original domestic epicenter). Conclusions and Significance: The timely launch of this systematic, communication-based intervention proved effective at preventing a dangerous spike in AHC and was able to bring this high-risk disease under control. We recommend that public health officials incorporate similar methods into existing guidelines for preventing pandemic influenza and other emerging infectious diseases.

Research paper thumbnail of Risk Factors of Enterovirus 71 Infection and Associated Hand, Foot, and Mouth Disease/Herpangina in Children During an Epidemic in Taiwan

Pediatrics, 2002

Objective. In 1998, an enterovirus 71 (EV71) epidemic in Taiwan was associated with hand, foot, a... more Objective. In 1998, an enterovirus 71 (EV71) epidemic in Taiwan was associated with hand, foot, and mouth disease (HFMD)/herpangina and involved 78 fatal cases. We measured EV71 seroprevalence rates before and after the epidemic and investigated risk factors associated with EV71 infection and illness. Methods. Neutralizing antibodies to EV71 were assayed for 539 people before the epidemic and 4619 people of similar ages after the epidemic. Questionnaires, which were completed during household interviews after the epidemic, solicited demographic variables, exposure history, and clinical manifestations. Results. A total of 129 106 cases of HFMD were reported during the epidemic. Age-specific pre-epidemic EV71 seroprevalence rates were inversely related to age-specific periepidemic mortality rates (r = −0.82) or severe case rates (r = −0.93). Higher postepidemic EV71 seropositive rates among children who were younger than 3 years positively correlated with higher mortality rates in dif...

Research paper thumbnail of Emergence and Evolution of Avian H5N2 Influenza Viruses in Chickens in Taiwan

Journal of Virology, 2014

Sporadic activity by H5N2 influenza viruses has been observed in chickens in Taiwan from 2003 to ... more Sporadic activity by H5N2 influenza viruses has been observed in chickens in Taiwan from 2003 to 2012. The available information suggests that these viruses were generated by reassortment between a Mexican-like H5N2 virus and a local enzootic H6N1 virus. Yet the origin, prevalence, and pathogenicity of these H5N2 viruses have not been fully defined. Following the 2012 highly pathogenic avian influenza (HPAI) outbreaks, surveillance was conducted from December 2012 to July 2013 at a live-poultry wholesale market in Taipei. Our findings showed that H5N2 and H6N1 viruses cocirculated at low levels in chickens in Taiwan. Phylogenetic analyses revealed that all H5N2 viruses had hemagglutinin (HA) and neuraminidase (NA) genes derived from a 1994 Mexican-like virus, while their internal gene complexes were incorporated from the enzootic H6N1 virus lineage by multiple reassortment events. Pathogenicity studies demonstrated heterogeneous results even though all tested viruses had motifs (R-X...

Research paper thumbnail of High rate of hepatitis C virus infection in an isolated community: Persistent hyperendemicity or period-related phenomena?

Journal of Medical Virology, 1997

We investigated underlying risks for hyperendemic hepatitis C virus (HCV) infection among the 185... more We investigated underlying risks for hyperendemic hepatitis C virus (HCV) infection among the 1853 inhabitants of a mountainous village in Eastern Taiwan with high prevalence of HCV and hepatitis B virus (HBV). Among the 80 selected adults, we found that having resided away from the village before 1985 was protective against HCV infection, while residing in the village after 1985 posed little risk for HCV infection to children and young adults < 30 years of age. Among the 559 school children 7 through 14 years of age, anti-HCV prevalence was 1.9%, and the HBV carrier rate was 29%. Following up 270 children 1 year later, we found that new HCV infection occurred in 0.74% and new or repeated HBV infection occurred in 6.5% of the children, indicating distinct transmission patterns between HBV and HCV. Children of anti-HCVpositive mothers were either anti-HCV-negative or were infected by distinct genotypes of HCV from those infecting their mothers; most married couples in whom both were infected, were infected by HCV of discordant genotypes, indicating negligible importance of sexual or vertical HCV transmission. A casecontrol study comparing 13 anti-HCV-positive and 53 anti-HCV-negative children showed that having received parenteral medication in local clinics was a significant risk for HCV infection. Our data indicate that, unlike the case of HBV, HCV transmission by vertical or sexual route, or through casual contact are extremely inefficient, and our data further suggest that HCV hyperendemicity is unlikely to persist as a result of the more stringent practice of parenteral precautions in nearly all aspects of daily life.

Research paper thumbnail of Facing the Global Challenges of Emerging and Re-emerging Infectious Diseases in Taiwan

International Journal of Infectious Diseases, 2008

Research paper thumbnail of Influenza pandemic plan: integrated wild bird/domestic avian/swine/human flu surveillance systems in Taiwan

International Congress Series, 2004

Background: Integrated virological surveillance systems along the transmission chains from animal... more Background: Integrated virological surveillance systems along the transmission chains from animals to humans in areas with large swine/chicken/duck populations and numerous wild migrating birds grasps the frontline timing to detect novel flu viruses. Materials and methods: Animal and human virological surveillance systems have been established to monitor evolutional changes of flu viruses in the same and different hosts/geographical areas over years. Selected sentinel physicians collected specimens from influenza-like patients at local clinics/hospitals in: (a) counties with high populations of swine/avian/wild birds in Taiwan and (b) Kinmen islet-closest to China. Results: Novel animal and human influenza viruses (swine H1N2, avian H5 and H7 and human H3N2 within the lineage of A/Fujian/411/2002) were detected in 2002. However, subtypes of H5, H7 and H9 were not found in human isolates in Taiwan till Oct. 2003. Sentinel physician and school absenteeism surveillance systems were more sensitive than human laboratory and respiratory syndromic surveillance systems. Variation patterns of antigenic sites of HA1 in human versus animal flu A viruses were also quite different. Conclusion: The integrated surveillance is very useful in disease control and understanding conditions for the emergence of novel flu viruses with pandemic potential.

Research paper thumbnail of Human influenza surveillance in areas with animal flu epidemics and China visitors in Taiwan

International Congress Series, 2004

Background: This study investigates the changes in human flu viruses in areas where unique animal... more Background: This study investigates the changes in human flu viruses in areas where unique animal flu viruses or epidemics were isolated in Taiwan and Kinmen islet. Materials and methods: Sentinel physicians obtained throat swabs from patients presenting with flu-like illness and two-step RT-PCR, using five sets of primers for matrix (M) and HA2, to detect all the animal influenza viruses and then typing/subtyping for human flu viruses. Questionnaires included travel history, animal contacts and occupations. Results: One flu B and eight flu A H3N2 isolates were identified in the flu season of 2002-2003, including 1, 2, 2 and 3 H3N2 in Taoyuan, Yilan, Tainan and Kinmen, respectively. Amino acid sequences of HA of human isolates revealed that Pro (P) at position 227 among most of the Kinmen isolates (2/3) replaced Ser (S) in the Taiwanese isolates, including one mutant from Gln (Q) to His (H) at position 156 of the HA gene for five out of eight H3N2 Taiwan isolates. Phylogenetic analysis demonstrated that all of the H3N2 viruses were of human origin (belonging to the lineage of A/Fujian/411/2002), with 80-90% homology in HA, NA and M gene segments of A/Swine/PingTung/Taiwan/199.2/02 (H3N2) and 75-77% homology in HA gene segment of A/Wild Bird/Taiwan/243/02(H3) and A/Mallard Duck/Taiwan/3.3/03 (H3). Conclusions: Residents in Kinmen islet frequently traveling from China need to monitor their flu A viruses that might be different from those obtained on the main Taiwan island.

Research paper thumbnail of Assessment of Intervention Measures for the 2003 SARS Epidemic in Taiwan by Use of a Back-Projection Method

Infection Control & Hospital Epidemiology, 2007

Objectives. To reconstruct the infection curve for the 2003 severe acute respiratory syndrome (SA... more Objectives. To reconstruct the infection curve for the 2003 severe acute respiratory syndrome (SARS) epidemic in Taiwan and to ascertain the temporal changes in the daily number of infections that occurred during the course of the outbreak. Method. Back-projection method. Results. The peaks of the epidemic correspond well with the occurrence of major infection clusters in the hospitals. The overall downward trend of the infection curve after early May corresponds well to the date (May 10) when changes in the review and classification procedure were implemented by the SARS Prevention and Extrication Committee. Conclusion. The major infection control measures taken by the Taiwanese government over the course of the SARS epidemic, particularly those regarding infection control in hospitals, played a crucial role in containing the outbreak.

Research paper thumbnail of Epidemiology of measles in Taiwan: dynamics of transmission and timeliness of reporting during an epidemic in 1988–9

Epidemiology and Infection, 1995

SummaryWe analysed nation-wide reported measles cases during the 1988–9 epidemic and found that l... more SummaryWe analysed nation-wide reported measles cases during the 1988–9 epidemic and found that longer duration and wider spread were two major characteristics of the outbreak. All the 22 county/city index cases were reported with a delay of > 4 days and 64% were aged 5–14 years. This epidemic occurred mainly among 5–14-year-old school-children (59%), infants under 1 year (19%), and pre-school children (18%). The overall attack rate was 0·63 cases per 10000 population, with the highest attack rate (7·4 cases per 10000 population) occurring in infants. Among 280 confirmed cases <15 months of age, 9-month-old infants (42 cases) had a higher risk of measles and peaked at 10 months (49 cases). This epidemic started in March 1988 among 5–9-year-old children in the northern suburban area, then spread to Taipei City and neighbouring counties or cities. It continued to spread from the northern to southern and western areas during the summer vacation and New Year holidays. Multiple log...