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ABSTRACT: Recently, enterovirus 71 (EV71) has caused life-threatening outbreaks involving neurological and cardiopulmonary complications in Asian children with unknown mechanism. EV71 has one single serotype but can be phylogenetically classified into 3 main genogroups (A, B and C) and 11 genotypes (A, B1∼B5 and C1∼C5). In Taiwan, nationwide EV71 epidemics with different predominant genotypes occurred in 1998 (C2), 2000-2001 (B4), 2004-2005 (C4), and 2008 (B5). In this study, sera were collected to measure cross-reactive neutralizing antibody titers against different genotypes.
We collected historical sera from children who developed an EV71 infection in 1998, 2000, 2005, 2008, or 2010 and measured cross-reactive neutralizing antibody titers against all 11 EV71 genotypes. In addition, we aligned and compared the amino acid sequences of P1 proteins of the tested viruses.
Serology data showed that children infected with genogroups B and C consistently have lower neutralizing antibody titers against genogroup A (>4-fold difference). The sequence comparisons revealed that five amino acid signatures (N143D in VP2; K18R, H116Y, D167E, and S275A in VP1) are specific for genogroup A and may be related to the observed antigenic variations.
This study documented antigenic variations among different EV71 genogroups and identified potential immunodominant amino acid positions. Enterovirus surveillance and vaccine development should monitor these positions.
PLoS Neglected Tropical Diseases 02/2013; 7(2):e2067. · 4.69 Impact Factor
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ABSTRACT: Enterovirus 71 (EV71) is causing life-threatening outbreaks in tropical Asia. In Taiwan and other tropical Asian countries, although nationwide EV71 epidemics occur cyclically, age-specific incidence rates of EV71 infections that are critical to estimate disease burden and design vaccine trials are not clear. A nationwide EV71 epidemic occurred in 2008-09 in Taiwan, which provided a unique opportunity to estimate age-specific incidence rates of EV71 infections.
We prospectively recruited 749 healthy neonates and conducted follow-ups from June 2006 to December 2009. Sera were obtained from participants at 0, 6, 12, 24, and 36 months of age for measuring EV71 neutralizing antibody titers. If the participants developed suspected enterovirus illnesses, throat swabs were collected for virus isolation.
We detected 28 EV71 infections including 20 symptomatic and 8 asymptomatic infections. Age-specific incidence rates of EV71 infection increased from 1.71 per 100 person-years at 0-6 months of age to 4.09, 5.74, and 4.97 per 100 person-years at 7-12, 13-24, and 25-36 months of age, respectively. Cumulative incidence rate was 15.15 per 100 persons by 36 months of age, respectively.
Risk of EV71 infections in Taiwan increased after 6 months of age during EV71 epidemics. The cumulative incidence rate was 15% by 36 months of age, and 29% of EV71 infections were asymptomatic in young children.
PLoS Neglected Tropical Diseases 02/2012; 6(2):e1476. · 4.69 Impact Factor
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ABSTRACT: Enteroviruses include over 100 serotypes and usually cause self-limited infections with non-specific symptoms in children, with the exceptions of polioviruses and enterovirus 71 which frequently cause neurologic complications. Therefore, early detection and serotyping of enteroviruses are critical in clinical management and disease surveillance. Traditional methods for detection and serotyping of enteroviruses are virus isolation and immunofluorescence assay, which are time-consuming. In this study, we compare virus isolation and two molecular tests for detection and serotyping of enteroviruses in clinical samples.
One hundred and ten throat swabs were collected from pediatric outpatients with enterovirus-like illnesses (hand-foot-mouth disease, herpangina, and non-specific febrile illness). Virus isolation was conducted using multiple cell lines and isolated viruses were serotyped using immunofluorescent assay. In the molecular tests, a semi-nested RT-PCR and a novel CODEHOP platform were used to detect the 5'UTR and VP1 genes of enteroviruses, respectively. Amplified nucleotides were sequenced and genotyped.
Among the 110 cases, 39(35%), 52(47%), and 46(42%) were tested positive with these three tests, respectively. Using the consensus results of these three tests as the gold standard, agreement of the VP1 CODEHOP test was 96%, which is higher than those of the virus isolation (89%) and the 5'-UTR test (88%). The VP1 CODEHOP test also has the best performance on serotyping confirmed with serum neutralization tests.
The VP1 CODEHOP test performed well for detection and serotyping of enteroviruses in clinical specimens and could reduce unnecessary hospitalization cares during enterovirus seasons.
PLoS ONE 01/2012; 7(10):e48269. · 4.09 Impact Factor
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Min-Shi Lee,
Tzou-Yien Lin,
Pai-Shan Chiang,
Wen-Chen Li, Shu-Ting Luo,
Kuo-Chien Tsao,
Guan-Yuan Liou,
Mei-Liang Huang,
Shao-Hsuan Hsia,
Yhu-Chering Huang,
Shih-Cheng Chang
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ABSTRACT: Enterovirus 71 (EV71) is causing life-threatening hand-foot-mouth disease in Asia. In Taiwan, EV71 epidemics with different predominant genotypes occurred in 1998 (C2), 2000-2001 (B4), and 2004-2005 (C4). This genotype replacement may have important implications for vaccine development and prediction of epidemics. A nationwide EV71 outbreak occurred again in 2008, which provided a unique opportunity to characterize clinical, virologic, and serologic features of this epidemic.
We analyzed clinical and virologic data of 111 EV71 patients hospitalized in 2008 and prospectively conducted follow-ups of healthy children from June 2006 to December 2008.
Among the 111 EV71 inpatients, 21 (19%) developed complications. Among the 21 complicated cases, 15 had central nervous system complication only, 2 had acute heart failure, and 4 had central nervous system and pulmonary complications. In the prospective study, 11 symptomatic infections and 4 asymptomatic infections were detected. Twenty-two EV71 isolates were genotyped, and 21 of them belong to genotype B5, which is phylogenetically close to B5 viruses circulating in Southeast Asia. Serologic tests show that children infected with B5 viruses have lower geometric mean titers of neutralizing antibody against genotype C4 than those against genotype B5 (P = 0.004, t test).
The 2008 nationwide EV71 epidemic was caused by genotype B5 that was likely introduced to Taiwan from Southeast Asia. Clinical features of the 2008 epidemic were not different from those observed before in Taiwan. Potential antigenic variations between genotype C4 and B5 viruses could be detected and its long-term epidemiologic significance needs further investigation to clarify.
The Pediatric Infectious Disease Journal 11/2010; 29(11):1030-4. · 3.58 Impact Factor
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ABSTRACT: Methods that can accurately predict breast cancer are greatly needed and good prediction techniques can help to predict breast cancer more accurately. In this study, we used two feature selection methods, forward selection (FS) and backward selection (BS), to remove irrelevant features for improving the results of breast cancer prediction. The results show that feature reduction is useful for improving the predictive accuracy and density is irrelevant feature in the dataset where the data had been identified on full field digital mammograms collected at the Institute of Radiology of the University of Erlangen-Nuremberg between 2003 and 2006. In addition, decision tree (DT), support vector machine-sequential minimal optimization (SVM-SMO) and their ensembles were applied to solve the breast cancer diagnostic problem in an attempt to predict results with better performance. The results demonstrate that ensemble classifiers are more accurate than a single classifier.
Journal of Medical Systems 05/2010; 36(2):569-77. · 1.13 Impact Factor
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ABSTRACT: Enterovirus 71 (EV71) is the main etiologic agent of hand, foot, and mouth disease (HFMD) and causes frequently severe neurological complications and mortality in young children. The serum neutralizing antibody response is the major indicator of EV71 infection and protective immunity. The current serum neutralization test based on inhibition of cytopathic effect (Nt-CPE) requires manual microscopic examination, which is time-consuming and labor-intensive. In this study, a high-throughput neutralization assay which employs enzyme immunoassay for detecting growth of EV71 in Rhabdomyosarcoma (RD) cells and measuring serum neutralizing antibody (Nt-EIA) against EV71 was developed. RD cells infected with 100 TCID(50) of EV71 for 36-42h had the best performance and were selected for Nt-EIA. One hundred and twenty human sera (59 negative sera, 61 positive sera) were measured for EV71 neutralization antibody titers by Nt-CPE and Nt-EIA. Neutralization antibody titers against EV71 determined by Nt-EIA had a high sensitivity (100%), specificity (94.9%) and agreement (97.5%) by a qualitative comparison with Nt-CPE. In the quantitative comparison, the correlation coefficient between Nt-EIA and Nt-CPE was 0.91 after log transformation. Overall, the Nt-EIA is a suitable alternative assay for the quantitation of EV71 neutralizing antibody to EV71.
Journal of virological methods 04/2010; 165(1):42-5. · 2.13 Impact Factor
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ABSTRACT: Enterovirus 71 (EV71) causes life-threatening disease outbreaks in young children in Asia. This cohort study was conducted to understand the dynamics of maternal EV71 antibodies in Taiwanese young infants. Approximately 50% of neonates had detectable EV71 neutralizing antibodies, which declined to almost undetectable levels by 6 months of age.
Emerging Infectious Diseases 05/2009; 15(4):581-4. · 6.79 Impact Factor
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Expert Syst. Appl. 01/2009; 36:7562-7566.
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ABSTRACT: Recently, credit scoring has become a very important task as credit cards are now widely used by customers. A method that can accurately predict credit scoring is greatly needed and good prediction techniques can help to predict credit more accurately. One powerful classifier, the support vector machine (SVM), was successfully applied to a wide range of domains. In recent years, researchers have applied the SVM-based in the prediction of credit scoring, and the results have been shown it to be effective. In this study, two real world credit datasets in the University of California Irvine Machine Learning Repository were selected. SVM and a new classifier, clustering-launched classification (CLC), were employed to predict the accuracy of credit scoring. The advantages of using CLC are that it can classify data efficiently and only need one parameter needs to be decided. In substance, the results show that CLC is better than SVM. Therefore, CLC is an effective tool to predict credit scoring.
Expert Systems with Applications.
