Recent Outbreak of Dengue in Taiwan

In 1987 a dengue outbreak occurred in southern Taiwan, and it persisted throughout the year 1988. Although some cases were reported yearly since then it did not constitute an epidemic as severe as that of 1988. During the period from November 1987 to 30 June 1993, a total of 5,168 serologically or virologically confirmed cases was detected. Of all the cases, 5,085 were considered locally infected, and 83 imported. The proportions of indigenous cases to imported cases were 527 to unknown in 1987, 4,389 to unknown in 1988, 16 to 19 in 1989, 0 to 10 in 1990, 149 to 26 in 1991, 4 to 19 in 1992, and 0 to 9 in 1993. The sources of the imported cases were Thailand (54 cases=65.1%), Philippines (11=13.3%), Singapore (8=9.6%), Indonesia (5=6%), Malaysia (2=2.4%), Vietnam (1=1.2%), India (1=1.2%) and Sri Lanka (1=1.2%). The dengue viruses were isolated both from mosquitoes and humans. Nine D-1 virus isolates were obtained from female mosquitoes of Aedes aegypti among the nine species of mosquitoes collected in houses in 1987 and 1988. The virus isolates from humans were 298 D-1 and 5 D-2 in 1987, 3,534 D-1, 3 D-4 and 1 D-3 in 1988, 5 D-1, 2 D-2 and 1 D-4 in 1989, 1 D-1 and 1 D-2 in 1990, 16 D-1 and 4 D-3 in 1991, and 2 D-1 and 2 D-3 in 1992

Serologic and Molecular Biologic Methods for SARS-associated Coronavirus Infection, Taiwan

Severe acute respiratory syndrome (SARS) has raised a global alert since March 2003. After its causative agent, SARS-associated coronavirus (SARS-CoV), was confirmed, laboratory methods, including virus isolation, reverse transcriptase–polymerase chain reaction (RT-PCR), and serologic methods, have been quickly developed. In this study, we evaluated four serologic tests ( neutralization test, enzyme-linked immunosorbent assay [ELISA], immunofluorescent assay [IFA], and immunochromatographic test [ICT]) for detecting antibodies to SARS-CoV in sera of 537 probable SARS case-patients with correlation to the RT-PCR . With the neutralization test as a reference method, the sensitivity, specificity, positive predictive value, and negative predictive value were 98.2%, 98.7%, 98.7%, and 98.4% for ELISA; 99.1%, 87.8%, 88.1% and 99.1% for IFA; 33.6%, 98.2%, 95.7%, and 56.1% for ICT, respectively. We also compared the recombinant-based western blot with the whole virus–based IFA and ELISA; the data showed a high correlation between these methods, with an overall agreement of >90%. Our results provide a systematic analysis of serologic and molecular methods for evaluating SARS-CoV infection

Protective Effects of Heated Killed Clostridium butyricum on Experimental

[[volume]]23

Sentinel Hospital Surveillance for Rotavirus Diarrhea in Taiwan, 2001- 2003

We examined the epidemiological profile of rotavirus infection among children hospitalized for diarrhea in Taiwan , to assess the burden of this disease. From 1 April 2001 through 31 March 2003, children <5 years old with gastroenteritis admitted to 4 sentinel hospitals were enrolled in a surveillance study and had stool specimens tested for the presence of rotavirus, enteric adenovirus, and the bacterial pathogens for which routine screening is performed. For 52% of patients, a recognized enteric pathogen was identified, including rotavirus (43% of patients), bacteria ( 11%), enteric adenovirus (2.5%), and a mixture of pathogens (3.9%). Rotavirus was detected year- round, but great month-to-month variability made it difficult to identify a distinct seasonal pattern. Rotavirus disease was most common among children 723 months old, but the rate of rotavirus detection varied little between the youngest and oldest age groups. The novel strain P[8]G9 was detected most commonly (37% of strains ), followed by strains P[8]G1 (31%), P[4]G2 (10%), P[8]G3 (9.3%), and P[8] G4 (3.7% ). Rotavirus infection is the most important cause of diarrhea among hospitalized children in Taiwan, and a rotavirus vaccination program for young children might significantly reduce this problem

Antigenic Divergence of Bordetella pertussis Isolates in Taiwan

In recent studies, antigenic divergence has been observed in Bordetella pertussis circulating isolates. We collected 80 Bordetella pertussis isolates in Taiwan from 1998 to 2004 and analyzed them using a combination of pulsed-field gel electrophoresis (PFGE) and sequencing of the ptxS1 and prn genes. The incidence of pertussis increases every 3 years, and most of the isolates prevalent since 1998 have expressed nonvaccine ptxS1A and prn2 alleles. Through PFGE analysis, all isolates could be classified into four major groups, and the incidence of these groups exhibited a correlation with the prn allele expressed by the isolates. We found that PFGE is more discriminative than gene sequencing, since it could divide the isolates expressing the prn2 allele into two groups: one group circulating from 1998 to 2001 and another group circulating from 2001 to 2004. The transition between the two groups in 2000 coincided with an outbreak of 326 cases. This research indicates that the antigenic divergence of B. pertussis circulating isolates has evolved over time in Taiwan. Such information will have implications for vaccine policy in Taiwan

Epidemiological and Genetic Correlates of Severe Acute Respiratory Syndrome Coronavirus Infection in the Hospital with the Highest Nosocomial Infection Rate in Taiwan in 2003

Taiwan experienced a series of outbreaks of nosocomial severe acute respiratory syndrome (SARS) infections in 2003. Two months after the final outbreak, we recruited 658 employees from the hospital that suffered the first and most severe SARS infections to help us investigate epidemiological and genetic factors associated with the SARS coronavirus (SARS-CoV). SARS-CoV infections were detected by using enzyme immunoassays and confirmed by a combination of Western blot assays, neutralizing antibody tests, and commercial SARS tests. Risk factors were analyzed via questionnaire responses and sequence-specific oligonucleotide probes of human leukocyte antigen (HLA) alleles. Our results indicate that 3% (20/658) of the study participants were seropositive, with one female nurse identified as a subclinical case. Identified SARS-CoV infection risk factors include working in the same building as the hospital's emergency room and infection ward, providing direct care to SARS patients, and carrying a Cw*0801 HLA allele. The odds ratio for contracting a SARS-CoV infection among persons with either a homozygous or a heterozygous Cw*0801 genotype was 4.4 (95% confidence interval, 1.5 to 12.9; P = 0.007)

Molecular Epidemiology of G9 Rotaviruses in Taiwan between 2000 and 2002

Since the mid-1990s, novel G9 rotaviruses have been detected in many countries, suggesting that G9 is a globally important serotype. The molecular epidemiology of G9 rotaviruses in Taiwan from 2000 to 2002 was investigated in this study. G9 rotavirus first appeared in 2000 with 4 cases and constituted 33.8% and 54.8% of the rotavirus-positive samples in 2001 and 2002, respectively. These G9 strains belonged to P[8]G9, subgroup II, and long electropherotype, except one belonged to P[4]G9, subgroup II, and short electropherotype. Nucleotide sequencing and phylogenetic analysis of 52 Taiwanese G9 rotaviruses showed that the VP7 genes shared a high degree of identity to overseas G9 rotaviruses detected after 1993 and that the VP8* portions of the VP4 genes were more closely related to those of local rotaviruses of other G types. The two P[8]G9 strains with high nucleotide identities in the VP7 and the partial VP4 genes, 01TW591 of Taiwan from 2001 and 95H115 of Japan from 1995, varied in four genes, genes 2, 3, 7, and 8, which was revealed by RNA-RNA hybridization. Representative strains for different RNA patterns were also analyzed in the partial VP2 and VP3 genes; the nucleotide identities were high between Taiwanese G9 strains and local G3 or G2 strains. These results suggested that Taiwanese G9 rotaviruses possibly had evolved through reassortment between overseas G9 strains and circulating rotaviruses of other G types