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Dengue-1 PDK 13, dengue-2 PDK53, dengue-3 PGMK30F3 and dengue-4 PDK48 in the live attenuated tetravalent dengue vaccine were assayed by identification and quantitation in a mosquito system (T. splendens). Each serotype of dengue v...
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Dengue-1 PDK 13, dengue-2 PDK53, dengue-3 PGMK30F3 and dengue-4 PDK48 in the live attenuated tetravalent dengue vaccine were assayed by identification and quantitation in a mosquito system (T. splendens). Each serotype of dengue virus was identifiedby dengue specific monoclonal antibodies in the indirect fluorescent antibody test. Virus content was estimated by calculating the 50% mosquito infectious dose (MID50). Differences from 0 to ±0.5 log10 were observed between the original monovalent titreand that from the blend which showed no significant difference at 95% confidence limit (P<0.05). This result indicates that there is no interference between dengue serotypes in mosquitoes infected by intrathoracic inoculation with the virus mixture. Itcan also be concluded that this mosquito system can be used as an effective measure for infectivity titration of each component in the tetravalent dengue vaccine.
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The epitope on NS3 recognized by dengue 2 virus serotype-cross-reactive CD4+ CD8- T cell clones (JK36 and JK46) was mapped. These CD4+ CTL clones recognized dengue 2, dengue 3 and dengue 4 viruses, but did not recognize dengue 1. ...
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The epitope on NS3 recognized by dengue 2 virus serotype-cross-reactive CD4+ CD8- T cell clones (JK36 and JK46) was mapped. These CD4+ CTL clones recognized dengue 2, dengue 3 and dengue 4 viruses, but did not recognize dengue 1. The minimum recognition unit of the epitope recognized by JK36 was 8 amino acids in length and was located between amino acids 226 and 233 of dengue 2, dengue 3 and dengue 4 viruses. The epitope recognized by JK46 consisted of 11 amino acids and was located between amino acids 224 and 234. Results of experiments to determine HLA-restriction in the recognition of the epitope suggested that JK36 and JK46 are HLA-DR15-restricted.
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Aedes notoscriptus colonized from Brisbane, Queensland, Australia, were fed on blood suspensions containing either Barmah Forest (BF) virus, dengue virus type 1 (DEN-1), dengue virus type 2 (DEN-2), dengue virus type 3 (DEN-3), or...
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Aedes notoscriptus colonized from Brisbane, Queensland, Australia, were fed on blood suspensions containing either Barmah Forest (BF) virus, dengue virus type 1 (DEN-1), dengue virus type 2 (DEN-2), dengue virus type 3 (DEN-3), or dengue virus type4 (DEN-4). A. notoscriptus was shown to be moderately susceptible to oral infection with BF virus, ID50=103.3 CCID50 per mosquito, with titres in infected mosquitoes peaking 10 days after infection. BF virus transmission occurred between days 5 and 12, with an average rate of 45% (range, 40-50%). For DEN 1-4, A. notoscriptus showed low level susceptibility to oral infection, with maximum head and thorax squash infection rates of 8, 5, 13 and 3%, respectively. Rates of infection were notably higher in anorth Queensland strain of A. aegypti used as a positive control, with maximum thorax squash infection rates of 58, 68, 78 and 60% for DEN 1-4, respectively. On the basis of these data, it is concluded that A. notoscriptus could act as an efficient vector of BF in urban environments, but it is unlikely to be an important vector of DEN.
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Background and purpose: Dengue fever (DF) is a major public health issue. However, it is unclear whether different dengue virus serotypes (DENV) are associated with different clinical manifestations and outcomes. This study invest...
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Background and purpose: Dengue fever (DF) is a major public health issue. However, it is unclear whether different dengue virus serotypes (DENV) are associated with different clinical manifestations and outcomes. This study investigated the association between viral serotype and clinical manifestations of DF. Methods: Adult patients with DENV-2 and DENV-3 who were treated at Kaohsiung Medical University Hospital and Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan, from January 1998 to September 2007 were enrolled. The patients' demographic data, underlying diseases, clinical manifestations, laboratory data, and disease outcomes were retrospectively analyzed. Results: 294 patients had DENV-2 and 91 had DENV-3. The median age was 50 years, and 45.7% of patients were men. Patients with DENV-3 were more likely to have a malignancy (p = 0.011), myalgia (p = 0.03), skin rash (p < 0.001), ascites (p = 0.04), and fever (p = 0.003) than patients with DENV-2. Patients with DENV-3 had their lowest levels of white blood cells and platelets, and peak plasma activated partial thromboplastin time (aPTT) 1 day later than patients with DENV-2. DENV-2 infection was associated with a higher monocyte count and more prolonged aPTT early in the clinical course. Infection by DENV-2 more commonly occurred as a secondary infection, while infection by DENV-3 was more common as a primary infection (p < 0.001). There were no differences between the groups in organ involvement, disease severity, duration of hospital stay, and medical expenditure. Conclusion: The symptoms, signs, and laboratory findings appear to be different for patients infected with DENV-2 and DENV-3, but there is no difference in outcomes.
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Background: We evaluated the validity of clinical diagnosis compared with Laboratory diagnosis of dengue in a retrospective sample of patients in Sao Jose do Rio Preto, Brazil.
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Background: Dengue is the most important arboviral disease in tropical and subtropical countries. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes...
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Background: Dengue is the most important arboviral disease in tropical and subtropical countries. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes. Over the past 20 years, dengue epidemics have become more wide-spread and frequent. Previous studies have shown that dengue is endemic in Jeddah, Makkah and Al-Madinah in western Saudi Arabia as well as in Jazan region in the southern part of the country. The four serotypes of dengue virus (DENV) have been reported from western Saudi Arabia. It has been suggested that pilgrims could play a significant and unique role in DENV-1 and DENV-2 introduction into Saudi Arabia, especially in the cities of Jeddah, Makkah and AlMadinah during Hajj and Umrah seasons. However, only limited data on DENV-3 in Saudi Arabia are available.
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Abstract Objective To investigate the link between fluctuations in the prevalence of dengue virus (DENV) serotypes and the number of dengue cases in the metropolitan area of Bucaramanga, Santander State, Colombia, in the 2007–201...
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Abstract Objective To investigate the link between fluctuations in the prevalence of dengue virus (DENV) serotypes and the number of dengue cases in the metropolitan area of Bucaramanga, Santander State, Colombia, in the 2007–2010 and 2014–2017 periods. Method Viruses were isolated from febrile patient samples by direct application to C6/36‐HT cells and typed using monoclonal antibodies. We performed autocorrelation and cross‐correlation analyses to determine whether fluctuations in the prevalence of DENV serotypes and dengue cases were correlated. Full envelope (E) gene sequences were employed to examine the genetic diversity of serotypes circulating by using a phylogenetic approach. Results All four dengue virus serotypes were detected. DENV‐1 was the dominant serotype in both periods followed by DENV‐3 or DENV‐2 depending on the period; DENV‐4 was the least prevalent virus in both periods. Cross‐correlation analyses suggest a temporal relation between the fluctuations in the prevalence of DENV serotypes, which were almost simultaneous (lag?=?0) or related to recent past fluctuations (lag?>?1.0) in the number of dengue cases. Data suggest that a sustained predominance of DENV‐1, an increase of the DENV‐4 prevalence, and a switch from DENV‐3 to DENV‐2 could be linked to an outbreak. Circulating viruses were grouped into Genotype V, Asia/American III and II for DENV‐1, ‐2, ‐3 and ‐4, respectively; intragenotypic diversity was detected. Conclusions The present work highlights the need of comprehensive studies on dynamics of DENV in Colombia to understand transmission of dengue and evaluate the effectiveness of a vaccination programme.
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Recently, in Pakistan, several cases of mysterious dengue‐like illness are being reported, which has concerned the authorities and requires prompt action. We present a case of a 52‐year‐old female patient presenting with a hist...
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Recently, in Pakistan, several cases of mysterious dengue‐like illness are being reported, which has concerned the authorities and requires prompt action. We present a case of a 52‐year‐old female patient presenting with a history of continuous fever, documented up to 104?F, for 5?days. The symptoms were associated with headache, nausea, retro‐orbital headache, arthralgia, and myalgia. Currently, to the best of our knowledge, this is the first reported case in the literature for the endemic mysterious virus and may serve as the groundwork for future studies.
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Genetic algorithm-based RNA secondary structure prediction was used in combination with comparative sequence analysis using sequences from the GenBank database to construct models of folding for the distal part of the 3'-untransla...
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Genetic algorithm-based RNA secondary structure prediction was used in combination with comparative sequence analysis using sequences from the GenBank database to construct models of folding for the distal part of the 3'-untranslated region of flaviviruses belonging to 4 serological groups. Elements of RNA secondary structure that are preserved among all the flaviviruses studied were revealed, despite the high degree of sequence divergence between them. At the same time, structural elements were observed that distinguish members of different serological groups and, in particular, a region of remarkable structural divergence between the tick-borne and mosquito-borne flaviviruses was found. Application of the genetic algorithm also revealed that the3'-terminus of flaviviral genomic RNA may take on alternative conformations, which are not observed in the 3'-terminus of complementary minus strand RNA. These alternative folding patterns may have roles in the regulation of transcription and translation initiation and in the switch between them.
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