Molecular epidemiology of dengue type 2 virus in Venezuela:: evidence for in situ virus evolution and recombination
Molecular epidemiology of dengue type 2 virus in Venezuela:: evidence for in situ virus evolution and recombination
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DOI：
10.1099/0022-1317-82-12-2945
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发表时间：
2001-12-01
影响因子：
3.8
通讯作者：
Gould, EA
中科院分区：
文献类型：
--
作者：
Uzcategui, NY;Camacho, D;Gould, EA
委内瑞拉于1978年首次记录了登革热疫情，随后于1989年出现了登革出血热疫情。为了更好地了解这些流行病的性质，确定了1997年至2000年期间分离的34种委内瑞拉登革热2型病毒的完整包膜(E)基因序列。在这些分离株中，16株来自DF患者，17株来自诊断为DHF的患者。他们之间没有诊断序列差异，这表明E基因本身并不能决定疾病的严重程度。这些序列数据还用于与全球DEN-2病毒样本（包括先前从委内瑞拉收集的毒株）的系统发育比较。这一分析表明，委内瑞拉病毒的祖先起源于亚洲，这意味着来自该地区的DEN-2病毒株在20世纪70年代末或80年代初被引入委内瑞拉和更广泛的加勒比地区。系统发育树进一步表明，委内瑞拉DEN-2病毒的进化发生在原地，分化为若干不同但共循环的谱系，而不是从其他地方反复引入新的毒株。通过结合来自病毒衣壳、膜前和膜基因的额外序列数据，提供了证据，证明先前测序的单一委内瑞拉毒株（命名为Mara4）是一种重组病毒，结合了来自委内瑞拉和亚洲亲本病毒的基因组序列。
Epidemic outbreaks of dengue fever (DF) were first recorded in Venezuela in 1978 and were followed by the emergence of dengue haemorrhagic fever (DHF) outbreaks in 1989. To gain a better understanding of the nature of these epidemics, the complete envelope (E) gene sequence of 34 Venezuelan dengue type 2 (DEN-2) viruses, isolated between 1997 and 2000 was determined. Of these isolates, 16 were from patients with DF and 17 were from patients diagnosed with DHF. There were no diagnostic sequence differences between them, suggesting that the E gene alone does not determine disease severity. These sequence data were also used in phylogenetic comparisons with a global sample of DEN-2 viruses, including strains collected previously from Venezuela. This analysis revealed that the ancestors of the Venezuelan viruses were Asian in origin, implying that a DEN-2 virus strain from this region was introduced into Venezuela and the wider Caribbean region during the late 1970s or the early 1980s. The phylogenetic trees further indicate that evolution of DEN-2 virus in Venezuela has occurred in situ, with differentiation into a number of distinct but co-circulating lineages, rather than the repeated introduction of new strains from other localities. By incorporating additional sequence data from the virus capsid, premembrane and membrane genes, evidence is provided that a single Venezuelan strain sequenced previously, designated Mara4, is a recombinant virus, incorporating genome sequence from Venezuelan and Asian parental viruses.