Rico-Hesse R
Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Connecticut 06510.
Virology. 1990 Feb;174(2):479-93. doi: 10.1016/0042-6822(90)90102-w.
During the past several decades, dengue viruses have progressively extended their geographic distribution, and are currently some of the most important mosquito-borne viruses associated with human illness. Determining the genetic variability and transmission patterns of these RNA viruses is crucial in developing effective control strategies for the disease. Primer-extension sequencing of less than 3% of the dengue genome (across the E/NS1 gene junction) provided sufficient information for estimating genetic relationships among 40 dengue type 1 and 40 type 2 virus isolates from diverse geographic areas and hosts. A quantitative comparison of these 240-nucleotide-long sequences revealed previously unrecognized evolutionary relationships between disease outbreaks. Five distinct virus genotypic groups were detected for each of the two serotypes. The evolutionary rates of epidemic dengue viruses of types 1 and 2 were similar, although the transmission pathways of these viruses around the world are different. For dengue type 2, one genotypic group represents an isolated, forest virus cycle which seems to have evolved independently in West Africa. This is the first genetic evidence of the existence of a sylvatic cycle of dengue virus, which is clearly distinct from outbreak viruses.
在过去几十年里，登革病毒逐渐扩大了其地理分布范围，目前是一些与人类疾病相关的最重要的蚊媒病毒。确定这些RNA病毒的遗传变异性和传播模式对于制定有效的疾病控制策略至关重要。对不到3%的登革热基因组（跨越E/NS1基因连接处）进行引物延伸测序，为估计来自不同地理区域和宿主的40株1型登革病毒和40株2型病毒分离株之间的遗传关系提供了足够的信息。对这些240个核苷酸长的序列进行定量比较，揭示了疾病暴发之间以前未被认识到的进化关系。两种血清型的病毒均检测到五个不同的基因型组。1型和2型流行登革病毒的进化速率相似，尽管这些病毒在世界各地的传播途径不同。对于2型登革热，一个基因型组代表一个孤立的森林病毒循环，似乎是在西非独立进化而来的。这是登革病毒存在丛林循环的首个遗传学证据，该循环明显不同于暴发病毒。
