Institut Pasteur de Nouvelle-Calédonie, URE Dengue et Arboviroses, Institut Pasteur International Network, Noumea, New Caledonia.
Institut Pasteur de Nouvelle-Calédonie, URE Entomologie Médicale, Institut Pasteur International Network, Noumea, New Caledonia.
PLoS Negl Trop Dis. 2020 May 14;14(5):e0008303. doi: 10.1371/journal.pntd.0008303. eCollection 2020 May.
In New Caledonia (NC), Aedes aegypti is the only proven vector of dengue virus (DENV), which is the most prevalent arbovirosis in NC. Since World War II, the four DENV serotypes have circulated regularly in NC. The epidemiological profile, however, has evolved over the last ten years, with the persistence of DENV-1 circulation and the co-circulation of several DENV serotypes. The current study evaluated the ability of Ae. aegypti from NC to transmit four DENV serotypes (and two DENV-1 genotypes) isolated during recent outbreaks in NC. An Ae. aegypti F1 generation was twice independently orally challenged with each DENV strain (107 FFU/ml). Infection, dissemination and transmission rates and transmission efficiency were measured at day 7 and 14 post-exposure, as well as the quantity of infectious virus particles. Mosquito infection was observed as early as 7 days post-infection. Infection rates between 18 and 58% were measured for all DENV serotypes/genotypes tested. Although dissemination rates ranged from 78 to 100%, transmission efficiencies were low, with values not exceeding 21% at 14 days post-infection for all DENV strains. This study shows that NC Ae. aegypti are moderately competent for DENV in laboratory conditions. In link with epidemiological data, these results suggest implication of other factors in the sustained circulation of DENV-1 in New Caledonia.
在新喀里多尼亚(NC),埃及伊蚊是登革热病毒(DENV)的唯一已知传播媒介,也是 NC 最流行的虫媒病毒病。自第二次世界大战以来,四种 DENV 血清型一直在 NC 内有规律地循环。然而,在过去十年中,登革热病毒的流行病学特征发生了演变,DENV-1 的持续传播和几种 DENV 血清型的共同传播。本研究评估了来自 NC 的埃及伊蚊传播在 NC 最近爆发期间分离的四种 DENV 血清型(和两种 DENV-1 基因型)的能力。埃及伊蚊 F1 代两次独立地用每种 DENV 株(107 FFU/ml)进行经口挑战。在感染后第 7 天和第 14 天测量感染、传播和传播效率以及感染性病毒颗粒的数量。在感染后 7 天即可观察到蚊虫感染。所有测试的 DENV 血清型/基因型的感染率在 18%至 58%之间。尽管传播率在 78%至 100%之间,但传播效率很低,在感染后 14 天,所有 DENV 株的传播效率均不超过 21%。本研究表明,NC 埃及伊蚊在实验室条件下对 DENV 的易感性中等。结合流行病学数据,这些结果表明其他因素可能参与了 DENV-1 在新喀里多尼亚的持续循环。