Abstract
BackgroundZika disease has transformed into a serious global health problem due to the rapid spread of the arbovirus and alarming severity including congenital complications, microcephaly and Guillain-Barré syndrome. Zika virus (ZIKV) is primarily transmitted to humans through the bite of an infective mosquito, with Aedes aegypti being the main vector.MethodsWe successfully developed a ZIKV experimental transmission model by single infectious Ae. aegypti bite to a laboratory mouse using circulating Brazilian strains of both arbovirus and vector. Mosquitoes were orally infected and single Ae. aegypti were allowed to feed on mouse ears 14 days post-infection. Additionally, salivary gland (SG) homogenates from infected mosquitoes were intrathoracically inoculated into naïve Ae. aegypti. Mosquito and mouse tissue samples were cultured in C6/36 cells and processed by quantitative real-time PCR.ResultsA total of 26 Ae. aegypti were allowed to feed individually on mouse ears. Of these, 17 mosquitoes fed, all to full engorgement. The transmission rate of ZIKV by bite from these engorged mosquitoes to mouse ears was 100%. The amount of virus inoculated into the ears by bites ranged from 2 × 102–2.1 × 1010 ZIKV cDNA copies and was positively correlated with ZIKV cDNA quantified from SGs dissected from mosquitoes post-feeding. Replicating ZIKV was confirmed in macerated SGs (2.45 × 107 cDNA copies), mouse ear tissue (1.15 × 103 cDNA copies, and mosquitoes 14 days post-intrathoracic inoculation (1.49 × 107 cDNA copies) by cytopathic effect in C6/36 cell culture and qPCR.ConclusionsOur model illustrates successful transmission of ZIKV by an infectious mosquito bite to a live vertebrate host. This approach offers a comprehensive tool for evaluating the development of infection in and transmission from mosquitoes, and the vertebrate-ZIKV interaction and progression of infection following a natural transmission process.
Highlights
Zika disease has transformed into a serious global health problem due to the rapid spread of the arbovirus and alarming severity including congenital complications, microcephaly and Guillain-Barré syndrome
There was a positive correlation between the Zika virus (ZIKV) cDNA copy number recovered from mouse ears and ZIKV cDNA copy number quantified from salivary gland (SG) from the mosquito that fed on each ear (Fig. 3b)
We demonstrate a mosquito-mouse transmission model for ZIKV that may be used for “natural transmission” studies ranging from vector competence to ZIKV transmission biology and immunology
Summary
Zika disease has transformed into a serious global health problem due to the rapid spread of the arbovirus and alarming severity including congenital complications, microcephaly and Guillain-Barré syndrome. Animal models using rhesus macaques, mice and hamsters have been proposed for understanding ZIKV infection, development and pathogenesis in vertebrates These animal models are experimentally infected by syringe inoculation of cultivated virus [4,5,6,7,8,9]. This bypasses natural transmission mechanisms and virus inoculum introduced by mosquito bite It is uncertain if infection initiated by syringe inoculation adequately mimics Zika disease progression and pathogenesis following natural transmission by mosquito bite. It is well documented in other models that syringe-inoculation of cultured vector-borne pathogen results in physiological conditions of the vertebrate host response that are altered, compared to natural vector transmission [10,11,12]. Establishing vector transmission by bite is the most epidemiologically relevant mode to study the infectious process of ZIKV transmission
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
