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Updated: Jan 2, 2026
Experimental Viral Infection in Adult Mosquitoes by Oral Feeding and Microinjection
Published on: July 28, 2022
Successive blood meals enhance virus dissemination within mosquitoes and increase transmission potential
Philip M Armstrong1,2, Hanna Y Ehrlich3, Tereza Magalhaes4
1Center for Vector-Borne and Zoonotic Diseases, Department of Environmental Sciences, The Connecticut Agricultural Experiment Station, New Haven, CT, USA. philip.armstrong@ct.gov.
Abstract:
The recent Zika virus (ZIKV) and chikungunya virus epidemics highlight the explosive nature of arthropod-borne viruses (arboviruses) transmitted by Aedes spp. mosquitoes1,2. Vector competence and the extrinsic incubation period (EIP) are two key entomological parameters used to assess the public health risk posed by arboviruses3. These are typically measured empirically by offering mosquitoes an infectious blood meal and temporally sampling mosquitoes to determine the infection and transmission status. This approach has been used for the better part of a century; however, it does not accurately capture the biology and behaviour of many mosquito vectors that refeed frequently (every 2-3 d)4. Here, we demonstrate that acquisition of a second non-infectious blood meal significantly shortens the EIP of ZIKV-infected Aedes aegypti by enhancing virus dissemination from the mosquito midgut. Similarly, a second blood meal increases the competence of this species for dengue virus and chikungunya virus as well as Aedes albopictus for ZIKV, suggesting that this phenomenon may be common among other virus-vector pairings and that A. albopictus might be a more important vector than once thought. Blood-meal-induced microperforations in the virus-impenetrable basal lamina that surrounds the midgut provide a mechanism for enhanced virus escape. Modelling of these findings reveals that a shortened EIP would result in a significant increase in the basic reproductive number, R0, estimated from experimental data. This helps to explain how A. aegypti can sustain explosive epidemics such as ZIKV despite relatively poor vector competence in single-feed laboratory trials. Together, these data demonstrate a direct and unrecognized link between mosquito feeding behaviour, EIP and vector competence.
Insights
Mosquitoes that take a second blood meal transmit Zika virus (ZIKV), dengue, and chikungunya faster by shortening the extrinsic incubation period (EIP). This feeding behavior increases arbovirus transmission risk.
Area of Science:
- * Arthropod-borne virus (arbovirus) transmission dynamics.
- * Mosquito vector biology and entomology.
Background:
- * Zika virus (ZIKV) and chikungunya virus epidemics underscore the threat of arboviruses transmitted by Aedes mosquitoes.
- * Vector competence and extrinsic incubation period (EIP) are crucial for assessing arbovirus public health risks.
- * Traditional EIP measurements do not account for the frequent refeeding behavior of many mosquito vectors.
Purpose of the Study:
- * To investigate the impact of secondary blood meals on arbovirus transmission by Aedes mosquitoes.
- * To determine if mosquito refeeding behavior influences EIP and vector competence.
- * To elucidate the physiological mechanisms underlying enhanced virus dissemination after secondary blood meals.
Main Methods:
- * Empirical measurement of EIP by offering mosquitoes infectious blood meals and temporal sampling.
- * Experimental assessment of ZIKV, dengue virus, and chikungunya virus transmission by Aedes aegypti and Aedes albopictus after single and secondary non-infectious blood meals.
- * Microscopic examination of mosquito midgut basal lamina.
- * Mathematical modeling of EIP and basic reproductive number (R0).
Main Results:
- * A second non-infectious blood meal significantly shortens the EIP for ZIKV in Aedes aegypti by enhancing virus dissemination.
- * Refeeding increases vector competence for dengue and chikungunya viruses in A. aegypti, and for ZIKV in A. albopictus.
- * Microperforations in the midgut basal lamina induced by blood meals facilitate enhanced virus escape.
- * Shortened EIP due to refeeding significantly increases the basic reproductive number (R0), explaining explosive epidemic potential.
Conclusions:
- * Mosquito feeding behavior, specifically refeeding, is a critical, unrecognized factor influencing EIP and vector competence.
- * Aedes albopictus may be a more significant vector for ZIKV than previously recognized.
- * The findings provide a mechanism to explain how Aedes mosquitoes can sustain explosive arbovirus epidemics despite seemingly low competence in single-feed trials.
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