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Updated: May 13, 2026
Protocol for Dengue Infections in Mosquitoes A. aegypti and Infection Phenotype Determination
Published on: July 4, 2007
Risk assessment of an Aedes flavivirus and its effect on pathogenic flavivirus replication in mosquitoes
Yumei Fu1,2, Wan Zhao1, Shaohui Wu1,2
1State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
Background:
Mosquitoes are efficient vectors of medically significant flaviviruses and serve as hosts for insect-specific flaviviruses (ISFs). Aedes flavivirus (AEFV) is a classical ISF. Given the increasing discovery of ISFs, it is urgent to evaluate the potential risk of ISFs to human health as well as their impact on the transmission of pathogenic flaviviruses.
Methods:
We isolated a strain of AEFV from wild Aedes albopictus populations in Hainan Province, China, using iodixanol density-gradient ultracentrifugation. The infection of the AEFV Hainan strain in Aedes, Culex, and four mammalian cell lines was investigated using fluorescence in situ hybridization (FISH) assays, and relative and absolute quantitative polymerase chain reaction (qPCR). Whether AEFV alters the vector competence of Ae. albopictus for pathogenic arboviruses and the underlying immune mechanisms were explored.
Results:
The AEFV Hainan strain showed close genetic similarity to strains from Yunnan province of China, Thailand, and Peru. This strain was capable of infecting Ae. albopictus and Ae. aegypti but not Culex quinquefasciatus. Cell entry was the critical barrier for AEFV infection in Cx. quinquefasciatus cells. The infection risk of the AEFV Hainan strain in four mammalian cells (BHK-21, Vero, 293 T, and HeLa) was quite low due to the failure of cell entry or extremely limited replication. Prior infection of AEFV was detrimental to the replication of Zika virus and dengue virus serotype 2 in Ae. albopictus through activation of the Janus kinase/signal transducer and activator of transcription, Toll, or RNA interference pathway.
Conclusions:
Our work excludes the risk of the AEFV Hainan strain to human health and highlights its potential as an immune inducer to sabotage Aedes mosquito ability for viral transmission.
Insights
Insect-specific flaviviruses (ISFs) like Aedes flavivirus (AEFV) do not pose a human health risk. AEFV infection in mosquitoes can, however, reduce their ability to transmit dangerous arboviruses such as Zika and dengue.
Area of Science:
- Virology
- Medical Entomology
- Molecular Biology
Background:
- Mosquitoes transmit medically significant flaviviruses.
- Insect-specific flaviviruses (ISFs) are increasingly discovered.
- The human health risk and transmission impact of ISFs require evaluation.
Purpose of the Study:
- To investigate the Aedes flavivirus (AEFV) Hainan strain's infectivity in various cell lines.
- To assess AEFV's potential risk to human health.
- To explore AEFV's impact on the vector competence of Aedes albopictus for pathogenic arboviruses.
Main Methods:
- Isolation of AEFV Hainan strain from Aedes albopictus.
- Infection assays in Aedes, Culex, and mammalian cell lines using FISH and qPCR.
- Evaluation of AEFV's effect on arbovirus replication and mosquito immune pathways.
Main Results:
- AEFV Hainan strain is genetically similar to other strains.
- AEFV infects Aedes mosquitoes but not Culex quinquefasciatus due to cell entry barriers.
- AEFV shows low infection risk in mammalian cells.
- AEFV pre-infection reduces Zika and dengue virus replication in Aedes albopictus via immune pathway activation.
Conclusions:
- AEFV Hainan strain poses no risk to human health.
- AEFV can act as an immune inducer in mosquitoes.
- AEFV has the potential to disrupt the transmission of pathogenic arboviruses by mosquitoes.
