Theses and Dissertations

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Christopher Vitek

Second Advisor

Dr. John Thomas

Third Advisor

Dr. Megan Keniry


The term co-infection describes an event when multiple pathogens infect a single host. For vector-borne diseases, a vector may become co-infected by feeding either on a single host that has multiple pathogens or feeding multiple hosts, each of which may be infected. Co-infection in non-vector hosts has been shown to influence immune response and eventual outcome of disease, and is likely to have a similar impact on vector species. With multiple vector-borne diseases circulating in South Texas, the potential for co-infection exists. We examined when mosquitoes are infected with one virus and subsequently infected with another. We hypothesized that the vectors would show an increase in dissemination rate and a shorter extrinsic incubation period on both primary and secondary infection. However, based on previous studies, we also hypothesized that the vectors would show an increase in transmission rate with the first virus but no change in the second virus, relative to controls. To test this, we utilized colony Aedes aegypti and Aedes albopictus mosquitoes from South Texas. Aedes aegypti and Aedes albopictus mosquitoes are primary vectors for Dengue virus and Zika virus. We infected them either with Zika virus and then dengue, or the reverse. We regularly removed and tested individuals to monitor infection rates, dissemination rates, and viral presence in saliva. Results were analyzed and implications of these results for disease transmission were made. This is the first examination of potential co-infection in US mosquito populations in locations where these two viruses are known to circulate.


Copyright 2018 Felicia Vazquez. All Rights Reserved.

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