Guiyun Yan

Public Health

Ph.D., University of Vermont, 1994, Biology

Phone: (949) 824-0175
Fax: (949) 824-0249

University of California, Irvine
Hewitt Hall, Room 3038
Mail Code: 4050
Irvine, CA 92697

picture of Guiyun  Yan

Vector-Borne Disease Epidemiology and Vector Biology
URLs Postdoctoral Positions Available Immediately
Ph.D. and Postdoctoral Fellowships for African Students and Scientists Available Immediately
Appointments Dr. Yan's lab members:

Dr. Guofa Zhou, Associate Scientist
Dr. Daibin Zhong, Assistant Scientist
Dr. Eugenia Lo, Assistant Scientist
Dr. Ming-chieh (Alex) Lee, Assistant Scientist
Dr. Solomon Kibret, Postdoc fellow
Amruta Dixit, PhD Student
Elizabeth Hemming, PhD Student
Xiaoming Wang, Research Specialist
Jennifer Nguyen, Lab Manager
Ecology of African Highland Malaria

Malaria is a major public health problem in sub-Saharan Africa. The East African highlands (1,500m above sea level) were either free of malaria or had very low incidences; however, since late 1980s malaria epidemics have frequently occurred in some highland areas. We examine the mechanisms leading to the resurgence of malaria in African high-elevation areas, including climate, land use, topography and antimalarial drug resistance in the Plasmodium parasites. We found that deforestation and swamp reclamation affect microclimatic and nutritional conditions of larval habitats, increase the survivorship of malaria vectors at larval and adult stages, shorten the development time of malaria parasites, and significantly increase mosquito vectorial capacity. We are developing models to predict the spread of malaria infections in an epidemic, and evaluating new malaria vector control methods for outdoor transmission control.

Molecular Epidemiology of vivax Malaria in Ethiopia

Vivax malaria is the most geographically widespread human malaria, causing tremendous suffering and major negative effects on economic productivity. African blacks or people with African ancestry, are thought to be protected from Plasmodium vivax infection because their lack of Duffy antigen expression on the surface of the erythrocytes renders P. vivax unable to invade the erythrocytes. However, recent studies challenge this conventional wisdom, raising the possibility that that some lineages of P. vivax may have evolved to use receptors other than Duffy for erythrocyte invasion. However, the epidemiological significance of vivax infection in Duffy-negative individuals is unknown. Furthermore, there is no information on the evolutionary history and infection diversity of P. vivax in Duffy-negative individuals. We are examining the molecular epidemiology and population genetics of P. vivax in endemic southwestern Ethiopia. Specifically we determined the prevalence of asymptomatic infections and the incidence of symptomatic malaria due to P. vivax in Duffy-negative and Duffy-positive individuals and are examining the role of mutations in PvDBP gene and gene copy numbers in vivax infections in Duffy-negative people.

Population Biology of African Malaria Vectors

We are interested in 1) larval population regulation of Anopheles gambiae and An. funestus mosquito, 2) outdoor malaria transmission, and 3) pyrethroid resistance. Previously, we have determined green algae are important food source for anopheline larvae. We are currently determining the species composition of green algae in larval habitats and identifying the gut contents of mosquito larvae using the pyrosequencing technique. Using bioassays we determine the nutritional values of algae to mosquito larvae and adults. We are also interested in the potential tradeoffs between larval nutritional status and adult survivorship, blood feeding and vectorial capacity. We are examining physiology, ecology and genetics of desiccation resistance, and age-grading molecular marker development for An. gambiae.
Publications Malaria Epidemiology

Zhou, G., Sun, L., Xia, R., Duan, Y., Xu, J., Yang, H., Wang, Y., Lee, M. C., Xiang, Z., Yan, G., Cui, L. and Yang, Z. (2014). Clinical malaria along the China-Myanmar border, Yunnan Province, China, January 2011-August 2012. Emerg Infect Dis. 20(4):675-8. doi: 10.3201/eid2004.130647.

Baum, E., Sattabongkot, J., Sirichaisinthop, J., Kiattibutr, K., Davies, D. H., Jain, A., Lo, E., Lee, M. C., Randall, A. Z., Molina, D. M., Liang, X., Cui, L., Felgner, P. L. and Yan, G. (2015). Submicroscopic and asymptomatic Plasmodium falciparum and Plasmodium vivax infections are common in western Thailand - molecular and serological evidence. Malar J. 14:95. doi: 10.1186/s12936-015-0611-9.

Lo, E., Yewhalaw, D., Zhong, D., Zemene, E., Degefa, T., Tushune, K., Ha, M., Lee, M. C., James, A. A. and Yan, G. (2015). Molecular epidemiology of Plasmodium vivax and Plasmodium falciparum malaria among Duffy-positive and Duffy-negative populations in Ethiopia. Malar J. 14:84. doi: 10.1186/s12936-015-0596-4.

Lo, E., Zhou, G., Oo, W., Lee, M. C., Baum, E., Felgner, P. L., Yang, Z., Cui, L. and Yan, G (2015). Molecular inference of sources and spreading patterns of Plasmodium falciparum malaria parasites in internally displaced persons settlements in Myanmar-China border area. Infect Genet Evol. 33:189-96. doi: 10.1016.

Zhou, G., D. Yewhalaw, E. Lo, D. Zhong, X. Wang, T. Degefa, E. Zemene, M. Lee, E. Kebede, K. Tushune and G. Yan (2016). "Analysis of asymptomatic and clinical malaria in urban and suburban settings of southwestern Ethiopia in the context of sustaining malaria control and approaching elimination." Malaria Journal 15:250. DOI: 10.1186/s12936-016-1298-2.

Lo, E., J. Nguyen, W. Oo, E. Hemming-Schroeder, G. Zhou, Z. Yang, L. Cui and G. Yan (2016). "Examining Plasmodium falciparum and P. vivax clearance subsequent to antimalarial drug treatment in the Myanmar-China border area based on quantitative real-time polymerase chain reaction." BMC Infect Dis 16(1): 154.

Gunalan, K., E. Lo, J. B. Hostetler, D. Yewhalaw, J. Mu, D. E. Neafsey, G. Yan and L. H. Miller (2016). The role of Plasmodium vivax Duffy binding protein 1 in invasion of Duffy null Africans. PNAS USA 113(22):6271-6. doi: 10.1073/pnas.1606113113

Vector Biology

Li, J., Wang, X., Zhang, G., Githure, J. I., Yan, G., & James, A. A. (2013). Genome-block expression-assisted association studies discover malaria resistance genes in Anopheles gambiae. PNAS USA 110(51), 20675-20680.

Zhong, D., X. Chang, G. Zhou, Z. He, F. Fu, Z. Yan, G. Zhu, T. Xu, M. Bonizzoni, M. Wang, L. Cui,, B. Zheng, B. Chen, G. Yan (2013). Relationship between Knockdown Resistance (kdr), Metabolic Detoxification and Organismal Resistance to Pyrethroids in Anopheles sinensis. PLos One 8(2):e55475. doi: 10.1371

Li, Y., Kamara, F., Zhou, G., Puthiyakunnon, S., Li, C., Liu, Y., Zhou, Y., Yao, L., Yan, G. and Chen, X. G. (2014). Urbanization increases Aedes albopictus larval habitats and accelerates mosquito development and survivorship. PLoS Negl Trop Dis. 8(11):e3301. doi: 10.1371.

Chang, X., Zhong, D., Fang, Q., Hartsel, J., Zhou, G., Shi, L., Fang, F., Zhu, C. and Yan, G. (2014). Multiple resistances and complex mechanisms of Anopheles sinensis mosquito: a major obstacle to mosquito-borne diseases control and elimination in China. PLoS Negl Trop Dis. 28(5):e2889. doi: 10.1371

Zhu, G., Zhong, D., Cao, J., Zhou, H., Li, J., Liu, Y., Bai, L., Xu, S., Wang, M. H., Zhou, G., Chang, X., Gao, Q. and Yan, G. (2014). Transcriptome profiling of pyrethroid resistant and susceptible mosquitoes in the malaria vector, Anopheles sinensis. BMC Genomics. 15:448. doi: 10.1186/1471-2164-15-448.

Neafsey, D. E., Waterhouse, R. M., Abai, M. R., Aganezov, S. S., Alekseyev, ............ Yan, G............ Besansky, N. J. (2015). Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes. Science 347(6217):1258522. doi: 10.1126.

Wanjala, C. L., Mbugi, J. P., Ototo, E., Gesuge, M., Afrane, Y. A., Atieli, H. E., Zhou, G., Githeko, A. K. and Yan, G (2015). Pyrethroid and DDT Resistance and Organophosphate Susceptibility among Anopheles spp. Mosquitoes, Western Kenya. Emerg Infect Dis 21:2178-81. DOI: 10.3201

Chen, X. G., Jiang, X., Gu, J., Xu, M., Wu, Y., Deng, Y., Zhang, C., Bonizzoni, M., Dermauw, W., Vontas, J., Armbruster, P., Huang, X., Yang, Y., Zhang, H., He, W., Peng, H., Liu, Y., Wu, K., Chen, J., Lirakis, M., Topalis, P., Van Leeuwen, T., Hall, A. B., Jiang, X., Thorpe, C., Mueller, R. L., Sun, C., Waterhouse, R. M., Yan, G., Tu, Z. J., Fang, X. and James, A. A. (2016). Genome sequence of the Asian Tiger mosquito, Aedes albopictus, reveals insights into its biology, genetics, and evolution. PNAS USA 112(44):E5907-E5915.
Grant Funded by NIH and NSF
Graduate Programs Public Health

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Last updated 07/25/2016