Date of Award

Summer 8-2019

Degree Name

Doctor of Philosophy (PhD)



Second Advisor


Third Advisor



Hepatitis C virus (HCV) infection is the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplantation. Current treatment rates and efficacy are inadequate to manage the disease burden caused by HCV; thus, efforts are needed to control HCV transmission. Besides the well-known transmission routes, which are health-care-associated transmission and transmission through injecting drugs, HCV could also be transmitted by sexual contact, especially among men having sex with men (MSM). MSM also have higher drug use prevalence than the general population, which may contribute to HCV infection by sexual disinhibition and other risky behavior. Since 2000, there have been emerging reports indicating HCV epidemics or outbreaks among HIV positive MSM in Europe, Australia and North America. However, previous studies often focused on HIV positive and/or injection drug using MSM, and there is still a need for study targeting on non-injection drug using MSM. The overall objective of this study is to investigate characteristics associated with HCV infection in MSM who used drugs but not injected drugs (NIDU MSM). This study used data from two projects, DASH project and YMAP project, and applied latent class analysis and dyadic data analysis to analyze the data. The main finding of this study included: (1) overall HCV prevalence in NIDU MSM was higher than the rest of general population; (2) NIDU MSM >=42 years old had a higher risk of HCV infection than NIDU MSM <42 years old; (3) NIDU MSM >=42 years old who used >6 drugs were associated with increased probability of HCV infection among all NIDU MSM; (4) among NIDU YMSM, syphilis mono-infection, HIV mono-infection, and syphilis/HIV co-infection were associated with increased risk of HCV infection. This study may provide a better understanding of HCV transmission among NIDU MSM. These results may provide a profile of subgroups with a higher HCV transmission possibility among NIDU MSM. In the long term, the results of the study may guide the development of healthcare and behavioral intervention programs related to HCV transmission, and may also guide tailored screening or treatment strategies for HCV infection.