Division of Infectious Diseases and Global Public Health

Susan Little, M.D.

Susan J. Little, MD

Professor of Medicine
Division of Infectious Diseases
Co-Director, AntiViral Research Center
UC San Diego School of Medicine
Department of Medicine
200 West Arbor Drive, MC 8208
San Diego, CA 92103-8208 USA

Telephone: (619) 543-8080
Fax: (619) 543-5066
Email: slittle@ucsd.edu



Background Information

Susan J. Little, M.D. is a Professor of Medicine in the Department of Medicine, Division of Infectious Diseases, at the University of California, San Diego (UCSD). Dr. Little received her medical degree in 1987 from the Washington University School of Medicine, and then completed her residency in Internal Medicine at Barnes Hospital in St. Louis, Missouri and her Infectious Diseases fellowship at UCSD.

Since joining the UCSD faculty in 1993, Dr. Little has developed one of the leading and most productive National Institute of Allergy and Infectious Diseases (NIAID)-sponsored programs in the United States for the identification, enrollment, and treatment of individuals with acute and recent HIV-1 infection. She directed an NIH-funded Program Project at UCSD to evaluate determinants of HIV transmission and now serves as PI of the San Diego Primary Infection Resource Consortium (PIRC), a program focused on research related to HIV prevention, transmission and pathogenesis. Dr. Little has published extensively in peer-reviewed journals including the New England Journal of Medicine, AIDS, Clinical Infectious Diseases, Journal of Virology, Lancet Infectious Diseases, and Annals of Internal Medicine.

Dr. Little is actively involved in the training and mentoring of undergraduate and graduate students, post-doctoral research fellows and junior faculty. She serves as Co-Director of the Antiviral Research Center (AVRC), the major site of UCSD clinical and translational research trials related to HIV/AIDS, hepatitis, influenza, tuberculosis and other infectious diseases of global impact.


Research Interests

Dr. Little conducts translational research and clinical trials to increase our understanding of the pathogenesis of acute and early HIV infection and transmission. She developed and now serves as PI of the Primary Infection Resource Consortium (PIRC), a highly collaborative research program that serves as a resource for investigators throughout the US and abroad. The PIRC has been tackling the evolving challenges in the field of primary/acute HIV infection for over twenty years. Dr. Little also has extensive experience leading large multi-site and multinational research projects and has served as chair/co-chair for several AIDS Clinical Trials Group and Acute Infection Early Disease Research Program clinical trials. Her research has extended to a wide variety of topics related to primary HIV infection, resulting in publications in the area of: 1) prevention, 2) drug resistance, 3) dynamics, 4) superinfection, 5) cellular reservoirs, 6) transmission, 7) treatment, 8) molecular epidemiology, 9) cost-effectiveness, 10) ethics, 11) diagnostic testing assays, and 12) end organ disease. Her current research interests are focused on the use of molecular epidemiologic methods to infer and characterize HIV transmission networks and the use of targeted prevention and treatment interventions to reduce HIV incidence.


Clinical Focus

Dr. Little’s clinical activities involve serving as Infectious Diseases attending on the inpatient services of the UC San Diego Hospitals. She also attends a weekly outpatient clinic, where she cares for HIV infected and at risk adults at the VA San Diego Healthcare System.



Significant Publications

  1. Little S, McLean AR, Spina CA, Richman DD, Havlir DV. Viral dynamics of acute HIV-1 infection. Journal of Experimental Medicine. 190(6): 841-850, 1999. PubMed PMID: 10499922.

  2. Little SJ, Daar ES, D’Aquila RT, Keiser PH, Connick E, Whitcomb JM, Hellmann NS, Petropoulos CJ, Sutton L, Pitt JA, Rosenberg ES, Koup RA, Walker BD, Richman DD. Reduced antiretroviral drug susceptibility among patients with primary HIV infection. Journal of the American Medical Association. 282(12): 1142-1149, 1999. PubMed PMID: 10501117.

  3. Little SJ, Holte S, Routy J-P, Daar ES, Markowitz M, Collier AC, Koup RA, Mellors JW, Connick E, Conway B, Kilby M, Whitcomb JM, Hellmann NS, Richman DD. Antiretroviral-drug resistance among subjects recently infected with HIV. New England Journal of Medicine. 347(6): 385-394, 2002. PubMed PMID: 12167680.

  4. Smith DM, Wong JK, Hightower GK, Ignacio CC, Koelsch KK, Daar ES, Richman DD, Little SJ. Incidence of HIV superinfection following primary infection. Journal of the American Medical Association. 292(10): 1177-1178, 2004. PubMed PMID: 15353529.

  5. Gorbach PM, Drumright LN, Daar ES, Little SJ. Transmission behaviors of recently HIV-infected men who have sex with men. Journal of Acquired Immune Deficiency Syndromes. 42(1): 80-85, 2006. PubMed PMID: 16763494.

  6. Smith D, Moini N, Pesano R, Cachay E, Aiem H, Lie Y, Richman D, Little S. Clinical utility of HIV standard genotyping among antiretroviral-naive individuals with unknown duration of infection. Clinical Infectious Diseases 44(3): 456-458, 2007. PubMed PMID: 17205459.

  7. Smith DM, Wong JK, Shao H, Hightower GK, Mai SH, Moreno JM, Ignacio CC, Frost SD, Richman DD, Little SJ. Long-term persistence of transmitted HIV drug resistance in male genital tract secretions: implications for secondary transmission. Journal of Infectious Diseases. 196(3): 356-360, 2007. PubMed PMID: 17597449.

  8. Butler DM, Smith DM, Cachay ER, Hightower GK, Nugent CT, Richman DD, Little SJ. Herpes simplex virus 2 serostatus and viral loads of HIV-1 in blood and semen as risk factors for HIV transmission among men who have sex with men. AIDS. 22(13): 1667-1671, 2008. PubMed PMID: 18670228.

  9. Little SJ, Frost SD, Wong JK, Smith DM, Pond SL, Ignacio CC, Parkin NT, Petropoulos CJ, Richman DD. Persistence of transmitted drug resistance among subjects with primary human immunodeficiency virus infection. Journal of Virology. 82(11): 5510-5518, 2008. PubMed PMID: 18353964.

  10. Smith DM, May SJ, Tweeten S, Drumright L, Pacold ME, Kosakovsky Pond SL, Pesano RL, Lie YS, Richman DD, Frost SD, Woelk CH, Little SJ. A public health model for the molecular surveillance of HIV transmission in San Diego, California. AIDS. 23(2): 255-232, 2009. PubMed PMID: 19098493.

  11. Markowitz M, Vaida F, Hare CB, Boden D, Mohri H, Hecht FM, Kalayjian RC, Conrad A, Mildvan D, Aberg J, Hogan C, Kilby JM, Balfour HH Jr, Schafer K, Richman D, Little S. The virologic and immunologic effects of cyclosporine as an adjunct to antiretroviral therapy in patients treated during acute and early HIV-1 infection. Journal of Infectious Diseases. 201(9):1298-302, 2010. PubMed PMID: 20235838.

  12. Woelk CH, Beliakova-Bethell N, Goicoechea M, Zhao Y, Du P, Rought SE, Lozach J, Pérez-Santiago R, Richman DD, Smith DM, Little SJ. Gene expression before HAART initiation predicts HIV-infected individuals at risk of poor CD4+ T-cell recovery. AIDS. (24)2: 217-212, 2010. PubMed PMID: 19952713.

  13. Hogan CM, Degruttola V, Sun X, Fiscus SA, Del Rio C, Hare CB, Markowitz M, Connick E, Macatangay B, Tashima KT, Kallungal B, Camp R, Morton T, Daar ES, Little S; A5217 Study Team. The setpoint study (ACTG A5217): effect of immediate versus deferred antiretroviral therapy on virologic set point in recently HIV-1-infected individuals. Journal of Infectious Diseases. 205(1):87-96, 2012. PubMed PMID: 22180621.

  14. Khanna AS, Goodreau SM, Gorbach PM, Daar E, Little SJ. Modeling the impact of post-diagnosis behavior change on HIV prevalence in southern California men who have sex with men (MSM). AIDS Behav. 18(8): 1523-31, 2014. PubMed PMID: 24165985.

  15. Mehta SR, Vinterbo SA, Little SJ. Ensuring privacy in the study of pathogen genetics. Lancet Infect Dis. 14(8): 773-7, 2014. PubMed PMID: 24721230.

  16. Little SJ, Kosakovsky Pond SL, Anderson CM, Young JA, Wertheim JO, Mehta SR, May S, Smith DM. Using HIV networks to inform real time prevention interventions. PLoS One. 9(6): e98443, 2014. PubMed PMID: 24901437.

  17. Hoenigl, M., Green, N., Mehta, S. R., & Little, S. J. Risk Factors for Acute and Early HIV Infection Among Men Who Have Sex with Men (MSM) in San Diego, 2008 to 2014: A Cohort Study. Medicine (Baltimore), 94(30), e1242, 2015. PubMed PMID: 26222863.

  18. Green N, Hoenigl M, Chaillon A, Anderson CM, Kosakovsky Pond SL, Smith DM, Little SJ. Partner services in adults with acute and early HIV infection. AIDS (London, England). 2017;31(2):287-93. PubMed PMID: 27831950.

  19. Vesa J, Chaillon A, Wagner GA, Anderson CM, Richman DD, Smith DM, Little SJ. Increased HIV-1 superinfection risk in carriers of specific human leukocyte antigen alleles. AIDS (London, England). 2017. PubMed PMID: 28244954.