Division of Infectious Diseases

Susan Little, M.D.

Susan Little, M.D.
Professor of Medicine

UCSD Antiviral Research Center
Department of Medicine, Mail Code 8208
150 W. Washington Street, Suite 100
San Diego, CA 92103 USA

Telephone: (619) 543-8080
Fax: (619) 298-0177
Email: slittle@ucsd.edu

Dr. Little conducts translational research and clinical trials to increase our understanding of the pathogenesis of acute or primary HIV infection and HIV transmission, and works with a large international collaborative team to improve our understanding of the biology and epidemiology of HIV transmission. Dr. Littleā€™s research focuses on the identification and systematic evaluation of individuals who have been recently infected with HIV and the sexual partners who transmitted HIV to them (Transmission Pairs) to elucidate and quantify epidemiologic, behavioral, biologic, virologic, and host factors that contribute to transmission. She has been heavily involved in the design of novel approaches to screen and identify acutely infected individuals, as well as the evaluation of important pathogenesis questions related to development of drug resistant variants in genital secretions and transmission of drug-resistant HIV-1. These studies also evaluate therapeutic intervention strategies, including antiretroviral therapy and vaccines to preserve immune function in recently infected subjects. Dr. Little is an active investigator in the UCSD unit of the AIDS Clinical Trials Group (ACTG, funded by the National Institutes of Health), and has developed numerous ACTG protocols to evaluate new strategies for treatment of acute infection.


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 did her residency in Internal Medicine at Barnes Hospital in St. Louis, Missouri. She then completed an 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 directs an NIH-funded Program Project at UCSD to evaluate determinants of HIV transmission. She oversees the integration of pathogenesis, translational, and clinical research in the UCSD Acute and Early HIV Infection (AEH) Program. Dr. Little conducts translational research and clinical trials to increase our understanding of the pathogenesis of acute or primary HIV infection and HIV transmission, and works with a large international collaborative team to evaluate viral dynamics, superinfection, viral drug resistance, and clearance of cellular reservoirs. . Dr. Little is currently Co-Chair of the HIV Prevention Science Committee, a joint committee of the HIV Prevention Trials Network (HPTN) and the AIDS Clinical Trials Group (ACTG).

Dr. Little has published extensively in peer-reviewed journals and has been invited to present her work at numerous international meetings, including the Conference on Retroviruses and Opportunistic Infections (CROI), the International HIV Drug Resistance Workshop, the Infectious Diseases Society of America (IDSA), and the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). She serves on the scientific committees of the International HIV Drug Resistance Workshop and the World Health Organization HIV Resistance Network (HIVResNet).

Selected Publications

  1. Little SJ, Holte S, Routy JP, 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 patients recently infected with HIV. New England Journal of Medicine 347:385-94, 2002.
  2. Smith DM, Wong JK, Hightower GK, Ignacio CC, Koelsch KK, Daar ES, Richman DD, Little SJ. Incidence of HIV superinfection following primary infection. JAMA 2004; 292(10):1177-1178.
  3. 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. Clin Infect Dis 2007;44(3):456-458.
  4. Little SJ, Frost SDW, Wong JK, Smith DM, Kosakovsky Pond SL, Ignacio CC, Parkin NT, Petropoulos CJ, Richman DD. The persistence of transmitted drug resistance among subjects with primary HIV infection. J Virol 2008;Jun; 82(11):5510-8.
  5. 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. 2008 Aug 20;22(13):1667-71.