How many sexually-acquired HIV infections in the USA are due to acute-phase HIV transmission?Pinkerton, Steven DAIDS: 31 July 2007 - Volume 21 - Issue 12 - p 1625–1629 doi: 10.1097/QAD.0b013e32826fb6a6 Epidemiology and Social Abstract Author Information Objective: To estimate the number of persons in the USA who acquire HIV as a consequence of risky sexual activities with an acutely-infected sex partner. Methods: Estimates of the number of incident infections in the USA that are due to acute-phase HIV transmission were derived from a simple mathematical model that combined epidemiological data with information regarding the relative transmission rates for acutely-infected, nonacutely infected but serostatus-unaware, and serostatus-aware persons living with HIV. Results: Approximately 2760 (8.6%) of the estimated 32 000 sexually-acquired HIV infections in the USA each year are due to acute-phase transmission of the virus. Multivariate sensitivity analyses with a liberal range of values for key parameters produced an upper bound of 5537 infections, representing 17.3% of the total number of sexually-acquired infections. Conclusions: Acute-phase HIV transmission accounts for fewer sexually-acquired infections in the USA than is generally assumed. From the Center for AIDS Intervention Research, Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, Milwaukie, Wisconsin, USA. Received 18 August, 2006 Revised 27 March, 2007 Accepted 3 April, 2007 Correspondence to Steven D. Pinkerton, PhD, Center for AIDS Intervention Research, Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, 2071 North Summit Avenue, Milwaukee, WI 53202, USA. E-mail: email@example.com © 2007 Lippincott Williams & Wilkins, Inc.