Perceptions of U = U Among Italian Infectious Diseases Specialists: A Nationwide Survey on Providers' Attitudes Toward the Risk of HIV Transmission in Virologically Suppressed Patients

AIDS Res Hum Retroviruses. 2022 Nov;38(11):847-855. doi: 10.1089/AID.2022.0056. Epub 2022 Oct 11.


This survey aimed to understand how far the Italian infectious diseases (ID) specialists are confident in the "Undetectable = Untransmittable" (U = U) message and translate this concept into clinical practice. An anonymous survey was distributed by e-mail to 286 clinicians to collect their opinions regarding six situations potentially at risk of HIV transmission between virologically suppressed patients and seronegative individuals who possibly require postexposure prophylaxis (PEP). Overall, 51% of ID specialists deemed zero risk of HIV transmission through condomless sex for undetectable patients. This answer was more frequent among HIV specialists (30% vs. 21%, p = .01) and clinicians working in teaching hospitals (35% vs. 16%, p = .03). Remarkably, 61% of participants would advise taking PEP for the HIV-negative partner in case of sexual intercourse with a seropositive person with a recent blip occurrence or absence of an HIV RNA test performed within the last 6 months (63%). Seventy-three percent of respondents deemed it essential to know patients' history of adherence to interpreting an HIV RNA test, regardless of its timing. When applying the U = U concept to daily clinical decisions, we observed an overall cautious attitude among physicians. Concerns mainly regarded the timing of the last HIV RNA test to the exposure event, especially in the absence of details on the patient's adherence. Wider diffusion and application of the U = U message are needed.

Keywords: HIV; HIV providers; PEP; U = U; survey.

MeSH terms

  • Anti-HIV Agents* / therapeutic use
  • Attitude
  • HIV Infections* / drug therapy
  • Humans
  • Physicians*
  • RNA / therapeutic use
  • Surveys and Questionnaires


  • Anti-HIV Agents
  • RNA