Undetectable Equals Untransmittable

The USMLE exam is not only getting harder but there is important emphasis on recent advances and trending topics. Microbiology & Infectious Diseases is a very big topic for the USMLE in 2020/2021. COVID-19 is not the only new disease principle to worry about as you approach the USMLE exam date. The new HIV Treatment Guidelines is now in force and it is destined to have an impact on content of the USMLE. Textbooks have not yet been updated to reflect these new principles, but you need to know them.

The Concept of U=U Is Now Important for USMLE Steps 1, 2 CK & 3

The decreasing numbers in HIV infections in recent years can largely be credited to wider use of PrEP (pre-exposure prophylaxis), an HIV prevention strategy that when practiced routinely makes it virtually impossible to contract the virus, as well as an increased effort to educate people that undetectable equals untransmittable (U=U), a global consensus proclaiming that when a person living with HIV is on meds and is virally suppressed, it's impossible to transmit HIV.

At USMLE Insider, we teach you the new elemental concepts and help you navigate the rapidly expanding universe of medical science. Are you familiar with these new USMLE treatment principles?

Reducing the Risk of HIV Transmission:
Antiretroviral therapy (ART) has the potential to lower HIV incidence at the population level and to decrease prevalence by preventing secondary transmission of HIV. In 3 studies, including the PARTNER study, there were no documented cases of transmission between someone who was virally suppressed and their partner who was HIV negative, even after reporting unprotected sex.

According to the CDC, 'undetectable viral load = effectively no risk of HIV transmission!' The sooner viral suppression is achieved, the shorter the period during which transmission can occur. Modelling studies indicate that incidence and prevalence of HIV on a community or population level might be lowered by expanded use of ART.
 

WHAT YOUR PATIENTS NEED TO KNOW ABOUT TREATMENT AS PREVENTION
1-6 months is the time required to achieve an undetectable viral load. 6 months (from the first undetectable test result) is the time required to maintain an undetectable viral load. If a patient achieves and maintains an undetectable viral load, there is effectively no risk of transmitting HIV. Patients must take every pill as prescribed and have viral load measured every 3-4 months.

The USMLE Insider course has updated its USMLE course notes to reflect these important milestones in Microbiology. Furthermore, we have brought our panel together to write challenging questions on these new concepts for USMLE Step 1. We have also updated our USMLE Step 2 CK and Step 3 course notes to reflect these advances in infectious diseases.

Check out one of our USMLE questions on these concepts. This is one of the questions written by our experts that our students that our students have to be able to answer during the USMLE Insider Prep Course for USMLE Step 1. Test yourself with this and let us see how you do. We will discuss the answer and offer explanations later.

1. A 38-year-old HIV-positive man presents to his primary care physician for a follow-up visit in the company of a female companion, whom he introduces to the physician as his fiancée. He says he intends to marry her in a month's time. They have been dating for a while but they have not yet engaged in sexual intercourse. He has informed her about his HIV-positive status and the woman wants to marry him so that she can 'help him beat the disease.' She informs the physician about her need to have children with the patient. He has a CD4 lymphocyte count of 380/microliter and an HIV-1 RNA of 9000 copies/mL. He has struggled with antiretroviral therapy (ART) compliance in the past, having often taken treatment breaks for months only to restart therapy upon stern warning from his physician. He says he wants to do everything in his capacity to ensure she does not ever get infected with the virus. He says he has heard of significant advances made in the field in recent times and wants to know if there is a method for eliminating his risk of transmitting the disease to her if they engage in unprotected intercourse. The physician should inform him of which of the following principles?

A. There are drugs that could be given to you to decrease your chance of transmitting the  disease, but they are very toxic and you cannot tolerate them
B. There are drugs that could be given to you to decrease your chance of transmitting the  disease, but they are only efficient in decreasing transmission in ART- naïve                               individuals
C. There are drugs that could be given to you to decrease your chance of transmitting the  disease, but they are only efficient in decreasing transmission in people with acute                     or recent (early) HIV infection
D. We can use drug therapy to achieve virologic suppression and undetectable viral load,  which would effectively lead to no risk of HIV transmission, but it requires compliance
E. You are likely to experience virologic failure because of resistance mutations that have  accumulated as a result of your past history of noncompliance with treatment
F. The virus is incurable, and so long as you are seropositive for the virus, you are going  to transmit it to her if you two engage in unprotected intercourse