South Africa clinics pilot Undetectable equals Untransmittable app to support HIV counselling

After identifying significant knowledge gaps about ‘Undetectable = Untransmitable’ (U=U), scepticism about its effectiveness, and hesitancy to endorse it, researchers from the University of the Witwatersrand in South Africa consulted with health workers who stressed the need for a simple and standardised presentation of U=U for their clients. In response, the researchers collaborated with people living with HIV, clinicians, and scientific experts to develop an easy-to-use web-based app to support HIV counselling in primary healthcare settings in South Africa.

“We developed a tablet-based application featuring a series of nine short video modules aimed at enhancing existing HIV counselling by emphasising the prevention benefits of ART leading to viral suppression”, writes the authors  “These videos include testimonials from people living with HIV regarding their U = U experiences, highlight motivations for adhering to ART, showcase diverse faces of the HIV community through relatable content and scenarios, and features a health worker question and answer session modelling U = U communication.”

The app, "Undetectable and You" can be accessed on personal phones or tablets by those receiving care at the three primary health clinics in Johannesburg where it is now being tested in a randomised control trial. It includes content in three widely spoken languages in the country: isiZulu, Sesotho, and English.


There is limited awareness of  U=U in Africa, where HIV prevalence is highest. In South Africa, counselling typically emphasises the health benefits of ART without describing its prevention benefits. There is reluctance to promote the U=U message due to concerns about the lack of locally acceptable communication tools, lack of confidence in the science behind U=U, and the perception that U=U contradicts existing messaging on condom use. However, integrating U=U into HIV counselling has the potential to increase the demand for ART and improve adherence.


Undetectable = Untransmittable (U=U)

U=U stands for Undetectable = Untransmittable. It means that when a person living with HIV is on regular treatment that lowers the amount of virus in their body to undetectable levels, there is zero risk of passing on HIV to their partners. The low level of virus is described as an undetectable viral load. 

virological suppression

Halting of the function or replication of a virus. In HIV, optimal viral suppression is measured as the reduction of viral load (HIV RNA) to undetectable levels and is the goal of antiretroviral therapy.

retention in care

A patient’s regular and ongoing engagement with medical care at a health care facility. 

focus group

A group of individuals selected and assembled by researchers to discuss and comment on a topic, based on their personal experience. A researcher asks questions and facilitates interaction between the participants.


Social attitudes that suggest that having a particular illness or being in a particular situation is something to be ashamed of. Stigma can be questioned and challenged.

The researchers therefore sought to develop a U = U communications intervention to support HIV counselling in primary healthcare settings in South Africa.

To ensure that the intervention was locally appropriate and contextually relevant, the researchers constituted a working group comprising key U = U and ART programme stakeholders, including people living with HIV, health care providers from the study sites, and communications specialists. This group:

  • Discussed the theoretical, contextual, and scientific foundations for the intervention.
  • Provided feedback on the researchers’ literature review and qualitative data analysis.
  • Defined intervention objectives and key messages.
  • Identified key approaches to deliver the material.
  • Selected participants for the videos.
  • Provided feedback on the scripts and videos.
  • Assisted in identifying forums to share the intervention with the government and civil society.

As aidsmap has previously reported, in-depth interviews and focus group discussions were conducted with 54 people living with HIV (nearly 90% were between 18-30 years) to assess their understanding of viral load suppression and U=U, how having HIV has affected their lives, the impact of HIV on their sexual relationships, and the information they received from healthcare workers about U=U. The discussions enabled the researchers to identify attitudes, beliefs and skills that were linked to adherence to ART and retention in care.

Focus group discussions with 64 health workers revealed varying levels of U = U knowledge. They emphasised the importance of providing clear and standardised information about U=U to encourage patients and illustrate successful cases. Health workers insisted on the need for information materials to state that U=U requires consistent adherence to ART and regular viral load testing. They also stressed the importance of these materials complementing other prevention messages, particularly regarding condom use.

Early versions of the intervention were presented at provincial and national HIV treatment literacy forums organised by the South African National AIDS Council. At these forums, the researchers received feedback from government officials, healthcare providers, and civil society groups.

The intervention

The app features nine short videos with personal testimonials of people living with HIV and their partners regarding their U = U experiences, highlighting diverse motivations for adhering to ART. For example, a man who struggled with self-stigma reports that U=U made him “feel fully human again.” A woman says that having an HIV-negative child made her believe U=U was real: “My child is my testimony”. Another sees U=U as a defence against stigma: “People on ART like me are not the ones spreading HIV. Being virally suppressed means I love myself.” Another speaker says that she has regained confidence in seeking a romantic partner now she knows she cannot pass HIV on.

These ‘role models’ are diverse in age, gender, sexuality, language, ethnicity and appearance.

The testimonials are mixed with messages from a public health nurse who provides accurate information about the science of U=U and addresses potential misunderstandings. Her clear, compassionate, and non-judgmental communication also provides a model for HIV counsellors to follow.

The app includes the following features:

  • Clear and simple communication: The terms “undetectable” and “untransmittable” are complex and need clear explanations. The app highlights the benefits of U = U and provides straightforward guidelines for people living with HIV in simple language.
  • Narrative storytelling: Presenting the science of U = U alone isn’t enough. To address this, the app features different people’s personal stories.
  • Branding: The app uses the slogan “Undetectable and You” to link U = U with individuals’ everyday realities and foster personal connection.
  • Delivery mechanism: An app provides wide accessibility and allows the team to track its reach. The app is used during HIV counselling sessions and is available for patients to access on their phones and tablets outside the counselling session.
  • HIV diagnostic and adherence counselling: The intervention focuses on two key moments. First, it supports counselling at HIV diagnosis by providing information and promoting ART initiation. It can then be used during ART adherence counselling to address adherence challenges and concerns.

“The app's design has been consciously crafted to resonate with healthcare workers, and its messaging is thoughtfully aligned to effectively address the concerns and inquiries we have gathered regarding the dissemination of U = U information,” conclude the researchers. “The U = U heroes underwent a meticulous selection process, ensuring that their stories were thoughtfully curated. This selection was driven by the goal of highlighting diverse reasons why U = U might hold significance for a wide range of individuals.”

The app is currently being piloted at three clinics to assess its feasibility, acceptability, and preliminary impact. Data extracted from clinical charts is being used to assess adherence to ART visits and viral suppression, providing insights into the intervention's impact on health-seeking behaviour.