The moving target: why mobility is the missing piece in South Africa's HIV and TB programme

South Africa confronts a paradox of global health significance. It operates the world's largest antiretroviral therapy programme while simultaneously battling one of the highest tuberculosis burdens. The success of both initiatives hinges on a simple, yet elusive, premise: treatment adherence. For human immunodeficiency virus, this means lifelong commitment, for TB, often many months of consistent treatment. A formidable, yet frequently overlooked, obstacle stands in the way: the sheer mobility of the South African population.

Genesis’s recent exploratory review illuminates the scale and nature of this challenge. The analysis distinguishes this mobility, defined as movement with the intention of maintaining ties to a primary home, from permanent migration. 

The findings are stark

An estimated 24% of people living with people living with HIV and 21% of those with TB in South Africa are considered mobile. 

The primary driver is economic necessity. This movement is concentrated within specific, highly active cohorts: commercial agriculture workers following harvests, miners and construction crews moving between sites, long-haul truck drivers traversing corridors, and individuals in the informal economy - from domestic workers to street vendors - whose livelihoods demand constant circulation. For them, movement is not optional, making fixed clinic appointments profoundly difficult to keep.

The consequences for individual and public health are severe. When individuals move, often without notifying their home clinic, they face immense barriers to accessing medication refills. This leads to treatment interruptions, which fuel drug resistance, particularly dangerous in the case of TB, and inflate official loss-to-follow-up statistics. The problem is exacerbated by fragmented health information systems and the fear of stigma or xenophobia, which deters cross-border migrants from engaging with health services at all.

Ways to turn the tide

The good news is that focused interventions can help. While the long-term goal of a centralised electronic health record system will mitigate some internal transfer issues, immediate, practical steps are required:

Streamline transfers: Simplify the patient transfer process, perhaps by introducing mobile-individual transfer cards that contain essential treatment history, allowing easy access to medication at any facility.

Targeted care: Establish targeted mobile clinics that move with seasonal populations, such as setting up services near agricultural farms during harvest seasons or at major trucking stops.

Improve health worker knowledge: Implement training programmes to increase health worker understanding and acceptability of mobility among patients, reducing the risk that mobile individuals are denied care.

Digitise: Push for a secure digital system to share patient records seamlessly across the public sector.

By recognising and actively supporting the quarter of our HIV and TB population that is constantly on the move, South Africa can ensure these individuals remain adherent, ultimately paving a clearer path toward global health targets.