Overview: Why this survey matters
Despite notable declines in new HIV infections across many high-prevalence countries, unsuppressed individuals engaging in high-risk sexual practices continue to drive transmission. A population-based, cross-sectional study conducted in KwaZulu-Natal, South Africa, focused on HIV-positive adults aged 15–59 to identify age-gender groups most responsible for sustaining transmission. Conducted from August to December 2018 in the Eshowe/Mbongolwane area, the survey examined how sexual behavior, HIV awareness, ART uptake, and viral suppression intersect to sustain the epidemic.
What the data show about awareness, treatment, and viral suppression
Among the 862 HIV-positive participants aged 15–59, awareness of HIV-positive status was not universal (10.1% were unaware). ART uptake stood at 84.2% among those aware, leaving 16.3% virally unsuppressed (VL ≥1000 copies/mL). Notably, youths aged 15–19 showed higher rates of unawareness and unsuppressed viral loads, underscoring the need for adolescent-focused testing and treatment interventions.
Condom use and the number of sexual partners emerged as key behavioral factors. Of the 671 who had sex in the preceding year, 46.9% used condoms consistently. About one in ten HIV-positive individuals reported more than one sexual partner in the last year, with men more likely than women to report multiple partners. Among those sexually active, half of the participants aged 20–34 did not consistently use condoms. These patterns contribute to a substantial pool of individuals who are virally unsuppressed while engaging in higher-risk sexual behavior.
Risk stratification reveals groups most likely to transmit HIV
The study classified transmission risk by combining viral load with sexual behavior. Approximately 10.6% of HIV-positive participants with usable data fell into high or very high risk categories for transmitting HIV. Within this group, a sizable share were unaware of their status (about half) and not on ART (roughly three quarters). Men aged 20–59 and women aged 20–34 formed prominent slices of this high-risk population, illustrating where targeted prevention efforts should concentrate.
A very small subset (2.3%) met the very high-risk criteria—virally unsuppressed with more than one partner and consistent or inconsistent condom use. In this group, most were men aged 20–59, with substantial gaps in awareness and treatment. These findings suggest that focusing on diagnosing undiagnosed individuals, ensuring ART initiation and adherence, and promoting safer sexual practices in these subgroups could dramatically reduce onward transmission.
Implications for policy and program design
The data reinforce that broad ART expansion and TasP benefits are not enough on their own. To reduce the transmission pool, programs must prioritize:
- Early HIV diagnosis and rapid linkage to ART, especially among young adults and men, who showed higher unsuppressed rates.
- Enhanced adherence support and access to second- and third-line ART for those failing first-line regimens.
- Behavioral-risk reduction strategies, including renewed condom promotion and targeted education for individuals with multiple partners.
- Continued expansion of HIV testing services to capture undiagnosed cases and reduce the undiagnosed fraction.
Cross-cutting messages should address stigma and provide adolescent-friendly services, aiming to decrease the time from infection to viral suppression and to curb onward transmission in the community.
Limitations and context
The analysis reflects data from 2018 in a specific rural area, and self-reporting may introduce bias. Nevertheless, the findings align with broader evidence that residual transmission persists in pockets where awareness, treatment access, and protective behaviors lag. Ongoing surveillance and targeted interventions are essential to sustain and accelerate progress against HIV in KwaZulu-Natal and similar settings.
