Leakages in ART treatment cascades in West Africa and Zambia

'Improving Timely Linkage to Lifesaving Treatment'. Baylor College of Medicine Children's Foundation–Malawi / Robbie Flick / USAID. Creative Commons licence.

Two studies presented at the 10th International AIDS Society Conference on HIV Science (IAS 2019) in Mexico City showed significant leakages in the antiretroviral therapy (ART) treatment cascade. A study of eleven West and Central African countries showed low numbers of viral load tests conducted as well as stock-outs of HIV tests, ART and viral load testing supplies. Another study looked at the cascade of virologically unsuppressed people living with HIV in Zambia and found gaps and substantial delays with provision of follow-up viral load testing.

In West and Central Africa, only 48% of people living with HIV are aware of their status, only 40% of which are accessing ART, and 29% of which are virally suppressed. Barriers include drug stock-outs, weak health systems, human rights barriers, and low quality of care.

In order to increase accountability for the UNAIDS 90-90-90 targets (90% of people living with HIV are diagnosed; 90% of diagnosed people are taking ART; and 90% of people taking ART are virally suppressed, by 2020), the International Treatment Preparedness Coalition trained and supported national networks of people living with HIV to collect and analyse facility-level data along the HIV treatment cascade from 103 health centres serving more than 80,000 people living with HIV, in eleven countries. Between July 2017 and June 2018, 538 health centre visits, 279 key informant interviews and 110 focus group discussions were conducted. The study used a patient-centred framework to accessibility, looking at availability, accessibility, acceptability, affordability and appropriateness of services.


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.

second-line treatment

The second preferred therapy for a particular condition, used after first-line treatment fails or if a person cannot tolerate first-line drugs.

treatment cascade

A model that outlines the steps of medical care that people living with HIV go through from initial diagnosis to achieving viral suppression, and shows the proportion of individuals living with HIV who are engaged at each stage. 


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.

90-90-90 target

A target set by the Joint United Nations Programme on HIV/AIDS (UNAIDS) for 90% of people with HIV to be diagnosed, 90% of diagnosed people to be taking treatment, and 90% of people on treatment to have an undetectable viral load. 

Linkage to care was high overall: of the 4692 people who tested positive for HIV, 93% initiated ART. However, ART initiation of people living with HIV was lower among key and vulnerable populations (16% of those testing positive for HIV but only 7% of people on ART), and in countries without test-and-treat policies.

Viral load testing of those who had initiated ART was significantly lower: of the 81,817 people on ART, only 20% (n = 16,491) had viral load tests performed. A quarter of viral load test results were returned within two weeks, with faster turnaround time associated with improved viral suppression (p < 0.05). 

In terms of availability, ART stock-outs were recorded during almost a quarter (23%) of health facility visits, lasting an average of 41 days. Stock-outs were less common for HIV tests (9% of visits) and viral load testing supplies (17% of visits), with variations across countries. Stock-outs were highest in Guinea, including stock-outs of HIV tests (46% of facility visits), ART (35%) and viral load laboratory supplies (55%). The least frequent stock-outs were found in Ghana: HIV tests (3%), ART (10%), no stock-outs of viral load testing supplies.

Long distances to health centres was the key barrier to HIV testing and ART, as cited by 35% and 32% of respondents respectively. Other barriers cited as reasons for not accessing HIV testing were fear of discovering one’s status (25%) and stigma (16%). Only 5% cited their reason as being that healthcare workers are unfriendly and only 2% did not access HIV testing due to a lack of confidentiality. Medication side-effects was the second highest reason for not accessing ART at 30% of respondents, followed by stock-outs (10%) and stigma and discrimination (8%).

The authors of the study recommend that the availability of non-facility-based HIV testing options, including community-led and community-based HIV testing, be expanded, and that community systems and responses be strengthened to support the roll-out of differentiated service delivery. They also recommend that knowledge among people living with HIV and healthcare workers be enhanced to increase demand for high-quality viral load testing services.

Focusing on those with unsuppressed viral load

A study in Zambia looked at the treatment cascade of people living with HIV with unsuppressed viral load, finding gaps in the provision of follow-up viral load testing and substantial delays in testing.

Achieving the third 90 in the UNAIDS 90-90-90 targets required sustained and appropriate ART as well as routine viral load monitoring to ensure viral suppression of less than 1000 copies/ml. The Zambian national ART guidelines state that people on ART with an unsuppressed viral load should enter a ‘failure’ cascade, requiring enhanced adherence counselling, follow-up viral load testing (within 90 days), and possible switch to second-line ART.

The researchers, led by the Centre for Infectious Disease Research in Zambia (CIDRZ), analysed routine data on adults accessing ART services in 74 CIDRZ-supported facilities in three Zambian provinces between 2016 and 2018.

Of the 14,291 individuals who had an unsuppressed viral load, only a third (4978 people) had a follow-up viral load test. Moreover, only 9.2% had it done within 90 days, at a median of 266 days (IQR: 174-402 days). This means that many people with unsuppressed viral loads are continuing to live with unsuppressed viral loads for months. Time to first follow-up viral load did not differ by gender (p = 0.23), but was faster for adolescents (18-24 years) than for those over 25 years of age (p< 0.001).

Half of patients with follow-up viral load testing achieved viral suppression (n = 2519, 51%), while 49% (n = 2459) experienced virological failure (two consecutive unsuppressed viral load tests). Of 2459 people with virological failure, only 720 (29%) switched to second-line ART as per the guideline recommendations, while 144 (6%) were already on second-line ART) and 1513 (61.5%) remained on first-line ART. A total of 1248 of those with an unsuppressed viral load received a third viral load test, of whom 720 (58%) still had unsuppressed viral loads.

Although antiretrovirals were often dispensed, viral suppression remained sub-optimal. The authors correlated data on the Medication Possession Ratio (MPR) (the amount of time with records of ART dispensed divided by the total time in HIV care as recorded in the electronic medical record) with data on viral suppression after first unsuppressed viral load. At one year of follow-up, 37% of individuals in the >90% MPR category were able to achieve viral load suppression, compared to 18% in the lowest (<50%) MPR category. This increases the risk of HIV drug resistance and associated morbidity and mortality.

Currently, the gaps in the failure cascade are being addressed by increasing laboratory and clinical capacity to work with people who have unsuppressed viral load, and peer educators and community health workers being assigned to contact and locate those with unsuppressed viral loads.

“New differentiated service delivery models are needed that offer unsuppressed patients expedited clinical and laboratory services, including enhanced adherence counselling, follow-up viral load and HIV genotype testing, and ART regimen change,” said Dr Ranjit Warrier, principal investigator of the study.


Mosime W et al. Understanding Gaps in the HIV Treatment Cascade in 11 West African Countries: Findings from the Regional Community Treatment Observatory. Tenth International AIDS Society Conference on HIV Science (IAS 2019), Mexico City, abstract TUPDB0103, 2019.

View this abstract on the conference website.

Warrier R et al. The "Failure Cascade" for Patients with Unsuppressed Viral Load in Zambia: Results from a Large HIV Treatment Cohort. Tenth International AIDS Society Conference on HIV Science (IAS 2019), Mexico City, abstract TUPDB0104, 2019.

View this abstract on the conference website.

Full image credit: 'Improving Timely Linkage to Lifesaving Treatment'. Baylor College of Medicine Children's Foundation–Malawi / Robbie Flick / USAID. Creative Commons licence. Available at www.flickr.com/photos/usaid_images/14742605707/ under a Creative Commons licence CC BY-NC-ND 2.0.