CD4 count testing halves in Southern Africa since 2008

04 September 2020

Rates of CD4 testing in Africa have halved, yet viral load testing is only reaching around a third of people on HIV treatment.

Nurse administers an HIV test

A study of around half a million people living with HIV in six southern African countries has found the proportion of adults receiving CD4 count testing before starting antiretroviral treatment (ART) halved between 2008 and 2017.

The coverage of viral load testing was also found to be low with only a third of people on ART receiving this type of test in 2017. 

Around a quarter of people starting ART in 2018 were also found to be at an advanced stage of HIV. 

Since 2013, the World Health Organization (WHO) has switched to recommending viral load testing to detect treatment failure, as it is faster and more accurate than CD4 monitoring at detecting this measure. But WHO still recommends people receive CD4 tests before they start ART as this type of test is a better predictor of disease progression and risk of death. These findings, therefore, indicate a concerning trend. 

The large-scale study, published by JIAS, analysed patient data from around 502,500 adults (64% of whom were female) starting ART between 2005 to 2018 in Lesotho, Malawi, Mozambique, South Africa, Zambia and Zimbabwe. 43% of adults began ART between 2009 and 2013, with 38% beginning between 2014 and 2018 and 18% between 2005 and 2008. 

Overall, around 60% of adults received CD4 monitoring before beginning ART, ranging from 30% in Malawi to 80% in South Africa. Over time, the proportion of adults receiving CD4 testing before starting treatment fell from 78% in 2008 to below 40% in 2017.

Among those with a CD4 count reading, the number with advanced HIV (<200 cells/mm3) declined over time, from around 83% in 2005 to 24% in 2018. South Africa had the highest percentage of adults with advanced HIV starting treatment (60%) and Mozambique the lowest (34%). 

Between 2005 and 2016, the percentage of adults receiving viral load testing ranged between 10% and 23%, then increased to 36% in 2017. A substantial increase in viral load testing parallel to the decrease in CD4 count testing was only seen in South Africa and Malawi. Around 60% of adults in South Africa and 10% in Malawi received viral load testing. But fewer than 2% received this type of testing in Lesotho, Mozambique, Zambia and Zimbabwe, all of which have only begun to scale‐up of viral load testing recently. 

Overall, 17% of adults received a viral load test three to nine months after starting ART, among whom 8.6% were virally unsuppressed. Among adults with viral load testing, the percentage of people who were virally unsuppressed ranged between 7% and 11%. The proportion of people who were virally unsuppressed was lowest in South Africa and Malawi (both 8.5%) and highest in Mozambique (70%). 

The trends in CD4 testing observed in this study are likely to reflect WHO’s revised ART guidelines. But they highlight a worrying gap – with CD4 testing declining and the expansion of viral load testing faltering many people with advanced HIV, or who are experiencing treatment failure, may go undetected, threatening the effectiveness of ART for people living with HIV in Southern Africa.

Written by Hester Phillips