Eswatini DNOs bring steady improvements to HIV and TB testing

Sub Title
Diagnostic network optimization in 2018 and 2021 yields results
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Related Global Health Areas
December 2, 2022
Lead Paragraph/Summary
This is the third story in our series of World AIDS Day "sneak peaks" of soon-to-be-published updates to the A Network Approach to Scaling Up Laboratory Services guide. Since Diagnostic Network Optimization implementation, Eswatini has made significant improvements, including achieving at least 82 percent viral load coverage for most patient groups. This country continues to invest in the program to achieve even greater results for people living with HIV.  

In 2018, Eswatini's laboratory system was experiencing challenges in meeting the need for viral load (VL) testing for people living with HIV. Viral load testing coverage was only 55 percent nationally, which meant that many patients being treated for HIV could not access testing to know their health status, and their clinicians could not monitor their treatment results.

At this time, Eswatini was just beginning to conduct viral load testing for HIV, having introduced a few VL instruments into its laboratory system. Viral load testing had become the preferred method of testing for HIV; the previous primary method, CD4 testing, was transitioning to being used only as an indicator for advanced HIV illness.

The country also introduced Early Infant Diagnosis (EID), placing one low-throughput EID machine at the National Reference Lab (NRL) to handle all testing for the country.

This new testing capacity was an important development for adults and infants who needed HIV testing in Eswatini. But the country still faced several challenges:

  • Viral load testing capacity was not sufficient to meet testing targets
  • EID was centralized, with a complex specimen referral network, hence had long turnaround times
  • Instrument downtime was too high
  • The CD4 network needed to be streamlined, with obsolete instruments removed

DNO in 2018

In August 2018, the country conducted its first DNO exercise to determine how the VL and EID laboratory system could be optimized and how point-of-care (POC) machines, which are placed at hospitals and other health facilities, could be integrated into the system for improved access to testing and reduced turnaround times.

Eswatini Health Laboratory Services (EHLS) and other stakeholders — including USAID, GHSC-PSM; laboratory implementing partner ICAP; and clinical partners Médecins Sans Frontières (MSF), Georgetown University, and the Elizabeth Glaser Pediatrics AIDS Foundation (EGPAF)— conducted the DNO workshop.

Based on the DNO exercise and recommendations, EHLS took the following actions:

  • Optimized the sample referral network so that samples would be transported to closer platforms
  • Balanced instrument workloads to prevent overutilization or under-utilization
  • Determined how to shift between Hologic to Roche platforms if reagent stock was a challenge

Eswatini also began utilizing GeneXpert POC machines —which already were placed throughout the country to conduct TB testing — for VL and EID testing as well, bringing testing closer to people and reducing turnaround time.

Additionally, EHLS began phasing out a Roche platform called CAP/CTM96, a low-throughput machine that was nearing the end of its life, and replacing it with a newer-generation, higher-throughput Roche instrument called Cobas 6800 that could do both EID and COVID-19 polymerase chain reaction (PCR) tests.

EHLS also moved to an innovative reagent rental model, in which it would rent VL instruments from manufacturers instead of own them, and the country would place guaranteed routine orders with the same manufacturers for reagents and other consumables. Manufacturers would also provide regular maintenance and repair for the machines to keep them operational. Costs to the country for instrument rental, reagents, and maintenance would be included in one all-inclusive price per test. This type of agreement has the potential to increase instrument uptime, prevent reagent stockouts, and increase testing access and coverage.

Outcomes of the 2018 DNO

By March 2021, Eswatini's laboratory system saw some significant improvements but challenges still remained. Viral load coverage had improved to 82 percent viral load coverage for people on antiretroviral treatment (ART). For children under 15 years old, VL coverage was 85 percent. However, for children under four years old, VL coverage was only around 65 percent. 

VL testing turnaround time was reported to be five working days, compared to two weeks in 2018. Coverage for EID testing at two months of age was strong at 95 percent; and at 12 months months of age, the EID network exceeded targets, achieving 107 percent of the testing coverage target.

CD4 testing was expected to reduce due to increased VL coverage, but it didn't reduce as much as expected. 

DNO in 2021

In October 2021, EHLS and stakeholders conducted a second DNO workshop to accomplish two objectives. 

Objective 1. To review performance and results for CD4, EID, VL, and TB testing following the first DNO workshop.

Referral network: Results showed that between the 2018 and 2021 DNOs, the total number of tests requested reduced from 410,330 to 320,680, mainly due to the introduction of viral load testing for HIV and the use of CD4 testing primarily as an indicator of advanced HIV. The total distance traveled by samples also reduced from 783,379 kilometers to 613,680 kilometers, showing an implementation of the optimal referral network from the 2018 exercise and also reflecting the fewer number of tests. The greatest distance traveled by samples also reduced from 154.9 kilometers to 117.2 kilometers.

VL: VL testing capacity increased from 180,000 to 292,320 tests for the plasma instruments; however, utilization decreased from 96.5 percent to 59.9 percent. This increase in testing capacity and reduction in utilization resulted from the greater-throughput Cobas 6800 instrument in Mbabane and Panther platforms in Nhlangano. Testing was highly centralized, with most samples having to travel to reach one of the regional labs with the necessary testing equipment.

EID: EID instrument utilization rates for both platforms — AlereQ and CAP/CTM96 —increased, from 41.5 percent to 55.6 percent and from 72.4 percent to 74.9 percent, respectively, reflecting the decentralization of EID testing. More samples (18.3 percent more) were being handled at POC sites than previously because of a decrease in turnaround time from two weeks with conventional EID testing to one day with the new instruments.

CD4: CD4 capacity increased for both conventional systems (instruments placed at a referral laboratory) and POC systems. Capacity for conventional CD4 instruments increased from 284,160 to 416,160 tests, while capacity for POC CD4 instruments increased from 585,600 to 801,600 tests. Utilization rates decreased for both testing platforms — from 10.8 percent to 9.6 percent for POC instruments, and from 11.3 percent to 4 percent for conventional platforms — due to the increase in viral load testing coverage. More of the tests were being handled at facilities, though the network was already fairly distributed to facilities via PIMA devices.

TB: For TB testing, the number of GeneXpert sites increased from 28 to 32 and testing capacity increased from 155,520 tests to 190,080 tests, a 30 percent increase. But the low utilization rates seen in 2018 further dropped more than 50 percent, from 20.6 percent to 8.8 percent. This could have been a result of decreased TB incidence due to mask wearing to prevent COVID-19 transmission. The capacity increase due to the added machines also contributed to the reduced utilization rates.

Objective 2. To examine different scenarios for phasing out the CAP/CTM96 machine for EID testing, increasing referrals to conventional sites for CD4 testing, and adjusting the GeneXpert multiplexing (TB, EID, and VL testing) strategy.

Final recommendations – and some subsequent actions – are as follows:

  • CAP/CTM96 machines in each site will be replaced with a GeneXpert machine that has the same functionality (the GeneXpert 4, 8, or 16).
  • Eswatini's National AIDS Program will lead discussions on CD4 testing demand and ensure test requests are according to the national guidelines: GHS-PSM procured Visitec CD4 rapid test kits for advanced HIV/AIDS disease, and the manufacturer provided training to a core team who, following a rollout plan, then provided training to health facility staff.
  • VL and sexually transmitted infection (STI) testing will be decentralized to hospitals and health centers, where GeneXpert platforms will be "multiplexed" (optimized) to include VL and STI testing in addition to TB testing: GHSC-PSM procured GenExpert cartridges, with delivery expected in December 2022. In October 2022 the Ministry of Health hired carefully selected technologists using resources from the Global Fund to run viral load on GeneXpert machines and will soon be deployed to the respective sites. EHLS and its partners ICAP and GHSC-PSM are currently working to finalize and share patient/sample workflow documentation.
  • Task teams will monitor and refine the phasing out of CAP/CTM96, CD4 test referral guidance, GeneXpert multiplexing, and waste and biosafety implementation plans.
  • DNO implementation will be documented: For DNO implementation, an assessment determined that the existing laboratory space was too small to accommodate a necessary C5800 analyzer and would require structural change. The Manzini Hospital management is currently considering the proposed renovation to accommodate the new analyzer. In the meantime, EHLS and GHSC-PSM hold quarterly meetings with suppliers to review key performance indicators related to VL supply contracts (such as down time days, repair turnaround time, tests performed, and invalid tests). 
  • A review of this DNO exercise will be done every two years: Eswatini established a technical working group to follow progress on implementation of the 2021 DNO recommendations.