A new generation of highly sensitive rapid diagnostic tests (HS-RDTs) has been developed in Uganda, an innovation officials say will go a long way in effectively combating the killer disease.
Unlike conventional means, the new test kit has a significantly lower limit of detection (LOD) of parasites, according to Dr Suzan Nabadda, an official at Uganda National Health Laboratory Services.
This was revealed on Wednesday during the launch of findings in an observational study of an ultra-sensitive RDT (HS-RDTs) with the ease of use smartphone reporting in Uganda.
The results of this study indicate a significant increase in sensitivity for Pf (Plasmodium falciparum, the parasite causing the deadliest form of malaria) detection in low-density, sub-clinical infections with HS-RDTs. compared to conventional RDTs (cRDTs).
The HS-RDT is highly promising and has received WHO pre-qualification as an effective diagnostic tool.
This tool is being evaluated as an elimination tool to inform malaria elimination strategies.
Malaria remains a leading cause of illness and death in Uganda.
Most of the country’s 43 million population is at risk. And the disease accounts for between a third and half of all outpatient consultations.
Each malaria episode costs a family on average 9 US dollars.
Abbot Rapid Diagnostics, a US-based pharmaceutical company and Lifecare Diagnostics supported the study.
The test kit was developed by Abbott.
How it works
For use with the HS-RDT, Abbott introduced another innovation, the Data Logger Smartphone App (SMAPP), to support enhanced case detection and surveillance systems.
This allows the healthcare worker to log a visually read RDT test result, as well as patient demographics, and transmit them securely together with the GPS location and the time of the test to the Uganda National Health Laboratory Services server.
The system displays geospatial tests information on a map and enables health program managers to see data in near real-time.
“The Smartphone Data Logger app also enables the user to view information on the tests they performed, the patients and their results,” the survey report reads in part.
“This empowers healthcare workers and managers to utilize real-time data for evidence-based decision-making, quality services, and improved disease management.”
The combination of HS-RDTs and the Data Logger SMAPP provides an opportunity for real-time disease surveillance and elimination interventions.
This allows the Health Ministry to implement strategies such as test and treat, index case finding, and identification of disease hotspots.
The simplicity of the two technologies allows for utilization of integrated community case management (ICCM) service providers to play the leading role in implementing malaria elimination strategies, with real-time technical oversight.
Even though Uganda had the second largest reduction in malaria cases (1.5 million) between 2017 and 2018, Uganda is still the third highest contributor of malaria cases and the seventh highest contributor of malaria deaths according to the 2019 WHO’s World Malaria Report.
Furthermore, malaria has a significant negative impact on the economy of Uganda due to decreased productivity, lower school attendance and performance, and reduced foreign investments.
In recent years, malaria prevalence, incidence and mortality have all declined steeply. However, this fell short of the targets from the Uganda Malaria Reduction Strategic Plan 2014-2020.
Despite efforts, the Uganda Ministry of Health reported an increase in malaria cases from about 1 million cases in June 2018 to 1.4 million in June 2019.
The upsurge affected about half the country with approximately 65 districts involved. The affected regions included: West Nile, Acholi, Lango, Busoga, Bunyoro, Buganda, Karamoja, Teso, Eastern and Western Uganda.
According to Health Ministry Permanent Secretary, Dr Diana Atwine, it is now observed that “accurate diagnosis of malaria infection is critical for effective management and reduction of malaria transmission.”
While rapid diagnostic tests (RDTs) can confirm the presence of infection, currently available RDTs have limitations including their poor performance with low-level infections.
Detecting these low-level infections becomes critical as the malaria burden decreases to fully eliminate parasite reservoirs.
There is also a need to increase case detection and treat all asymptomatic reservoirs at all levels.
Findings from the study indicated the following:
In the outpatient group (OPD), the parasite positivity rate was 13.3% for HS-RDTs, more than double that of 6.4% with cRDTs on the same patients. A large percentage of these was from school-age children and adolescents (5-17 years).
In the antenatal care group (ANC), 11% (384/3490) of the pregnant women were positive with malaria parasites despite existing prophylactic measures provided during pregnancy (intermittent preventive treatment and insecticide-treated bed nets). HS-RDTs again detected most of these positive cases (10.4%), much more than cRDTs (7.0%).
In the community setting, 79.7% (2,397/3,009) of children under-five years tested positive with malaria parasites. These 2,397 children led to the testing of 8,888 asymptomatic people in their households with HS-RDTs. From these family members, 21.1% (1,877) were positive.
Health workers from different backgrounds and with training levels were able to learn how to effectively perform the HS-RDT tests and use the Data Logger technology.
This study demonstrated the ability to of HS-RDT to detect asymptomatic cases and increase case findings of low-parasite density infections. This provides more opportunities to eliminate parasite reservoirs.
Increased sensitivity as demonstrated by HS-RDTs was at an acceptable level of accuracy (sensitivity, specificity and positive predictive value) when a subset was compared to PCR.
Real-time data reporting facilitated quick decision-making thanks to the Data Logger.
Officials said findings from this study will further accelerate efforts toward the Uganda Malaria Reduction and Elimination Plan (UMREP) 2021 – 2025.