An SA company, ERADA Technology Alliance, has announced the "imminent launch" of what it says is a world-first diagnostic saliva test for malaria.
The saliva-based diagnostic tool, to be marketed by ERADA as a Saliva-based Malaria Asymptomatic and Asexual Rapid Test (SMAART) for subclinical infection, is set to transform malaria detection worldwide in the fight against one of the globe’s most deadly diseases. Malaria, globally kills an estimated 435,000 each year, mostly children under the age of five, mainly in sub-Saharan Africa.
The SMAART detection tool, says ERADA, is the invention of leading researchers in the field of malaria diagnostics at the Johns Hopkins Bloomberg School of Public Health, Johns Hopkins Malaria Research Institute, University of Florida, United States Naval Research Laboratory, George Mason University, Thermo Fisher Scientific, Oasis Diagnostics, Laboratoire de Recherche sur le Paludisme, Institut de Recherche pour le Développement–Organisation de Coordination et de Coopération pour la Lutte Contre les Grandes Endémies en Afrique Centrale, Yaoundé, Cameroon, University of Douala, Cameroon, Tropical Disease Research Centre, Ndola, Zambia and Mercy Hospital Research Laboratory – Sierra Leone.
ERADA says its solution is easy- to-use, as it includes a simple device for standardised collection of saliva that can be implemented in the community by health care professionals, teachers and parents, contrasting with invasive blood tests, which must be administered by trained clinicians. Other drawbacks to blood tests include cultural ‘blood taboos’ existing in many countries whilst, furthermore, skin-prick tests are often stressful for children and parents.
Existing tests using blood may be invariably less reliable because subclinical infections with malaria-carrying parasites can be missed, leading some patients to come down with the disease, without knowing they have already been infected.
ERADA’s SMAART-1 test, "leads to early detection, treatment and prevention of the disease as well as reducing further transmission of malaria". The test detects a unique biomarker from female parasites circulating in an infected human who is asymptomatic, but is carrying the parasite and likely to come down with malaria within a week. Early, subclinical detection of malaria is crucial to malaria eradication because individuals who carry the parasite without exhibiting symptoms, known as carriers, are the reservoir that leads to infection of mosquitoes and transmission of the disease. Detecting the presence of the parasite before symptoms appear can save lives because malaria visible disease only erupts a couple of days after the mosquito bite.
The SMAART detection tool works by detecting a novel biomarker for Plasmodium falciparum parasites. In some areas of the world, the parasites have acquired a mutation and are therefore no longer detected by current blood-based tests. But ERADA’s saliva test detects an essential protein the parasite needs for survival, which should avoid the problem of influence from the mutation and keep the test effective long-term.
“As someone who has suffered from malaria, I know first-hand that if the parasite had been detected early, I could have been treated and cured before the symptoms of the disease made me unwell,” Dr Benji Pretorius, ERADA’s founder and MD says. “As a practising clinician myself and following my personal experience of this debilitating disease, I was spurred on to work with my colleague Dr Richard Schmidt in our small community, Musina, in South Africa, together with a global team of scientists.
“Our vision is to bring to market ERADA’s SMAART diagnostic tool as quickly as possible in the belief that it will go on to save literally millions of lives in the future.”
The World Health Organisation’s recently published World Malaria Report 2018 reinforces the message that the world is currently behind 2020 milestones of the WHO Global Technical Strategy for Malaria 2016–2030. Reduction in malaria cases has stalled and of particular concern is the report’s finding that, in 2017, there were an estimated 3.5m more cases of malaria in the 10 highest burden African countries.
“The introduction of SMAART is going to play a major part in achieving effective diagnostic testing and surveillance; as well as prevention and treatment of this disease, and therefore will be a major catalyst in meeting the WHO’s 2030 target to reduce malaria incidence and mortality by 90%,” Pretorius says.
Abstract
A large proportion of ongoing malaria parasite transmission is attributed to low-density subclinical infections not readily detected by available rapid diagnostic tests (RDTs) or microscopy. Plasmodium falciparum gametocyte carriage is subclinical, but gametocytemic individuals comprise the parasite reservoir that leads to infection of mosquitoes and local transmission. Effective detection and quantification of these carriers can help advance malaria elimination strategies. However, no point-of-need (PON) RDTs for gametocyte detection exist, much less one that can perform noninvasive sampling of saliva outside a clinical setting. Here, we report on the discovery of 35 parasite markers from which we selected a single candidate for use in a PON RDT. We performed a cross-sectional, multi-omics study of saliva from 364 children with subclinical infection in Cameroon and Zambia and produced a prototype saliva-based PON lateral flow immunoassay test for P. falciparumgametocyte carriers. The test is capable of identifying submicroscopic carriage in both clinical and nonclinical settings and is compatible with archived saliva samples.
Authors
Dingyin Tao, Brent McGill, Timothy Hamerly, Tamaki Kobayashi, Prachi Khare, Amanda Dziedzic, Tomasz Leski, Andrew Holtz, Bruce Shull, Anne E Jedlicka, Andrew Walzer, Paul D Slowey, Christopher C Slowey, Sandrine E Nsango, David A Stenger, Mike Chaponda, Modest Mulenga, Kathryn H Jacobsen, David J Sullivan, Sadie J Ryan, Rashid Ansumana, William J Moss, Isabelle Morlais, Rhoel R Dinglasan
[link url="http://stm.sciencemag.org/content/11/473/eaan4479"]Science Translational Medicine abstract[/link]