Rapid Diagnostic Tests for Malaria: Challenges and Future Prospects, a Brief Review

Abstract

Malaria imposes great socio-economic burden on humanity and accounting for one of the major cause of global infectious disease .This parasitic disease affects almost 90-95% countries and territories in the tropical and subtropical regions.Approximately 40% of world populationpossess a risk to contract malaria. Malaria is a major vector-borne disease in India. Climatic diversity, extensive geographical distribution and variable malarial epidemiology in India is associated with high parasite genetic diversity and rapidly evolving drug resistance. Malaria presents a diagnostic challenge to laboratories in most countries.

In suspected cases of malaria accurate and raid diagnosis is needed. It makes some of the more sensitive methods like skill based conventional, fluorescence based microscopy and PCR methodsless suitable for routine laboratory use.Laboratory methods that require more than 1-2 hour to provide a clear diagnosis of malaria are not considered rapid tests, although they might be used for reference procedures.Recently, there has been an upsurge of interest in developing malaria rapid diagnostic test (RDT) kits for the detection of Plasmodium species. Tests targeting HRP-2 protein, p-LDH and Aldolase contribute to more than 90 % of the malaria RDTs in current scenario. However, the variable specificities, sensitivities and number of false positives with or without false negatives illustrates the difficulties and challenges in view of using RDTs. The major challenges while using RDTs are genetic variability in the Pfhrp2 gene and the persistence of antigens in the bloodstream even after the elimination of parasites. The future prospects of resolving theseminor issues associated with current RDTs with a newer generation of alternative malaria antigen targets are being studied. Various studies have provided effective comparisonsas well as clarification on the feasibility and clinical relevance of using non-microscopic methods such as RDTs for diagnosing malaria.