The RAPID 1-2-3® HEMA CASSETTE MALARIA PF/PV (the TEST) is a rapid, qualitative, two site sandwich immunoassay for the detection of P. falciparum specific histidine rich protein-2(Pf. HRP-2) and P. vivax specific pLDH. The test can also be used for specific detection and differentiation of P. falciparum and P. vivax malaria in areas with high rates of mixed infections.
Four species of the Plasmodium parasites are responsible for malaria infections in human viz. P. falciparum, P. vivax, P. ovale and P. malariae. Of these, P. falciparum and P. vivax are considered the most important due to incidence of cerebral malaria and drug resistance associated with P. falciparum malaria, and high rate of infectivity and relapse associated with P. vivax. As the course of treatment is dependent on the species, differentiation between P. falciparum and P. vivax is of utmost importance for better patient management and speedy recovery.
The RAPID 1-2-3® HEMA CASSETTE MALARIA PF/PV detection system for P. falciparum malaria is based on the detection of P. falciparum specific histidine rich protein-2 (Pf. HRP-2) which is a water soluble protein that is released from parasite containing erythrocytes of infected individuals. The detection system of P. vivax malaria is based on the presence of P. vivax specific pLDH.
PRINCIPLES OF THE TEST
The RAPID 1-2-3® HEMA CASSETTE MALARIA PF/PV utilizes the principle of immunochromatography. As the test sample flows through the membrane assembly of the device after addition of the clearing buffer, the colored colloidal gold conjugates of monoclonal anti Pf. HRP-2(IgG) antibody and anti-pLDH antibody complexes the HRP-2 /pLDH in the lysed sample. This complex moves further on the membrane to the test region where it is immobilized by the anti-pLDH (monoclonal) antibody and/or the monoclonal anti Pf. HRP-2(IgM) antibody (monoclonal) coated on the membrane leading to formation of a pink-purple colored band/s which confirms a positive test result. A band will appear under Pf at the test region in falciparum positive samples, while a band will appear under Pv in vivax malaria positive samples. Appearance of band under Pf as well as Pv in the test region suggests a mixed infection.
Absence of colored band/s in the test region indicates a negative test result. The remaining conjugate and unbound complex if any, move further on the membrane and are subsequently immobilized by anti rabbit antibodies coated on the membrane at the control region, forming a pink-purple band. The control band formation is based on the ‘Rabbit/anti-Rabbit globulin’ system. Since it is completely independent of the analyte detection system, it facilitates formation of consistent control band signal independent of analyte concentration. This control band serves to validate the test performance.