Malaria

Malaria is one of the world’s most common diseases, it affects over 200 million people and causes up to three million deaths each year, the majority being young children. In non-endemic areas, it is one of the most important imported diseases, resulting in a number of deaths in late-diagnosed or unsuspected cases each year.

The disease is caused by protozoan parasites of the genus Plasmodium. Four species of Plasmodium cause human malaria: P.falciparum, P.vivax, P.ovale and P.malariae. P. falciparum is the most common and the most virulent, causing most malaria-related deaths. P. vivax is next and although rarely fatal, the associated malaria can be accompanied by severe clinical symptoms. It is a common cause of malaria in South East Asia and South America.

These mosquito borne parasites are injected into the human bloodstream by the bite of female Anopheles mosquitoes. Once in the blood the parasite makes its way to the liver where the merozoite form is produced and released into the blood. Invasion and subsequent rupturing of red blood cells is responsible for the clinical symptoms.

Human-to-human transmission can occur through blood transfusion from infected donors. For this reason blood banks in non-endemic countries either defer all donors who are classified as ‘malaria-risk’, or employ an alternative strategy of effective targeted blood screening with restricted deferral.


The number of blood donations lost as a result of the deferral of malaria-risk donors can be significant, up to 60,000 per year in the UK. This loss, in addition to an increasing number of deferrals due to other possible infection risks, can lead to difficulties in maintaining a sufficient blood supply. A strategy which allows earlier reinstatement of potential malaria-risk donors reduces this loss without increasing the risk of releasing a malaria infected donation.

People infected with Plasmodium species develop an antibody response. The CAPTIA™ Malaria EIA kit is designed to detect antibodies occurring in patients infected with P. falciparum, P. vivax, P. ovale and P. malariae. Study results show that the CAPTIA™ Malaria EIA is a sensitive and specific assay which may be used effectively as part of a screening strategy combining targeted antibody testing and restricted donor deferral.