Guideline: the laboratory diagnosis of malaria. General Haematology Task Force of the British Committee for Standards in Haematology.
UK National External Quality Assessment Service surveys indicate continuing problems in malaria diagnosis: inaccurate calculation of parasitaemia or failure to estimate it altogether, difficulty distinguishing Plasmodium vivax from P. ovale, reporting malaria parasites when none were present and misidentification of P. falciparum as another species still occur. Therefore, the British Committee for Standards in Haematology Guidelines for the Laboratory Diagnosis of Malaria have been revised. They are intended for use in the UK but may also prove useful in other non-endemic areas. Routine use of thick and thin films is advised for malaria diagnosis. Thick films should be stained using Giemsa or Field stain. Thin films should be stained with Giemsa stain or Leishman stain. Thick films should be examined by two observers, each viewing a minimum of 200 high power fields. If thick films are positive, the species should be determined by examination of a thin film. In the case of P. falciparum or P. knowlesi infection, the percentage of parasitized cells or the number of parasites per microlitre (/μl) should be estimated and reported. Rapid diagnostic tests (RDTs) for malarial antigen cannot replace microscopy but are indicated as a supplementary test when malaria diagnosis is performed by relatively inexperienced staff. Malaria RDTs are negative in babesiosis.
Clinical Diagnostic Parasitology Laboratory, Liverpool School of Tropical Medicine, Liverpool, UK.
J Wendi
JW
Bailey
John
J
Williams
Barbara J
BJ
Bain
John
J
Parker-Williams
Peter L
PL
Chiodini
D006801:Humans; D000953:Antigens, Protozoan / Q000097:blood; D000962:Antimalarials / Q000494:pharmacology; D002846:Chromatography, Affinity; D019411:Clinical Laboratory Techniques / Q000592:standards; D016054:DNA, Protozoan / Q000097:blood; D004351:Drug Resistance; D005188:False Negative Reactions; D005189:False Positive Reactions; D008288:Malaria / Q000175:diagnosis / Q000469:parasitology; D008853:Microscopy / Q000379:methods; D015588:Observer Variation; D018512:Parasitemia / Q000175:diagnosis / Q000469:parasitology; D010961:Plasmodium / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction; D011996:Records / Q000592:standards; D013045:Species Specificity; D013194:Staining and Labeling / Q000379:methods; D006113:United Kingdom
D000953:Antigens, Protozoan; D000962:Antimalarials; D016054:DNA, Protozoan
diagnosis; malaria