Sensitivity of laser light depolarization analysis for detection of malaria in blood samples.
Automated light depolarization analysis could be a useful tool for diagnosing malarial infections. This work discusses the results of a diagnostic efficacy study on 411 samples from patients with suspected malaria infection performed with a Cell-Dyn 4000 analyser. Light dispersed at 90 degrees and depolarized can be used for identifying and counting eosinophils. However, other cell populations with depolarizing capacity occur in malarial samples; these result from leukocytes ingesting haemozoin that is derived from the degradation of the haem group of haemoglobin performed by the parasite. A sensitivity of 72 % and specificity of 98 % were recorded, with positive and negative predictive values of 78 % and 97 %, respectively. Although the sensitivity level of the automated light depolarization analysis is not adequate to replace the existing methods for the diagnosis of parasitic diseases, it could alert clinicians to unsuspected infections by parasites, particularly those from the genus Plasmodium.
Padial
Manuel Martínez
MM
Laboratory of Microbiology1 and Department of Infectious Diseases2, Hospital Carlos III, Madrid, Spain 3Megalab Laboratories, Madrid, Spain 4Abbott Diagnostics Division, Costa Brava 13, 28034 Madrid, Spain.
Subirats
Mercedes
M
Laboratory of Microbiology1 and Department of Infectious Diseases2, Hospital Carlos III, Madrid, Spain 3Megalab Laboratories, Madrid, Spain 4Abbott Diagnostics Division, Costa Brava 13, 28034 Madrid, Spain.
Puente
Sabino
S
Laboratory of Microbiology1 and Department of Infectious Diseases2, Hospital Carlos III, Madrid, Spain 3Megalab Laboratories, Madrid, Spain 4Abbott Diagnostics Division, Costa Brava 13, 28034 Madrid, Spain.
Lago
Mar
M
Laboratory of Microbiology1 and Department of Infectious Diseases2, Hospital Carlos III, Madrid, Spain 3Megalab Laboratories, Madrid, Spain 4Abbott Diagnostics Division, Costa Brava 13, 28034 Madrid, Spain.
Crespo
Santiago
S
Laboratory of Microbiology1 and Department of Infectious Diseases2, Hospital Carlos III, Madrid, Spain 3Megalab Laboratories, Madrid, Spain 4Abbott Diagnostics Division, Costa Brava 13, 28034 Madrid, Spain.
Palacios
Gonzalo
G
Laboratory of Microbiology1 and Department of Infectious Diseases2, Hospital Carlos III, Madrid, Spain 3Megalab Laboratories, Madrid, Spain 4Abbott Diagnostics Division, Costa Brava 13, 28034 Madrid, Spain.
Baquero
Margarita
M
Laboratory of Microbiology1 and Department of Infectious Diseases2, Hospital Carlos III, Madrid, Spain 3Megalab Laboratories, Madrid, Spain 4Abbott Diagnostics Division, Costa Brava 13, 28034 Madrid, Spain.
D000328:Adult; D000818:Animals; D001772:Blood Cell Count; D002675:Child, Preschool; D006420:Hemeproteins; D006801:Humans; D007834:Lasers; D008027:Light; D008288:Malaria / Q000097:blood / Q000175:diagnosis*; D008859:Microscopy, Polarization / Q000379:methods; D018512:Parasitemia / Q000175:diagnosis*; D010860:Pigments, Biological; D010961:Plasmodium / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
D006420:Hemeproteins; D010860:Pigments, Biological; C020753:hemozoin