Real time polymerase chain reaction for the detection of malarial parasite.
OBJECTIVE
To evaluate the sensitivity and specificity of real time polymerase chain reaction (PCR) for the detection of Malarial parasite.


METHODS
Descriptive cross-sectional study.


METHODS
The Armed Forces Institute of Pathology (AFIP), Rawalpindi, from April to June 2010.


METHODS
A total of 60 Leishman stained blood films with clinical suspicion of malaria were studied by light microscopy for detection of malaria parasite (MP). The samples were also subjected to real time PCR for the small subunit (SSU) rRNA gene of MP found in all the four subspecies of Plasmodium. Real time PCR was done by the Taqman probe method. One sample positive for MP was serially diluted with ABO compatible blood, and light microscopy and real time PCR were performed on all dilutions. Results of light microscopy and real time PCR were compared. Sensitivity and specificity were calculated using PCR as the gold standard.


RESULTS
PCR detected MP in 33 samples with sensitivity and specificity of 100% whereas light microscopy could detect MP in 30 samples. Sensitivity and specificity of light microscopy was 90.9% and 100% respectively. In the serially diluted blood sample, MP was visible at 1/16 dilution whereas the PCR showed positive results even at 1/512 dilution.


CONCLUSIONS
Real time PCR is more sensitive than light microscopy for the detection of malarial parasite.
Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan. jawadzafar2000@yahoo.com
Jawad Zafar
JZ
Chaudry
Suhaib
S
Ahmed
Tanveer Zia
TZ
Qureshi
Nadir
N
Ali
D000818:Animals; D003430:Cross-Sectional Studies; D016054:DNA, Protozoan / Q000032:analysis*; D005260:Female; D006801:Humans; D008288:Malaria / Q000175:diagnosis / Q000469:parasitology*; D008297:Male; D008853:Microscopy / Q000379:methods; D010961:Plasmodium / Q000145:classification* / Q000302:isolation & purification / Q000648:ultrastructure; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
D016054:DNA, Protozoan