Sensitivity of the nested-polymerase chain reaction (PCR) assay for Brugia malayi and significance of 'free' DNA in PCR-based assays.
The blood filtration method was used as the gold standard to determine the detection level of simple blood-spot sampling and nested-polymerase chain reaction (PCR) for Brugia malayi. Of 100 samples, 48 were filtration-positive. Of these, 26 had microfilaria counts that were low enough (<1-29 microfilariae/ml) to accurately assess the limit of detection by nested-PCR. Nested-PCR consistently detected B. malayi DNA in samples with > or = 10 microfilariae/ml. Post-filtration, microfilaria-depleted, blood-spots from microfilaria-positive samples were screened by nested-PCR and B. malayi specific 'free' DNA was detected in 51.7% of these samples. There was no evidence for 'free' DNA in microfilaria-negative individuals from this endemic community.
Cox-Singh
J
J
Faculty of Medicine and Health Sciences, University Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia. cox@tm.net.my
Pomrehn
A S
AS
Wolfe
N D
ND
Rahman
H A
HA
Lu
H Y
HY
Singh
B
B
D000818:Animals; D017178:Brugia malayi / Q000235:genetics / Q000302:isolation & purification*; D018509:DNA, Helminth / Q000097:blood*; D005368:Filariasis / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008842:Microfilariae / Q000302:isolation & purification; D018512:Parasitemia; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D018509:DNA, Helminth