title: Comparison of a quantitative PCR assay with peripheral blood smear examination for detection and quantitation of Babesia microti infection in humans.
abstract: Using a real-time quantitative PCR (qPCR), we determined the number of DNA copies/mL of blood of a Babesia microti gene in infected patients. Thirty-six patients (whose median age was 62.5years and 75.0% were male) with at least 1 qPCR-positive blood sample were included in this analysis, including 16 with serial blood samples. Based on testing of serial blood samples, it could be demonstrated that the smear became negative while the qPCR remained positive. A moderate to strong correlation was found between the DNA copy number and the number of infected erythrocytes per milliliter of blood (Pearson's r=0.68, P<0.001). Based on limited data, the DNA copy number fell by a mean of 4.1-12.9% per day on active treatment and by 3.5-7.1% per day off therapy. qPCR methodology may permit systematic evaluations of the relative efficacy of various antiparasitic drug regimens and other therapeutic modalities, although a limitation of such testing is that DNA detection per se does not establish the presence of viable parasites.
authors: Department of Pathology, New York Medical College, Valhalla, NY 10595; Department of Pathology and Clinical Laboratories, Westchester Medical Center, Valhalla, NY 10595.
authors: Guiqing
authors: G
authors: Wang
authors: Division of Infectious Diseases of the Department of Medicine, New York Medical College, Valhalla, NY 10595.
authors: Patrick
authors: P
authors: Villafuerte
authors: Department of Pathology and Clinical Laboratories, Westchester Medical Center, Valhalla, NY 10595.
authors: Jian
authors: J
authors: Zhuge
authors: Baystate Medical Center, Springfield, MA, USA.
authors: Paul
authors: P
authors: Visintainer
authors: Division of Infectious Diseases of the Department of Medicine, New York Medical College, Valhalla, NY 10595. Electronic address: gwormser@nymc.edu.
authors: Gary P
authors: GP
authors: Wormser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D041001:Babesia microti / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D001404:Babesiosis / Q000175:diagnosis*; D001769:Blood / Q000469:parasitology*; D002648:Child; D002675:Child, Preschool; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008853:Microscopy / Q000379:methods*; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Babesia microti; Babesiosis; Microscopic examination; Polymerase chain reaction