title: Hemozoin Pigment: An Important Tool for Low Parasitemic Malarial Diagnosis.
abstract: Low parasitemic condition in malaria remains a diagnostic challenge; as the available diagnostic methods failed to detect. Currently, hemozoin (Hz) pigment is gaining attention in the diagnosis of malaria. The major drawback is ease of detection of Hz in routine practice. A pilot study was conducted to evaluate the role of Hz pigment and to compare the performance of quantitative buffy coat assay (QBC) and PCR in such conditions. Clinically suspected cases of malaria were examined by both Giemsa stain and immunochromatographic test (ICT). Samples positive by ICT and negative by Giemsa stain were further examined by nested PCR targeting 18S rRNA and QBC for the presence of malaria parasites and pigments. Thirty blood samples fulfilled the inclusion criteria out of which 23 were Plasmodium vivax (Pv), 4 Plasmodium falciparum (Pf), and 3 mixed (Pv and Pf) by immunochromatographic test. Twenty-one out of 30 (70%) were positive by nested PCR in comparison to 25/30 (83%) by QBC. Samples containing both malaria parasites and Hz pigment by QBC completely showed concordance with the PCR result. However, 61% of total samples containing only Hz pigment were observed positive by PCR. Hz pigment remains an important tool for malaria diagnosis. Identification of leukocytes containing pigments by QBC not only indicates recent malarial infections but also puts light on severity of the disease. QBC assay is a rapid, highly sensitive, and cost-effective method to detect malaria parasites and Hz pigment especially in low parasitemic conditions.
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Sarita
authors.initials: S
authors.lastname: Mohapatra
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Arnab
authors.initials: A
authors.lastname: Ghosh
authors.affiliation: National Institute of Pathology, Safdarjung Hospital, New Delhi, India.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Singh
authors.affiliation: National Institute of Pathology, Safdarjung Hospital, New Delhi, India.
authors.forename: Dhirendra Pratap
authors.initials: DP
authors.lastname: Singh
authors.affiliation: Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India.
authors.forename: Bhawna
authors.initials: B
authors.lastname: Sharma
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Jyotish Chandra
authors.initials: JC
authors.lastname: Samantaray
authors.affiliation: Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India.
authors.forename: Manorama
authors.initials: M
authors.lastname: Deb
authors.affiliation: Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India.
authors.forename: Rajni
authors.initials: R
authors.lastname: Gaind
mesh_terms: D058621:Blood Buffy Coat / Q000737:chemistry* / Q000469:parasitology*; D002846:Chromatography, Affinity / Q000379:methods*; D006420:Hemeproteins / Q000032:analysis*; D006801:Humans; D008288:Malaria / Q000175:diagnosis*; D010865:Pilot Projects; D016133:Polymerase Chain Reaction / Q000379:methods*; D016053:RNA, Protozoan / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D006420:Hemeproteins; D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S; C020753:hemozoin
keywords: Plasmodium falciparum; Plasmodium vivax; QBC; hemozoin pigment; low parasitemia; nested PCR