Diagnosis of symptomatic kala-azar by polymerase chain reaction using patient's blood.
BACKGROUND
Detection of Leishmania parasite in patients by classical methods at the early stage of infection is limited. Several studies have shown that polymerase chain reaction (PCR) is more effective for the diagnosis of visceral Leishmaniasis (VL) in clinical samples. The purpose of this study was to develop a simple, specific and sensitive PCR-based assay for detecting VL caused by any species of the genus Leishmania.


METHODS
We examined blood samples from twenty suspected kala-azar patients by polymerase chain reaction (PCR) using Leishmania specific primers. The results of the PCR-based procedure were compared with those of the Leishman-Donovan (LD) body test, immunodiffusion assay (IDA), and direct agglutination test (DAT).


RESULTS
Out of the twenty samples, only five were found to be positive using all four tests. However, twelve samples were positive using the PCR assay, and among these only ten samples were found to be positive by LD body test of bone marrow smears. The results clearly indicated that, unlike the LD body test routinely used for diagnosis of kala-azar, the PCR assay is 100% sensitive.


CONCLUSIONS
This method is very useful for primary screening of blood samples of patients suffering from kala-azar-like symptoms, especially in endemic areas.
Pal
Sampa
S
Department of Medicine, Calcutta Medical College & Hospital, Calcutta, India. sampa@u.washington.edu
Aggarwal
Gautam
G
Haldar
Amit
A
Majumdar
Amit
A
Majumdar
Hemanta K
HK
Duttagupta
Swadesh
S
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D016054:DNA, Protozoan / Q000097:blood / Q000235:genetics; D006801:Humans; D007893:Leishmania donovani / Q000235:genetics / Q000302:isolation & purification; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000469:parasitology*; D010274:Parasitology / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods*
D017931:DNA Primers; D016054:DNA, Protozoan