[Validation of PCR as a tool for the detection of Leishmania (Vianna) spp. parasites in the Lutzomyia (Diptera: Psychodidae) vector].
BACKGROUND
The applicability of the polymerase chain reaction (PCR) was evaluated for the detection and identification of parasites in sand fly vectors and thereby precluding the necessity of dissecting them. DNA was extracted from individual, laboratory infected sand flies, and subjected to PCR amplification using specific B1 and B2 primers for parasites of the Leishmania (Viannia) subgenus.


METHODS
The sensitivity and specificity of the PCR primers were defined by means of serial dilutions of a Leishmania culture. Pooled samples of 1 to 5 sandflies were examined in association with the parasite dilutions to determine the point at which sensitivity became reduced. Experimentally infected sand flies were used to compare the sensitivity of the PCR with sand fly dissection and searching for flagellated parasites by microscopic examination.


RESULTS
As few as a single parasite was detected, and the sensitivity remained unaltered up to 3 female sand flies per pool. Detection rates were 33% for the traditional technique and 33.3% for PCR. The B1 and B2 primers were confirmed as specific for Leishmania (Viannia) parasites.


CONCLUSIONS
The demonstrably high sensitivity and specificity of PCR warrant the use of PCR in assessing natural infection rates of Leishmania (Viannia) in field populations of sand fly vectors.
Santamaría
Erika
E
Laboratorio de Entomología, Subdirección de Investigación, Instituto Nacional de Salud, Bogotá, DC, Colombia.
Ponce
Nubia
N
Puerta
Concepción
C
Ferro
Cristina
C
D000818:Animals; D005260:Female; D007891:Leishmania / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D011576:Psychodidae / Q000469:parasitology*