The aim of the present study was to detect natural infection by
Leishmania (Leishmania) infantum in
Lutzomyia longipalpis
captured in Barcarena, state of Pará, Brazil, through the use of three primer sets. With this approach,
it is unnecessary to previously dissect the sandfly specimens. DNA of 280
Lu. longipalpis female specimens were
extracted from the whole insects. PCR primers for kinetoplast minicircle DNA (kDNA), the mini-exon gene and the
small subunit ribosomal RNA (SSU-rRNA) gene of
Leishmania were used, generating fragments of 400 bp, 780 bp
and 603 bp, respectively. Infection by the parasite was found with the kDNA primer in 8.6% of the cases, with the
mini-exon gene primer in 7.1% of the cases and with the SSU-rRNA gene primer in 5.3% of the cases. These data
show the importance of polymerase chain reaction as a tool for investigating the molecular epidemiology of visceral
leishmaniasis by estimating the risk of disease transmission in endemic areas, with the kDNA primer representing
the most reliable marker for the parasite.
