Temporal dynamics and <i>Leishmania infantum</i> infection prevalence of <i>Phlebotomus perniciosus</i> (<i>Diptera</i>, <i>Phlebotominae</i>) in highly endemic areas of visceral leishmaniasis in Tunisia

<div><p><i>Phlebotomus perniciosus</i> is one of the major vectors of <i>Leishmania infantum</i> in the Mediterranean basin. The aim of this work was (i) to provide information about abundance and temporal dynamics of this <i>Larroussius</i> species in a hot spot area of visceral leishmaniasis in Tunisia, (ii) to detect <i>L</i>. <i>infantum</i> DNA in wild caught female sandflies and (iii) to measure <i>Phlebotomus perniciosus</i> infection rate throughout the active season. Sandflies were collected monthly during one year using CDC miniature light-traps in house and in animal shelters. Male specimens were identified at species level according to morphological characters. Female specimens were conserved individually for molecular study. <i>Leishmania</i> infection was tested by kinetoplast DNA real-time PCR and ITS-1 PCR-sequencing. Subsequent sandfly species identification of infected specimens was done by mitochondrial cytochrome b sequencing. In one year period, overall 4,441 specimens (2230 males and 2211 females) were collected. Sandfly activity started in end-April and ended in early-November. Mean sandfly density in house was significantly lower than in animal shelters (51 ± 50 <i>versus</i> 504 ± 460 sandflies /CDC night, p<0.05). However, a higher proportion of females was found in house (58.4% <i>versus</i> 49.2%, p<0.001). Based on species identification of male specimens, <i>Phlebotomus perniciosus</i> was the dominant species (56% of the whole male sandfly fauna, p<0.0001). It showed two peaks of density in the active season, a sharp one in early May and a higher long lasting one from end-July to end-September. DNA was extracted from 190 female specimens randomly sampled and corresponding to 96 specimens from house and 94 from animal shelters. Twenty four female sandfly were infected by <i>Leishmania infantum</i>. All infected specimens were recognized as <i>Phlebotomus perniciosus</i>. <i>Leishmania infantum</i> infection rate in female sandflies was 2.3 fold higher in house than in animal shelters (17.7% versus 7.4%, p<0.05). In house, estimated number of infected specimens was the highest at the end of the active season. Abundance, dynamics of density and <i>Leishmania infantum</i> infection prevalence of <i>Phlebotomus perniciosus</i> in Tunisian hot spot of visceral leishmaniasis highlight the major role of this <i>Phlebotominae</i> species in <i>L</i>. <i>infantum</i> transmission.</p>