BACKGROUND Knowledge on synanthropic phlebotomines and their natural infection by
Leishmania is necessary for the
identification of potential areas for leishmaniasis occurrence.
OBJECTIVE To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to
determine the rate of natural infection by trypanosomatids.
METHODS Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014.
The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae
females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid
species were identified using sequencing.
FINDINGS A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered
in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and
Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again,
Ny. whitmani was the
predominant species.
Lutzomyia longipalpis
was commonly found in domestic areas, while
Bichromomyia flaviscutellata was
most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified
Leishmania amazonensis
,
L. infantum
, and
Crithidia fasciculata in
Ny. whitmani, as well as
L. amazonensis in
Lu. longipalpis,
Trypanosoma
sp. and
L.
amazonensis in
Pintomyia christenseni, and
L. amazonensis in both
Psathyromyia hermanlenti and
Evandromyia walkeri.
MAIN CONCLUSIONS These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry
month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify
Leishmania,
Trypanosoma, and
Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil.
