First molecular detection of Leishmania infantum in Sergentomyia minuta (Diptera, Psychodidae) in Alentejo, southern Portugal

- S. minuta by CDC-light-traps presented higher abundance than other sandfly species.
- It was confirmed by PCR that S. minuta feeds on human host in Alentejo, Portugal.
- PCR/dot blot hybridization detected a female S. minuta infected with L. infantum.
- For the first time in Europe a wild S. minuta was found infected with L. infantum.
- S. minuta might be a potential vector with importance in leishmaniasis.

Protozoan parasites, such as Leishmania spp., are the causative agents of many insect-borne infectious diseases with medical and veterinary importance. Leishmaniasis, caused by Leishmania spp., is transmitted by female phlebotomine sand flies. In the Alentejo region of Portugal, located at the north of Algarve, cases of human and canine leishmaniasis caused by Leishmania infantum have been notified. However, no recent studies regarding the sand fly fauna in the region are available. We therefore aimed to explore the phlebotomine sand fly species found in both, Évora and Beja Districts, to gain an insight about the leishmaniasis epidemiology in these areas. After the identification of the insect species, PCR molecular tests were used to assess L. infantum infection rate in the sand fly captured females, together with the analysis of blood meal sources of the insect vectors. One Sergentomyia minuta female was positive for L. infantum infection and another for human blood as a meal source. The occurrence of this phlebotomine species infected with L. infantum may suggest that, in the Mediterranean basin, leishmaniasis epidemiology is changing. Also, if the importance of S. minuta for the zoonotic and anthroponotic cycle of leishmaniasis is later proven, the strategies to control its vector will inevitably to be rethought.

Portugal is an endemic region of human and canine leishmaniasis. Our study reports, for the first time in Europe, Sergentomyia minuta infected with Leishmania infantum.157