Utilising a novel surveillance system to investigate species of Forcipomyia (Lasiohelea) (Diptera: Ceratopogonidae) as the suspected vectors of Leishmania macropodum (Kinetoplastida: Trypanosomatidae) in the Darwin region of Australia

Elina Panahi; Martin Shivas; Sonja Hall-Mendelin; Nina Kurucz; Penny A Rudd; Rachel De Araujo; Eloise B Skinner; Lorna Melville; Lara J Herrero

doi:10.1016/j.ijppaw.2020.06.004

Utilising a novel surveillance system to investigate species of Forcipomyia (Lasiohelea) (Diptera: Ceratopogonidae) as the suspected vectors of Leishmania macropodum (Kinetoplastida: Trypanosomatidae) in the Darwin region of Australia

Int J Parasitol Parasites Wildl. 2020 Jun 17:12:192-198. doi: 10.1016/j.ijppaw.2020.06.004. eCollection 2020 Aug.

Authors

Elina Panahi¹, Martin Shivas², Sonja Hall-Mendelin³, Nina Kurucz⁴, Penny A Rudd¹, Rachel De Araujo⁵, Eloise B Skinner⁶, Lorna Melville⁵, Lara J Herrero^{1

7}

Affiliations

¹ Institute for Glycomics, Griffith University, Southport, QLD, 4222, Australia.
² Mosquito Management, Brisbane City Council, Eagle Farm, QLD, 4009, Australia.
³ Public Health Virology, Forensic and Scientific Services, Queensland Health, Coopers Plains, QLD, 4108, Australia.
⁴ Medical Entomology, Centre for Disease Control, Top End Health Service, Casuarina, NT, 0811, Australia.
⁵ Berrimah Veterinary Laboratory, Department of Primary Industry and Resources, Berrimah, NT, 0828, Australia.
⁶ Environmental Futures Research Institute, Griffith University, Southport, QLD, 4222, Australia.
⁷ Redland Hospital, Metro South, Queensland Health, Cleveland, QLD, 4163, Australia.

Abstract

Up until recently, Australia was considered free of Leishmania due to the absence of phlebotomine sandfly species (Diptera: Phlebotominae) known to transmit Leishmania parasites in other parts of the world. The discovery of Leishmania (Mundinia) macropodum (Kinetoplastida: Trypanosomatidae) in Northern Australia sparked questions as to the existence of alternative vectors of Leishmania. This has added to the complexity of fully understanding the parasite's interaction with its vector, which is known to be very specific. Previous findings demonstrated L. macropodum infection beyond the blood meal stage in the day-biting midges Forcipomyia (Lasiohelea) Kieffer (Diptera: Ceratopogonidae) implicating them in the parasite's life cycle. Currently, there is no conclusive evidence demonstrating this suspected vector to transmit L. macropodum to a naïve host. Therefore, this research aimed to investigate the vector competency of day-biting midge F. (Lasiohelea) to transmit L. macropodum utilising a novel technology that preserves nucleic acids. Honey-soaked Flinders Technology Associates (FTA®) filter-paper cards were used to obtain saliva expectorated from biting midges while sugar-feeding. F. (Lasiohelea) were aspirated directly off macropods from a known Leishmania-transmission site and were kept in a waxed-paper container holding a honey-coated FTA® card for feeding. Insect identification and Taqman quantitative real-time PCR (qPCR) screening assays revealed L. macropodum DNA in F. (Lasiohelea) up to 7 days post field-collection, and in an unidentified biting midge, previously known as F. (Lasiohelea) sp.1. Moreover, 7/145 (4.83%) of FTA® cards were confirmed positive with L. macropodum DNA after exposure to field-collected F. (Lasiohelea). Additionally, FTA® cards were found to be a valuable surveillance tool, given the ease of use in the field and laboratory. Overall, our findings support previous reports on L. macropodum transmission by an alternative vector to phlebotomine sandflies. Further studies identifying and isolating infective L. macropodum promastigotes is necessary to resolve questions on the L. macropodum vector.

Keywords: Australia; Day-biting midge; FTA® cards; Leishmania; Macropod; Saliva; Transmission.