Spatial Distribution of Phlebotomine Sand Flies (Diptera: Psychodidae) as Phlebovirus Vectors in Different Areas of Iran

Abstract

Sand fly fever is caused by Naples (SFNV) and Sicilian viruses (SFSV) and the closely related Toscana virus of the Phlebovirus genus in the family Bunyaviridae, and transmitted by Phlebotomine sand flies. Phlebotomus papatasi Scopoli, 1786 is known as the main vector of the disease. This study aimed to investigate the distribution of Phlebotomine sand flies as vector of sand fly fever viruses, and the effects of some environmental variables on their potential dispersion to new areas in some provinces of Iran. Sand flies were collected during their active season in the region using CDC light traps. Ecological parameters were recorded for each collection site. Arc GIS 10.3 software was used for data analysis and mapping the distribution of sand flies. Sampling in the study areas was carried out in six different climatic zones. Seventeen sand fly species were collected including eight species of genus Phlebotomus and nine species of genus Sergentomyia. The Medium Semi-Arid climatic zone had the highest species diversity. Fourteen species of sand flies were collected at altitude between 2 and 325 m, and seven species were collected between 326 and 1380 m above sea level. There was significant correlation between sand fly density and all tested environmental variables. Phlebotominae sand flies have wide distribution in Iran and have a major public health concern in the country. P. papatasi and Sergentomyia sintoni Pringle, 1933 prefers hot summers and rainfall. This poses a threat of transmission of sand fly fever caused by SFSV and SFNV across the country.

Emerging and Re-emerging Infectious Diseases in the WHO Eastern Mediterranean Region, 2001-2018

“…Dashli virus belonging to the Sicilian serogroup and two cases of severe encephalitis caused by sandfly fever virus were reported from Iran and occupied Palestine. [128][129][130] Furthermore, antibodies against sandfly fever virus have been detected in Iran. 131 In 2010-2011, a serological investigation in Djibouti indicated the circulation of Toscanarelated viruses.…”

Medically Significant Vector-Borne Viral Diseases in Iran

“…papatasi was the most abundant species, present in all studied areas and most of the climatic zones, which poses a threat of transmission of SBPVs across the country [176]. Furthermore, the wide distribution of sandflies in Iran creates the opportunity for extended spread of current known SFVs [176], making the monitoring of sandflies of importance to mitigate the potential for spread of SF. [2,27,28,173,180,186,187] in Iran in either humans, animals, or sandflies by indirect and direct evidences.…”

“…SBPV infections are characterized as febrile illnesses with symptoms similar to influenza, with severe cases involving the disruption of the central nervous system resulting in signs such as trembling and unconsciousness [176]. SBPVs are extensively dispersed over Africa, the Mediterranean Basin, the Indian subcontinent, the Middle East, and the former USSR territories in the Far East [177].…”

“…SBPVs are extensively dispersed over Africa, the Mediterranean Basin, the Indian subcontinent, the Middle East, and the former USSR territories in the Far East [177]. Furthermore, as climate changes increase and vector ranges expand to new habitats, SBVs will most likely subsequently spread [176]. 4.1.1.…”

“…The subfamily Phlebotominae includes the genera Phlebotomus and Sergentomyia, which both bite humans, with Phlebotomus mainly feeding on mammals. Phlebotomine sandflies are widely distributed globally, including Asia, South America, and Australia, and with the effect of climate change, their distribution and colonization of new suitable habitats is predicted to increase [176]. The combination of several surveillance studies in Iran, indicates the presence of 48 sandfly species belonging to two genera of Phlebotomus (30 species) and Sergentomyia (18 species) [184,185] (Figure 4).…”