Sandfly-Borne Phleboviruses in Portugal: Four and Still Counting

Abstract

According to ICTV, there are currently 66 known phlebovirus species. More than 40 of these viruses were isolated or detected in phlebotomine sandflies and some of them are known pathogens. In Portugal, information about sandfly-borne phleboviruses is scarce and scattered sandfly-borne diseases are neglected and often not considered in differential diagnoses. The main objective of this work was to gather the existing information and to raise awareness about the circulating phleboviruses in this country. To date, Massilia and Alcube phleboviruses have been isolated from sandflies in southern Portugal. Human infections with Toscana and Sicilian phleboviruses have been reported, as well as seroprevalence in cats and dogs. More studies are needed in order to understand if the viruses isolated during the entomological surveys have an impact on human health and to fully understand the real importance of the already recognized pathogens in our country.

Co-Circulation of Leishmania Parasites and Phleboviruses in a Population of Sand Flies Collected in the South of Portugal

“…Currently, the ICTV uses criteria to differentiate phleboviruses’ species [ 17 ]. These findings were already discussed in a previous publication [ 19 ]. Still, we can hypothesize that at least two phlebovirus species were in circulation in the same location at that time.…”

“…The other obtained sequence (530 nucleotides, ON807200) seems to belong to a Massilia virus strain. These findings were all previously published, including the sequence files and the respective phylogenetic trees, and can be found in Amaro et al [19].…”

“…Nevertheless, the sequence obtained from the standard nucleotide BLAST (blastn) [ 43 ] presented similarities with Phlebovirus hediense [ 49 ], which is a largely unknown phlebovirus, previously isolated from sand flies in China, and with phleboviruses collected in Italy, with only partial sequences available in GenBank. The other detected phlebovirus seems to be a Massilia virus strain since it clustered together with other strains isolated or detected previously in the south of Portugal [ 19 ]. However, the partial phleboviruses sequences obtained in the Algarve in 2018 are too small to make a valid assumption.…”

“…This virus has been considered the third main cause of aseptic meningitis in the Mediterranean region during the summer months and, as such, a major public health concern [ 18 ]. Furthermore, TOSV has been associated with unusual clinical manifestations, with or without permanent sequelae, and even with some cases of fatal outcomes [ 19 , 20 , 21 ]. Although human seroprevalence studies for TOSV show numbers around 10–24%, in endemic regions such as Tuscany, this value can go up to 77% [ 19 , 22 ].…”

“…Furthermore, TOSV has been associated with unusual clinical manifestations, with or without permanent sequelae, and even with some cases of fatal outcomes [ 19 , 20 , 21 ]. Although human seroprevalence studies for TOSV show numbers around 10–24%, in endemic regions such as Tuscany, this value can go up to 77% [ 19 , 22 ].…”