Epidemiological, clinical and laboratory aspects of sandfly fever

Abstract

Purpose of review: Sandfly fever viruses are still a significant health problem in many regions of the world, such as Africa, the Mediterranean basin, the Middle East, and Central Asia. This review provides an update on the advances in knowledge about epidemiological, clinical, and laboratory aspects of infections caused by Toscana, Sicilian and Naples viruses.

Recent findings: Diagnosis of Toscana virus infection has been facilitated by new molecular methods and by immunoenzymatic tests based on the recombinant nucleoprotein. Gene analysis has allowed identification of circulating Toscana variants possibly involved in the protean pathomorphism and extreme variability of the clinical picture. New attention has been addressed to the antigenic properties of the viral proteins (the nucleoprotein N and the surface glycoproteins G1 and G2), in order to understand their immunogenetic role. High genetic divergence within the serocomplexes belonging to each of the Sicilian and the Naples viruses has suggested that infection with one genotype may not completely immunize against infection with all other genotypes in a given serocomplex. These findings could serve as a basis for vaccine development and may account for reports of multiple episodes of sandfly fever in the same host. Recently, the performance of analysis models based on weather data and reported vector surveys has allowed the prediction of the risk of acquiring sandfly infection in the endemic geographic areas.

Summary: Recent developments include a better knowledge of the epidemiological, clinical, and laboratory aspects of sandfly infection, while the search for effective drugs and vaccines is still in progress.