Other pathogenic sandfly-borne viruses

3.1 Rhabdoviridae family

The Rhabdoviridae family includes 18 genera and 134 species with negative­sense, single-stranded RNA genomes [118]. In this family, members of the Vesiculovirus genus are able to infect at least 28 invertebrates and vertebrates including human [27, 119].

The disease manifests itself into two different forms in the United States; either as sporadic outbreaks with a 10-year intervals in the southwestern states (New Mexico, Arizona, Utah and Colorado) [120]. However, in some other states as Georgia, Alabama, North and South Carolina, the disease occurred yearly with clinical signs in cattle, pig and horses. Since 1970, viral activity has been focal and limited to isolated wildlife populations. [120]. In addition, the virus is considered as endemic in Colombia, Venezuela, Ecuador, Peru and Mexico, where outbreaks occur every year [121, 122].

In the old world, another vesiculovirus, Chandipura virus has recently emerged and caused severe encephalitis in human in different parts of India [6, 123]. The first isolation of Chandipura virus was from two patients with febrile illness in 1965 [6]. In 2003, the virus caused the first outbreak of acute encephalitis in children with high fatality rate (183 deaths out of 329 cases, 55.6%) in Andhra Pradesh, India [124]. The second outbreak has occurred in the eastern state of Gujarat with higher fatality rate in 2004 (>75%) [123]. Recently, an outbreak of acute encephalitis syndrome was recorded in Maharashtra, India with 43.6% fatality rate in children younger than 15-year-old [125].

Chandipura virus has been isolated from field-collected Phlebotomus spp. sandflies [7]. The virus was also detected in sandflies belonging to the genus Sergentomyia in India [126]. This virus has not only been detected in India but also in Senegal and Nigeria, respectively, from phlebotomine sandflies and hedgehog (Atelerix spiculus) [127]. This suggests that Chandipura virus is widely distributed and should be investigated in a more detailed manner.

3.2 Reoviridae family

Changuinola virus was first isolated from Lutzomyia sp. sandflies in 1960 in Panama [128]. Since then 12 isolates were described from phlebotomine flies [129]. Another, seven strains were isolated from 80 wild-trapped sloths (Bradypus variegatus and Choloepus hoffmanni) from Central Panama [109]. Neutralizing antibody were detected in these two sloth species, despite they were virtually absent from other wild vertebrate species tested. Several strains were associated with prolonged or recrudescent viremias in slots [130]. Besides, one strain of Changuinola virus was identified from a febrile patient [8]. Changuinola virus can replicate in mosquito cell lines (C6/36 [Aedes albopic- tus cells]), Culicoidessonorensis KC and African green monkey kidney Vero cells [131].

4.