Several of these viruses, such as Akabane virus
, Aino virus, and Schmallenberg virus, are arboviruses associated with abortion, premature birth, stillbirth, and congenital malformations in ruminants (2-4).
Other viruses, such as Akabane virus
, Rift Valley Fever virus, Cache Valley virus, Border disease virus, and Wesselsbron disease virus, are also associated with the occurrence of CNS malformations (OBERST, 1993), but these viruses have not yet been diagnosed in cattle in Brazil.
Different arboviruses have also shown neurological consequences in perinatal infections, such as encephalopathy by CHIKV in humans (41) and necrotizing encephalopathy and white matter vacuolization by the Akabane virus
in sheep and goats.
Estao incluidos patogenos virais de significante importancia humana e veterinaria, tais como, Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Akabane virus
(AKAV), Nairobi sheep disease virus (NSDV), Aino virus (AINV) e Peaton virus (PEAV) (4), assim como virus ja isolados na Amazonia Brasileira como: Guaroa virus (GROV), Maguari virus (MAGV), Tacaiuma virus (TCMV), Guama virus (GMAV), Caraparu virus (CARV), Oropouche virus (OROV), Catu virus (CATUV), Icoaraci virus (ICOV) e Belem virus (BLMV), entre outros (2).
(AKAV), Aino virus (AINV), and Schmallenberg virus are the most studied in this serogroup; Shuni, Sabo, Shamonda, and Sango viruses (1,2) are examined less frequently.
Genetic diversity and reassortments among Akabane virus
Similar to the situation with Akabane virus
infection (8), the clinical picture shown by in utero SBV-infected newborn calves is likely to depend largely on the age of the fetus at the time of infection.
Tsutsui and colleagues (9) showed that dairy calves lost their maternally derived antibodies against Akabane virus
at -4 months of age, and Grimstad and colleagues (10) showed that young white-tailed deer lost their maternally derived antibodies against Jamestown Canyon virus at 5-6 months of age.
In contrast, viremia was detected in most cows that were artificially inseminated and simultaneously inoculated in the uterus with cell culture--passaged Akabane virus
, a teratogenic orthobunyavirus closely related to SBV (9).
The Simbu serogroup (family Bunyaviridae, genus Bunyavirus) includes Shamonda virus, Akabane virus
, Sathuperi virus, and Aino virus.
No reaction was detected in SBV-negative (as determined by qRT-PCR) goats, sheep, and calves; in ruminants with various non--SBV-associated nervous system lesions; or in the brain of a mouse that was experimentally infected with Akabane virus
Similar to Akabane virus
(AKAV), another Simbu serogroup virus, SBV can cause fatal congenital defects by infection of fetuses during a susceptible stage in pregnancy (2).