Cache valley virus is a bunyavirus that causes fetal death, still-birth and congenital malformations such as arthrogryposis and anencephaly in sheep. This is an arbovirus that is transmitted by mosquitoes.

Cache Valley virus as a human pathogen?

• Cache Valley virus has been suggested to be a cause of neural tube defects in humans, although a study in 1997 could not serologically link infection with anencephaly and other defects.
• Cache Valley virus was isolated from a deer hunter in North Carolina who suffered life-threatening, multi-organ failure, and recent serologic evidence suggests that deer may be a reservoir in nature. However, the true zoonotic impact of Cache Valley virus remains to be determined, and people are most likely infected via mosquito bites rather than by direct contact with infected animals.

References:

Edwards, J.F. and K. Hendricks. 1997. Lack of serologic evidence for an association between Cache Valley virus infection and anencephaly and other neural tube defects in Texas. Emerg. Infect. Dis. 3:195-197.

McLean, R.G. et al. 1996. The role of deer as a possible reservoir host of potosi virus, a newly recognized arbovirus in the United States. J. Wildlife Dis. 32:444-452. (Also discusses CVV serology in deer)

Sexton, D.J. et al. 1997. Life-threatening Cache Valley virus infection. N. Eng. J. Med. 336:547-549.