Approximately 1% of humans infected with RVFV die of the disease. By contract, case-fatality proportions for infected livestock are significantly higher, with RVFV infection causing abortion in nearly 100% of pregnancies.
For humans, studies have shown that spending time in rural areas and sleeping outdoors at night in regions where outbreaks occur could be a risk factor for exposure to mosquito and other insect vectors. Animal herdsmen, abattoir workers, veterinarians, and other individuals who work with potentially-infected animals in RVF-endemic areas (areas where the virus is present) have an increased risk for infection. International travelers increase their chances of getting the disease when they visit RVF-endemic locations during periods when sporadic cases or epidemics are occurring.