University of Florida veterinary scientists find uncommon virus in U.S. ticks

Known as the Tacaribe virus, it has never been found in an animal or human species in the United States-until now. Scientists from the University of Florida colleges of Veterinary Medicine and Public Health and Health Professions have discovered the unusual virus in ticks common to the southeastern part of the country. The discovery was reported in a study that appeared in the journal PLOS ONE in December.

Scientists say the virus belongs to the family Arenaviridae. Some arenaviruses are associated with severe hemorrhagic disease and significant mortality in people in South American and sub-Saharan Africa. While the Tacaribe virus is not known to cause human infections, a release from the University of Florida says the virus' relative rarity and unknown host in nature intrigue the study's authors.

The study's lead author, Katherine Sayler, PhD, who completed her doctoral degree at the UF veterinary college in December, says the discovery expands the range in which these viruses might be circulating and raises interesting questions about human risk. According to the study, the last time Tacaribe virus was isolated was in bats in Trinidad in the late 1950s. A sample from that survey and the new tick-derived specimen was nearly identical genetically, the study says. “We never thought we would find an arenavirus in a tick,” Sayler says in a UF release. “These types of viruses are usually transmitted by rodents.”

Sayler says it is still unknown which animal is the natural host of the virus. Her future research will center on whether ticks have harbored the virus for a long time or if this is relatively new.

“Healthcare professionals should also be aware of the potential tick-transmitted pathogens that occur besides the one that causes Lyme disease,” Sayler says. “Medical doctors can't be aware of every emerging tropical disease, but if we have greater awareness of emerging diseases, we can move forward from a proactive surveillance effort instead of from a reactive effort, when there is suddenly a huge outbreak and a crisis situation.”