Una oscura familia de virus, que ya es endémica en los primates africanos salvajes y que se sabe que causa síntomas fatales similares al ébola en algunos monos, está “preparada para propagarse” a los humanos.
Evocando paralelismos con el VIH, los autores piden a la comunidad mundial de la salud que esté atenta.
Según una nueva investigación, una oscura familia de virus, que ya es endémica en los primates africanos salvajes y que se sabe que causa síntomas fatales similares al ébola en algunos monos, está “preparada para propagarse” a los humanos. El estudio, realizado por la Universidad de Colorado Boulder, fue publicado en línea en la revista Célula el 30 de septiembre.
“Este virus animal ha descubierto cómo acceder a las células humanas, multiplicarse y escapar de algunos de los mecanismos inmunológicos importantes que esperaríamos para protegernos de un virus animal. Eso es bastante raro. — Sara Sawyer
Aunque tales arterivirus ya se consideran una amenaza crítica para los monos macacos, hasta el momento no se han informado infecciones en humanos. Además, no está claro qué impacto tendría el virus en las personas si salta de especie.
Sin embargo, los autores, evocando paralelismos con el VIH (cuyo precursor se originó en los monos africanos), hacen un llamado a la vigilancia: al observar los arterivirus ahora, tanto en animales como en humanos, la comunidad mundial de la salud podría evitar potencialmente otra pandemia, dijeron. .
“Este virus animal ha descubierto cómo acceder a las células humanas, multiplicarse y escapar de algunos de los mecanismos inmunológicos importantes que esperaríamos para protegernos de un virus animal. Eso es bastante raro”, dijo la autora principal Sara Sawyer. Es profesora de biología molecular, celular y del desarrollo en CU Boulder. “Deberíamos prestarle atención”.
Hay miles de virus únicos que circulan entre los animales de todo el mundo y la mayoría de ellos no causan síntomas en el huésped. Un número cada vez mayor de estos virus ha saltado a los humanos en las últimas décadas, causando estragos en los sistemas inmunológicos ingenuos sin experiencia en combatirlos. Esto incluye el Síndrome Respiratorio del Medio Oriente (MERS) en 2012, el coronavirus del Síndrome Respiratorio Agudo Severo (SARS-CoV) en 2003 y[{” attribute=””>SARS-CoV-2 (the virus that causes COVID-19) in 2020.
Sara Sawyer. Credit; UC Boulder
For 15 years, Sawyer’s lab has used laboratory techniques and tissue samples from wildlife from around the globe to investigate which animal viruses may be prone to jump to humans.
For the latest study, she and first author Cody Warren, then a postdoctoral fellow at the BioFrontiers Institute at CU, zeroed in on arteriviruses. These are common among pigs and horses but understudied among nonhuman primates. Specifically, they looked at simian hemorrhagic fever virus (SHFV), which causes a lethal disease similar to the Ebola virus disease. Dating back to the 1960s, it has been causing deadly outbreaks in captive macaque colonies.
According to the research, a molecule, or receptor, called CD163, is crucial to the biology of simian arteriviruses, enabling the virus to invade and cause infection of target cells. Through a series of laboratory experiments, the scientists discovered, much to their surprise, that the virus was also remarkably skilled at latching on to the human version of CD163, getting inside human cells, and quickly making copies of itself.
Like human immunodeficiency virus (HIV) and its precursor simian immunodeficiency virus (SIV), simian arteriviruses also appear to attack immune cells. This means they can disable key defense mechanisms and take hold in the body long-term.
“Just because we haven’t diagnosed a human arterivirus infection yet doesn’t mean that no human has been exposed. We haven’t been looking.” — Cody Warren
“The similarities are profound between this virus and the simian viruses that gave rise to the HIV pandemic,” said Warren. He is now an assistant professor in the College of Veterinary Medicine at The Ohio State University.
The authors stress that another pandemic is not imminent, and the public should not be alarmed.
However, they do suggest that the global health community prioritize the further study of simian arteriviruses and develop blood antibody tests for them. They should also consider surveillance of human populations with close contact with animal carriers.
An expansive variety of African monkeys already carry high viral loads of diverse arteriviruses, often without symptoms. Additionally, some species frequently interact with humans and are known to bite and scratch people.
“Just because we haven’t diagnosed a human arterivirus infection yet doesn’t mean that no human has been exposed. We haven’t been looking,” said Warren.
Warren and Sawyer note that in the 1970s, no one had heard of HIV either.
Scientists now know that HIV likely originated from SIVs infecting nonhuman primates in Africa, likely jumping to humans sometime in the early 1900s.
When it began killing young men in the United States in the 1980s, no serology test existed, and no treatments were in the works.
Sawyer said there is no guarantee that these simian arteriviruses will jump to humans. But one thing is for sure: More viruses will jump to humans, and they will cause disease.
“COVID is just the latest in a long string of spillover events from animals to humans, some of which have erupted into global catastrophes,” Sawyer said. “Our hope is that by raising awareness of the viruses that we should be looking out for, we can get ahead of this so that if human infections begin to occur, we’re on it quickly.”
Reference: “Primate hemorrhagic fever-causing arteriviruses are poised for spillover to humans” by Cody J. Warren, Shuiqing Yu, Douglas K. Peters, Arturo Barbachano-Guerrero, Qing Yang, Bridget L. Burris, Gabriella Worwa, I-Chueh Huang, Gregory K. Wilkerson, Tony L. Goldberg, Jens H. Kuhn and Sara L. Sawyer, 30 September 2022, Cell.
DOI: 10.1016/j.cell.2022.09.022
