West Nile virusFLICKR, CDC/CYNTHIA GOLDSMITHIt’s a truism that antibiotics won’t help treat a viral infection. And it now appears they could even hurt, making viral infections more severe. In a study out today (March 27) in Cell Reports, researchers found that when mice were treated with antibiotics and then infected with pathogens in the flavivirus family (which includes Zika, West Nile, and dengue), they fared far worse than their untreated counterparts. The authors suggest the antibiotics may have compromised the animals’ immunity by altering their microbiomes.
“The clinical phenotype of the animals when they got antibiotics, compared to those that didn’t, was pretty dramatic. They got a lot sicker and then they died, ultimately, of West Nile encephalitis,” says Michael Diamond, an immunobiology researcher at Washington University School of Medicine in St. Louis who led the study. “And this was true not just for West Nile virus, but also for two related viruses in the family, Zika virus and also dengue virus.”
While the idea that antibiotics can modulate antiviral immunity is not new, an interesting aspect of this study is that it suggests a mechanism for that effect, says Paulo Verardi, a virologist at the University of Connecticut who was not involved in the study—namely, that changes in gut microbes ...
