U.S. issue warning about return of potentially deadly virus

The American South has been under constant duress from extreme weather events spurred by rising global temperatures, but the region could face a different kind of threat that it hasn’t experienced in over a century: yellow fever.

What’s happening?

A joint report from the Baylor College of Medicine and the Stanford School of Medicine published in the New England Journal of Medicine warned that warmer climates, urbanization, and “shifting patterns of human migration” are increasing the likelihood of a rapid spread of mosquito-borne infections in the States.

It noted that “extreme poverty throughout Texas and the Gulf Coast states, where inadequate or low-quality housing, absent or broken window screens, and a pervasive dumping of tires in poor neighborhoods” can become breeding sites for mosquitoes, make the South particularly vulnerable.

“We’ve seen a rise in mosquito-transmitted illnesses in Texas and Florida, including malaria, dengue, chikungunya and Zika virus, but now we’re also worried about yellow fever since it seems to be accelerating in tropical regions of Latin America such as Brazil and Venezuela,” Dr. Peter Hotez, professor and dean of Baylor College of Medicine and co-author of the paper, said in a statement.

Why is the return of yellow fever concerning?

According to the WHO, common symptoms of yellow fever include fever, headaches, muscle pain, nausea, vomiting, and fatigue. It can affect the liver and kidneys in severe cases and cause jaundice, the yellowing of skin, from which the virus gets its name.

While yellow fever falls under the same classifications as dengue and Zika virus, it has a higher mortality rate, killing approximately half of the afflicted patients within seven to 10 days after they enter the toxic phase.

Yellow fever’s potential return to prominence underscores the ripple effects of a warming planet. Rising temperatures have allowed mosquitoes to migrate to newer environments while lengthening the season in which the insects are active.

“One of the reasons we established National School of Tropical Medicine at Baylor was in recognition that tropical infections have become a new normal due to a confluence of climate change, urbanization and poverty on the U.S. Gulf Coast and Texas,” Dr. Hotez added.

What is being done about the potential threat of yellow fever?

The researchers called for mosquito control through the development of antiviral drugs, vaccines, and genetic engineering to permanently alter mosquito genes.

“The mosquitoes that spread yellow fever are here in the U.S. and conditions are increasingly favorable for them as our world warms,” said Dr. Desiree LaBeaud, professor of pediatrics-infectious disease at Stanford School of Medicine and publication co-author. “We need a comprehensive plan to better protect at-risk communities in the southern U.S. from mosquito-borne diseases.”

In the meantime, individuals can prepare by taking a single-dose yellow fever vaccine that has been available for over eight decades or using pesticide-free measures to either repel mosquitoes or prevent their reproduction.