A study in mice published Thursday in the journal Cell Stem Cell revealed that the Zika virus could cause brain damage in adults. Cells that are vital for learning and memory might be just as vulnerable to the mosquito-spread virus as fetal cells.

Experts and governments have mostly focused their efforts to prevent infections in babies due to the link between the virus and microcephaly, but this new research shows that infected adults might also be exposed to brain damage. The research team was surprised to discover that those mice infected with the Zika virus had more death cells in their brains, and they could only generate a reduced amount of new neurons, which is a key factor in the processes of learning and memory. This study could change the way Zika is viewed, as most adult neurons are currently thought to be resistant to the virus.


These mosquitoes are day-feeders, associate closely with humans, rather than being restricted to wetlands, and are vectors of many diseases besides Zika, such as yellow fever, dengue fever, chikungunya, and filariasis. Image Credit: ABC News

If researchers find that the same mice model translates to the human brain, damaged neural progenitor cells could bring significant cognitive problems. Depression and Alzheimer’s disease could be among the conditions most likely to be triggered as a consequence of Zika infection.

“We asked whether [these cells] were vulnerable to Zika in the same way the fetal brain is,” said co-author Joseph Gleeson, a professor at Rockefeller University, according to The Washington Post.  “The answer is definitely yes.”

Sujam Shresta, another study co-author who teaches at the La Jolla Institute for Allergy and Immunology, said in a statement that Zika has the potential to “wreak havoc” once it enters the brain of adults, The Washington Post reported. Shresta addressed the fact that most adults who have contracted the virus rarely experience symptoms, which is one of the characteristics of the very complex disease.

Further research is necessary to understand the actual threat fully

Because the research has only been conducted in mice and at a single point in time, Gleeson acknowledged that further research would be needed to prove whether Zika represents a clear threat to adult brain cells. It is necessary to find out whether the virus can affect behavior in adults or cause long-term damage to the neurons.

“We don’t want to have this be a panic. Zika, for the most part, is a benign condition in healthy humans,” Gleeson pointed out, according to the Post. “But we also need to look at the potential consequences in a careful way.”

William Shaffner, who is an infectious-disease expert at Vanderbilt University and was not part of the study, agreed that these findings are an initial step. Still, he said this research triggered alarms as it suggested that the Zika virus can endanger adult brain cells as it does fetal cells.

He said such a terrible possibility needed further examination given that the number of people infected with Zika in the United States and more than 60 other countries continue to increase. Shaffner added that studies should be conducted in older children and adults as well to know whether the primary focus of prevention should include those groups aside from pregnant women and newborns.

CDC issues new travel advice for pregnant women, this time in Florida

The latest travel advice the Centers for Disease Control and Prevention has issued involving pregnant women and Zika virus suggests that the group at apparently higher risk should avoid travel to all of Miami-Dade County. The second zone of local transmission has been identified in Florida, specifically in a swatch of Miami Beach, according to a report by The New York Times.

“Pregnant women and their sexual partners who are concerned about potential Zika virus exposure may also consider postponing non-essential travel to all parts of Miami-Dade County,” the CDC said, as The New York Times reported.

The newspaper informed that two Florida residents and three people who had traveled to Miami Beach from New York, Texas and Taiwan represent the five cases of Zika transmitted by mosquitoes in the area, Gov. Rick Scott declared. The other active zone for Zika transmission in the state is in the Wynwood neighborhood in Miami.

Federal authorities pointed out that separate communities in Miami-Dade County may have active Zika transmission that is not yet clear because many cases show no apparent symptoms. Moreover, diagnosis can take several weeks mainly because the virus has the potential to incubate for two weeks before showing symptoms such as rash, fever, joint pain, headache and pink eye.

“We have two small areas,” Scott said, as quoted by The New York Times. “One less than a mile, and we’ve already been able to reduce the footprint. We have another area now that’s 1.5 miles on Miami Beach. That’s out of a state that takes 15 hours to drive from Key West to Pensacola, so let’s put things in perspective.”

Even though pregnant women are believed to be at greater risk than other groups given the virus’ link with birth defects, Scott asked every Floridian to take precautions by wearing bug spray and dumping standing water, where the mosquitoes can breed.

Source: Washington Post