Developing new approaches to control Zika outbreak

The Zika virus, infecting people in 39 countries and territories, currently has no approved treatments or vaccines.

Problems associated with the disease are abundant. The United States Centers for Disease Control and Prevention (CDC) website explains, “Guillain-Barré Syndrome <an autoimmune disease that damages nerve cells> is very likely triggered by Zika in a small proportion of infections, much as it is after a variety of other infections.”

Further, research correlates mothers with the Zika virus to infants with the fetal malformation microcephaly. The Zika outbreak that began in 2015 caused an increase in frequency of Guillain-Barré Syndrome, microcephaly, and other fetal malformations.

Currently, the CDC reports that just over 1,100 people have contracted the Zika virus in the United States, along with just over 2,500 people in United States territories.

A Medical News Today article adds, “It is expected that at least four million people will be infected [with Zika] by the end of the year.

Zika is an arbovirus, meaning it is primarily transmitted by mosquitoes, ticks, or other arthropods; it should be noted, however, that a mosquito must be of the Aedes genus to carry the Zika virus.

Other means of transmission include from mother to child, sexual contact, blood transfusions, or laboratory exposure.

“The best way to prevent diseases spread by mosquitoes is to protect yourself and your family from mosquito bites,” believes the CDC.

A research team at the University of Wisconsin-Madison is taking a different approach to preventing the spread of Zika. Instead of preventing mosquito bites, they modify the mosquitoes to harbor the benign bacteria Wolbachia pipientis.

The Medical News Today article explains of the University of Wisconsin-Madison research, “Wolbachia pipientis can completely block transmission of Zika virus in Aedes aegypti, the mosquito species responsible for passing the virus to humans.”

The methodology originated more than six years ago with the Eliminate Dengue Program out of Australia.

Prior to the study, Wolbachia was already being utilized in field studies in Colombia, Brazil, Australia, and Vietnam to prevent the spread of dengue virus, an arbovirus in the same family as Zika.

The authors of the study, Matthew Aliota, scientist with UW-Madison’s School of Veterinary Medicine, Jorge Osorio, UW-Madison professor of pathobiological science, along with co-authors Stephen Penaido, also with UW-Madison’s School of Veterinary Medicine, and Ivan Dario Velez, scientist at the Universidad de Antioquia in Colombia, sought out whether introducing Wolbachia to Aedes aegypti would similarly be effective in preventing the transmission of Zika.

The study, published in the journal Scientific Reports, concludes that Aedes aegypti infected with a specific strain of Wolbachia “have reduced vector competence” for Zika.

In other words, mosquitoes exposed to Wolbachia have a decreased ability to support the spread of the virus.

Osorio explained, “Mosquitoes with Wolbachia <are> less capable of harboring Zika virus, and though they do get infected with Zika, it is to a lesser extent than wild-type mosquitoes.”

“Given the size of the outbreak, and that we think mosquitoes are the driver of the outbreak, the results were somewhat unexpected,” Aliota continued on the Medical News Today article.

“It just goes to show you how much we still need to understand about the basic biology of this virus.”

Aliota and Osorio will continue their research on the impact of benign bacteria on virus transmission, in hopes of improving their grasp on the relationship between Wolbachia, Aedes aegypti, and Zika.

Overall, Aliota hopes their research to be a “novel biological control mechanism.”

Their efforts, along with many other research scientists across the globe, work to manage the Zika outbreak.