Nav: Home

UW-Madison researchers find Zika virus in Colombia, look for ways to stop it

January 26, 2016

MADISON, Wis. -- In October 2015, a team of researchers at the University of Wisconsin-Madison and Universidad de Sucre in Colombia ran the first tests confirming the presence of Zika virus transmission in the South American country.

In a study published today [Jan 26, 2016] in the journal Emerging Infectious Diseases, the team documents a disease trajectory that started with nine positive patients and has now spread to more than 13,000 infected individuals in that country.

"Colombia is now only second to Brazil in the number of known Zika infections," says study lead author Matthew Aliota, a research scientist in the UW-Madison School of Veterinary Medicine (SVM).

Zika virus, which spreads among humans via mosquitoes, causes illness characterized like many other viral infections by fever, rash and joint pain. Officials estimate that four out of five people who contract the virus do not get sick and the virus is rarely fatal. However, pregnant women in Brazil infected with Zika have given birth to babies with small heads and underdeveloped brains, a condition called microcephaly.

"If you're pregnant or planning on being pregnant, absolutely, cancel your vacation," says Aliota, echoing the Centers for Disease Control and Prevention warning that pregnant women not travel to the more than 20 countries now known to have active Zika transmission, like Brazil, Colombia, Ecuador and in the Caribbean. In these countries, mosquitoes are spreading the virus to people.

For the Colombian finding, Aliota and his research team, which includes Jorge Osorio, professor of pathobiological sciences at SVM, and two visiting doctoral students from Colombia, tested samples from 22 patients for the genetic fingerprints of Zika, dengue and chikungunya viruses.

Nine came back positive for Zika virus. Now, 13,500 cases have been identified in Colombia. The researchers' findings highlight the need for better, more accurate laboratory diagnosis of Zika virus.

The symptoms of Zika virus are "really nonspecific and it overlaps with a lot of things, especially with dengue virus and chikungunya," says Aliota. "It's hard when someone comes in with a fever and a rash to narrow it down."

Zika virus was first found in Uganda in 1947 but remained limited to Africa and Southeast Asia for decades. But in 2007, an outbreak occurred in the Pacific Islands and recently the virus began to spread in the Western Hemisphere.

"Historically, Zika virus has just caused mild disease, but as it moved into the New World, in Brazil, we started to notice these more serious consequences associated with it," says Aliota. "There is a lot that is unknown."

Aliota hopes to help change that.

His research on Zika virus and others like it is focused on how the viruses evolve and adapt to their hosts, including mosquitoes and humans. As he and the team show in the study, the Zika virus has split into two distinct lineages, African and Asian. The Colombia strain of the virus can be tracked to Brazil, which can be traced to a strain that originated in French Polynesia.

"There is certainly something different about these viruses that have allowed or facilitated this geographic expansion," Aliota says.

He and Osorio are now looking for ways to control it. As members of the Eliminate Dengue Program, an international effort managed by Monash University in Melbourne, Australia, they have explored how a bacterium that infects 60 percent of insects around the world may be used as a tool to combat the spread of dengue and similar mosquito-borne viruses.

Zika, dengue and chikungunya (which are also found in Colombia) are RNA viruses, which refers to how they encode their genetic material, and each is transmitted by a specific mosquito called Aedes aegypti. The mosquito is common in Colombia and other countries where Zika has become prevalent.

The bacterium, Wolbachia, is not naturally found in the Aedes aegypti mosquito, but researchers with Eliminate Dengue have found that when they infect mosquitoes with the bacteria in the lab, it prevents them from transmitting dengue, chikungunya and yellow fever.

"The Eliminate Dengue Program is doing field experiments to see, will we be able to replace wild-type, existing populations of mosquitoes with these Wolbachia-infected ones and does it block dengue transmission?" Aliota says. "Now, we're going to start looking at how that might be used for Zika virus control as well in South America."

Here in Madison, Aliota is also trying to better understand how these viruses might evolve and adapt to this potential control strategy, to try to stay ahead of any potential issues they might encounter in the field.

But while Texas and Florida need to be on alert, Aliota says Wisconsinites need not be worried about transmission of Zika virus here.

"We're not going to get Zika transmission in Wisconsin. We don't have Aedes aegypti," he says. "The cold winters are good for something."
-end-
Kelly April Tyrrell, kelly.tyrrell@wisc.edu, 608-262-9772

University of Wisconsin-Madison

Related Mosquitoes Articles:

In urban Baltimore, poor neighborhoods have more mosquitoes
A new study published in the Journal of Medical Entomology reports that in Baltimore, Maryland, neighborhoods with high levels of residential abandonment are hotspots for tiger mosquitoes (Aedes albopictus).
Researchers use light to manipulate mosquitoes
Scientists at the University of Notre Dame have found that exposure to just 10 minutes of light at night suppresses biting and manipulates flight behavior in the Anopheles gambiae mosquito, the major vector for transmission of malaria in Africa.
Mosquitoes that spread Zika virus could simultaneously transmit other viruses
A new study led by Colorado State University found that Aedes aegypti, the primary mosquito that carries Zika virus, might also transmit chikungunya and dengue viruses with one bite.
Insecticide-induced leg loss does not eliminate biting in mosquitoes
Researchers at LSTM have found that mosquitoes that lose multiple legs after contact with insecticide may still be able to spread malaria and lay eggs.
New study sheds light on how mosquitoes wing it
The unique mechanisms involved in mosquito flight have been shared for the first time in a new Oxford University collaboration, which could inform future aerodynamic innovations, including tiny scale flying tech.
For female mosquitoes, two sets of odor sensors are better than one
A team of Vanderbilt biologists has found that the malaria mosquito has a second complete set of odor receptors that are specially tuned to human scents.
Common bacterium may help control disease-bearing mosquitoes
Genes from a common bacterium can be harnessed to sterilize male insects, a tool that can potentially control populations of both disease-bearing mosquitoes and agricultural pests, researchers at Yale University and Vanderbilt University report in related studies published Feb.
Scientists opened a new chapter in the study of malaria mosquitoes
In December 2016, the American Journal of Vector Ecology published two articles by Yuri Novikov, a scientist at the TSU Biological Institute devoted to the study of ecology and the distribution one of the species of malaria mosquito of the maculipennis complex and its laboratory cultivation.
Blocking hormone activity in mosquitoes could help reduce malaria spread
Disruption of hormone signaling in mosquitoes may reduce their ability to transmit the parasite that causes malaria, according to a new study published in PLOS Pathogens.
Experimental insecticide explodes mosquitoes, not honeybees
In a new study, Vanderbilt pharmacologist Jerod Denton, Ph.D., Ohio State entomologist Peter Piermarini, Ph.D., and colleagues report an experimental molecule that inhibits kidney function in mosquitoes and thus might provide a new way to control the deadliest animal on Earth.

Related Mosquitoes Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".