Zika monkey study suggests worse fetal effects for vaginal versus mosquito transmission

August 24, 2017, Public Library of Science
Zika monkey study suggests worse fetal effects for vaginal versus mosquito transmission. Credit: Renato Araújo/Agência Brasília. via Flickr

Rhesus macaques that were vaginally infected with Zika virus showed higher prevalence of Zika in the reproductive tract than previously seen in macaques that received skin injections of the virus. The findings, published in PLOS Pathogens, suggest that vaginal transmission may increase the risk or severity of fetal Zika disease compared to mosquito transmission.

Zika infection causes mild symptoms in adults, but it can cause severe birth defects in the fetuses of infected pregnant women. Usually, Zika virus spreads via mosquito bites, but it can also be transmitted during sex. Little is known about the different effects of mosquito transmission versus .

To improve understanding of the role of sexual transmission in Zika infection, Timothy Carroll of U.C. Davis and colleagues vaginally injected six female with Zika virus. Then, as the infection progressed and the virus began to replicate, the scientists monitored the amount of the virus in the monkeys' blood and secretions.

The researchers detected Zika virus in the reproductive tracts of all six infected macaques several days before it appeared in blood plasma samples. In contrast, previous studies in which monkeys were infected via skin injection have reported detection of the virus in the blood shortly after injection, and Zika was only rarely found in reproductive tract secretions.

These results suggest that Zika virus prefers the reproductive tract after vaginal transmission, but not after skin transmission. Thus, fetal Zika disease may be more likely or more severe after sexual transmission than after mosquito transmission. With further research, these findings could aid efforts to understand, prevent, or treat Zika infection.

"The high levels of Zika virus replication in the after vaginal inoculation of rhesus macaques was unexpected because virus shedding in genital secretions is difficult to detect after subcutaneous inoculation," the authors further explain. "This finding suggests that fetuses may be especially at risk for virus infection, and associated complications, when women acquire Zika virus through sex."

Explore further: Scientists track Zika virus transmission in mice

More information: Timothy Carroll et al, Zika virus preferentially replicates in the female reproductive tract after vaginal inoculation of rhesus macaques, PLOS Pathogens (2017). DOI: 10.1371/journal.ppat.1006537

Related Stories

Scientists track Zika virus transmission in mice

August 3, 2017
National Institutes of Health (NIH) scientists have developed a mouse model to study Zika virus transmitted sexually from males to females, as well as vertically from a pregnant female to her fetus. They are using the model ...

Prior dengue or yellow fever exposure does not worsen Zika infection in monkeys

August 4, 2017
Rhesus macaques previously infected with dengue or yellow fever viruses appear to be neither more nor less susceptible to severe infection with Zika virus, according to new research published in PLOS Pathogens.

Maternal-fetal transmission of Zika virus and therapeutic approaches to prevent it

June 5, 2017
The devastating effects of Zika virus on the brain of the developing fetus during infection in pregnancy have led to intensive research to understand the routes of Zika virus transmission and how the virus travels to and ...

Can a Zika outbreak be sustained sexually?

August 8, 2017
In most ways, Zika is a lot like other tropical fevers. People become infected when they are bitten by mosquitos. Infected mothers pass the virus to their unborn children.

Zika virus may persist in the vagina days after infection

August 25, 2016
The Zika virus reproduces in the vaginal tissue of pregnant mice several days after infection, according to a study by Yale researchers. From the genitals, the virus spreads and infects the fetal brain, impairing fetal development. ...

Argentina: 1st local transmission of Zika, likely by sex

February 26, 2016
Argentine authorities say they've detected the country's first case of local infection with the Zika virus and say it's apparently due to sexual transmission.

Recommended for you

Study identifies a key cellular mechanism that triggers pneumonia in humans

December 11, 2018
The relationship between influenza and pneumonia has long been observed by health workers. Its genetic and cellular mechanisms have now been investigated in depth by scientists in a study involving volunteers and conducted ...

Human antibody discovery could save lives from fungal killer

December 11, 2018
A new way to diagnose, treat and protect against stealth fungal infections that claim more than 1.5 million lives per year worldwide has been moved a step closer, according to research published in Nature Communications.

Effect of oral alfacalcidol on clinical outcomes in patients without secondary hyperparathyroidism

December 11, 2018
Treatment with active vitamin D did not decrease cardiovascular events in kidney patients undergoing hemodialysis, according to a research group in Japan. They have reported their research results in the December 11 issue ...

Dialysis patients at risk of progressive brain injury

December 10, 2018
Kidney dialysis can cause short-term 'cerebral stunning' and may be associated with progressive brain injury in those who receive the treatment for many years. For many patients with kidney failure awaiting a kidney transplant ...

Silicosis is on the rise, but is there a therapeutic target?

December 6, 2018
Researchers from the CNRS, the University of Orléans, and the company Artimmune, in collaboration with Turkish clinicians from Atatürk University, have identified a key mechanism of lung inflammation induced by silica exposure, ...

PET scans to optimize tuberculosis meningitis treatments and personalize care, study finds

December 6, 2018
Although relatively rare in the United States, and accounting for fewer than 5 percent of tuberculosis cases worldwide, TB of the brain—or tuberculosis meningitis (TBM)—is often deadly, always hard to treat, and a particular ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.