Marmosets as the canary in the coal mine for Zika

A highly sensitive primate model of the effects of placental Zika virus infection on fetal health

Date: May 1, 2018

Source: Texas Biomedical Research Institute

New research shows small, New World monkeys called marmosets may be an important animal model for emerging viruses with the potential for harmful effects on fetuses. Establishing animal models for emerging diseases, like Zika, is necessary for the development of vaccines, therapies and diagnostics. Results of a study published in the journal Scientific Reports showed pregnant marmosets inoculated with the Zika virus at a specific point during the first half of their pregnancy spontaneously aborted the fetuses at almost exactly the same time -- about two weeks after the infection. In addition, histology on the fetuses showed neurological abnormalities.

"There is strong interest in the scientific community in developing animal models to understand Zika virus with the goal of developing vaccines and therapies," said lead author Suzette Tardif, Ph.D., a Scientist at Texas Biomedical Research Institute and Associate Director of Research at the Southwest National Primate Research Center. "We believe marmosets may be an especially relevant model for effects on infection in pregnancy."

While a number of different animals are being studied as possible models for investigations of the Zika virus, including macaques and baboons, this is one of several studies that showed marmosets may be especially sensitive to the infection.

Read on  

Zika Can Cause Birth Defects in Monkeys Too

By Rachael Rettner, Senior Writer | September 12, 2016 05:45pm ET

Some monkeys can contract Zika virus in the womb and show signs of brain damage similar to those seen in human babies, according to a new study.

The findings mark the first time that a monkey has shown signs of "congenital Zika syndrome" — the range of health problems linked with Zika virus infection in the womb. The results suggest that researchers may be able to develop a model of Zika virus infection in monkeys that could help with the development of vaccines or other approaches that would help prevent birth defects caused by Zika, the researchers said.

Researchers have been trying to develop a model of congenital Zika syndrome in nonhuman primates (such as monkeys) because pregnancy in nonhuman primates more closely resembles human pregnancy, compared to pregnancy in other animals such as rodents. However, in a previous study of pregnant monkeys infected with Zika, the virus did not appear to make its way into the fetus's brain tissue, as it does in humans.

In the new study, the researchers used a different species of monkey, called a pigtail macaque, and used a slightly higher dose of Zika virus for infection.

Read on

Bees die needlessly as Zika prompts US state to spray pesticide

By Anna Nowogrodzki

It was an avoidable massacre. Beekeepers in Dorchester County, South Carolina, saw 48 of their hives killed off on 28 August. The culprit was a pesticide, sprayed from a plane with the aim of killing mosquitoes that can carry the Zika virus.

But South Carolina’s mosquito population isn’t yet known to carry Zika – and even if the virus is present, there are ways to kill the mosquitoes without killing bees.

In response to four local cases of Zika, Dorchester County sprayed a pesticide called Naled, a neurotoxin which kills adult mosquitoes and other insects. The four people infected all caught the virus before arriving in South Carolina: no one in the state has yet acquired Zika locally.

The aerial spraying killed millions of bees. Commercial beekeeper Juanita Stanley lost 46 hives, and a hobbyist beekeeper lost two. “Of course this is a tragedy,” says Michael Weyman at Clemson University, South Carolina, which is investigating claims by the beekeepers that the pesticide was misused.

Any actions that cause mass bee deaths are particularly concerning, given the fragility of bee populations in general – a consequence of the mysterious colony collapse disorder.

Bees can be spared by spraying at night instead of in the early morning. Bees don’t fly at night, and Naled only kills insects while they are airborne, says Mark Latham, director of Manatee County Mosquito Control in Palmetto, Florida, an area with commercially important beekeeping. Latham has carried out aerial spraying for 35 years, including of Naled, and almost always sprays at night.

The approach should work even though Aedes aegypti – the mosquito that can carry Zika – is a species active by day.

Continued 

Millions of GM mosquitoes could be released in Florida to combat Zika virus

Sarah Knapton, science editor 

3 AUGUST 2016 • 6:57PM

Millions of genetically modified mosquitoes could be released into the state of Florida to combat Zika virus after 15 people caught the disease from local insects.

Congress could decide within weeks to grant an emergency licence to British biotech company Oxitec, which has engineered a line of insects whose offspring are unable to grow to adulthood, and so cannot reproduce.

The company has already build a lab in the Florida Keys and is just waiting for the green light from the government and health officials.

Trials in the Cayman Islands and Brazil have already shown the technique can wipe out up to 96 per cent of dangerous aedes aegypti mosquito and Oxitec believe that the technique could eventually eliminate diseases like Zika, Dengue and Yellow Fever.

Oxitec Chief Executive Hadyn Parry who attended a recent Congress hearing and called for emergency use, said they were expecting a decision soon.  

“The Zika threat is here and now and there is now local transmission in Florida so that is why I urged Congress to seriously consider emergency use,” he said.

Continued