Tracking the Zika outbreak in the Americas

The Zika virus lingers in the saliva, sex organs, and nervous systems of monkeys long after the infection is gone from the blood, new research shows. This means that certain organs might harbor the virus even after the immune system has beaten it back, extending the risk that Zika might be spread. And if the virus infects adult human brains as well, it could mean that Zika might be causing more neurological issues than we realized.

The study, published today in the journal Nature Medicine, shows that there’s still a lot we don’t know about the virus that has infected thousands of people, including more than 50 who contracted Zika in the continental US. Scientists are still scrambling to find a vaccine.

Mosquito moms can transmit zika virus to their offspring — at least in the lab, a new study shows. If this also happens in nature, the virus might be able to survive in tough mosquito eggs even when cold weather, dry spells, and pesticides kill off the infectious adults.

Mosquitoes can transmit viruses in the same family as Zika, such as yellow fever and dengue, to their offspring — but it wasn’t clear whether this was also true for Zika. So scientists led by Robert Tesh, an epidemiologist at the University of Texas Medical Branch, injected Zika virus into approximately 200 females from two different species of mosquitoes: Aedes aegypti, and Aedes albopictus. None of the A. albopictus offspring tested positive for the virus, but about one in every 290 A. aegypti offspring were infected. They published these results today in the American Journal of Tropical Medicine and Hygiene.

In a major expansion of its policy on Zika virus, the Food and Drug Administration says it now recommends all blood donated in the United States be screened for possible Zika infection.

As the Zika virus has gained a foothold in Miami, Florida the US Food and Drug Administration (FDA) has approved a field test of a genetically modified mosquito to help combat the virus.

The engineered Aedes aegypti mosquitoes were created by Oxitec Ltd. as a means to control the diseases that the insect typically carries. The male members of the modified line are designed to transmit a fatal gene when it mates with a female. The gene kills the offspring, which will help reduce the larger population of this particular species.

The vaccine in question is called a DNA Vaccine, a third-generation vaccine that contains some specific antigens from the disease in question. The host body will pick up the DNA from the pathogen and begin to formulate an immune response. This type of vaccine is different from others, which utilize weakened or dead germs to stimulate a response (such as for polio or smallpox) or a subunit of a pathogen.

Currently, there aren’t any such vaccines that can be used on people in the United States, although Australia permits the use of one for Japanese encephalitis, another mosquito-borne illness. According to the National Institutes of Health, this Zika vaccine is similar to another third-generation vaccine trial that had been developed for the West Nile Virus, which was demonstrated to be safe.

A new diagnostic tool could make detecting Zika infection in patients much easier and cheaper in remote areas of Latin and Central America. The new technology was developed by several universities, including MIT, Harvard, University of Toronto, and Cornell University, and it will be presented tomorrow at the 68th AACC Annual Scientific Meeting & Clinical Lab Expo in Philadelphia.

Though several diagnostics tools already exist to detect the virus, the new tool does stand out for how portable and cheap it is. The diagnostic test, which was described in a study published in May in the journal Cell, allows medical professionals to test a sample of saliva, urine, or blood. The device can then analyze the samples to detect whether the Zika genome is present, indicating that a person is infected. If the virus is detected, a paper disc with synthetic biomolecular sensors changes color.

The Centers for Disease Control and Prevention has issued a travel warning for Wynwood, a neighborhood in Miami where 14 people have been infected with mosquito-borne transmissions of the Zika virus. At the request of Florida Governor Rick Scott, the CDC is sending an Emergency Response Team to Miami to assist in the investigation and response effort.

"I have requested that the CDC activate their Emergency Response Team to assist DOH in their investigation, research and sample collection efforts," said Governor Scott in a statement. "Their team will consist of public health experts whose role is to augment our response efforts to confirmed local transmissions of the Zika virus."

For the first time, the Zika virus might have been transmitted from mosquitoes to humans inside the United States, according to Florida Governor Rick Scott. Scott confirmed that four cases under investigation in his state were not brought in from outside the country.

The four cases, which occurred in Miami-Dade and Broward Counties, were "the result of local transmission," and are "likely mosquito-borne," according to the Florida Department of Health. However, health officials have yet to locate mosquitoes infected with the virus, and have yet to rule out sexual transmission of the virus.

Scientists have successfully infected a group of rhesus macaque monkeys with Zika, marking the first time that non-human primates have been shown to be susceptible to the mosquito-borne virus. That’s good news for researchers, as it potentially opens up a new animal model to study Zika. Scientists could use the monkeys to trace how the virus spreads and test new vaccines or treatments on the animals.

Specifically, scientists infected eight macaques with an Asian strain of the Zika virus, according to a new paper published in Nature Communications. This strain of the virus is very closely related to Zika strains currently spreading throughout Central and South America. All of the monkeys — two of which were pregnant — contracted Zika when exposed to the virus. The non-pregnant animals stayed infected for around 10 days, which is similar to the length of infection in humans. But the pregnant animals remained infected longer, for at least 57 days.

Scientists have found two potential vaccine candidates that may help combat the Zika virus. A single shot of each vaccine was shown to completely protect mice against two strains of the mosquito-borne disease, according to a new paper published in the journal Nature. These shots still need to be tested on humans, but the researchers are hopeful that either could eventually prove to be a safe and effective Zika vaccine.

"These two vaccine candidates both provided complete protection against Zika virus challenge in mice," said study author Dan Barouch, a virologist at Beth Israel Deaconess Medical Center at Harvard Medical School. "To the best of our knowledge, this is the first report of Zika virus vaccine protection in an animal model. The protection was striking."

Women who live in some Latin American countries where the Zika virus is spreading are increasingly seeking access to abortion — even though, in many instances, abortion is illegal or restricted. Since November 17th, 2015, when the Pan American Health Organization (PAHO) issued an epidemiological alert about Zika, the number of requests for abortion medications has increased significantly, sometimes even doubling, scientists have found.

The Zika virus causes microcephaly, a condition in which babies conceived by infected moms are born with abnormally small heads. Since no Zika vaccine has been approved, some infectious disease specialists think that delaying or avoiding pregnancies is the only safe way to avoid giving birth to babies with brain damage. The PAHO alert prompted several Latin American countries to declare national emergencies, caution citizens about Zika-related birth defects, and urge women to avoid pregnancies.

Three babies have been born in the United States with Zika virus-related birth defects, according to figures released today by the Centers for Disease Control and Prevention. The report noted an additional three "pregnancy losses with birth defects" in Zika-infected mothers.

Since Zika was declared a public health emergency by the World Health Organization five months ago, doctors have been working to understand and track the disease. This is the first time the CDC has reported any pregnancy losses or babies born in the United States with Zika-related defects, according to Stat.

Mothers who are infected with Zika in the third trimester of their pregnancy won’t have babies with noticeable brain defects, researchers announced today in a study published in the New England Journal of Medicine. Birth defects are linked to the virus, but today’s study shows that the time at which a mother is infected is key. The risk of having a child with a brain deformity is much higher if the mother is infected early in the pregnancy.

People who live in areas where the Zika virus is spreading are now recommended by the World Health Organization to delay pregnancies, The New York Times reports. That's to avoid having babies with birth defects like microcephaly, a condition that causes babies to be born with abnormally small heads.

The new WHO guidelines are directed at millions of people in Latin America and the Caribbean, including Puerto Rico, where the first Zika-related death was reported in April. For people who visit countries where the virus is circulating, the WHO recommends couples to wait at least eight weeks before trying to conceive. Puerto Rico’s health secretary has already been advising couples to delay pregnancies. And health officials in other countries where Zika is circulating, like Colombia and El Salvador, are urging women to avoid pregnancies.

When Australia's athletes travel to Rio for the Olympics this summer, they'll be equipped with "anti-Zika condoms" — or at least that's how Reuters, Gizmodo, Fusion, and Jezebel portrayed condoms made through a collaboration between the companies Starpharma and Ansell. Here’s the thing: all condoms protect against Zika infection when used correctly. But the bigger question is this: in an age where disease outbreaks are becoming commonplace, why didn't journalists verify this claim before spreading information that could make their audience feel like the average condom isn't protective enough?

For the first time, researchers have confirmed that the Zika virus indeed causes birth defects — in mice, anyway. After deliberately infecting pregnant mice, they found that the pups were born with brain damage and slightly abnormally small heads, a condition called microcephaly.

This is the first study to directly prove that the virus causes birth defects, the study authors write in Nature. The virus appears to have crossed the placenta, restricting the pups’ growth — and not just in their heads, either, but all over their bodies. The animal model may help researchers aiming to develop vaccines, or treatments that could prevent pregnant women from passing the virus to their developing child.

For the first time, a person in the US has died of complications related to the Zika virus, CNBC reports. Puerto Rico's health secretary announced today that a 70-year-old man with Zika died in February from severe thrombocytopenia, a condition of the blood that can lead to internal bleeding.

For the first time, US disease experts have agreed that the mosquito-borne Zika virus does indeed cause babies to be born with abnormally small heads — a condition known as microcephaly. Until now, the two conditions were linked — but experts didn’t know for sure if Zika caused the brain-damaged condition. After reviewing existing data about Zika, researchers from the US Centers for Disease Control and Prevention have declared in the New England Journal of Medicine that the relationship was, as suspected, causal.

"This study marks a turning point in the Zika outbreak," CDC Director Tom Frieden said in a statement. "It is now clear that the virus causes microcephaly."

The incredible image above is the 3D structure of the Zika virus, which has only just been revealed. The finding could help scientists determine how the virus is transmitted and, hopefully, how to prevent infection.

A fetus that was aborted weeks after the mother was infected with Zika provides striking evidence that the virus causes fetal brain abnormalities, researchers say. The report, published today in the New England Journal of Medicine, isn't the first to document a case of a mother passing on the virus to a fetus, but it does provide the most detailed look yet at changes that occurred in the fetus' brain following a mother's Zika infection.

Women who have been diagnosed with Zika should wait eight weeks before trying to conceive, the US government announced today. It also said that men should wait at least six months after their symptoms first appear to have unprotected sex. Even though scientists haven't yet conclusively determined that the Zika virus causes birth defects, the guidance is intended to minimize the risk.

World Cup travelers who came to Brazil in 2014 probably weren't the source of the country's Zika virus outbreak, a study published today in Science reveals. A DNA analysis of seven Zika virus samples suggests the virus arrived in Brazil sometime between May and December 2013 — a full six months before the June soccer tournament.

Women infected with the Zika virus during the first trimester of pregnancy face a roughly 1 in 100 chance that their unborn child will develop the serious birth defect microcephaly. This is according to a new study published earlier this week in The Lancet, which is the first to give a concrete estimate of the risks associated with the virus.

The study itself looked at the prevalence of birth defects during a recent outbreak of the Zika virus in French Polynesia. The region has a small population — around 270,000 — making it easy for researchers to collect all the relevant cases. During the outbreak between 2013 and 2015 there were eight cases of microcephaly, with seven of these occurring over the last four months of this period. This clustering, say the researchers, strongly supports the proposed association between the virus and the birth defect, although the exact mechanism that's at work is still unknown.

The federal government has given preliminary approval for a trial to deploy genetically altered mosquitoes in the US as a possible method of fighting the Zika virus. The Food and Drug Administration (FDA) said today that such a field trial would have no significant impact on animal or human health, or on the wider environment. However, the agency still needs to collect comments from the public on the trial — a process that could take months — before the tests can actually go ahead.