Zika: Vietnamese authorities report first microcephaly case likely linked to mosquito-borne virus

Updated

Vietnam's Health Ministry has reported a microcephaly case that it says is likely to be the country's first linked to the mosquito-borne Zika virus.

The case, a four-month old baby whose mother was diagnosed with Zika when she was pregnant, was found in the central province of Dak Lak.

"This is a microcephaly case with a high probability of being related to the Zika virus and also the first such case in Vietnam," the General Department of Preventive Medicine, a department of the nation's health ministry, said in a statement posted on its official website.

Vietnam so far has reported a total of nine cases of Zika infection, with more cases expected to be confirmed in the next few days, the department's director Tran Dac Phu said.

If the microcephaly case is confirmed to be linked to Zika, Vietnam would become the second South-East Asian country after Thailand to report such a case.

Vietnam earlier this month raised the threat level for Zika and stepped up monitoring of pregnant women in the country after detecting more cases and amid growing outbreaks in the region.

Zika infections in pregnant women have been shown to cause microcephaly — a severe birth defect in which the head and brain are undersized — as well as other brain abnormalities.

The connection between Zika and microcephaly first came to light in Brazil, which has confirmed more than 1,800 cases of microcephaly.

In adults, Zika infections have also been linked to a rare neurological syndrome known as Guillain-Barre, as well as other neurological disorders.

Reuters

Topics: infectious-diseases-other, diseases-and-disorders, vietnam, asia

First posted</s>The case, a four-month old baby whose mother was diagnosed with Zika when she was pregnant, was found in the central province of Dak Lak.

"This is a microcephaly case with a high probability of being related to the Zika virus and also the first such case in Vietnam," the General Department of Preventive Medicine, a department of the nation's health ministry, said in a statement posted on its official website.

Vietnam so far has reported a total nine cases of Zika infection, with more cases expected to be confirmed in the next few days, the department's director Tran Dac Phu told Reuters on Sunday.

If the microcephaly case is confirmed to be linked to Zika, Vietnam would become the second Southeast Asian country after Thailand to report such a case.

Vietnam earlier this month raised the threat level for Zika and stepped up monitoring of pregnant women in the country after detecting more cases and amid growing outbreaks in the region.

Zika infections in pregnant women have been shown to cause microcephaly - a severe birth defect in which the head and brain are undersized - as well as other brain abnormalities.

The connection between Zika and microcephaly first came to light in Brazil, which has confirmed more than 1,800 cases of microcephaly.

In adults, Zika infections have also been linked to a rare neurological syndrome known as Guillain-Barre, as well as other neurological disorders.</s>HANOI, Vietnam (AP) — Vietnam has reported its first case of microcephaly likely linked to the mosquito-borne Zika virus.

The 4-month-old girl with an abnormally small head was born in central Vietnam to a mother confirmed to have had the virus when she was pregnant.

The Ministry of Health’s General Department of Preventive Medicine said on its website Sunday that the case had a “high probability of being linked to Zika virus and also the first in Vietnam.”

If confirmed, Vietnam would be the second country in Southeast Asia after Thailand to have microcephaly case linked to Zika.

The virus generally causes a mild flu-like illness, but a major outbreak in Brazil last year revealed that it can result in severe birth defects when pregnant women are infected.

Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.</s>HANOI: The Department of Preventive Medicine under the Ministry of Health on Sunday confirmed Vietnam’s first microcephaly case likely related to the Zika virus.

Vietnam News Agency (VNA) reports that the link to the virus was confirmed by laboratory tests, said health officials.

The first suspected case of the Zika-linked brain defect syndrome microcephaly was reported on October 14 in the Central Highlands province of Dak Lak. It affected a four-month-old baby whose mother was affected by the virus when she was pregnant.

The local hospital took samples from the baby girl and her mother and sent them to Japan’s Nagasaki University for further tests.

The National Institute of Hygiene and Epidemiology found after at least five rounds of tests that the 23-year-old mother experienced Zika-like symptoms such as rash and high fever during the first and second trimesters of her pregnancy.

The Preventive Medicine Department has warned pregnant women to cancel non-essential travel to areas where the Zika virus is prevalent.

The disease is spread primarily by mosquitoes and the Health Ministry is urging people, particularly pregnant women, to take measures to prevent mosquito bites.

A total of 11 Zika virus cases has been confirmed in the country so far, including that four-month-old baby in Dak Lak, according to the Health Ministry. – Bernama</s>Not only did male mice infected with the Zika virus have a tougher time getting females pregnant, their levels of sex hormones crashed, and their testicles shrunk by 90%, possibly permanently, according to new research by the Washington University School of Medicine in St. Louis.

Of course, these are mice, not men.

"We undertook this study to understand the consequences of Zika virus infection in males," said co-senior author Dr. Michael Diamond, associate director of the school's Center for Human Immunology and Immunotherapy Programs

"While our study was in mice -- and with the caveat that we don't yet know whether Zika has the same effect in men -- it does suggest that men might face low testosterone levels and low sperm counts after Zika infection, affecting their fertility."

It's well-known that Zika can survive in the testes of some men long after the virus has cleared their blood and urine. One man harbored live virus in his testes for three months, and traces of the RNA that makes up Zika has been found in other men's sexual organs for up to six months. That's why both the Centers for Disease Control and Prevention and the World Health Organization have told men who have traveled to an area where Zika is active to use condoms for a full six months after exposure.

Not only does Zika live and grow in some men's testes, but the viral load can continue to climb to a level much higher than was originally found at the time of infection. The question no one can yet answer: What does that do to a man's sexual organs and performance?

"Of course, a mouse is not human," said Sujan Shresta, an associate professor at the La Jolla Institute for Allergy and Immunization. "But there has to be some aspects of this virus interacting with a mammalian host that we can take away from this type of research.

"The last thing I want to do is scare people, but I can imagine as a scientist if the virus is always replicating, then chances are that it is destroying your sperm," Shresta added. "Eventually, that person will be infertile, right? And we don't know right now. We don't have the data."

No one knows how many men who get Zika might continue to harbor the virus in their testes. Studies are underway to figure that out.

"You have to have keep in the back of your mind that what's making it into publications are what are the exceptions, not the rules," said Dr. John Brooks, a medical epidemiologist at the CDC. "And we don't yet know with any kind of confidences, as far as I know, what is the average. Where do most people fall?"

It didn't take long for the Zika virus to wreak havoc in the sexual organs of male mice. Within one week of infection, the virus arrived in the testes. Within two weeks, Sertoli cells were dead or dying, and the testes were already significantly smaller. Sertoli cells, which nourish developing sperm cells, are also responsible for keeping a blood-testes barrier in place to protect those new cells as they grow.

"There is a blood-testes barrier that immune cells don't normally cross unless something is very wrong," Diamond said. "And you don't want them to cross because you don't want to eliminate germ cells, which are going to propagate the species."

"There are very few microbes that can cross the barrier that separates the testes from the bloodstream to infect the testes directly," said Moley, who is also a fertility specialist and director of the university's Center for Reproductive Health Sciences.

The study found that Zika not only crossed that barrier, it attacked and destroyed the Sertoli cells, which do not regenerate.

At three weeks after infection, according to the study, the male mice's testicles were one-tenth of their normal size. The organs showed no signs of healing when examined at six weeks, even though the virus had long cleared the bloodstream. Sperm counts and levels of testosterone in the male mice also dropped tenfold.

"We don't know for certain if the damage is irreversible, but I expect so, because the cells that hold the internal structure in place have been infected and destroyed," Diamond said.

Whether any of this damage will also occur in men is unknown, say the researchers, but it's worth studying in areas of the world with high rates of Zika infection, such as Central and South America.

"Wouldn't a man notice if his testicles shrank?" Moley asked. "Well, probably. But we don't really know how the severity in men might compare with the severity in mice. I assume that something is happening to the testes of men, but whether it's as dramatic as in the mice is hard to say."

"We don't know what proportion of infected men get persistently infected or whether shorter-term infections also can have consequences for sperm count and fertility," Diamond said. "These are things we need to know."</s>Frozen samples of Zika virus from Africa and the Americas are stored in a lab at Washington University School of Medicine in St. Louis, where they are used to study the impact of Zika virus infection on the body. A new study in mice suggests that Zika infection may have consequences for men that interfere with their ability to have children. Studies in people are needed to determine if men are similarly affected. (Video: Huy Mach/School of Medicine)

Most of the research to understand the consequences of Zika virus infection has focused on how the virus affects pregnant women and causes severe birth defects in their developing fetuses.

But a new study in mice suggests that Zika infection also may have worrisome consequences for men that interfere with their ability to have children. The research indicates that the virus targets the male reproductive system. Three weeks after male mice were infected with Zika, their testicles had shrunk, levels of their sex hormones had dropped and their fertility was reduced. Overall, these mice were less likely to impregnate female mice.

The study is published Oct. 31 in Nature.

“We undertook this study to understand the consequences of Zika virus infection in males,” said Michael Diamond, MD, PhD, a co-senior author on the study and the Herbert S. Gasser Professor of Medicine. “While our study was in mice – and with the caveat that we don’t yet know whether Zika has the same effect in men – it does suggest that men might face low testosterone levels and low sperm counts after Zika infection, affecting their fertility.”

The virus is known to persist in men’s semen for months. The Centers for Disease Control and Prevention recommend that men who have traveled to a Zika-endemic region use condoms for six months, regardless of whether they have had symptoms of Zika infection. It is not known, however, what impact this lingering virus can have on men’s reproductive systems.

To find out how the Zika virus affects males, Diamond, co-senior author Kelle Moley, MD, the James P. Crane Professor of Obstetrics and Gynecology, and colleagues injected male mice with the Zika virus. After one week, the virus had migrated to the testes, which bore microscopic signs of inflammation. After two weeks, the testicles were significantly smaller, their internal structure was collapsing, and many cells were dead or dying.

After three weeks, the mice’s testicles had shrunk to one-tenth their normal size and the internal structure was completely destroyed. The mice were monitored until six weeks, and in that time their testicles did not heal, even after the mice had cleared the virus from their bloodstreams.

“We don’t know for certain if the damage is irreversible, but I expect so, because the cells that hold the internal structure in place have been infected and destroyed,” said Diamond, who is also a professor of pathology and immunology, and of molecular microbiology.

The structure of the testes depends on a type of cell called Sertoli cells, which maintain the barrier between the bloodstream and the testes and nourish developing sperm cells. Zika infects and kills Sertoli cells, the researchers found, and Sertoli cells don’t regenerate.

The testes normally produce sperm and testosterone, and as the mice’s testes sustained increasing levels of damage, their sperm counts and testosterone levels plummeted. By six weeks after infection, the number of motile sperm was down tenfold, and testosterone levels were similarly low.

When healthy females were mated with infected and uninfected male mice, the females paired with infected males were about four times less likely to become pregnant as those paired with uninfected males.

“This is the only virus I know of that causes such severe symptoms of infertility,” said Moley, a fertility specialist and director of the university’s Center for Reproductive Health Sciences. “There are very few microbes that can cross the barrier that separates the testes from the bloodstream to infect the testes directly.”

No reports have been published linking infertility in men to Zika infection, but, Moley said, infertility can be a difficult symptom to pick up in epidemiologic surveys.

“People often don’t find out that they’re infertile until they try to have children, and that could be years or decades after infection,” Moley said. “I think it is more likely doctors will start seeing men with symptoms of low testosterone, and they will work backward to make the connection to Zika.”

Men with low testosterone may experience a low sex drive, erectile dysfunction, fatigue and loss of body hair and muscle mass. Low testosterone can be diagnosed with a simple blood test.

“If testosterone levels drop in men like they did in the mice, I think we’ll start to see men coming forward saying, ‘I don’t feel like myself,’ and we’ll find out about it that way,” Moley said. “You might also ask, ‘Wouldn’t a man notice if his testicles shrank?’ Well, probably. But we don’t really know how the severity in men might compare with the severity in mice. I assume that something is happening to the testes of men, but whether it’s as dramatic as in the mice is hard to say.”

Diamond and Moley said human studies in areas with high rates of Zika infection are needed to determine the impact of the virus on men’s reproductive health.

“Now that we know what can happen in a mouse, the question is, what happens in men and at what frequency?” Diamond said. “We don’t know what proportion of infected men get persistently infected, or whether shorter-term infections also can have consequences for sperm count and fertility. These are things we need to know.”

This work was supported by the National Institutes of Health (NIH), grant numbers AI073755, AI104972, HD065435, HD083895 and AI007163; the Washington University Institute of Clinical and Translational Sciences; the National Center for Advancing Translational Science, grant number UL1 TR000448; the National Institute of General Medical Sciences, grant number P41 GM103422-35; and the Veteran Affairs Office of Research and Development, grant number IO1BX007080.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.

Originally published by the School of Medicine
Vietnam reports its first microcephaly case likely to be linked to the Zika virus.