Causes of Zika virus Harm Male Fertility?

UntitlCauses of Zika virus Harm Male Fertility?

Researchers at the CDC are working with a fertility clinic in Puerto Rico, which has done hard-hit by Zika, to decide if men affected by the virus should lower sperm counts or sperm that doesn't work as great in the weeks and months after virus.

That study took begun just last month and so far has enrolled just a handful of men. It usually takes about 90 days for a man to generate sperm, so researchers are preparing to track them for at least 6 months to estimate any changes.

"It's going to be important for us to follow them up for many months to rule in or rule out any results of Zika infection," says Tyler Sharp, Ph.D., chief epidemiologist at the CDC's Dengue Branch in San Juan, Puerto Rico.

The reason why they're concerned is that in recent months, three separate investigations have documented the critical damage the Zika virus can do to the male testes, at least in mice."It just looks like it's been destroyed," says Kelle Moley, MD, co-director of the Institute of Clinical and Translational Sciences at Washington University in St. Louis. "As a result, you're left with a testis that's regarding a tenth of the size of a normal, non-infected testis." Moley has documented the same appearance in mice but was not included in the current study.The most current study, published Wednesday by a team at Yale and the Howard Hughes Medical Institute, found that Zika attacked specialized cells called Leydig cells that provide the hormone testosterone and support sperm reproduction. About 3 weeks after the poisoning, the mouse testes were much less than those of mice that were not affected, and they had far less testosterone in their blood.

The studies suggest the possibility that Zika infection may have permanent impacts on men. The virus is already known for producing birth deficits in developing babies."No one has connected this to infertility in men," Moley says, "but infertility is not something that comes to the forefront when you have a cold. No one is going to get a semen report on someone who has an illness and a rash and chills. We may not understand if people are infertile because of Zika for 20 or 30 years."

A disease, fever, and colds are among the symptoms of Zika.In addition to being nerve-loving, or neurotropic, the Zika virus also appears to approach to the reproductive region. Researchers have documented that the infection can be transferred sexually, as well as through the bite of an infected mosquito.

Sharp's team recorded just last week that Zika persists in the semen of any men for months.Sharp says that so distant, he has not heard any case comes from Brazil or other countries with general Zika outbreaks of reproductive effects or shrinkage of the testes in men. He says he is doubtful that what's happening in mice is also happening to people.

He says typically when scientists use rats to examine the disease, it's because they see an impact in humans and need to study it more exactly in an animal model."What looks to have happened now is the reverse of that. We have [observable effects] in a mouse model, and now we're talking if we can find it in humans. That doesn't mean that it doesn't survive, but typically it's the reverse order," he says."I think it wants to be studied at a population level, and I think that's anything the CDC is trying to do," she says.

Moley and her colleagues watched what appeared to the male reproductive systems in mice in the weeks after poisoning with the Zika virus. They found that the virus hits cells that are responsible for building a barrier between sperm and blood. This limit is critical because it protects the sperm from attack by the body's immune system. When the barrier is breached, the immune system comes in, and by about 21 days after disease, Moley says, very little of the interior architecture of the testes is left.

The mice in her study, which was announced last October, had lowered sperm counts, lower testosterone, and were far less likely to produce female mice.The study out Wednesday found the same outcome, though the researchers think the testes shrink because Zika makes a direct assault on Leydig cells, slashing the reproduction of testosterone.

Ryuta Uraki, Ph.D., a postdoctoral researcher at Yale, tells other questions to remain, like whether the testes can increase after a Zika infection."We want to investigate whether the damage in the testes can be changed after the virus is cleared and fertility can be replaced," he says.Moley agrees with Sharp that her judgments need to be confirmed in men.