The enemy is invisible, but deadly.

While many U.S. troops say they are well-equipped to combat the deadly Ebola epidemic in Africa, the fight against the virus is one that few have ever seen -- including the most experienced military personnel in Iraq and Afghanistan.

President Obama is sending 3,000 American troops to West African countries in the coming days to help arrest the spread of a new Ebola epidemic that since March has claimed the lives of more than 4,000 people in the region -- and one in the U.S. 

The humanitarian mission, expected to last up to a year, includes building new medical facilities in hot spots, such as Liberia, and training thousands of health care workers. U.S. troops have since undergone rigorous training in disease prevention, wearing hooded chemical suits, breathing masks and multi-layers of gloves, and learning how to scrub and spray with bleach. 

But the plan has caused some service members and their families concern following the infection of a Texas nurse, who wore protective gear as she helped treat a dying Liberian man infected with the disease inside a U.S. hospital last month.

"Of course I have concerns," said Maria Gothard, whose husband will lead a small team of Fort Bragg soldiers from the 27th Public Affairs Detachment.

"I have two children," she said, though stressed that her husband is highly confident U.S. troops can safely execute the mission they've been ordered to do. 

Capt. Vincent C. Gothard told FoxNews.com the training he and his unit underwent over the last 18 months was "spot on in how to protect in this type of environment." 

"I completely support it [the deployment]. We’re doing the right thing and I understand why my unit was chosen. This isn't one continent's problem. This has a global impact."

Gothard, however, acknowledged that the fight against such a deadly virus is a threat few troops, if any, have faced in the past. 

"This is a unique challenge," he said. "You don’t have what we’re so comfortable with and that’s the direction of the enemy. Our threat is everywhere now. It's a lot different." 

Gothard compared the Ebola mission to fighting a chemical or biological weapon, saying, "You kind of treat this as a chemical threat even though it's not. It's a virus."

"I think any family has concerns, whether it’s going to Afghanistan or this mission," he said. "You go in with caution and concern and respect."

Other military personnel, like Sgt. Jesus Sanchez, were more vocal in expressing their apprehension about the mission.

"We’re so used to being in Iraq and Afghanistan, where you know what you’re going to get. This is a lot different," Sanchez told The Courier-Journal while undergoing training at Fort Campbell. 

"I'll be honest with you," he told the newspaper. "I’m kind of scared ... but we're going out there to help." 

"The environment we're going into is drastically different [from Afghanistan] ... the stuff that can kill you is much worse," Capt. Tyler Mark also told the paper. 

Sanchez and Mark are not alone in their concern over the virus, which has no proven cure.

"I have two kids ... Of course they're worrying about their dad," Lt. Col. Scott Sendmeyer, the chief engineer now in Monrovia, told Reuters by phone. "At the same time, I've shared the training that I've received with my family ... That's the way I [relieve] them of their fears."

Treating a single Ebola patient each day requires 52.8 gallons of water, 20 gallons of bleach, 8 pairs of rubber gloves and about 3 body suits, according to a report in the Wall Street Journal. The virus, which is spread through bodily fluids, has a 21-day incubation period, though the most common incubation period is about 10 days. Health experts say the virus can survive in a man's semen for as long as three months after recovery from the infection. 

Jason Beardsley, special operations adviser at the Concerned Veterans for America, said that while the U.S. military has "excellent procedures and methodology," the protocols must be 100 percent safe-proof.

"We’ve had two cases come to the United States," Beardsley told FoxNews.com, noting the 26-year-old nurse who contracted the disease while treating an infected man at Texas Health Presbyterian Hospital. U.S. officials have not yet determined whether a breach in protocol caused Nina Pham -- who wore a mask, gown, shield and gloves -- to become infected with the hemorrhagic fever. 

"If we have not fixed the protocols, I’m very concerned," Beardsley said. "We cannot, should not execute these missions if we don’t have the answer to how do we protect our force from catching this disease. That has to be very specific. If you cannot stand in front of your force with confidence and say these protocols will defend you, then you’re going to lose [the confidence of] soldiers and families."

FoxNews.com's Cristina Corbin contributed to this report.