The rapidly spreading Ebola outbreak in West Africa is the deadliest ever, health officials say.

Guinea, Sierra Leone, and Liberia have reported hundreds of cases since March this year and more than 1,000 deaths. Nigeria is on high alert after the first known case was reported in Lagos.

West Africa Battles Worst Ever Ebola Outbreak

As of July 20, some 1,093 people in the region have been infected, according to the . At least 660 of those people have died.

West Africa Battles Worst Ever Ebola Outbreak

Africa's most populous country, Nigeria, is bracing for an outbreak after a Liberian man hospitalized with Ebola in Lagos died last week. Liberia is closing most of its borders.

West Africa Battles Worst Ever Ebola Outbreak

The Nigerian government is currently working to identify every person who came into contact with Patrick Sawyer during his journey from Liberia to Nigeria early last week. Sawyer, 40, was a consultant for the country's finance ministry and he was immediately quarantined in Lagos upon arrival.

But State Heath Commissioner Jide Idris says many more people may have had contact with Sawyer than is currently known. According to Idris, the first plane Sawyer traveled on stopped briefly in Ghana before going on to Togo, where he switched planes. He said the airline has not provided a manifest for the first two flights.

Both the Nigerian health and aviation departments are still searching, but so far, Idris said they are not aware of any other potential Ebola cases.

“We call on all Nigerians to be calm and not to panic and do hereby ensure them that both the state and the federal government are up in arms to ensure that the virus does not escape and that no Nigerian is infected with this virus," he said.

“Ebola is an incredibly dangerous, deadly disease,” noted Melissa Strickland, spokesperson for the international relief group one of whose medical doctors was struck down with the illness while caring for patients at a facility in Liberia.

“Just a little while ago, Dr. Kent Brantly’s condition was stable,” she said. “His fever is fluctuating. He has body aches, pains, the typical Ebola symptoms. He’s receiving intensive medical care from our team on the ground and we are hopeful for his recovery.”

, 33, contracted the disease despite taking every precaution against it.

“Our medical personnel follow very strict protocols that were devised by the U.S. Centers for Disease Control and World Health Organization,” Strickland said. “When they treat patients, not an inch of their body is uncovered. They are fully covered in personal protection equipment.

The were identified in 1976, in Sudan and former Zaire, now the Democratic Republic of Congo (DRC).

Humans become infected with Ebola by close contact with the blood, secretions, organs or other bodily fluids of infected animals.

Fruit bats are believed to be the natural reservoirs of the virus, which means that they carry the virus but don’t become infected themselves. Ebola has also been found in found in a number of African monkeys, chimpanzees and other primates in areas where so-called “” is part of the diet.

The United Nations Food and Agriculture Organization and the World Health Organization (WHO) are working together to help educate rural populations about the risks of hunting wildlife.

“We are not suggesting that people stop hunting altogether, which isn’t realistic,” said FAO Chief Veterinary Officer Juan Lubroth in a .

“But communities need clear advice on the need not to touch dead animals or to sell or eat the meat of any animal that they find already dead. They should also avoid hunting animals that are sick or behaving strangely, as this is another red flag," he said.

Ebola can also be contracted by contact with bodily fluids of patients, which is why health care workers, traditional healers and family members are at increased risk. Victims of the disease are still highly contagious after the death, and health workers are warning families against , such as washing the body or touching it before burial.

According to the , symptoms of the virus show up anywhere from two to 21 days of being exposed to the virus. They experience fever, extreme weakness and body aches, headache, diarrhea and vomiting. Chest pain, skin rashes, mental confusion and jaundice (yellow skin) can also occur.

Patients are contagious only after they begin to show symptoms. Health workers will confirm an ebola diagnosis through that measure white blood cells, platelet counts, and liver enzymes.

“There’s no cure, there’s no medication that you can give to actually deal with the virus itself,” Strickland said. “But what we can do is keep the patient hydrated, as comfortable as possible and as supported as possible medically to give them the best fighting chance against the disease.”