The US Centers for Disease Control and Prevention has sent a five-person team to Guinea to assist in treating a deadly outbreak of Ebola.

Guinea's Ministry of Health is reporting 122 probable and suspected cases of the viral hemorrhagic fever that have resulted in 80 deaths as of March 31, according to the CDC. 

The outbreak is worrying because it appears to be spreading across Guinea, including eight confirmed cases in the densely populated capital city Conakry, and the virus may have crossed borders to neighboring countries.

According to Médecins Sans Frontières (Doctors without Boarders, MSF) the outbreak features the most aggressive and deadly strain of Ebola, the Zaire strain.

In addition to Conakry, Ebola has been reported in Gueckedou, Macenta, Kissidougou, and Nzerekore districts, representing a wide swath of the West African nation.

Several of these districts are in a forested region that borders Sierra Leone and Liberia.

Additional reports of Ebola in the neighboring countries are being investigated, according to the CDC.

"This geographical spread is worrisome because it will greatly complicate the tasks of the organizations working to control the epidemic," said MSF's Mariano Lugli who is based in Conakry.

"We are facing an epidemic of a magnitude never before seen in terms of the distribution of cases in the country," Lugli said.

According to Reuters, the World Health Organization is downplaying the extent of the Ebola outbreak in Guinea. WHO spokesman Gregory Hartl told Reuters there have been much larger Ebola outbreaks in the Democratic Republic of Congo and Uganda.

"Ebola already causes enough concern and we need to be very careful about how we characterize something which is up until now an outbreak with sporadic cases," Hartl said, adding the largest Ebola outbreaks have had more than 400 reported cases. Hartl suggested the 122 reported Ebola cases in the Guinea outbreak - of which 24 have been confirmed in a lab - is relatively small.

Ebola is commonly transmitted by direct contact with infected blood, feces or sweat, though it can also be spread through improper handling of infected corpses, from sexual contact or through direct contact with infected bedding or clothing.

Ebola causes a severe, high fever resulting in hemorrhage of internal organs and into the skin. Other symptoms of Ebola include extreme weakness, muscle pain and headaches, followed by vomiting diarrhea, rash, impaired kidney and liver functions, and in some cases, both internal and external bleeding, according to a WHO fact sheet.

There is no human or animal treatment or vaccine available for Ebola, according to the WHO, which notes that some strains of Ebola can carry a 90 percent mortality rate.