The threat can mean other health facilities close, as staff members choose to stay home rather than risk their lives. This means other medical needs, such as help with childbirth and malaria treatment, are neglected.
"The fact that so many medical staff have developed the disease increases the level of anxiety: if doctors and nurses are getting infected, what chance does the general public have?" the group wrote.
"In some areas, hospitals are regarded as incubators of infection and are shunned by patients with any kind of ailment, again reducing access to general health care."
The heavy toll is also making it harder to secure support from sufficient numbers of foreign medical staff, the group said.
Last week, a WHO health care worker was infected with Ebola in Sierra Leone. The organization has temporarily pulled its health workers from the Kailahun post and has sent a team to review the incident.
"This was the responsible thing to do. The field team has been through a traumatic time through this incident," Dr. Daniel Kertesz, a WHO representative in Sierra Leone, said in a statement. "They are exhausted from many weeks of heroic work, helping patients infected with Ebola. When you add a stressor like this, the risk of accidents increases."
Blood and other bodily fluids
Ebola is one of the world's most virulent diseases and is transmitted through direct contact with blood or other bodily fluids of infected people.
The outbreak has forced various nations to take drastic action, including Ivory Coast, which has said it is closing borders it shares with Guinea and Liberia for an indefinite period.
Senegal also closed its borders over Ebola fears. The closure includes any aircraft and ships traveling to Senegal from Guinea, Sierra Leone or Liberia.
Amid fears of the disease's spread, the Philippines recalled 115 peacekeepers from Liberia.
Dr. Peter Paul Galvez, a spokesman for the Philippines' Department of National Defense, said they would be repatriated as soon as possible. They will be quarantined before departure for 21 days, then quarantined again in the Philippines for another 21 days.
Early symptoms of Ebola include sudden onset of fever, weakness, muscle pain, headaches and a sore throat. These symptoms can appear two to 21 days after infection.