The numbers of orphaned African children being rejected by their family relatives during the Ebola outbreak is growing, the United Nations says.

At least 3,700 children in Guinea, Sierra Leone and Liberia have suffered the loss of one or both their parents since the start of the outbreak, the child agency UNICEF is reporting.

Traditionally, orphans would be taken in by members of their extended families, but many are now being abandoned over fears of infection, the agency says.

Even neighbors of a family wanting to take in an orphan often refuse to let it happen over fears the child might be infected, even if testing has shown a negative result, it says.

"In some communities, the fear surrounding Ebola is becoming stronger than family ties," says Manuel Fontaine, UNICEF Regional Director for West and Central Africa.

"These children urgently need special attention and support; yet many of them feel unwanted and even abandoned."

UNICEF is initiating a program involving Ebola survivors in Sierra Leone believed to be immune to the disease, and will train more than 2,500 of them in the next 6 months to provide support and care to children who have lost parents and have been abandoned or quarantined.

Although foreign governments are beginning to respond, such support is arriving slowly, UNICEF says, noting just 25 percent of the $200 million it needs to aid families and children affected by the crisis has been received so far.

"The vast majority of the children affected by Ebola are still left without appropriate care," Fontaine says. "We cannot respond to a crisis of this nature and this scale in the usual ways."

Aid workers have compared the situation to that faced by children during the wars in Liberia and Sierra Leone that occurred in the 1990s.

A difference, they say, is that the newly orphaned children have to be monitored for possible infection by the disease.

"You cannot just set up a center and put 400 children in it like we used to do," says Andrew Brooks, UNICEF's regional head of child protection. "It is much more complicated than that."

Still, Fontaine says, the core problem is that thousands of orphans are being shunned by surviving relatives over the stigma of infection fears.

"Ebola is turning a basic human reaction like comforting a sick child into a potential death sentence," Fontaine says.