In a shaded jungle clearing, John Otolany watched grimly as ghostlike men in white protective clothing lowered a small body bag into the ground and sprayed the grave with disinfectant. He then reached for the edge of his T-shirt and wiped away a tear.

Otolany's 5-year-old nephew was the fifth member of his family to die of the Ebola disease. His eldest son died two days later.

"I can't cry any more," he said. "If I do, everything will fall apart."

This is the fourth time this rare, highly contagious form of hemorrhagic fever has struck Ogooue Ivindo, a remote, northeastern province inhabited by Pygmies and other hunter tribes — and researchers and villagers alike are struggling to explain why.

Rumors abound, blaming everything from plants and monkeys to politics and vampires.

Twenty-three people have died so far in the region — 17 in Gabon and six in neighboring Republic of Congo. In the normally sleepy town of Mekambo, a 10-hour drive down a dirt road that winds through a tangle of brush, trees and vines, the outbreak has caused panic.

The sick refuse to go to the town's crumbling medical center, afraid they will be told they have the disease and isolated from all human contact. Health workers refuse to treat patients. Those with money send their wives and children away for safety.

"People cross the street to avoid me," Otolany said. "I smell of death."

Otolany's sister, a nurse, was the first in the family to die. She caught the disease from a patient — a typical pattern with Ebola, which is transmitted through bodily fluids and can be passed by a simple handshake.

It is one of the deadliest viral diseases, killing 50 to 90 percent of those who become infected.

The disease can incubate for up to three weeks before flu-like symptoms set in. It then starts attacking internal organs, causing bloody diarrhea and vomiting. Within two weeks, the victim usually is dead from massive blood loss.

There is no cure. But the virus usually kills its victims faster than it can spread, burning out before it can reach too far.

More than 800 people have died of Ebola since it was first identified in 1976 in western Sudan and in a nearby region of Congo, according to the World Health Organization.

Outbreaks are often years and hundreds of miles apart. The disease last struck in Uganda, killing 224 people last year.

Death tolls have been lower in Ogooue Ivindo, the only place in the world where outbreaks have occurred repeatedly. When Ebola last struck the thinly populated province in 1996-97, it killed 45 of the 60 people infected.

Ebola is believed to be carried by some animals and insects that live with the virus in Africa's vast rain forests. But researchers have been unable to pin down the illusive reservoir, in part because of the variety of wildlife.

Most outbreaks begin with a single introduction of the virus into a human, who then spreads the disease in a community. But researchers say this time there is evidence of at least two independent transfers in Gabon and one in Republic of Congo.

This suggests a high number of the virus' natural hosts in the area, or a high proportion of them infected with Ebola, said Dr. Daniel Bausch, a medical epidemiologist with the U.S.-based Centers for Disease Control and Prevention.

Much attention has focused on primates. Gabon's outbreaks have all been accompanied by reports of unusually high numbers of dead chimpanzees, gorillas and other animals.

A 1996 case was even traced to hunters who skinned and chopped a chimpanzee found dead in the forest. But researchers say primates are unlikely to be natural hosts, as they too become sick and die.

Still, authorities have advised local villagers to avoid bush meat for now. But with food scarce, hunters armed with rifles and machetes are still seen carrying dead monkeys home.

Many villagers question whether Ebola really is the cause of the latest deaths, which have mostly been confined to two families.

"If there was Ebola here, the whole village would be dead," said Jean-Claude Ndjibadi, who has lost eight members of his extended family.

He still lives in the same mud house in Mendemba, a tiny hunting village about 30 miles east of Mekambo, and sleeps on the same mattress where his brother, sister and mother died.

He blames an ancient family feud — involving tales of theft, murder, adultery and vampires — and accuses a cousin who lived next door of using witchcraft to poison five loved ones. The cousin, his mother and baby have also died.

Most villagers seem to agree with Ndjibadi, and resent WHO's daily visits to monitor all who have had contact with victims. They blame the international medical teams for the difficulties they now have selling their bush meat, cocoa, coffee and other crops — their only source of income.

When a parliamentary vote was postponed in the region, disappointed candidates even started accusing the government of inventing the outbreak for their own political purposes.

Otolany, however, has no doubt that Ebola is ravaging his family and is angry authorities did not act sooner. The outbreak was only officially confirmed Dec. 11, though WHO was notified earlier.

Regional health officials say their efforts were hampered by a critical lack of resources and experienced personnel.

Protective equipment, including gloves and face masks, had to be flown in from the capital, Libreville. Blood samples had to be sent 370 miles south to a laboratory in Franceville. Phone lines are erratic, and the provincial health authority owns just one vehicle.

"We should have had the material in place, as we know Ogooue Ivindo is a region susceptible to outbreaks," provincial health director Prosper Abessolo Mengue acknowledged. Next time, he hopes, things will be different.

Just up the hill from John Otalany's house lives his father, Marcellin Otolany. Once one of the village's richest landowners, living surrounded by family, he is now alone.

As he tends the family graves in the tidy front yard, shaded by a flowering tree, he explains with quiet dignity: "I couldn't abandon the graves of my wife and daughter."