There is no cure for Ebola. It kills everyone in its path. And it is back with a vengeance

In surreal scenes worthy of science fiction coming to the Third World, masked men and women dressed in sterile overalls will today start quarantining the crowded Gulu district of northern Uganda where 63 cases of the highly contagious and deadly Ebola virus have been confirmed.

In surreal scenes worthy of science fiction coming to the Third World, masked men and women dressed in sterile overalls will today start quarantining the crowded Gulu district of northern Uganda where 63 cases of the highly contagious and deadly Ebola virus have been confirmed.

The World Health Organisation (WHO) said only 20 of the victims had survived so far, but all figures were provisional.

Specialists from the region, helped by others from Switzerland, the United States and South Africa, will try to isolate the sick and prevent the huge refugee population of Gulu from fleeing the area. Kenya has sent health officials to try to stem any influx of people from north-east Uganda.

Unchecked Ebola, identified in 1976, can cut through a population like a scythe, killing everyone in contact with it. There is no vaccination, no known cure, and it can kill in 48 hours, although incubation can take 14 days. The only effective action is to isolate the infected area and allow those with the disease to die. Only three out of every 10 will survive.

In the blighted sprawl of Gulu - the region's largest town and a trading post on routes leading to the Democratic Republic of Congo (DRC) and Sudan - the government hospital cannot cope.

Yesterday, 16 patients in various stages of the viral haemorrhagic fever filled the only supposedly isolated ward, with no glass in its windows and exposed effluent in slop trays. One patient lay on the verandah.

The world's latest encounter with Ebola was revealed, officially, five days ago when Dr Francis Omaswa, Uganda's director of general health services, said 30 people, including a family of eight, had died from a form of viral haemorrhage fever (VHF).

Ugandan officials had been criticised as being slow to react, sending their first fact-finding mission from Kampala on 8 October, seven days after the first reported hospital death. South Africa's Institute of Virology, in Johannesburg, which used antigens to confirm the identity of the virus last week, refuses to reveal when Ugandan officials were informed.

The WHO and its team in Gulu, nearly 300km north of the capital Kampala, is callingfor assistance from the Ugandan health ministry and theAtlanta-based Centers For Disease Control.

"Gulu is a sprawl and we are getting reports of Ebola cases beyond the district," said a spokesman, Valery Abromov. "We still consider it is confined to the Gulu administrative area.''

The logistics for deploying a large germ offensive on Gulu, which tourists know as an access point to the Murchison Falls and Kidepo national parks, are complicated. It has one airstrip, suitable only for small aircraft and a decrepit railway line. The road is poor but passable, because October is a relatively dry month.

The greatest challenge facing health officials in their bid to seal off the area and ascertain the spread of the disease is the inestimable size of the population.

Gulu district has two refugee camps containing a third of the district's population. Displaced by a 12-year insurgency and fear of attack by the Lord's Resistance Army from southern Sudan, Gulu's refugees live under tarpaulin-covered mud huts, and most do not have access to sanitation.

Ebola, which causes victims to bleed to death through every orifice, is not airborne and spreads only through physical contact with an infected person or their fluids. In its early stages, the victims suffer high fever, severe muscle pain and oral bleeding.

Dr Omaswa had warned people to take care when handling patients or the deceased, after three student nurses died treating patients at Lacor Mission Hospital in Gulu.

"Wherever possible, gloves and masks should be worn and excreta should be disposed of safely," he said. "Washing hands with soap and water after contact with suspected cases should be done. Special care should be taken during funerals and burials.'' Two more nurses have Ebola.

Among the first 30 victims, the eight-member Akello family are believed to have caught the virus when, in a local custom symbolising unity, they washed their hands in a shared bowl of water at the burial of the first victim. It is still unclear how the virus reached Gulu. The last big outbreak of Ebola was in 1995 when 245 people died in Kikwit, in the DRC. The virus is carried by wild animals and could spread to humans who eat bushmeat, common in refugee camps.

There is also speculation that Ebola could have been carried by a Ugandan soldier returning from the war in the DRC. Early in August, some 4,000 soldiers returned to Uganda from service in the former Zaire and many are believed to have been stationed in Aswa county, part of Gulu district. The first 30 victims were from Rwot-Obillo village in Aswa county. But Uganda's military chiefs deny any soldiers or their families have died from the virus.

Ebola, first recognised in the DRC (then Zaire) in 1976 and named after a river there, is one of the most terrifying infections known to mankind. It has killed in 793 of 1,100 known cases, says the WHO. Virologists and epidemiologist who have worked on previous Ebola outbreaks describe their work in remote African field hospitals as the most gruesome and hopeless they have known. The US epidemiologist, David Heymann, worked on the original 1976 outbreak and the most recent one in Kikwit, DRC, in 1995.

He told an American medical reporter, Laurie Garrett: "There was blood everywhere. Blood on the mattresses, the floors, the walls. Vomit, diarrhoea ... wards were full. [Non-Ebola] patients and their families were milling around, wandering in and out. There was lots of exposure.

"There were people dying everywhere and the women were wailing," he added. "It was surreal.''