31 Dec 2007

Ebola spreads panic better than disease

Few diseases inspire as much panic as an outbreak of Ebola fever.

In Uganda - where 100,000 people die of malaria each year - an epidemic of a new Ebola strain has killed just 36 people and infected 135 others but is spreading terror.

Yet apart from a doctor who died in Kampala after arriving from an affected area, all cases have been in western Uganda's Bundibugyio district. Medics say the epidemic in the remote region along the Congo border could be contained within months.

But tell that to Thomas Ssema, an engraver in Kampala.

"This isn't over yet," he said, extending his fist as an alternative to shaking hands he fears could be carrying the lethal virus.

"It could spread everywhere. You only need one of those people to get to Kampala on a bus. I'm terrified."

Bank tellers have donned gloves to handle money and President Yoweri Museveni has told Ugandans to wave instead of shaking hands. But experts say much of the panic is overblown.

At a doctor's surgery in Kampala, a notice entitled "Ebola" in bold letters urges calm, pointing out that though the virus is spread easily through body fluids like blood, saliva and sweat, victims are not infectious until they show symptoms.

"As usual, the panic is out of proportion with the threat," said one general practitioner, who declined to be named.

Less lethal
Symptoms of Ebola start with a fever, vomiting and diarrhoea. Victims quickly degenerate. Most die of shock or multiple organ failure, unless their immune systems beat it back. Some bleed through the eyes, mouth, nose and other orifices.

The disease was first identified in the Democratic Republic of Congo and Sudan in 1976, which suffered simultaneous outbreaks of different strains miles apart.

In Congo, its most lethal mutation - the Zaire strain - infected 318 people, killed 280 and earned its name after the Ebola River where the epidemic was first identified.

The last time Uganda was hit, the milder Sudan strain infected 425 people. Just over half died. The other strains - Reston and Ivory Coast - did not cause human epidemics.

Uganda's current outbreak represents a fifth strain and the World Health Organization says it is concerned because the initial symptoms are milder, making it harder to diagnose.

"The way it presents, you could mistake it for malaria, at the very early stage -- high fever and headache. This strain has put us on so much alert," said Dr Andrew Bakinaga of WHO Uganda.

Medecins sans Frontieres says it is concerned the Christmas season will give Ebola opportunities to spread if the sick go to big family gatherings common in Ugandan villages at this time.

Government officials prefer to look on the bright side, pointing out that the 25 percent death rate makes it less lethal than the Zaire strain's 80 to 90 percent. Some even speculate the virus could have adapted.

"We think something is happening to the virus - it is mutating to a less lethal form," said Dr Sam Zaramba, Uganda's director of health services.

"Kills so quickly"
Dr Pierre Rollin, a specialist in hemorrhagic fevers at the US Centers for Disease Control and Prevention, doubts this.

"It's still too lethal," he told Reuters on a visit to Uganda. "If humans were the main host of the virus it would make no sense for it to kill the people it infects so quickly."

"HIV is fantastic from (this) point of view. People survive for 10 years and ... spread it. It's perfect adaptation. Ebola is not adapted to humans."

It is even more lethal to other primates like monkeys and chimpanzees, which means they cannot be its main store, either.

"The host must be something else," said Rollin. "We think it's bats. We found bats with antibodies and genetic material from the virus. When infected, it doesn't seem that they die."

Rollin thinks fruit bats excrete on trees and monkeys then climb on them and get infected. Humans catch it when they cook and eat the sick monkeys. He thinks each Ebola strain evolved in a different species of bat over many millennia.

A study in August found Marburg - a close cousin of Ebola - in fruit bats.

Ebola's grisly symptoms have provided fertile ground for thrillers and raised concerns it could be used as a biological weapon, though a short incubation means it wouldn't be effective.

The 1995 disaster film "Outbreak", staring Dustin Hoffman, featured a fictional virus loosely based on Ebola, which helped spread fears about the disease to a global audience.

"It's full of trash ... the patient explodes, you have blood spitting everywhere. In reality there's not much bleeding," Rollin said. "But they had to sell it." - (Tim Cocks/Reuters Health)