West Africa was on high alert Tuesday after Sierra Leone warned an Ebola outbreak ravaging Guinea may have crossed its borders and five deaths in Liberia were being tested for the killer virus.
More than 60 people have died of haemorrhagic fever in Guinea since the start of February, with the Ebola virus identified as the cause in 13 of 45 samples tested by scientists.
"We still do not have any confirmed cases of Ebola in the country. What we do have are suspected cases which our health teams are investigating," Sierra Leone's chief medical officer Brima Kargbo told reporters.
Kargbo said one of the cases concerned a 14-year-old boy thought to have died two weeks ago in Guinea before being buried in a village on the Sierra Leone border. The second was a patient who was still alive in the northern district of Kambia.
A variety of deadly, highly-contagious tropical bugs, including the Marburg virus and Lassa fever, can lead to similar symptoms—vomiting, diarrhoea and profuse bleeding—but the authorities have not announced which other pathogens have been picked up in samples.
The Ebola disease has never before been detected among people in west Africa.
Liberia, which borders Guinea to the south, reported on Monday that four women and a boy had died of suspected Ebola.
Canada's health ministry had feared the virus may have crossed continents after a man was hospitalised with symptoms consistent with Ebola infection after returning from Liberia.
But a spokesman for Canadian Health Minister Rona Ambrose told AFP on Tuesday tests on the patient had proved negative.
Bats off the menu
Meanwhile Guinea announced it had banned inhabitants of the Ebola-hit south from eating bats, a common feature of the local diet, as the creatures are considered to be the natural host of the virus.
"At the moment they are migrating between (four) prefectures and the Diecke area... I have formally forbidden the consumption of bats in the region," Health Minister Remy Lamah said during a visit to the epicentre of the epidemic.
Doctors Without Borders, which is known by its French initials, MSF, said other traditional rituals were hampering its response to the outbreak.
Emergency coordinator Marie-Christine Ferir said in an interview late Monday the suspected spread to neighbouring Liberia was linked to people travelling great distances to attend funerals in which mourners touch the dead person's body.
"It requires special precautions to be taken, while respecting local customs," Ferir told AFP, adding that Ebola had spread to Liberia when mourners with cross-border family ties had attended funerals in Guinea before returning home with the virus.
MSF has sent 35 of its health workers to Gueckedou, in the country's heavily-forested south close to the centre of the outbreak, with the aim of treating those affected, identifying possible new cases and providing information to limit the spread of the disease.
No treatment or vaccine is available for Ebola, which kills between 25 and 90 percent of those who fall sick, depending on the strain of the virus, according to the World Health Organization (WHO).
WHO spokesman Tarik Jasarevic told a United Nations briefing in Geneva the west African Ebola species had been confirmed to be the Zaire strain, the most lethal of all.
Three cases of haemorrhagic fever, two fatal, have also been reported in Conakry, but tests for Ebola proved negative and the cause has not been made public.
Transmission of Ebola to humans can come from wild animals, direct contact from another human's blood, faeces or sweat, as well as sexual contact or the unprotected handling of contaminated corpses.
The tropical virus—described in some health publications as a "molecular shark"—can fell its victims within days, causing severe fever and muscle pain, weakness, vomiting and diarrhoea, shutting down organs and causing unstoppable bleeding in severe cases.
It was first discovered in the Democratic Republic of Congo in 1976. The central African country has since suffered eight outbreaks.
The most recent epidemic, also in the DR Congo, infected 62 people and left 34 dead between May and November 2012, according to the country's health ministry.