In what the World Health Organization (WHO) has called a rapidly evolving Ebola virus outbreak in Guinea, sick patients in neighboring Liberia are being tested, and officials today ruled out an Ebola infection in a Canadian traveler who had recently visited West Africa.

The count of lab-confirmed cases in Guinea stayed at 13, as reported by the WHO late yesterday, with the numbers of suspected cases and deaths also remaining the same at 86 and 59, the WHO said in a note e-mailed to the media today.

WHO spokesman Gregory Hartl said in a Twitter post today that many different diseases produce symptoms similar to Ebola and other viral hemorrhagic fevers and that some cases will undoubtedly be ruled out.

Six of seven blood samples had tested positive for the virus at the Pasteur Institute in Lyon, France, and seven other cases were confirmed at a Pasteur Institute lab deployed from Dakar, Senegal.

Tests have confirmed that that the subtype involved in the outbreak is Zaire, the WHO said. Earlier tests on a gene segment from one of the samples initially suggested the outbreak likely involved the Zaire subtype, which has a mortality rate as high as 90%.

Of six suspected cases in Liberia, which borders the districts in Guinea that have reported cases, two samples have been obtained and are being tested. Yesterday, health officials said suspected cases were being investigated in neighboring Sierra Leone as well.

The patients in Liberia—four women, a boy, and a girl—came from Guinea for treatment in a hospital in the northern part of the country, Agence-France Presse (AFP) reported today. A government official said health inspectors have been in the area since Mar 21 and are collecting samples, tracing contacts, and educating local health teams.

Meanwhile, the Public Health Agency of Canada (PHAC) released a statement today that said a patient in Saskatchewan does not have Ebola, Lassa, Marburg, or Crimean Congo virus. It added that more tests are under way to diagnose the patient's illness.

Provincial health officials said yesterday that a man who had recently visited Liberia was hospitalized in critical condition in Saskatoon with a suspected viral hemorrhaging fever infection, according to a report today from CBC News.

In a Twitter post today, the WHO's Hartl said testing continues and that the man might have malaria.

The US embassy in Conakry, Guinea, yesterday in a security statement warned US citizens about the outbreak in the country's forest region and strongly recommended that they avoid individuals with symptoms including diarrhea, vomiting, high fever, and heavy bleeding until more information is available.

It also warned that Ebola can spread quickly in healthcare settings, especially when hospital staff are not equipped with protective equipment such as masks, gowns, and gloves.

The outbreak in Guinea marks the first appearance of the disease in the country, as well as in West Africa.

See also:

Mar 25 WHO statement

Mar 24 AFP statement

Gregory Hartl Twitter feed

Mar 25 PHAC statement

Mar 25 CBC story

Mar 24 CIDRAP News story "Ebola outbreak kills 59 in Guinea"

Mar 24 US embassy security message