To get to zero new Ebola cases in Guinea and Sierra Leone, whose outbreaks are still considered active, health officials will need to isolate suspected patients and prevent new chains of transmission. Reuters

A recent spike in new Ebola cases in Guinea has been traced to patients contracting the deadly disease at funeral ceremonies, government health officials said. Ebola is easily spread through contact with the bodily fluids of an infected person, or the remains of someone who has died from the virus. The rise in cases comes a week after another Ebola-hit country, Liberia, was officially declared Ebola-free.

Guinea, whose outbreak is still considered active, has struggled to contain the virus that has killed an estimated 11,000 people across West Africa and sickened 15,600 others. The country’s Ebola treatment centers were still accepting patients this week. "Today we have 27 sick in our treatment centers, including 18 confirmed cases," a spokesperson for the country’s government health department told Reuters. "Yesterday alone we recorded five sick."

West Africa’s first Ebola cases were reported in March 2014. At the height of the outbreak in the fall, health officials were seeing hundreds of new cases pouring into health centers across Guinea, Liberia and Sierra Leone -- the three countries hit the hardest by the outbreak -- every week.

New cases dropped dramatically in January. Last week, health officials confirmed just nine cases of Ebola across the region, including seven in Guinea and two in Sierra Leone -- the lowest weekly total this year, according to the latest World Health Organization report.

To get to zero new Ebola cases, health officials will need to isolate new patients to keep them from exposing others and triggering a new chain of transmission, the New York Times reported. Liberia’s Ebola outbreak was declared over May 9 after the country went 42 days without a new case. More than 4,700 Liberians died from the virus.