Ebola has made a reappearance in West Africa despite the World Health Organization declaring its disappearance after two years, health officials report.

The body of 22-year-old Sierra Leone native, Mariatu Jalloh, tested positive for the disease, according to the New York Times. Not once between the exposure to Ebola—predicted sometime in late December to early January and her death on Tuesday (Jan. 12)—did doctors draw her symptoms to the epidemic. The Ebola virus travels though the blood and bodily fluids. At least 27 people were reportedly put at risk of contraction due to inadequate medical procedures as signs like vomiting and diarrhea progressed and through burial methods conducted by family and friends.

WHO requires a 42-day period without any new diagnoses in order to declare a region disease-ridden. Sierra Leone passed the test three months ago (Nov. 7), and entered a 90-day period of "enhanced surveillance."

Even still, survivors can carry the virus and spread it through regular modes of transport. WHO’s Special Representative for the Ebola Response, Dr. Bruce Aylward, said in a statement yesterday (Jan. 14), "We are now at a critical period in the Ebola epidemic as we move from managing cases and patients to managing the residual risk of new infection." Because of this, the organization expects the occasional case of Ebola here and there, or flare-ups. However, the organization doubts such a large-scale outbreak as past years will happen again.