A new case of Ebola virus has been reported from Sierra Leone within only hours of the World Health Organization declaring the whole of West Africa - including Sierra Leone - as free of the virus, according to CNN.

The new case is that of a woman named Mariatu Jalloh, who was apparently traveling around the northern part of the country and visited areas along the country's border with Guinea.

Jalloh first had symptoms of vomiting and diarrhoea on Thursday of last week. She took herself to a government hospital in the town of Magburaka. There, even though a sample of her body tissue was taken, her condition was diagnosed as that of "severe cold," and she was apparently given some medicines to cure that and asked to go home. From that time, her health gradually deteriorated and she died on Tuesday.

After her death, nearly five people (not belonging to her family) were also involved in death ceremonies and the disposing of her corpse. In the meantime, a swab that was taken from her corpse was looked at in three separate tests by a lab run by Public Health England. It turned out that each of those three tests ended up positive for the Ebola virus.

The government of Sierra Leone has since quarantined all the family members of her family in order to isolate potential carriers of the virus. The people that were involved in dealing with her corpse were also added to that list. Now, the government is trying to trace all the other people that could potentially have come into contact with Jalloh before her death and then figure out if any of those other people also need to be quarantined, Reuters reported.

People in these areas are being advised not to take Ebola lightly. Even though the WHO may make formal declarations that a particular country is Ebola-free, people have to continue to adopt the strictest of health and hygiene guidelines and practices that they adopted on a daily basis during the peak of the outbreak, according to Channel News Asia/AFP.