The quarantine period for more than 160 possible Ebola contacts in Liberia has finally ended. The surveillance efforts were part of the mandatory policy of the country to ensure that the virus does not spread any further following a reported case.

The Friday announcement puts Liberia one step closer to achieving disease-free status for the third time since the virus emerged in the country.

Among the individuals included in the quarantine are healthcare workers, who tried to treat the country's last Ebola victim - a 15-year-old boy, who died of the disease on Nov. 23. His brother and father also tested positive for the disease.

"We went 21 days and nobody became symptomatic," said Tolbert Nyenswah, the leader of the nation's Ebola response team. Such finding means that there are no active spreads of the virus at the moment.

Out of the 11,300 total victims, over 4,800 Liberians died due to the hemorrhagic fever.

The country has already been declared disease-free in May and September this year. Despite the glorious announcements, the virus just keeps on finding its way back to the communities.

Sierra Leone and Guinea, two of the other African countries severely struck by the disease, has already ended the epidemic.

In a new study, published in the journal Cell, researchers studied 165 Ebola genomes obtained during the second wave of the epidemic, which was in May 2014.

The experts found that Liberia got its first case from Guinea in March 2014. Shortly after, the country was able to eliminate the virus in April 2014.

In July 2014, the second wave of the infection occurred. However the researchers found that all the collated viral samples had a single lineage, which is called SL2. For this wave, a woman from Sierra Leone is suspected to have travelled to Monrovia, Liberia, carrying the said lineage.

The virus was transmitted to Guinea for five more times at the minimum and one of the sublineages was spread from Guinea to Mali in two different times.

The Centers for Disease Control and Prevention (CDC) said the 2014 Ebola outbreak is the largest in history.

Photo: CDC Global | Flickr