Update as of 7:43 a.m. EST: Beatrice Yardolo, who is Liberia's last patient to have recovered from the deadly Ebola virus, was released from hospital Thursday, BBC reported. Yardolo, a 58-year-old English teacher, said she was "one of the happiest persons on earth" the report added.

Original story:

Liberian health officials are preparing to release the country's last Ebola patient on Thursday. The virus' spread has slowed down and this week marked the first time that no new cases of Ebola were reported in Liberia in a week since May 2014, according to the World Health Organization (WHO).

The patient, who has fully recovered, is to be released from a Chinese-built Ebola treatment unit in Monrovia. After 42 days of the person’s release, the country can officially announce itself as Ebola-free, The Associated Press reported, citing Tolbert Nyenswah, head of the Incidence Management System. The country, which once had the highest number of deaths from the virus, has since reopened its schools. However, the spread of Ebola continues to be on the rise in neighboring Sierra Leone and Guinea, according to reports.

"We look at the three countries as really a single country, so while it's good news that Liberia itself has no new cases, the populations are so mobile in that region that there could easily be re-importations of cases," Gregory Hartl, a WHO spokesman, said, according to BBC, adding: "We have to get down to zero in all three countries before we can consider this thing beaten."

Despite no new cases being reported in the last one week in Liberia, officials from WHO say that surveillance for the virus in the country "may not be optimal," due to the small sample sizes.

Meanwhile, earlier in the week, Sierra Leone reported 81 new cases of Ebola even as Liberian President Ellen Johnson- Sirleaf noted the importance of eradicating the virus from Sierra Leone and Guinea. The virus has so far killed nearly 10,000 people since the outbreak began last year, mostly in the three West African nations.

"Until the other two affected countries (Guinea and Sierra Leone) have made equal progress we'll continue to be at risk," Johnson- Sirleaf said Monday, according to Heritage Liberia, a local newspaper.