After Two Years and Thousands of Deaths, Guinea Is Finally Ebola Free

Two years ago Guinea recorded the first death of what would eventually become the largest Ebola outbreak since the virus was first discovered in the forests of central Africa nearly 40 years ago. Patient Zero, as these first cases are referred to by virologists, was a 2-year-old boy named Emile Ouamouno who fell ill with a mysterious sickness and died just days later on December 28, 2013 in the remote village of Meliandou.

It took months before tests confirmed that the Ebola virus was the culprit and the World Health Organization (WHO) did not officially declare the outbreak until March 2014. Since Ouamouno's death, 3,504 people have contracted the virus and 2,536 have died in Guinea alone. There are many theories, but it is believed the boy likely contracted Ebola from a bat in the area.

After making a jump from animal to human in Meliandou, the virus subsequently spread across borders and took hold in Sierra Leone and Liberia, infecting nearly 26,000 additional people. It also traveled to Nigeria, Mali, and Senegal — all of which quickly stamped out the virus.

Both Liberia and Sierra Leone have seen the outbreaks end there, although Liberians are now fighting a third comeback of the virus. But Ebola was stubborn in Guinea and lingered on throughout the last two years, most recently infecting a 1-month-old baby girl who left the hospital at the end of November. Now, exactly 24 months and one day later — and for the first time since Patient Zero turned up — the WHO officially declared on Tuesday that the West African nation has ended Ebola transmission within its borders — meaning the country has gone the required 42-days without recording a new infection.

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"This is the first time that all three countries — Guinea, Liberia, and Sierra Leone — have stopped the original chains of transmission that were responsible for starting this devastating outbreak two years ago," said Matshidiso Moeti, WHO's regional director for Africa. "As we work towards building resilient health care systems, we need to stay vigilant to ensure that we rapidly stop any new flares that may come up in 2016."

Guinea will now enter what WHO calls a "critical 90-day period of heightened surveillance," in order to ensure that there are no missed chains of transmission. This phase will last until March 2016, and both international and national Ebola response teams will remain in the country to provide support.

Before this most recent outbreak, a country was thought to be in the clear for Ebola after going without a new case for 42 days — a period which took into account the 21-day incubation period for the virus and an additional 21 days as a safeguard. As with many other unprecedented occurrences in this spread in West Africa, however, the international response was caught off guard in June when a cluster of cases emerged in Liberia after the country had already hit the all-clear mark.

After an analysis of the new cases, the latest strain that showed up in Maghribi country was genetically similar to the one that had previously spread through that same part of Liberia the previous year. This led scientists to determine it had likely re-emerged from Ebola survivors. Again, this development and other similar occurrences changed common understandings of the virus.

New research also indicates that the virus may last in semen nine months after an individual recovers, increasing earlier estimates of 90 days. Since March, WHO said the transmission through survivors is believed to have sparked 10 new chains of minor Ebola outbreaks, known as flares, in addition to the original outbreak. With more than 10,000 survivors across the three countries, WHO's special representative for the Ebola response, Bruce Aylward, has stressed the importance of continued vigilance in the region as the persistence of the virus in this population could give rise to new Ebola flares into 2016.

"The coming months will be absolutely critical," Aylward said. "This is the period when the countries need to be sure that they are fully prepared to prevent, detect, and respond to any new cases."

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The coming months will also see a continued evaluation into the impact the Ebola virus had in Guinea. Rebuilding the devastated healthcare system will be a main focus of recovery efforts, according to Timothy La Rose, UNICEF's chief of communications in Guinea. According to La Rose, this will require a massive investment in areas like training doctors and building and supplying health centers, as well as improving birth registration and systems for the better collection and analysis of medical data.

As in Liberia and Sierra Leone, the virus setback an already underdeveloped healthcare system. More than 500 healthcare workers died across the three countries. From laboratory technicians to doctors, healthcare workers were 42 times as likely to get Ebola as the rest of the population in Guinea, according to the US Centers for Disease Control (CDC). In a country that previously had just 10 doctors for every 100,000 people, the Ebola outbreak is likely to have an enduring effect on the local healthcare capacity.

"We are trying to build a new health system after the devastation left in the wake of Ebola," La Rose said. "We have to ensure that it never falls to these levels again."

Beyond the healthcare system, La Rose said a primary concern is that there are currently 6,220 orphans from Ebola in Guinea in need of care.

"For thousands of children in Guinea, the impact of Ebola will continue long after the outbreak is declared over," he said. "Many children have lost one or both parents, siblings, and caregivers. They have been traumatized and stigmatized."

Guinea also sustained major economic impact as a result of the outbreak. The country lost a total of $540 million worth of income in 2015 as a result of the outbreak, according to World Bank figures.

Related: Sierra Leone's Ebola Outbreak Is Officially Over — But the Country Is Still Recovering

Despite the lengthy span of Ebola's first-ever appearance in the three countries, there may be ways to look at the last two years with an optimistic spin. At the very least, there is something to be said for the mere fact that the outbreak didn't infect and kill more people, according to UK's University of Reading virologist Benjamin Neuman. At the height of the virus' spread in 2014, projections from places like the CDC warned as many as 100,000 could contract the virus if the world didn't do something to stop the hemorrhagic fever's grip.

"Soon we as a species will be able to say 'we did it' — we stopped the longest, worst, most serious threat that Ebola has ever posed to humanity," Neuman said. "As bad as Ebola was, it could have been much worse without so many dedicated people giving so much."

Furthermore, the last two years have propelled the world's Ebola knowledge, research, and treatment or vaccine potentials well beyond where it was.

"We went into this outbreak with nothing, and came out with a treatment and a vaccine that works," Neuman said. "And every time we beat a virus like Ebola, humanity gets a little bit closer to the point where infectious diseases become things to be managed, not feared."

Liberia will receive its third declaration of being Ebola free after the latest 42-day period comes to an end in mid-January.

Follow Kayla Ruble on Twitter: @RubleKB