Liberia suffered immensely with Ebola in 2014. But the tide started turning towards the end of the year and by early 2015, Liberia was well on it's way to being declared Ebola free. There were fewer new cases each week AND the probability that every new person who became diagnosed with Ebola came from the 'contact list'. This mattered since if there was a 100% concordance between new patients with ebola and those on the contact list - then epidemiologists had found ALL the transmission chains. Eventually, by May 2015, every 'contact' had gone through the 21 day waiting period (incubation time of Ebola) and Liberia was declared Ebola free!
Sadly, Ebola re-reared it's ugly head in Liberia a week ago. There has already been 1 death and 2 other confirmed cases - all about an hour outside of the capital city of Monrovia. The first priority should be to treat these two living confirmed cases, find all the contacts and follow them for 21 days (it's not necessary to 'isolate them'). But after these initial steps, we're left with two equally scary propositions: a) we either didn't have a good enough understanding of the transmission chains or b) there's a different mode of transmission.
For option A - this means that there may have either been ongoing transmissions in Liberia with likely secret burials and obfuscation from the public health authorities OR people travelled to Guinea/Sierra Leone and the cross-border epidemiological links have not been made properly. This would show a persistent mistrust of the public health authorities and general fear among the population. This would indicate that we really don't have the epidemic under control in Liberia.
For option B - there are early theories about non-human-to-human transmission and consideration that these three 'new' cases got infected through sharing dog meat: "Dr Moses Massaquoi, case management team leader for Liberia's Ebola task force, said the three villagers who had tested positive for the disease "have a history of having had dog meat together." Dog meat is commonly eaten in Liberia. In spite of this huge epidemic in West Africa, fairly little is known about this dangerous disease. One of the unknowns is the animal reservoir - where does the virus stay when it's not infecting humans. Bats are the most likely reservoir - but maybe pigs and even dogs are also potential reservoirs? If this is true, however, what does this imply about how dangerous the future is for the population and for health workers in Liberia? How endemic will it become and will everyone who comes to a health center with fever need to be asked about dietary habits? In the end, it would likely mean that we can't have the epidemic under control in Liberia.
Either way, the bottom line is that these new cases of Ebola are a tragic recurrence in Liberia. The secondary question now is the quality (not the quantity) of this recurrence - is it due to the failings of the public health system or the emergence of new modes of transmission?