A recent study reveals that 23 countries remain at risk of Ebola.

While the Ebola outbreak, which began in West Africa in 2013, is currently under control, 23 countries remain "environmentally suitable" for animal-to-human transmission of the virus, the study said.

According to the researchers from the Institute of Health Metrics and Evaluation (IHME) at the University of Washington in Seattle, seven of the countries identified have already experienced cases of Ebola, but the other 16 countries are still unaware of the regions of suitability and may be unprepared for future outbreaks.

The study, which was published in the journal eLife, is an update on a 2014 study that created a zoonotic niche map used in identifying regions where the virus could be transmitted from animals to humans.

Alongside this study, IHME also launched a new online data visualization tool that can be viewed by stakeholders and the public.

"The visualization tool provides an important way for various end users to engage and interrogate these updated maps," Dr. David Pigott, assistant professor at IHME and study lead author, said in a press release.

"Unlike with the previous publication, anyone can now directly interact with the maps, use the tool, and better assess the potential threat that Ebola virus disease poses to their regions of interest," Pigott said.

The new geospatial mapping tool allows users to view previous Ebola index cases and explore the areas where bat species capable of transmitting the virus are living.

The maps are displayed in a 5-by-5 km grid across Africa, which allows users to zoom into their countries to view their areas.

According to the new analysis from the revised map, regions predicted to be environmentally suitable for animal-to-human Ebola transmission include Cameroon, Gabon, Republic of Congo and mainland Equatorial Guinea. Regions of Central Africa identified to be most environmentally suitable in previous analysis remain so in the new analysis.

Ebola viruses are found in several African countries and outbreaks have appeared sporadically in Africa after its discovery in 1976 in the Democratic Republic of the Congo. Symptoms include fever, severe headache, fatigue, diarrhea and unexplained bleeding and bruising among others.