Now that the 42nd instance of the novel coronavirus (NCoV) since 2012 was confirmed by health authorities in Tunisia on Tuesday, it’s quite possible that that the virus is spreading person-to-person, according to the World Health Organization.

So far more than half the people who’ve contracted the infection have died, bringing the death toll to 21, according to the Center for Disease Control. 16 of these deaths were in Saudi Arabia.

The WHO only suspect that the virus, which is in the same family of viruses as Severe Acute Respiratory Syndrome (SARS), may be transmitted from person-to-person, but aren’t quite sure how exactly it is spreading.

“There are many other things that we don’t understand,” said the WHO press release, “For example, how are people getting infected? Is it from animals? Is it from contaminated surfaces? Is it from other people? Finally, we don’t know how widespread is this virus, both in this region [France] and in other countries.”

Which is why the WHO is encouraging countries to step up monitoring for the virus in order to quickly identify clusters and better understand how the virus is spreading. Check out this map of all reported cases of the novel coronavirus since 2012. Click on any bubble to see how many cases of the infection were reported in that region, and how many of those afflicted died. A larger bubble indicates a higher number of reported cases in that country.