The World Health Organisation (WHO) has warned the risk of an epidemic spreading is high after more than 231 cases were identified in Madagascar in just two months.
Madagascar is the most seriously affected country in the world and, although large outbreaks of the disease are rare, it is also endemic in the Congo and Peru.
And there are a surprisingly large number of other nations, including the US, which occasionally experience cases of the deadly disease due to animals carrying the bacteria.
In the US, the plague is commonly spread by rats in rural areas and humans can become infected by cats and dogs.
Recently a public health warning was issued in northern Arizona, although there have not been more than a couple of isolated cases.
Elsewhere, the bacteria exists in countries across the planet, and it is still a major problem in central Asia where many animals are hosts.
From 2010 to 2015 there were 584 deaths from the plague reported around the world.
However, these were isolated cases, with only a few large-scale epidemics recognised by WHO this century.
The last major emergency was declared in Peru back in 2010 after 17 cases of the plague were reported in the Ascope province of Department La Libertad.
And, a year before, a cluster outbreak of pulmonary plague cases were found in the remote town of Ziketan in China’s Qinghai province.
Twelve people were confirmed to have the disease while hundreds more had to be quarantined.
One man died after helping to bury the first victim, a 64-year-old man, as the disease swept through the town.
The pneumonic, highly contagious, form of plague – known as the Black Death – is particularly dangerous, and can be passed on through coughing and always proves fatal unless it is caught early.
Less contagious, but still dangerous is the bubonic strain of the disease.
It is passed on by a bacteria found in small mammals and their fleas.
Both types contributed to the deaths of more than 50 million people in Europe during the Middle Ages.
WHO says the number of people dying from plague in Madagascar has risen in recent years even though the total number of infections has not increased.
This has been blamed on a deteriorating health system and rising poverty in the country.
Last week, the WHO delivered 1.2 million doses of antibiotics and released $1.5 million to fight the new epidemic.