In Madagascar, an outbreak of plague has killed 40 people, the World Health Organization said, warning that the disease could spread rapidly in the country's densely populated capital Antananarivo.
The first victim was identified on August 31 in a district to the west of the capital, and died three days later, the UN health agency said in a statement Friday.
By mid-November, some 119 plague cases had been confirmed, with two percent of them of the pneumonic strain -- one of the deadliest infectious diseases with a very high mortality rate.
Plague mostly affects rats and is spread by fleas, but humans can also contract the disease if they are bitten by an infected flea.
The situation in Madagascar is all the more worrying because of a high level of resistance to insecticides targeting fleas, the UN health agency said.
There have been three plague pandemics since the Middle Ages, inflicting an estimated death toll of 200 million people. In the 14th century, the disease wiped out an estimated third of Europe's population.
Modern sanitation and the advent of antibiotics have mistakenly led many to believe that the plague is a disease of the past.
In fact, a number of people, albeit relatively small, die from the disease in poorer countries each year and doctors are worried at the rise of several antibiotic-resistant strains of the bacterium.