GENEVA - The World Health Organization warns a highly infectious, deadly form of pneumonic plague is spreading rapidly in Madagascar and quick action is needed to stop it.

Pneumonic plague, which is transmitted from person to person, has been detected in several cities in Madagascar. This worries the World Health Organization as the disease is highly contagious and quickly causes death without treatment.

Plague is endemic to Madagascar resulting in around 400 cases annually. Most are cases of bubonic plague, which is spread by the fleas of rats and other small rodents. The disease is usually confined to rural areas, but this year it has spread to large urban areas and port cities.

WHO spokesman, Tarik Jasarevic, says cases of bubonic, as well as the human transmissible pneumonic plague have been found in the capital Antananarivo and the port cities of Majunga and Toamasina.

"So far, 104 cases of plague were reported since the first case has been identified that was dating from the 23rd of August," said Jasarevic. "So, from the 23rd of August to 28th September, 104 cases that have been reported, including 20 deaths.”

Jasarevic notes the fatality rate is more than 19 percent. He tells VOA this outbreak is very dangerous and must be brought under control quickly.

“The plague epidemic season usually runs from September to April, so we really are at the beginning of the epidemic season of plague," said Jasarevic. "And, we have already from the 23rd of August until yesterday—so that is like five-weeks-time—we had 104 cases and again half of those cases were pneumonic plague.”

WHO says urgent public health response in terms of surveillance and treatment is required. The health agency has released $250,000 from its emergency fund to get immediate action underway. It plans to appeal for $1.5 million to fully respond to the needs.