Madagascar announced Monday it was attempting to contain a bubonic plague outbreak that has claimed the lives of 47 people and is spreading to its capital Antananarivo, reports Discovery News.

Two residents of Antananarivo have been infected. One victim is dying.

The bubonic plague is caused by the bacterium Yersinia pestis, which is carried by fleas and mostly affects rats. Humans can become infected with the disease if bitten by a flea or a rat.

Victims of the disease first notice a swelling of the lymph node. At this early stage, the victim can be effectively treated with antibiotics. If the disease progresses and reaches the lungs, it becomes pneumonic plague, which can kill its victims within 24 hours.

Bubonic plague can be spread person-to-person by cough or sneezing. This type of transmission is the only way that plague can spread between people, reports the Centers for Disease Control and Prevention.

Health workers have started a pest control campaign in city slum areas, the World Health Organization (WHO) said.

In addition to pest control, the health ministry has disinfected 200 households and anyone who had contact with an infected person has been given antibiotics in an attempt to stop the disease.

Disease-carrying fleas are showing a high level of resistance to insecticides, which is worrying, the U.N. health agency said.

Madagascar has recorded about 500 cases of plague every year since 2009, according to the International Committee of the Red Cross, but the disease has not infected Antananarivo residents in the past 10 years.

"It is possible that the plague continued to survive in Antananarivo for 10 years without touching humans," Christophe Rogier, a representative of the island's Institut Pasteur, said. "Rats are a natural reservoir of the plague, and they also survive the plague."

The bubonic plague has nearly vanished from the developed world, with 90 percent of modern day cases now found in Africa.