A bubonic plague outbreak in Madagascar that has seen more than 130 confirmed cases and claimed 47 lives is spreading to the island nation's capital, officials have warned.
Two people in the capital city of Antananarivo have been infected and one of them is not expected to survive, officials announced as health workers initiated a pest control operation in slum areas surrounding the city.
Fleas carrying the plague mostly affect rats, but the bite from a disease-carrying flea can infect people.
In the bubonic form of plague, where there are swellings known as buboes in the lymph nodes, the disease is susceptible to treatment with antibiotics; however, in the pneumonic form of the disease, which affects the lungs, the disease can be communicated from one person to another through coughing.
The disease can kill in just 24 hours.
In areas surrounding the capital, "two hundred households have been disinfected," according to Philemon Tafangy, secretary general of the country's health ministry.
People who had any contact with people with confirmed infections were being given antibiotics in an effort to slow or hopefully halt the spread of the disease, he said.
The United Nations' health agency WHO says there is considerable concern over how effective the pest control effort will be because of a high level of resistance in Madagascar to the usual insecticides targeting fleas.
The huge island country is prone to plague outbreaks, usually at their worst from October to March, although it has been 10 years since a case was diagnosed in the capital, said Christophe Rogier of the island's Institut Pasteur.
"It is possible that the plague continued to survive in Antananarivo for 10 years without touching humans," if the virus remained restricted to the city's rat population, he said. "Rats are a natural reservoir of the plague, and they also survive the plague."
Madagascar has seen an average 500 cases annually since 2009, figures from the International Committee of the Red Cross indicate.
The first cases of the current outbreak were identified in August.
Some form of plague, either bubonic or pneumonic or both, is commonly believed to have been responsible for the Black Death that swept across 14th century Europe, with a death toll of an estimated 25 million people.
Thought to have arisen in central Asia, it moved with traders along the Silk Road westward into the Mediterranean region and then Europe, most likely carried there by fleas on rats that were commonly seen on merchant ships.