The thoracic plague outbreak in Madagascar has killed at 48 people since August, officials said.

The office of the president said 21 of the victims came from the capital Antananarivo, while the seaport of Toamasina accounted for nine deaths.

Some 450 cases of infection have been confirmed, with some 190 people recovering after treatment, according to the office of the president.

The office further said some 217 infected people were undergoing treatment after being infected by the plague.

International organisations and the US government have stepped in to help Madagascar combat the worrying situation.

President Hery Rajaonarimampianina said there were drugs supplies and human resources to put the situation under control.

He spoke on Tuesday while receiving additional medicines and equipment from the World Health Organisation (WHO).

“We have to reinforce the early detection measures and to urgently take care of any sick persons,” stated President Rajaonarimampianina.

The government is also carrying out intensive awareness campaigns to educate the population about the plague.

Meanwhile, the gathering of people, including at funerals and learning institutions, has been banned in the affected areas.

The measures have occasioned the closure of the Antananarivo and Toamasina universities, as well as schools in some 30 districts.

Air Seychelles has since Sunday cancelled its flights to the country.

Seychellois basketball coach Alix Allisop, 49, died from the thoracic plague in an Antananarivo hospital on September 27 during the Indian Ocean Club championship.

The Geneva-headquartered WHO said plague was endemic to Madagascar, where around 400 cases of mostly bubonic type, were reported annually.

It said the current outbreak had affected large urban areas, a scenario which increased the risk of transmission.

"The number of cases identified thus far is higher than expected for this time of year,” WHO noted.

The UN agency initially appealed for $1.5 million to support the response, but was now asking for at least $5 million.