A plague outbreak in Madagascar has killed at least 33 people and infected 231 since August, the World Health Organization said. The international body has delivered 1.2 million doses of antibiotics and released $1.5 million dollars in emergency funds to fight the disease in Madagascar.

Plague is endemic to Madagascar, where there are normally 400 cases every year, though these are mostly cases of the less deadly bubonic plague that spreads only from fleas to humans.

But a majority of the deaths the Ministry of Health has reported since August are associated with the pneumonic plague – a more dangerous form of the disease that affects the lungs and is transmitted through coughing at close range, the WHO said.

To contain its spread, authorities have banned public gatherings. It has also stopped prison visits as the risk of contamination is high in the country’s overcrowded and unsanitary jails, BBC reported. A specialised hospital in the capital Antananarivo is struggling to cope, as queues outside for face masks and medicine grow longer, the report said.

Aid agencies said this year’s outbreak was a cause of concern as even urban areas have been affected.

“Plague is curable. The faster we move, the more lives we save,” said Dr Charlotte Ndiaye, WHO Representative in Madagascar.