The organisation has released $300,000 following the outbreak of the potentially deadly disease, which has spread to Madagascar’s capital and port towns, infecting more than 100 people in a few weeks.

The emergency funds, as well as medical supplies, have been released to support operational efforts in response to the illness.

“WHO is concerned that plague could spread further because it is already present in several cities and this is the start of the epidemic season, which usually runs from September to April,” said Dr Charlotte Ndiaye, WHO representative in Madagascar.

“Our teams are on the ground in Madagascar providing technical guidance, conducting assessments, supporting disease surveillance, and engaging with communities,” she said.

“We are doing everything we can to support the government’s efforts, including by coordinating health actors.”

Twenty one people have died since the outbreak was identified in late August, and at least 114 people are believed to have been infected.

There are usually around 400 cases of plague reported annually in Madagascar, but the number of cases identified thus far is higher than expected for this time of year, WHO said in a statement.

Plague thrives in places with poor sanitary conditions and inadequate access to health services. It can be cured by antibiotics if delivered early, but can be fatal if left untreated.