In a follow-up on the plague cases reported in Madagascar, as of 27 September 2018, a total of 25 cumulative cases including five community deaths (case fatality ratio 20%) have been reported.

Soon the proventriculus, or esophagogastric junction will become blocked with a bacterial mass preventing the flea from swallowing food.

Six of these 25 suspected cases have been laboratory confirmed by RDT, PCR and/or culture at IPM (three pneumonic and three bubonic cases) and 19 are currently classified as suspected cases. Four of the five deaths were reported among confirmed cases; three in confirmed pneumonic cases and one in confirmed bubonic cases.

Plague is endemic on the Plateaux of Madagascar. Cases are typically recorded from September to April. Although bubonic cases are predominantly reported during the endemic season, pneumonic cases are also expected and are associated with human-to-human transmission and a high case fatality of 30-100% if left untreated.

The recently notified cases of confirmed pneumonic cases have been reported from endemic and non-overcrowded areas so far. However, deaths among these cases have occurred in the community. There is currently no information concerning the source of infection of the three confirmed pneumonic cases. But, given their classification as primary pneumonic plague cases, it is important to investigate potential unidentified transmission chains in order to mitigate the risk of spread of the disease to other districts and major urban centres.