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Since August 2017, Madagascar is experiencing a large outbreak of plague affecting major cities and other non-endemic areas.

From 1 August through 30 October 2017, a total of 1801 confirmed, probable and suspected cases of plague, including 127 deaths, have been reported by the Ministry of Health of Madagascar to WHO. Of these, 1111 (62%) were clinically classified as pneumonic plague, including 257 (23%) confirmed, 374 (34%) probable and 480 (43%) suspected cases. In addition to the pneumonic cases, 261 (15%) cases of bubonic plague, one case of septicaemic plague and 428 cases (24%) where the type has not yet been specified, have been reported (Figure 1). As of 30 October, 51 of 114 districts of Madagascar have been affected (Figure 2 and 3). Since the beginning of the outbreak, 71 healthcare workers have had illness compatible with plague, none of whom have died.

Laboratory confirmation of plague is being conducted by the Institut Pasteur of Madagascar. Twenty-three isolates of Yersinia pestis have been cultured and all are sensitive to antibiotics recommended by the National Program for the Control of Plague.

Since the second week of October 2017, there has been a decline in the number of new cases (Figure 4). There is also a decrease in the number of patients hospitalized due to suspicion of plague. Due to enhanced surveillance and ongoing investigations the cumulative number of cases continues to increase, however, some of the cases are not recently infected.

In Madagascar, the number of cases of plague is highest during the period of September through April. It is therefore important that control measures continue through to the end of April 2018.

Eighty-three percent of 6492 individuals identified as contacts of a person suspected of having plague have completed follow-up monitoring, which includes a seven day follow-up and a course of prophylactic antibiotics. On 30 October 2017, 95% of the 972 contacts currently under follow-up were reached by field teams and have been provided with antibiotics as precautionary measure.