Thw World Health Organization continues to refine their numbers from Madagascar, with a new update that now places the total number of suspected and confirmed plague cases over 2000.
Perhaps most noticable is the recent jump in deaths (n=165), which are usually a trailing indicator in any major epidemic.The number of new cases continues to slow (see epi curve below) , although the crisis still continues, and addtional cases are expected for months to come.
Some excerpts from today's Sitrep follow:
WHO continues to support the Ministry of Public Health and other national authorities in Madagascar to monitor and respond to the outbreak of plague. Since mid-October 2017, there has been a decline in the overall incidence of the disease and the number of patients hospitalized due to plague infection across the country. From 7 - 8 November 2017, no new suspected cases of pulmonary plague and no new deaths have been reported in Madagascar.
From 1 August to 8 November 2017, a total of 2 034 confirmed, probable and suspected cases of plague, including 165 deaths (case fatality rate 8%), have been reported from 55 of the 114 districts in the country. Of these, 1 565 (77%) were clinically classified as pulmonary plague, 297 (15%) were bubonic plague, one was septicaemic, and 171 were not yet classified (further classification of cases is in process). Since the beginning of the outbreak, 82 healthcare workers (with no deaths) have been affected.
Of the 1 565 clinical cases of pneumonic plague, 371 (24%) have been confirmed, 581 (37%) are probable and 613 (39%) remain suspected (additional laboratory results are in process). Twenty-eight specimens cultured Yersinia pestis, which were sensitive to antibiotics recommended by the National Program for the Control of Plague.
Overall, 14 of the 22 (64%) regions in Madagascar have been affected. Analamanga Region has been the most affected, with 71% of all recorded cases.
About 95% (6 866) of 7 122 contacts identified thus far have completed their 7-day follow up and a course of prophylactic antibiotics. Only eleven contacts became suspected cases. On 8 November 2017, 316 out of 343 (92%) contacts under follow-up were reached and provided with prophylactic antibiotics.
Plague is endemic on the Plateaux of Madagascar, including Ankazobe District, where the current outbreak originated. A seasonal upsurge, predominantly of the bubonic form, usually occurs yearly between September and April. This year, the plague season began earlier and the current outbreak is predominantly pneumonic, and is affecting both endemic and non-endemic areas, including major urban centres such as Antananarivo (the capital city) and Toamasina (the port city).
There are three main forms of plague, depending on the route of infection: bubonic, septicaemic and pneumonic (for more information, see the link http://www.who.int/mediacentre/factsheets/fs267/en/).
Current risk assessment
While the number of new cases and hospitalizations due to plague is declining in Madagascar, WHO cannot rule out the possibility of flare ups of additional cases until the typical plague season ends in April 2018, and thus recommends maintaining vigilance until then.
Based on available information and response measures implemented to date, the potential risk of further spread of plague at national level remains high. The risk of international spread is mitigated by the short incubation period of pneumonic plague, implementation of exit screening measures and advice to travellers to Madagascar, and scaling up of preparedness and operational readiness activities in neighbouring Indian Ocean islands and other southern and east African countries. The overall global risk is considered to be low.
WHO is re-evaluating the risk assessment based on the evolution of the outbreak and information from response activities.