#12,873
While recent trends (see epi curve above) suggest the plague outbreak on Madagascar is slowing, the number of reported cases continues to rise at an impressive rate, due in no small part to the inclusion of older cases which were not originally reported.
Looking back at the epi curve published last Friday in SitRep #6 - and comparing it to today's - you'll find daily cases counts from earlier in the month have been adjusted upward by 20% or more.The `fog' inherent in any large outbreak, and delays in transmitting and collating data, often affect the accuracy of real time reporting, and is a big reason behind the report's disclaimer, which reads:
The figures in the External Situation report are subject to change due to continuous data consolidation, cleaning and reclassification, and ongoing laboratory investigations. The data reported are based on best available information reported by the Ministry of Public Health.Todays report also indicates a jump of 34 fatalities since the last update. Since deaths are often delayed by treatment, they are generally a trailing indicator in any outbreak scenario, and may continue for weeks after community transmission has ended.
WHO continues to support the Ministry of Public Health and other national authorities in Madagascar to monitor and respond to the outbreak of plague. The number of new cases of pulmonary plague is declining across the country. While progress has been made in response to the plague outbreak in Madagascar, sustainability of ongoing operations (during the outbreak and through the plague season usually from September to April) remains critical.
From 1 August to 30 October 2017, a total of 1 801 suspected cases of plague, including 127 deaths (case fatality rate 7%), were reported. Of these, 1 111 (62%) were clinically classified as pulmonary plague, 261 (15%) were bubonic plague, one was septicaemic, and 428 were unspecified (further classification of cases is in process). Since the beginning of the outbreak, 71 healthcare workers (with no deaths) have been affected.
Of the 1 111 clinical cases of pneumonic plague, 257 (23%) have been confirmed, 374 (34%) are probable and 480 (43%) remain suspected (additional laboratory results are in process). Fourteen strains of Yersinia pestis have been isolated and are sensitive to antibiotics recommended by the National Program for the Control of Plague.+
Overall, 51 of 114 (45%) districts in 16 of 22 (73%) regions of Madagascar have been affected. Analamanga Region has been the most affected, with 64% (1 149) of all recorded cases.
About 83% (5 357) of 6 492 contacts identified thus far have completed their 7-day follow up and a course of prophylactic antibiotics. A total of nine contacts developed symptoms and became suspected cases. On 30 October 2017, 925 out of 972 (95%) 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 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
The risk assessment is in the process of being reviewed based on the evolving situation. While the current outbreak began with one large epidemiologically linked cluster, cases of pneumonic plague without apparent epidemiologic links have since been detected in regions across Madagascar, including the densely populated cities of Antananarivo in the central highlands and Toamasina on the east coast of Madagascar. Due to the increased risk of further spread and the severe nature of the disease, the overall risk at the national level is considered very high.
The risk of regional spread is moderate due to the occurrence of frequent travel by air and sea to neighbouring Indian Ocean islands and other southern and east African countries, and a limited number of cases observed in travellers. This risk of international spread is mitigated by the short incubation period of pneumonic plague, implementation of exit screening measures and advice to traveller 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.
The risk assessment will be re-evaluated by WHO based on the evolution of the situation and the available information.
(Continue . . . )
