Epidemiological update: outbreak of Ebola virus disease in West Africa, 11 September 2014

epidemiological update

Since December 2013 and as of 7 September 2014, 4 388 cases of Ebola Virus disease (EVD), including 2 226 deaths have been reported by WHO.

Since December 2013 and as of 7 September 2014, 4 388 cases of Ebola Virus disease (EVD), including 2 226 deaths have been reported by WHO.

This is the first outbreak of EVD in West Africa and it is unprecedented in size and geographical distribution, affecting densely populated urban areas. The outbreak is currently rapidly increasing and has not yet peaked:

Distribution of reported cases of EVD by week in Guinea, Sierra Leone, Liberia, Nigeria and Senegal week 48/2013 to 36/2014 (as of 6 September 2014) 

Source: adapted from WHO (Ebola virus disease, West Africa – update)

 

Reported figures are believed to be underestimations of the magnitude of this outbreak.

On 11 September 2014, the Senegalese Minister of Health reported that two suspected cases in contact with the confirmed case in Senegal tested negative for Ebola virus.

 

Distribution of EVD cases (confirmed, probable and suspected) by district and week of reporting, weeks 33-36, 2014

 

Source: adapted from national situation reports when available

 

 Cases, deaths and case-fatality ratios in the EVD-affected countries in West Africa, as of 7 September 2014

​Country ​Cases as of week 36/2014 Deaths as of week ​36/2014 ​Case-fatality ratio
Guinea​ ​861 557​ 64.7%​
​Sierra Leone ​1424 524​ 36.8%​
​Liberia ​2081 1137​ 54.6%​
​Nigeria ​21 ​8 38.1%​
​Senegal ​1 0​ 0.0%​
​TOTAL ​4388 2226​ 50.7%​

 

 

 

Source: adapted from WHO and Senegal Ministery of Health (Ebola virus disease, West Africa – update)

 

ReliefWeb reports that 20% more EVD cases are expected to be identified in Sierra Leone as the government will conduct door-to-door searches for cases and bodies during the three day curfew starting on 19 September. More than 20 000 volunteers will be involved in the process.

According to media, an American aid worker who contracted EVD in Sierra Leone was medically evacuated on the 9 September to Atlanta. This was the fourth American citizen evacuated during this outbreak.

Distribution of cases of EVD by week of reporting in Guinea, Sierra Leone, Liberia, Nigeria and Senegal (as of 6 September 2014)

 

Source: Adapted from WHO (Ebola virus disease, West Africa – update)

 

Continuous reports about investigations of susptected EVD cases in several countries indicate that surveillance systems are working. To date, no cases have been found to be positive in West Africa outside Guinea, Liberia, Nigeria or Sierra Leone, except for one case in Senegal (Guinean citizen returning from Guinea).

On 8 August 2014, the World Health Organization declared the outbreak of Ebola in West Africa a Public Health Emergency of International Concern.

 

 

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