Data for epidemiological week 41 are incomplete, with missing data for 12 October from Liberia. This reflects the challenging nature of data gathering in countries with widespread and intense EVD transmission. These challenges remain particularly acute in Liberia, where there continues to be a mismatch between the relatively low numbers of new cases reported through official clinical surveillance systems on one hand, and reports from laboratory staff and first responders of large numbers of new cases on the other. Efforts are ongoing to reconcile different sources of data, and to rapidly scale-up capacity for epidemiological data gathering throughout each country with widespread and intense transmission.
It is clear, however, that the situation in Guinea, Liberia, and Sierra Leone is deteriorating, with widespread and persistent transmission of EVD. An increase in new cases in Guinea is being driven by a spike in confirmed and suspected cases in the capital, Conakry, and the nearby district of Coyah. In Liberia, problems with data gathering make it hard to draw any firm conclusions from recent data.
There is almost certainly significant under-reporting of cases from the capital Monrovia. There does appear to have been a genuine fall in the number of cases in Lofa district, but a concerted effort will be required to sustain that drop in cases and translate it into an elimination of EVD in that area. In Sierra Leone, intense transmission is still occurring in the capital Freetown and the surrounding districts.
Of the countries with localized transmission, Nigeria and Senegal are now approaching 42 days since the date of last potential contact with a probable or confirmed case. Both Spain and the United States continue to monitor potential contacts.