SUMMARY
No confirmed cases of Ebola virus disease (EVD) were reported in the week to 13 December. All contacts associated with the cluster of 3 confirmed cases of EVD reported from Liberia in the week to 22 November have now completed 21-day follow-up. The first-reported case in the cluster, a 15-year-old boy, died on 23 November. Two subsequent cases, the boy’s father and younger brother, tested negative twice for Ebola virus on 3 December and were discharged. As of 11 December, 210 eligible recipients associated with the cluster had received the rVSV-ZEBOV Ebola vaccine as part of the Partnership for Research on Ebola Vaccines in Liberia (PREVAIL study), which is administered by the Government of Liberia and the US National Institutes of Health.
Human-to-human transmission linked to the recent cluster of cases in Liberia will end on 14 January 2016, 42 days after the 2 most-recent cases received a second consecutive negative test for Ebola virus, if no further cases are reported. Human-to-human transmission linked to the primary outbreak in Guinea will end on 28 December 2015, 42 days after the country’s most recent case, reported on 29 October, received a second consecutive negative test for Ebola virus. In Sierra Leone, human-to-human transmission linked to the primary outbreak was declared to have ended on 7 November 2015. The country has now entered a 90-day period of enhanced surveillance scheduled to conclude on 5 February 2016.
The recent cluster of cases in Liberia is now understood to have been a result of the re-emergence of Ebola virus that had persisted in a previously infected individual. Although the probability of such re-emergence events is low, the risk of further transmission following a re-emergence underscores the importance of implementing a comprehensive package of services for survivors that includes the testing of appropriate bodily fluids for the presence of Ebola virus RNA. The governments of Liberia and Sierra Leone, with support from partners including WHO and US CDC, have implemented voluntary semen screening and counselling programmes for male survivors in order to help affected individuals understand their risk and take necessary precautions to protect close contacts. A network of clinical services for survivors is also being expanded in Liberia and Sierra Leone, with plans for comprehensive national policies for the care of EVD survivors due to be completed in January 2016.
In order to effectively manage and respond to the consequences of residual Ebola risks, Guinea, Liberia, and Sierra Leone have each put surveillance systems in place to enable health workers and members of the public to report any case of illness or death that they suspect may be related to EVD to the relevant authorities. In the week to 13 December, 1014 community deaths alerts were reported in Guinea from all of the country’s 34 prefectures. Over the same period 8 operational laboratories in Guinea tested a total of 593 new and repeat samples from 12 of the country’s 34 prefectures. In Liberia, 1027 alerts were received from all 15 of the country’s Counties. The country’s 5 operational laboratories tested 1277 samples for EVD over the same period. In Sierra Leone, 1446 alerts were reported from all of the country’s 14 districts in the week ending 29 November (the most recent week for which data are available). 1151 samples were tested for EVD by the country’s 8 operational laboratories in the week ending 13 December.
The deployment of rapid-response teams following the detection of a new confirmed case continues to be a cornerstone of the national response strategy in Guinea, Liberia, and Sierra Leone. Each country has at least 1 national rapid-response team, with strengthening of national and subnational rapid-response capacity and validation of incident-response plans continuing through December and January.