Human-to-human transmission directly linked to the 2014 Ebola virus disease (EVD) outbreak in West Africa was declared to have ended in Sierra Leone on 7 November 2015. The country then entered a 90-day period of enhanced surveillance to ensure the rapid detection of any further cases that might arise as a result of a missed transmission chain, reintroduction from an animal reservoir, or re-emergence of virus that had persisted in a survivor. On 14 January, 68 days into the 90-day surveillance period, a new confirmed case of EVD was reported after a post-mortem swab collected from a deceased 22-year-old woman tested positive for Ebola virus. On 20 January, the aunt of the index case developed symptoms and tested positive for Ebola virus. No further cases were reported, and the aunt was discharged from treatment on 4 February after providing a second consecutive negative blood sample (RT-PCR) and was discharged. All contacts linked to the two cases had completed follow-up by 11 February 2016. If no further cases are detected, transmission linked to this cluster of cases will be declared to have ended on 17 March.
Human-to-human transmission linked to the most recent cluster of cases in Liberia was declared to have ended on 14 January 2016. Guinea was declared free of Ebola transmission on 29 December 2015, and is approximately halfway through a 90-day period of enhanced surveillance that is due to end on 27 March 2016.
With guidance from WHO and other partners, ministries of health in Guinea, Liberia, and Sierra Leone have plans to deliver a package of essential services to safeguard the health of the estimated more than 10 000 survivors of EVD, and enable those individuals to take any necessary precautions to prevent infection of their close contacts. Over 300 male survivors in Liberia have accessed semen screening and counselling services. In addition, over 2600 survivors in Sierra Leone have accessed a general health assessment and eye exam.
To achieve the second key phase 3 response framework objective of managing residual Ebola risks, WHO has supported the implementation of enhanced surveillance systems in Guinea, Liberia, and Sierra Leone to enable health workers and members of the public to report any case of febrile illness or death that they suspect may be related to EVD. In the week to 28 February, 1474 alerts were reported in Guinea from all of the country’s 34 prefectures. The vast majority of alerts (1467) were reports of community deaths. Over the same period, 9 operational laboratories in Guinea tested a total of 392 new and repeat samples (14 samples from live patients and 378 from community deaths) from 20 of the country’s 34 prefectures. In Liberia, 1062 alerts were reported from all of the country’s 15 counties, most of which (925) were related to live patients. The country’s 5 operational laboratories tested 815 new and repeat samples (657 from live patients and 158 from community deaths) for Ebola virus over the same period. In Sierra Leone 1865 alerts were reported from the country’s 14 districts. The majority of alerts (1479) were for community deaths. 1114 new and repeat samples (34 from live patients and 1080 from community deaths) were tested for Ebola virus by the country’s 7 operational laboratories over the same period. The overall trend in 2016 is one of an increase in the number of alerts reported, suggesting a continuing improvement in disease surveillance capacity throughout the three countries. The number of new samples tested has remained stable week on week, but with an average of 330 samples tested per week Guinea tests around one-third the volume of samples as do Liberia and Sierra Leone. However, the geographical distribution of sampling is improving, with an increased number of prefectures submitting samples for testing.