Lessons learned by surveillance during the tail-end of the Ebola outbreak in Guinea, June-October 2015: a case series

Abstract

Background: By the end of the 2013–2016 West African Ebola Virus Disease (EVD) outbreaks, a total of 3814 cases (probable and confirmed) and 2544 deaths were reported in Guinea. Clearly, surveillance activities aiming at stopping human-to-human transmission have been the breakthrough of EVD outbreak management, but their application has been at times easier said than done. This article presents five confirmed or probable EVD cases that arose in Conakry towards the end of the Guinea epidemic, which demonstrate flaws in surveillance and follow-up.

Case presentation: For case 1, safe burial requirements were not followed. For cases 1 and 2, negative Polymerase Chain Reaction (PCR) results were interpreted as no infection. For the first case, the sample may have not been taken properly while for the second the disease was possibly at its early stage. Case 3 was stopped at a border health checkpoint and despite her high temperature she was allowed to continue the bus journey. For case 4, an oral swab sample was supposedly taken after death but could not be found for retrospective testing. Despite characteristic symptomatology, case 5 was not identified as a suspect case for as long as 3 weeks.

Conclusion: In epidemic contexts, health systems must be able to track all samples of suspect cases and deaths, regardless of their laboratory results. Social mobilization in communities and training in health care facilities must be strengthened at the tail of an outbreak, to avoid the natural slackening of disease surveillance, in particular for long-lasting and deadly epidemics.

Keywords: Case series; Contact tracing; Ebola; Epidemic; Guinea; Outbreak; Surveillance; Transmission.

Fig. 1

Epidemiological curve of Ebola virus disease in Guinea, January, 2014 to October, 2015

Fig. 2

Chains of transmission of Ebola virus in Conakry, the capital of Guinea, and in a surrounding prefecture (Forécariah), from June to September 2015. a The chain of transmission initiated by Case 1 which lasted 3 months and resulted at least 30 confirmed and 2 probable cases, including 16 deaths. b A hidden chain discovered during the epidemiological investigation whose source remains unknown. This chain extended to the prefecture of Forécariah where it made 4 confirmed cases

Fig. 3

a) Timeline of events of cases 2 & 3 from 18th August to 15th September 2015. These two cases are confirmed. b) Timeline of events of cases 4 (probable) & 5(confirmed) from 13th August to 18th September 2015