The 2013-2016 West African Ebola Epidemic- An overview of central aspects

Abstract

Abstract

Background Ebola is a filovirus and one of the most virulent organisms identified. It’s a zoonosis with fruit bats as the likeliest reservoir. Pathogen spill-over from infected animals causes human outbreaks with subsequent human-human transmission. The purpose of this thesis is to provide an overview of central aspects of the 2013-2016 West African Ebola Epidemic.

Methods This thesis is based on references retrieved through the search engine PubMed, online WHO and CDC documents and on personal communication. References were sorted according to inclusion and exclusion criteria: language, abstract and full-text availability. Search results were scanned and screened by title and further assessed for relevancy by reading the abstract. External references were included after screening reference lists of included articles.

Results Ebola was in 2013 a novel agent in West Africa. It took 3 months before its probability was identified. The rural epicentre with 80% forest loss is in proximity to borders of Liberia and Sierra Leone. Case amplification occurred through burial ceremonies and health facilities. The populations are highly mobile and convenient access across borders and to cities existed. A total of 815 probable and confirmed cases of health worker infections were identified from 01.01.14-31.03.15. CFR was 2/3. Most health worker infections occurred outside Ebola Treatment Units (ETUs). Several risk factors in the work setting were identified and opportunities for community-acquired infections also existed. The keys to stop transmission include rapid detection of cases, construction of ETUs, contact tracing, safe burials and strict adherence to established protocols. The rVSV-ZEBOV vaccine show promising results.

Conclusion West Africa’s lack of experience with Ebola, delayed identification, geographical and demographic characteristics contributed to the scale of The Epidemic. A high number of infected health workers were observed with many potential risk factors, both in and outside work settings. This undermined the overall response to The Epidemic. Preventative measures aim to break subsequent chains of transmission. These were challenging during The Epidemic, contributing to the scale.