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. 2022 Apr:117:295-301.
doi: 10.1016/j.ijid.2022.02.020. Epub 2022 Feb 12.

A challenging response to a Lassa fever outbreak in a non endemic area of Sierra Leone in 2019 with export of cases to The Netherlands

Charles Njuguna  1 , Mohamed Vandi  2 , Evans Liyosi  3 , Jane Githuku  3 , Alie Wurie  2 , Ian Njeru  3 , Philomena Raftery  3 , Claudette Amuzu  3 , Anna Maruta  3 , Robert Musoke  3 , Mukeh Fahnbulleh  2 , Joseph Bunting  2 , Simeon Gbandeh  2 , Ambrose Talisuna  4 , Zabulon Yoti  4
Affiliations

A challenging response to a Lassa fever outbreak in a non endemic area of Sierra Leone in 2019 with export of cases to The Netherlands

Charles Njuguna et al. Int J Infect Dis. 2022 Apr.

Abstract

Introduction: On November 20, 2019, the Sierra Leone International Health Regulations (IHR) National Focal Point was notified of an exported case of Lassa fever in The Netherlands, by a Dutch doctor who previously practiced in a rural hospital in Sierra Leone. This report describes the extent of the outbreak, possible sources of infection, and the outbreak response measures taken.

Methods: Response measures implemented to control the outbreak included coordination across multiple countries and cities, outbreak investigation, active case finding, contact tracing and monitoring, laboratory investigation, and isolation and treatment of cases.

Results: We report a hospital-associated outbreak that resulted in 3 confirmed cases (health workers) and 2 probable cases (patients). The case fatality rate was 60%, whereas the secondary attack rate was 14%. Two cases involved exportations to The Netherlands. Failure to detect the index case and poor adherence to infection prevention and control (IPC) protocols contributed to disease spread. Pregnancy status and nonspecific signs and symptoms of the index case contributed to failure in early case detection.

Conclusions: Rapid activation of national and subnational incident management systems resulted in rapid outbreak control. We recommend regular training for clinicians on surveillance and IPC protocols and strengthening in-country Lassa virus diagnostic capacity.

Keywords: Hospital-Associated Infection; Lassa Fever; Outbreak; Sierra Leone.

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Conflict of interest statement

Declaration of Competing Interest The authors declare that they have no conflict of interest.

Figures

Figure 1
Figure 1
Chronology of Events, Lassa Fever Outbreak, Tonkolili District, Sierra Leone, Nov-Dec 2019. IHR NFP: International Health Regulations National Focal Point; RRT: Rapid Response Team; WHO: World Health Organization.
Figure 2
Figure 2
Map of Sierra Leone showing 16 districts and the location of Lassa fever cases in Tonkolili District from 2016–2019. For 2019, only the 3 laboratory-confirmed cases have been included (probable cases have been excluded).
See this image and copyright information in PMC

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