A cluster of nosocomial Lassa fever cases in a tertiary health facility in Nigeria: description and lessons learned, 2018

Abstract Background Lassa feveris an acute viral haemorrhagic disease endemic in Nigeria. The 2018 Lassa feveroutbreak in Nigeria was unprecedented, with 8% of all cases occurring among healthcare workers (HCWs). A disproportionately high number of these infections occurred in HCWs working in a tertiary health facilityin Nigeria. This paper describes the cluster of Lassa feverinfections among HCWs in a treatment centre and the lessons learnt. Methods We analysed clinical, epidemiological and laboratory data from surveillance and laboratory records kept during the 2018 outbreak. Interviews were conducted with surviving HCWs using a questionnaire developed specifically for the investigation of Lassa feverinfections in HCWs. Descriptive analysis of the data was performed in Microsoft excel. Results The index casewas a 15-year-old male who presented at the health facilitywith fever and uncontrolled nasopharyngeal bleeding, following a recent uvulectomy by a traditional healer. Overall, 16 HCWs were affected (15 confirmed and 1 probable) with five deaths (CFR-31.6%). Of the 15 confirmed cases, five (33.3%) were asymptomatic. Nine HCWs were direct contacts of the index case; the remaining six HCWs had no direct contact with the index case. HCW interviews identified a low index of suspicion for Lassa feverleading to inadequate infection prevention and control (IPC) practices as possible contributing factors to nosocomial transmission. Conclusion Maintaining a high index of suspicion for Lassa feverin all patients especially in endemic areas, is essential in maintaining adequate IPC practices in health facilitiesin order to prevent nosocomial transmission of Lassa feveramong HCWs. There is need to continually trainand sensitise HCWs on strict adherence to IPC measures while providing care, irrespective of a patient’s provisional diagnosis.