Trend of Lassa fever cases and factors associated with mortality in Liberia, 2016 - 2021: a secondary data analysis.

Introduction: Lassa fever (LF) is endemic in Liberia and is immediately reportable. Suspected cases are confirmed at the National Public Health Reference Laboratory. However, there is limited information on the trend and factors associated with mortality. We described the epidemiological characteristics of LF cases and determined factors associated with mortality in Liberia from 2016 to 2021. Methods: we reviewed 867 case-based LF surveillance data from 2016 to 2021 obtained from the National Public Health Institute of Liberia (NPHIL). The cases that met the suspected LF case definition were tested with RT-PCR. Using Epi Info 7.2.5.0. We conducted univariate, bivariate, and multivariate and analysis. We calculated frequencies, proportions. Positivity rate, case fatality rate, and factors associated with LF mortality using chi-square statistics and logistics regression at 5% level of significance. Results: eighty-five percent (737/867) of the suspected cases were tested and 26.0% (192/737) were confirmed LF positive. The median age of confirmed LF cases was 21(IQR: 12-34) years. Age 10-19 years accounted for 24.5% (47/192) and females 54.2% (104/192). Bong 33.9% (65/192), Grand Bassa 31.8% (61/192), and Nimba counties, 21.9% (42/192) accounted for most of the cases. The median duration from symptom onset to hospital admission was 6 (IQR: 3-9) days. A majority, 66% (126/192) of the cases were reported during the dry season (October-March) and annual incidence was highest at 12 cases per 1,000,000 population in 2019 and 2020. The overall case fatality rate was 44.8%. Non-endemic counties, Margibi, 77.8% and Montserrado, 66.7% accounted for the highest case fatality rate (CFR), while 2018, 66.7% and 2021, 60.0% recorded the highest CFR during the period. Age ≥30 years (aOR=2.1,95% CI: 1.08-4.11, p=0.027) and residing in Grand Bassa County (aOR=0.3, 95% CI: 0.13-0.73, p=0.007) were associated with LF mortality. Conclusion: Lassa fever was endemic in three of the fifteen counties of Liberia, case fatality rate remained generally high and widely varied. The high fatality of LF has been reported to the NPHIL and is currently being further investigated. There is a need to continuously train healthcare workers, especially in non-endemic counties to improve the LF treatment outcome.

Detecting, reporting, and analysis of priority diseases for routine public health surveillance in Liberia.

An essential component of a public health surveillance system is its ability to detect priority diseases which fall within the mandate of public health officials at all levels. Early detection, reporting and response to public health events help to reduce the burden of mortality and morbidity on communities. Analysis of reliable surveillance data provides relevant information which can enable implementation of timely and appropriate public health interventions. To ensure that a resilient system is in place, the World Health Organization (WHO) has provided guidelines for detection, reporting and response to public health events in the Integrated Disease Surveillance and Response (IDSR) strategy. This case study provides training on detection, reporting and analysis of priority diseases for routine public health surveillance in Liberia and highlights potential errors and challenges which can hinder effective surveillance. Table-top exercises and group discussion lead participants through a simulated verification and analyses of summary case reports in the role of the District Surveillance Officer. This case study is intended for public health training in a classroom setting and can be accomplished within 2 hours 30 minutes. The target audience include residents in Frontline Epidemiology Training Programs (FETP-Frontline), Field Epidemiology and Laboratory Training Programs (FELTPs), and others who are interested in this topic.

Investigating an outbreak of measles in Margibi County, Liberia, October 2015.

The emergence and re-emergence of infectious diseases highlights the need to have well-trained field epidemiologists who will be at the forefront in the fight against these diseases, especially during an outbreak. Training for outbreak investigation is most effective when participants can develop their competencies in a practical exercise. To that end, this case study was based on a measles outbreak investigation conducted in Liberia during October 2015 by Liberia Frontline Field Epidemiology Training Program (FETP) residents, simulating steps to perform outbreak investigation in a real-life situation as a field epidemiologist. This case study is ideally suited to reinforce principles and skills already covered in a classroom lecture or in background reading by providing a practical training beyond the scope of theoretical learning. It is primarily intended for training novice public health practitioners who should be able to complete the exercises in approximately 3 hours.

Detecting, reporting, and analysis of priority diseases for routine public health surveillance in Liberia.

Public health officials depend on timely, complete, and accurate surveillance data for decision making. The quality of data generated from surveillance is highly dependent on external and internal factors which may either impede or enhance surveillance activities. One way of identifying challenges affecting the quality of data generated is to conduct a data quality audit. This case study, based on an audit conducted by residents of the Liberia Frontline Field Epidemiology Training Program, was designed to be a classroom simulation of a data quality audit in a health facility. It is suited to enforce theoretical lectures in surveillance data quality and auditing. The target group is public health trainees, who should be able to complete this exercise in approximately 2 hours and 30 minutes.

Conducting a surveillance problem analysis on poor feedback from Reference Laboratory, Liberia, February 2016.

The laboratory plays a major role in surveillance, including confirming the start and end of an outbreak. Knowing the causative agent for an outbreak informs the development of response strategies and management plans for a public health event. However, issues and challenges may arise that limit the effectiveness or efficiency of laboratories in surveillance. This case study applies a systematic approach to analyse gaps in laboratory surveillance, thereby improving the ability to mitigate these gaps. Although this case study concentrates on factors resulting in poor feedback from the laboratory, practise of this general approach to problem analysis will confer skills required in analysing most public health issues. This case study was developed based on a report submitted by the district surveillance officer in Grand Bassa County, Liberia, as a resident of the Liberian Frontline Field Epidemiology Training Program in 2016. This case study will serve as a training tool to reinforce lectures on surveillance problem analysis using the fishbone approach. It is designed for public health training in a classroom setting and can be completed within 2 hours 30 minutes.