Document Type: Original Article

Authors

1 World Health Organization, Benin City, Nigeria

2 Cedar Centre for Health and Development, Ekpoma, Nigeria

3 World Health Organization, Port Harcourt, Nigeria

4 nstitute of Lassa Fever Research and Control, ISTH, Irrua, Nigeria

5 Edo State Ministry of Health, Benin City, Nigeria

6 Nigeria Centre for Disease Control (NCDC) Surveillance Desk, ISTH, Irrua, Nigeria

Abstract

Background
Edo State has recorded recurrent Lassa fever (LF) outbreaks in the past and had the highest proportion of confirmed cases in Nigeria in 2018. The aim of this study was to profile Lassa fever contacts and demonstrate the implications of contact tracing in the control of the disease.
Methods
This is a cross-sectional study which was based on secondary analysis of information derived from Lassa fever contact tracing forms used during the response to the LF outbreak of 2018 in Edo State. Contact tracing and data management were part of WHO’s support to the State. Using SPSS, associations and other relationships between selected variables were tested. The significance level was set at p< 0.05.
Results
Total contacts followed up were 2527 during the period under consideration. Higher mean contacts per case (CPC) was significantly associated with contacts in Edo South, with contacts of cases that died and with cases with symptomatic contacts (F= 8.307, p<0.001; t= 14.995, p<0.001; t= 6.161, p= 0.014 respectively). Following the integration of contact tracing with awareness campaigns, the number of newly diagnosed cases per week dropped from over 30 in the 7th week to 2 in the 13th week (42 days or 2 incubation periods).
Conclusion
Effective contact tracing contributed significantly to the identification of symptomatic contacts and to rapid control of the 2018 Lassa fever outbreak in Edo State. We recommend the deployment of effective contact tracing in the control of outbreaks of viral haemorrhagic fevers especially Lassa fever.

Keywords

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