Lassa Fever Outbreak Toolbox

Lassa Fever Outbreak Toolbox

Updated | October 2024

WHO/Hotowossi Komi Vewonyi
© Credits

Welcome to the Lassa Fever Outbreak Toolbox

Key reference documents

Case definitions

WHO suggested outbreak case definition

Suspected case: 

  • Any person with gradual onset of one or more of the following: malaise, fever, headache, sore throat, cough, nausea, vomiting, diarrhoea, myalgia (muscle pain), central chest pain or retrosternal pain, or hearing loss and:

    a. History of contact with excreta or urine of rodents; OR

    b. History of contact with a probable or confirmed Lassa fever case within a period of 21 days of onset of symptoms OR

    c. Inexplicable bleeding/haemorrhaging

Any suspected case who died without collection of specimens for laboratory testing.

Confirmed case: 

Any suspected case with laboratory confirmation (positive IgM antibody, PCR or virus isolation).

Discarded case: 

Any suspected or probable case with a negative laboratory result (showing no specific antibodies, RNA or specific detectable antigens).

 

 

Data collection tools

  • Case investigation forms: PDF | Word
  • Line list: Not available. 
  • Electronic tools: Not available

Response tools and resources

Training

Other resources