Undiagnosed acute viral febrile illnesses, Sierra Leone

Emerg Infect Dis. 2014 Jul;20(7):1176-82. doi: 10.3201/eid2007.131265.

Abstract

Sierra Leone in West Africa is in a Lassa fever-hyperendemic region that also includes Guinea and Liberia. Each year, suspected Lassa fever cases result in submission of ≈500-700 samples to the Kenema Government Hospital Lassa Diagnostic Laboratory in eastern Sierra Leone. Generally only 30%-40% of samples tested are positive for Lassa virus (LASV) antigen and/or LASV-specific IgM; thus, 60%-70% of these patients have acute diseases of unknown origin. To investigate what other arthropod-borne and hemorrhagic fever viral diseases might cause serious illness in this region and mimic Lassa fever, we tested patient serum samples that were negative for malaria parasites and LASV. Using IgM-capture ELISAs, we evaluated samples for antibodies to arthropod-borne and other hemorrhagic fever viruses. Approximately 25% of LASV-negative patients had IgM to dengue, West Nile, yellow fever, Rift Valley fever, chikungunya, Ebola, and Marburg viruses but not to Crimean-Congo hemorrhagic fever virus.

Keywords: ELISA; IgM; Lassa virus; Sierra Leone; West Africa; arthropod-borne; diagnostics; febrile; hemorrhagic fever; immunodiagnostics; serologic; undiagnosed; vector-borne infections; viruses.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antibodies, Viral / blood
  • Antibodies, Viral / immunology
  • Antigens, Viral / blood
  • Antigens, Viral / immunology
  • Arthropods / immunology
  • Hemorrhagic Fever Virus, Crimean-Congo / immunology
  • Hemorrhagic Fevers, Viral / blood
  • Hemorrhagic Fevers, Viral / diagnosis*
  • Hemorrhagic Fevers, Viral / immunology
  • Humans
  • Immunoglobulin M / blood
  • Immunoglobulin M / immunology
  • Lassa virus / immunology*
  • Sierra Leone
  • Virus Diseases / blood
  • Virus Diseases / diagnosis*
  • Virus Diseases / immunology
  • Virus Diseases / virology

Substances

  • Antibodies, Viral
  • Antigens, Viral
  • Immunoglobulin M