title: Development and validation of serological assays for viral hemorrhagic fevers and determination of the prevalence of Rift Valley fever in Borno State, Nigeria.
abstract: BACKGROUND
  Rift Valley fever (RVF) is endemic to the tropical regions of eastern and southern Africa. The seroprevalence of RVF was investigated among the human population in Borno State, Nigeria to determine the occurrence of the disease in the study area in comparison with that of Lassa fever and Crimean-Congo Hemorrhagic fever.
  
  
  METHODS
  Recombinant nucleoprotein (rNP)-based IgG-ELISAs for the detection of serum antibodies against RVF virus (RVFV), Lassa fever virus (LASV), and Crimean-Congo hemorrhagic fever virus (CCHFV) were used to test human sera in Borno State, Nigeria. The presence of neutralizing antibody against the RVFV-glycoprotein-bearing vesicular stomatitis virus pseudotype (RVFVpv) was also determined in the human sera.
  
  
  RESULTS
  Of the 297 serum samples tested, 42 (14.1%) were positive for the presence of RVFV-IgG and 22 (7.4%) and 7 (2.4%) of the serum samples were positive for antibodies against LASV and CCHFV, respectively. There was a positive correlation between the titers of neutralizing antibodies obtained using RVFVpv and those obtained using the conventional neutralization assay with the attenuated RVFV-MP12 strain.
  
  
  CONCLUSIONS
  The seroprevalence of RVF was significantly higher than that of LASV and CCHF in Borno State, Nigeria. The RVFVpv-based neutralization assay developed in this study has the potential to replace the traditional assays based on live viruses for the diagnosis and seroepidemiological studies of RVF.
authors.affiliation: Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Maiduguri, Maiduguri, Nigeria.
authors.forename: David Nadeba
authors.initials: DN
authors.lastname: Bukbuk
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan fukushi@nih.go.jp.
authors.forename: Shuetsu
authors.initials: S
authors.lastname: Fukushi
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Tani
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Yoshikawa
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Taniguchi
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Iha
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Fukuma
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shimojima
authors.affiliation: Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Morikawa
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Saijo
authors.affiliation: Disease Prevention and Control Cluster at the WHO Regional Office for Africa, Congo-Brazzaville.
authors.forename: Francis
authors.initials: F
authors.lastname: Kasolo
authors.affiliation: Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, University of Maiduguri, Maiduguri, Nigeria.
authors.forename: Saka Saheed
authors.initials: SS
authors.lastname: Baba
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D062665:Epidemiological Monitoring; D003225:Hemorrhagic Fever Virus, Crimean-Congo / Q000276:immunology / Q000302:isolation & purification; D006482:Hemorrhagic Fevers, Viral / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D007835:Lassa Fever / Q000097:blood / Q000453:epidemiology / Q000276:immunology; D009549:Nigeria / Q000453:epidemiology; D012295:Rift Valley Fever / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D012296:Rift Valley fever virus / Q000276:immunology / Q000302:isolation & purification; D016036:Seroepidemiologic Studies; D012698:Serologic Tests / Q000379:methods
chemical_list: D000914:Antibodies, Viral
keywords: Nigeria; Rift Valley fever; Seroprevalence