title: Human herpesvirus 8 seroconversion in Kenyan women by enzyme-linked immunosorbent assay and immunofluorescence assay.
abstract: BACKGROUND
  Human herpesvirus 8 (HHV-8) antibody tests vary in reported sensitivity and specificity, depending on the population tested and the assay.
  
  
  OBJECTIVE
  The purpose of this study was to compare the ability to detect seroconversion to HHV-8 in a cohort of HHV-8 seronegative female commercial sex workers in Kenya using three tests: HHV-8 viral lysate-based enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay for HHV-8 lytic antigens (IFA-lytic) and IFA for latent nuclear antigens (IFA-LANA).
  
  
  METHODS
  By ELISA, 16 women from a prospective cohort of commercial sex workers were identified as seroconverting to HHV-8. A total of 124 post-enrollment samples from these 16 women as well as the enrollment samples were tested for HHV-8 antibodies by all three assays to monitor seroconversion.
  
  
  RESULTS
  Of 16 women with apparent seroconversion by ELISA, 8 had a rise in IFA-lytic titers either concomitant with or prior to the first positive ELISA sample and no initial LANA by IFA. Five of the 16 women were IFA-LANA positive at entry, indicating prior infection with HHV-8. Three women had no evidence of seroconversion by either IFA-lytic or IFA-LANA and two of these three had increased ELISA reactivity concomitant with HIV-1 infection.
  
  
  CONCLUSIONS
  Conversion from a negative to a positive ELISA result for HHV-8 antibody indicated seroconversion in only half of the study cohort of 16 women when IFA-lytic and IFA-LANA results were considered. The IFA-lytic assay was more sensitive than ELISA for early antibody responses. The IFA-LANA was positive in some women who had neither IFA-lytic nor ELISA antibodies suggesting it may be a marker for latent infections. Presumptive identification of incident HHV-8 infection by ELISA screening followed by IFA-lytic testing to confirm the positive test and IFA-LANA to rule out prior infection provides the most accurate documentation of HHV-8 seroconversion.
authors.affiliation: Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya.
authors.forename: Bhavna H
authors.initials: BH
authors.lastname: Chohan
authors.forename: Heather
authors.initials: H
authors.lastname: Taylor
authors.forename: Rosemary
authors.initials: R
authors.lastname: Obrigewitch
authors.forename: Ludo
authors.initials: L
authors.lastname: Lavreys
authors.forename: Barbra A
authors.initials: BA
authors.lastname: Richardson
authors.forename: Kishorchandra N
authors.initials: KN
authors.lastname: Mandaliya
authors.forename: Job J
authors.initials: JJ
authors.lastname: Bwayo
authors.forename: Joan K
authors.initials: JK
authors.lastname: Kreiss
authors.forename: Rhoda Ashley
authors.initials: RA
authors.lastname: Morrow
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000032:analysis; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005455:Fluorescent Antibody Technique / Q000379:methods; D006679:HIV Seropositivity / Q000276:immunology / Q000821:virology; D019288:Herpesvirus 8, Human / Q000302:isolation & purification*; D006801:Humans; D007630:Kenya; D015203:Reproducibility of Results; D012514:Sarcoma, Kaposi / Q000097:blood / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral