title: Evaluation of a newly developed lateral flow immunoassay for the diagnosis of cryptococcosis.
abstract: BACKGROUND
  Cryptococcosis is a common opportunistic infection of human immunodeficiency virus (HIV)-infected individuals mostly occurring in resource-limited countries. This study compares the performance of a recently developed lateral flow immunoassay (LFA) to blood culture and enzyme immunoassay (EIA) for the diagnosis of cryptococcosis.
  
  
  METHODS
  Archived sera from 704 HIV-infected patients hospitalized for acute respiratory illness in Thailand were tested for cryptococcal antigenemia using EIA. All EIA-positive and a subset of EIA-negative sera were tested by LFA, with results recorded after 5 and 15 minutes incubation. Urine from patients with LFA- and EIA-positive sera was tested by LFA. Antigen results from patients with positive cryptococcal blood cultures were compared.
  
  
  RESULTS
  Of 704 sera, 92 (13%) were positive by EIA; among the 91 EIA-positive sera tested by LFA, 82 (90%) and 87 (96%) were LFA positive when read after 5 and 15 minutes, respectively. Kappa agreement of EIA and LFA for sera was 0.923 after 5 minutes and 0.959 after 15 minutes, respectively. Two of 373 EIA-negative sera were LFA positive at both time points. Of 74 urine specimens from EIA-positive patients, 52 (70.3%) were LFA positive. EIA was positive in 16 of 17 sera from blood culture-positive patients (94% sensitivity), and all sera were positive by LFA (100% sensitivity).
  
  
  CONCLUSIONS
  A high level of agreement was shown between LFA and EIA testing of serum. The LFA is a rapid, easy-to-perform assay that does not require refrigeration, demonstrating its potential usefulness as a point-of-care assay for diagnosis of cryptococcosis in resource-limited countries.
authors.affiliation: Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Lindsley
authors.forename: Nanthawan
authors.initials: N
authors.lastname: Mekha
authors.forename: Henry C
authors.initials: HC
authors.lastname: Baggett
authors.forename: Yupha
authors.initials: Y
authors.lastname: Surinthong
authors.forename: Rinrapas
authors.initials: R
authors.lastname: Autthateinchai
authors.forename: Pongpun
authors.initials: P
authors.lastname: Sawatwong
authors.forename: Julie R
authors.initials: JR
authors.lastname: Harris
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Park
authors.forename: Tom
authors.initials: T
authors.lastname: Chiller
authors.forename: S Arunmozhi
authors.initials: SA
authors.lastname: Balajee
authors.forename: Natteewan
authors.initials: N
authors.lastname: Poonwan
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D000946:Antigens, Fungal / Q000032:analysis* / Q000097:blood / Q000652:urine; D003453:Cryptococcosis / Q000097:blood / Q000175:diagnosis* / Q000652:urine / Q000821:virology*; D015658:HIV Infections / Q000097:blood / Q000382:microbiology* / Q000652:urine; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D000946:Antigens, Fungal