Comparison among the BED capture enzyme immunoassay test and AxSYM avidity index assay for determining recent HIV infection and incidence in two Voluntary Counselling and Testing Centres in Northeast Brazil.
The aims of this study were to compare the automated AxSYM avidity assay index with the BED capture enzyme immunoassay test and to calculate the HIV-1 incidence using the BED capture enzyme immunoassay and AxSYM avidity assay index algorithms within a population seeking the Voluntary Counselling and Testing Centres in two municipalities in the Metropolitan Region of Recife, Northeast of Brazil. An analysis was conducted in 365 samples that tested positive for HIV infection from frozen serum collected during the period 2006-2009. There was a similar proportion of males and females; most patients were heterosexual (86%) with a median age of 29 years. Of the 365 samples, 102 (28%) and 66 (18.1%) were identified as recent infections by BED capture enzyme immunoassay and AxSYM avidity assay index, respectively. The HIV-1 total incidence in the BED capture enzyme immunoassay and AxSYM avidity assay index algorithms were: 0.79 (95% CI: 0.60-0.98) and 0.34 (95% CI: -0.04 to 0.72), respectively. Incidence was higher among men. There was good agreement between the tests, with a kappa of 0.654 and a specificity of 95.8%. AxSYM avidity assay index may be helpful in improving the quality of the estimates of recent HIV infection and incidence, particularly when used in a combined algorithm with BED capture enzyme immunoassay.
The Herbert de Souza Counselling and Testing Centre, Cabo de Santo Agostinho, PE, Brazil; Post-graduation in Tropical Medicine, Universidade Federal de Pernambuco, PE, Brazil. Electronic address: danisalustiano@yahoo.com.br.
Daniela Medeiros
DM
Salustiano
Post-graduation in Tropical Medicine, Universidade Federal de Pernambuco, PE, Brazil; The Paulista Counselling and Testing Centre, Paulista, PE, Brazil.
Kledoaldo Oliveira de
KO
Lima
Department of Virology, Laboratório Central de Pernambuco (LACEN-PE), Recife, PE, Brazil.
Ana Maria Salustiano
AM
Cavalcanti
Retrovirology Laboratory, Universidade Federal de São Paulo, SP, Brazil.
Ricardo Sobhie
RS
Diaz
Post-graduation in Tropical Medicine, Universidade Federal de Pernambuco, PE, Brazil.
Heloisa Ramos
HR
Lacerda
D000328:Adult; D000915:Antibody Affinity; D001938:Brazil / Q000453:epidemiology; D003376:Counseling; D005260:Female; D015483:HIV Antibodies / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
D015483:HIV Antibodies
Avidity index assay; BED-CEIA; HIV; Recent infection