10.1007/s10096-012-1760-1. history included treated syphilis 2 years earlier, treated infection, treated infection, and recurrent anal infection with herpes PF-915275 simplex virus (type unknown, with no recent symptoms). Previous regular screening for HIV infection was negative, most recently 3 months earlier. The screening was performed at South Eastern Area Laboratory Services (SEALS), where a fourth-generation screening immunoassay (Abbott Architect HIV Ag/Ab Combo [Abbott Laboratories, Abbott Park, IL, USA]) was incorporated into the routine diagnostic algorithm (Fig. 1), consistent with national and international standards of testing. The patient denied use of intravenous drugs or prophylactic antiretrovirals, although confirmatory testing of blood for antiretroviral use was not performed. Open in a separate window FIG 1 SEALS HIV diagnostic algorithm. ?, nonreactive result; +, reactive result; ?, equivocal result. Architect, Abbott Architect Ag/Ab Combo; Genscreen Ag, Bio-Rad Genscreen HIV-1 Ag; Serodia, Serodia HIV-1 Ab assay; Western blot, MP Biomedicals Western blot. Screening for HIV-1 and HIV-2 was performed using the routine testing algorithm. Initial screening (day 0 of testing, following recent high-risk activities) was consistent with HIV viremia without seroconversion (Table 1). Specifically, the Abbott Architect HIV Ag/Ab Combo assay and Genscreen HIV p24 Ag assay (Bio-Rad, Marnes-la-Coquette, France) were reactive, with the latter result confirmed by neutralization. However, the Serodia HIV-1 Ab assay (Fujirebio, Tokyo, Japan) was nonreactive, and no bands were present on Western blots (MP Biomedicals, Illkirch, France). HIV Western blots were interpreted using accepted criteria for diagnosis in Australia, which differ from criteria proposed by the Centers for Disease Control and Prevention in the United States (1, 2). On day 7, the Abbott Architect HIV Ag/Ab Combo assay, Bio-Rad Genscreen HIV p24 antigen assay, and Serodia HIV-1 antibody assay showed no reaction, and no bands were Rabbit Polyclonal to CADM2 present on the Western blot. Given the day 0 result, an HIV viral load test (COBAS AmpliPrep/COBAS TaqMan HIV-1 test, v2.0 [Roche Molecular Systems, Inc., Branchburg, NJ, USA]) was performed on plasma, revealing 11,352 copies/ml. The patient’s serum transaminases were mildly elevated (AST 61 [upper limit of normal, 45 IU/liter] and ALT 97 [upper limit of normal, 45 IU/liter]), with later testing showing variable results. The viral load was initially very high and then progressively fell to PF-915275 175 copies/ml by day 35 (Table 1). The Serodia HIV-1 antibody assay became positive on day 10. The Western blot was indeterminate on day 10, with only p24 antibody detected, followed by the gp160 band (day 21), p18 band (day 49), p65 and p51 bands (day 62), and gp41 to gp43, gp120, and p55 bands (day 175). The Abbott Architect HIV Ag/Ab Combo assay (tested using two different i2000SR machines) became reactive on day 35. Throughout the testing period of 175 days, the Oraquick HIV-1/2 Ab (OraSure Technologies, Bethlehem, PA, USA) point-of-care test (POCT) remained unreactive when oral fluid was used (blood-derived specimens were not tested). TABLE 1 Comparative performance of assays em a /em thead th rowspan=”2″ align=”left” colspan=”1″ Day /th th colspan=”9″ align=”left” rowspan=”1″ Result of: hr / /th th align=”left” rowspan=”1″ colspan=”1″ Roche COBAS AmpliPrep/TaqMan HIV-1 (copies/ml) /th th align=”left” rowspan=”1″ colspan=”1″ Bio-Rad Genscreen p24 Ag (pg/ml) /th th align=”left” rowspan=”1″ colspan=”1″ Abbott Architect HIV Ag/Ab Combo (s/co) /th th align=”left” rowspan=”1″ colspan=”1″ Roche Elecsys HIV Combi PT (s/co) /th th align=”left” rowspan=”1″ colspan=”1″ Bio-Rad Genscreen Ultra HIV Ag-Ab (s/co) /th th align=”left” rowspan=”1″ colspan=”1″ Determine HIV 1/2 Ag/Ab Combo /th th align=”left” rowspan=”1″ colspan=”1″ Orasure Oraquick HIV-1/2 Ab /th th align=”left” rowspan=”1″ colspan=”1″ Fujirebio Serodia HIV-1 Ab (titer) /th th align=”left” rowspan=”1″ colspan=”1″ MP Biomedicals Western blot (band[s] present) /th /thead ?980 em b /em NR (0.20)0288,8068 em c /em R (449)R (17.78)R (15.08)R (4.87)NRNRNB711,352NRNR (0.82)R (1.31)R (2.23)NRNRNB107,591NRNR (0.89)R (2.20)R (3.41)NRR (1:128)IND3 (p24)212,648NRNR (0.90)R (11.08)R (8.57)NRR (1:256)IND4 (p24, gp160)241,809NRNR (0.93)R (12.86)R (7.30)NRR (1:256)IND4 (p24, gp160)35175NRR (1.13)R (27.32)R (4.26)NRNRR (1:256)IND4 (p24, gp160)49254NRR (1.23)R (51.40)R (5.66)R (Ab only)NRR (1:256)IND4 (p18, p24, gp160)6299 em b /em NRR (2.04)R (117.30)R (9.10)R (Ab only)R (1:1,024)IND4 (p18, p24, p51, p65, gp160)98609NRR (3.01)R (130.15)R (10.27)R (Ab only)R (1:2,048)IND4 (p18, p24, p51, p65, gp160)175294NRR (6.81)R (272.7)R (6.94)R (Ab only)NRR (1:2,048)P (p18, p24, gp41C43, p51, p55, p65, gp120, gp160) Open in a separate window aThe Abbott Architect HIV Ab/Ag Combo remained nonreactive from day 7 through 24, becoming reactive at day 35. The Roche Elecsys HIV Combi PT and Bio-Rad Genscreen Ultra HIV Ag-Ab were reactive throughout the testing period. R, reactive; NR, PF-915275 nonreactive; NB, no bands; IND, indeterminate; P, positive; s/co, signal-to-cutoff.