Combination of line immunoassays Mikrogen recomLine CMV IgG and recomLine CMV IgG Avidity helps to date the onset of CMV primary infection.

CMV IgG avidity assays are widely used and can be helpful in pregnant women to date the onset of CMV primary infection; however, these tests are not standardized and sometimes give inconclusive results. We evaluated the performances of Mikrogen recomLine CMV IgG and IgG Avidity compared to the VIDAS CMV IgG Avidity. On a first sample set of 89 sequential sera collected from 40 women with precisely determined onset of CMV primary infection, the combination of Mikrogen recomLine CMV IgG and IgG Avidity showed an accurate interpretation in 83.1% (74/89), an incorrect result in 4.5% (4/89), and an inconclusive result in 12.4% (11/89) and showed a better sensitivity to diagnose infections <14 weeks compared to VIDAS (85.9% vs. 76.9%). On a second sample set of 89 sera with an intermediate VIDAS CMV IgG Avidity, the combination of line immunoassays provided additional information on the time of infection in 79% (70/89) of the samples. This combination of line assays is useful as additional confirmatory testing and can help to date more precisely the onset of CMV primary infection.

Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay.

OBJECTIVES: We have evaluated the recently Conformité Européenne (CE)-marked Bio-Rad Geenius human immunodeficiency virus (HIV)1/2 as a rapid and simple alternative to western blot for confirmation of HIV screening results. METHODS: A total of 160 serum samples were tested: 44 HIV-1 reactive samples by a fourth-generation Murex HIV Ag/Ab and/or Vidas HIV Duo Ultra, five HIV-2 reactive samples, 15 HIV-1 non-B subtype samples and 11 confirmed HIV-1 early seroconversion samples, 72 nonreactive samples, eight indeterminate samples by MP HIV BLOT 2.2 confirmed negative after follow-up and five low-reactive samples by enzyme immunoassay (EIA) negative by MP HIV BLOT 2.2. The samples were tested according to the manufacturer's guidelines. RESULTS: The overall sensitivity for Bio-Rad Geenius HIV1/2 assay was 92%. Five out of 11 early seroconversion samples were tested positive, four negative and two indeterminate. All HIV-1 non-B subtype samples were tested positive. Two out of the five HIV-2 reactive samples were tested positive HIV-2, two positive HIV-2 with HIV-1 cross-reaction and one HIV positive untypable. After excluding early seroconversion samples, the sensitivity of Bio-Rad Geenius HIV1/2 assay reached 100%. Overall specificity was 96%. All HIV negative serums by fourth-generation EIA were tested negative. All five low-reactive samples by EIA, negative by HIV BLOT 2.2 were tested negative by Bio-Rad Geenius HIV1/2. Two out of the eight indeterminate samples by MP HIV BLOT 2.2 that were confirmed negative after follow-up were tested indeterminate and one invalid, the other five were negative. After excluding these last 13 samples, the specificity of Bio-Rad Geenius HIV1/2 assay reached 100%. In comparison with MP HIV BLOT 2.2, the Bio-Rad Geenius HIV1/2 assay was markedly time saving, allowed full traceability, automatic reading and interpretation. CONCLUSIONS: The Bio-Rad Geenius HIV1/2 confirmatory system represents a reliable alternative to other confirmatory assays in HIV testing algorithms and provides clear improvement in quality management.