Validation study of a conventional enzyme immunoassay to detect HIV antibodies in oral fluid

OBJECTIVES

The aim of our study was to validate the Genscreen HIV ½ version 2 (BIO-RAD) for detecting HIV antibodies in oral fluid specimens (OF).

BACKGROUND

The advantage of assays to detect HIV infection in OF lies in the on-site easy access and noninvasive sample collection.

METHODS

Paired serum and OF were collected from 496 subjects (263 HIV-positive and 233 HIV-negative) using the Oracol test kit (Oracle Diagnostics, Inc). The quality of OF was verified by measuring total IgGs using the Human IgG ELISA Quantitation Kit (Bethyl Lab.inc). All reactive OF samples were retested by Western blot HIV1/2 BLOT 2.2 (MP Biomedical, Singapore, China).

RESULTS

Of 263 OF samples from participants with blood-based HIV-positive results, 259 were positive by Genscreen HIV ½ version 2 (98.48% sensitivity, 95% CI; 96.2-99.6). The 233 individuals who had a non-reactive HIV blood test were found negative on testing their OF by Genscreen HIV ½ version 2 (100% specificity, 95% CI; 98.4-100). NPV and PPV of the assay were 98.31% (95% CI; 95.74-99.34) and 100%, (95% CI; 98.53-100.00), respectively.

CONCLUSION

Genscreen HIV ½ version 2 (Bio-Rad) is a prospective method for HIV surveillance studies in hard-to-reach populations with high risk behavior using non-invasive OF collection (Tab. 1, Fig. 1, Ref. 16).

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Genetic subtypes of HIV type 1 circulating in Slovakia

Slovakia belongs to the group of European countries with a low prevalence of HIV infection. The major proportion of HIV-positive cases in Slovakia is still represented by MSM, followed by heterosexuals infected through unprotected sexual intercourse. This study was conducted to update the description of HIV subtypes circulating in Slovakia. HIV-1 partial pol gene sequences from 143 individuals were prospectively collected from 2004 to 2008 and analyzed. Phylogenetic analysis based on HIV-1 partial pol gene sequences revealed the highest prevalence of HIV-1 B subtype (93.0 %), predominantly associated with the MSM group. Ten (7.0%) individuals were infected with HIV-1 non-B subtypes. The pure subtypes were more frequent (7; 4.9%) than CRFs (3; 2.1%) and their occurrence was as follows: subtype C (3; 2, 1%), subtype A (2; 1.4%), subtype F (2; 1.4%), CRF_01AE (1; 0.7%), CRF_02AG (1; 0.7%), and CRF08_BC (1; 0.7%). Data show slightly increasing HIV-1 subtype diversity, with HIV-1 subtype B still having the highest prevalence in the Slovak-infected population.