Low-level HIV viraemia during antiretroviral therapy: Longitudinal patterns and predictors of viral suppression.

OBJECTIVES: Our objective was to characterize longitudinal patterns of viraemia and factors associated with viral suppression in people with HIV and low-level viraemia (LLV) during antiretroviral therapy (ART). METHODS: We included people with HIV in the EuResist Integrated Database with LLV following ART initiation after 2005. LLV was defined as two or more consecutive viral load (VL) measurements of 51-199 copies/mL 30-365 days apart after >12 months of ART. Viraemia patterns were analyzed over 24 months. Factors associated with viral suppression at 12 months after LLV episodes were identified using univariable and multivariable logistic regression. RESULTS: Of 25 113 people with HIV, 2474 (9.9%) had LLV. Among 1387 participants with 24 months of follow-up after LLV, 406 (29%) had persistent suppression, 669 (48%) had transient viraemic episodes, 29 (2%) had persistent LLV, and 283 (20%) had virological failure. Following LLV episodes, the proportion with detectable viraemia declined (p for trend <0.001 and 0.034, in the first and second year, respectively). At 12 months, 68% had undetectable VL, which was associated with suppression before LLV (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI] 1.2-2.4) and ART modification after LLV (aOR 1.6; 95% CI 1.0-2.4). The following factors were negatively associated with undetectable VL at 12 months: higher VL during LLV (aOR 0.57 per log10 copies/mL; 95% CI 0.37-0.89), injecting drug use (aOR 0.67; 95% CI 0.47-0.96), and regimens with protease inhibitors (aOR 0.65; 95% CI 0.49-0.87) or combined anchor drugs (aOR 0.52; 95% CI 0.32-0.85). CONCLUSION: Most people with LLV did not experience sustained viral suppression during 24-month follow-up, supporting the association between LLV and inferior treatment outcome.

Transmitted drug resistance to NRTIs and risk of virological failure in naïve patients treated with integrase inhibitors.

OBJECTIVES: Nucleoside reverse transcriptase inhibitor (NRTI) transmitted drug resistance mutations (TDRMs) could increase the risk of virological failure (VF) of first-line integrase strand transfer inhibitor (InSTI)-based regimens. METHODS: Patients starting two NRTIs (lamivudine/emtricitabine plus abacavir/tenofovir) plus raltegravir or dolutegravir were selected from the EuResist cohort. The role of NRTI genotypic susceptibility score and of specific TDRMs in VF (i.e. two consecutive viral loads > 50 HIV-1 RNA copies/mL or a single viral load ≥ 200 copies/mL after 3 months from antiretroviral therapy start) was evaluated in the overall population and according to the InSTI employed. RESULTS: From 2008 to 2017, 1095 patients were eligible for the analysis (55.5% men, median age 39 years). In all, 207 VFs occurred over 1023 patient-years of follow-up. The genotypic susceptibility score (GSS) had no effect on the risk of VF in the overall population. However, the presence of M184V/I independently predicted VF of raltegravir- but not dolutegravir-based therapy when compared with a fully-active backbone [adjusted hazard ratio (aHR) = 3.09, P = 0.035], particularly when associated with other non-thymidine analogue mutations (aHR = 27.62, P = 0.004). Higher-zenith HIV-RNA and lower nadir CD4 counts independently predicted VF. CONCLUSIONS: NRTI backbone TDRMs increased the risk of VF with raltegravir-based but not dolutegravir-based regimens.

Microfluidic centrifugation assisted precipitation based DNA quantification.

Nucleic acid amplification methods are increasingly being used to detect trace quantities of DNA in samples for various diagnostic applications. However, quantifying the amount of DNA from such methods often requires time consuming purification, washing or labeling steps. Here, we report a novel microfluidic centrifugation assisted precipitation (µCAP) method for single-step DNA quantification. The method is based on formation of a visible precipitate, which can be quantified, when an intercalating dye (GelRed) is added to the DNA sample and centrifuged for a few seconds. We describe the mechanism leading to the precipitation phenomenon. We utilize centrifugal microfluidics to precisely control the formation of the visible and quantifiable mass. Using a standard CMOS sensor for imaging, we report a detection limit of 45 ng µl-1. Furthermore, using an integrated lab-on-DVD platform we recently developed, the detection limit is lowered to 10 ng µl-1, which is comparable to those of current commercially available instruments for DNA quantification. As a proof of principle, we demonstrate the quantification of LAMP products for a HIV-1B type genome containing plasmid on the lab-on-DVD platform. The simple DNA quantification system could facilitate advanced point of care molecular diagnostics.

A high rate of HIV-1 acquisition post immigration among migrants in Sweden determined by a CD4 T-cell decline trajectory model.

OBJECTIVES: There is a lack of knowledge about the extent to which migrants become HIV-1 infected after arrival in European countries. The objective of this study was to assess the extent to which migrants to Sweden become HIV-1 infected post immigration using a CD4 T-cell decline trajectory model. METHODS: All migrants (n = 2268) who were ≥ 15 years old, were diagnosed with HIV-1 infection in the period 1983-2013, had a known year of arrival in Sweden, did not have primary HIV infection and were not infected via mother-to-child transmission were included in the study. The CD4 T-cell decline trajectory model was applied and estimates of HIV acquisition were compared to the clinical reports. Phylogenetic analysis was performed in a subset of patients to explore whether this would favour the model or the doctor's estimate. RESULTS: The model estimated 19% of individuals to have been infected after arrival in Sweden, whereas the physician's estimate was 12%. In 79% of cases the estimates agreed. Discordance was predominantly seen when the doctor estimated HIV acquisition to have occurred before arrival in Sweden, while the model estimated it to have occurred after arrival in Sweden, and this type of discordance was seen in 10% of all patients. The probability of a discordance was greater for older patients, those with a high first CD4 T-cell count and those infected via heterosexual transmission. The phylogenetic analysis showed a higher concordance with the CD4 model than with the clinical reports (36 vs. 13%, respectively). CONCLUSIONS: The model indicated that a substantially higher proportion of migrants are infected after arrival in Sweden than estimated using clinical routine reports. It is therefore important to further emphasize primary preventive measures among migrants who have established themselves in their new country.

Assessing cervical intraepithelial neoplasia as an indicator disease for HIV in a low endemic setting: a population-based register study.

OBJECTIVES: To analyse whether the prevalence of undiagnosed HIV among (1) all women in Sweden and (2) migrant women, diagnosed with cervical intraepithelial neoplasia grade 2 or worse CIN2+ reaches the threshold of 0.1%, which has been suggested to be cost-effective for HIV testing. DESIGN: Population-based register study. SETTING: Counties of Stockholm and Gothenburg, Sweden, 1990-2014. POPULATION: All women, born between 1940 and 1990, with at least one cervical cytology or histology registered in the Swedish National Cervical Screening Register (NKCx). METHODS: Data were collected from the NKCx and the Swedish National HIV register. The proportion of women with undiagnosed HIV among women with CIN2+ compared with women with a normal/mildly abnormal cytology/histology was assessed. MAIN OUTCOME MEASURES: Proportion of women with undiagnosed HIV. RESULTS: The proportion of undiagnosed HIV was higher among all women with CIN2+ than among those without CIN2+ : 0.06% (95% CI 0.04-0.08) versus 0.04% (95% CI 0.04-0.04); P = 0.017). Among migrant women, the proportion of undiagnosed HIV was higher among those with CIN2+ than among those without [0.30% (95% CI 0.20-0.43) versus 0.08% (95% CI 0.07-0.10); P < 0.001] and exceeded 0.1%, suggesting the cost-effectiveness of HIV testing. Women with undiagnosed HIV at the time of CIN2+ had a significantly lower nadir CD4+ T-cell count, as a measure of immunosuppression, compared with women without CIN2+ before HIV diagnosis (median nadir CD4, 95 cells/mm3 versus 210 cells/mm3 ; P < 0.01). CONCLUSIONS: HIV testing should be performed in migrant women with unknown HIV status diagnosed with CIN2+ . TWEETABLE ABSTRACT: HIV testing should be performed in migrant women with unknown HIV status diagnosed with CIN2+ .

Sweden, the first country to achieve the Joint United Nations Programme on HIV/AIDS (UNAIDS)/World Health Organization (WHO) 90-90-90 continuum of HIV care targets.

OBJECTIVES: The Joint United Nations Programme on HIV/AIDS (UNAIDS)/World Health Organization (WHO) 90-90-90 goals propose that 90% of all people living with HIV should know their HIV status, 90% of those diagnosed should receive antiretroviral therapy (ART), and 90% of those should have durable viral suppression. We have estimated the continuum of HIV care for the entire HIV-1-infected population in Sweden. METHODS: The Swedish InfCare HIV Cohort Study collects viral loads, CD4 counts, and viral sequences, along with demographic and clinical data, through an electronic clinical decision support system. Almost 100% of those diagnosed with HIV infection are included in the database, corresponding to 6946 diagnosed subjects living with HIV-1 in Sweden by 31 December 2015. RESULTS: Using HIV surveillance data reported to the Public Health Agency of Sweden, it was estimated that 10% of all HIV-infected subjects in Sweden remain undiagnosed. Among all diagnosed patients, 99.8% were linked to care and 97.1% of those remained in care. On 31 December 2015, 6605 of 6946 patients (95.1%) were on ART. A total of 6395 had been on treatment for at least 6 months and 6053 of those (94.7%) had a viral load < 50 HIV-1 RNA copies/mL. CONCLUSIONS: The 2014 UNAIDS/WHO 90-90-90 goals for HIV care means that > 73% of all patients living with HIV should be virologically suppressed by 2020. Sweden has already achieved this target, with 78% suppression, and is the first country reported to meet all the UNAIDS/WHO 90-90-90 goals.

Deficiencies in the health care system contribute to a high rate of late HIV diagnosis in Sweden.

OBJECTIVES: The aim of the study was to identify factors in HIV-infected patients and the health care system which contribute to late diagnosis. METHODS: All patients who were newly diagnosed with HIV infection at 12 clinics in Sweden over a period of 2.5 years (n = 575) were included in the study, corresponding to three-quarters of newly diagnosed HIV infections in the country. The patients were classified as non-late presenters or late presenters (LPs), defined as those with a CD4 count < 350 cells/µL or AIDS. LPs were subdivided into those without and those with advanced HIV disease, which was defined as a CD4 count < 200 cells/µL or AIDS. Demographics, missed AIDS and HIV-associated symptoms in the preceding 3 years, immigration date, and health examination at immigration were recorded. RESULTS: Fifty-eight per cent of the patients were LPs, of whom 66% had advanced disease. Age > 30 years, origin in sub-Saharan Africa or Eastern Europe/Asia/the Pacific region, and country of transmission being in sub-Saharan Africa or unknown were associated with late presentation. Half of the patients of non-Swedish origin had lived for more than 1 year in Sweden at diagnosis and 66% had a missed HIV testing opportunity at immigration. Twenty-seven per cent of all patients had presented for health care with AIDS- and/or HIV-associated conditions without having an HIV test. Sixteen per cent had a history of symptoms without seeking care. CONCLUSIONS: Deficiencies in the health care system with missed HIV testing opportunities contribute to the high proportion of late presenters in Sweden, especially among migrants. With increased testing at immigration and further incorporation of "indicator-guided" testing in general practice, most patients could be diagnosed earlier.

Efficacy of etravirine combined with darunavir or other ritonavir-boosted protease inhibitors in HIV-1-infected patients: an observational study using pooled European cohort data.

OBJECTIVES: This observational study in antiretroviral treatment-experienced, HIV-1-infected adults explored the efficacy of etravirine plus darunavir/ritonavir (DRV group; n = 999) vs. etravirine plus an alternative boosted protease inhibitor (other PI group; n = 116) using pooled European cohort data. METHODS: Two international (EuroSIDA; EUResist Network) and five national (France, Italy, Spain, Switzerland and UK) cohorts provided data (collected in 2007-2012). Stratum-adjusted (for confounding factors) Mantel-Haenszel differences in virological responses (viral load < 50 HIV-1 RNA copies/mL) and odds ratios (ORs) with 95% confidence intervals (CIs) were derived. RESULTS: Baseline characteristics were balanced between groups except for previous use of antiretrovirals (≥ 10: 63% in the DRV group vs. 49% in the other PI group), including previous use of at least three PIs (64% vs. 53%, respectively) and mean number of PI resistance mutations (2.3 vs. 1.9, respectively). Week 24 responses were 73% vs. 75% (observed) and 49% vs. 43% (missing = failure), respectively. Week 48 responses were 75% vs. 73% and 32% vs. 30%, respectively. All 95% CIs around unadjusted and adjusted differences encompassed 0 (difference in responses) or 1 (ORs). While ORs by cohort indicated heterogeneity in response, for pooled data the difference between unadjusted and adjusted for cohort ORs was small. CONCLUSIONS: These data do not indicate a difference in response between the DRV and other PI groups, although caution should be applied given the small size of the other PI group and the lack of randomization. This suggests that the efficacy and virology results from DUET can be extrapolated to a regimen of etravirine with a boosted PI other than darunavir/ritonavir.

Evolution of fibrosis during HCV recurrence after liver transplantation--influence of IL-28B SNP and response to peg-IFN and ribavirin treatment.

The IL-28 gene is associated with sustained viral response (SVR) after treatment with peg-IFN and ribavirin in liver transplant recipients with chronic hepatitis C genotype 1 infection. We analysed the importance of recipient and donor IL-28B genotype for response to treatment and fibrosis progression in 54 liver transplant recipients. Fibrosis stage (F) was defined as mild when F≤2 and severe when F≥3 in a liver biopsy or according to liver elasticity analysis. We found a significantly lower prevalence of IL-28B SNP CC in the recipients (22%) than in the donors (67%), P<0.0001. SVR was seen in 61% of the recipients with mild and 27% with severe fibrosis pretreatment, P=0.01. Recipients with IL-28 CC and non-CC had mild fibrosis in 64% and 38% prior to treatment, P=0.13. At follow-up, after treatment, significantly more recipients with CC had mild fibrosis than non-CC recipients (75% versus 32%, P=0.0072), and all with CC and SVR had mild fibrosis. The strongest baseline factor predicting SVR was genotype. Hence, 13/19 (68%) genotype non-1 patients reached SVR versus only 9/35 (26%) genotype 1 patients, P=0.0022. In summary, we found that liver transplant recipients with IL-28B CC tended to have less advanced fibrosis prior to and significantly less after SOC treatment and that all recipients with IL-28B CC who achieved SVR had mild fibrosis at follow-up. A significantly higher SVR rate was achieved in recipients with mild than severe fibrosis pretreatment and with genotype non-1 than 1 infection. Our findings indicate that treatment for post-transplant HCV recurrence should be offered before advanced fibrosis is seen in the recipient.

HCV RNA decline in chronic HCV genotype 2 and 3 during standard of care treatment according to IL28B polymorphism.

The IL28 gene is highly associated with sustained viral response (SVR) in patients infected with genotype 1 after standard of care (SOC) treatment with peg-IFN and ribavirin. It is also associated with a steeper first phase HCV RNA decline during treatment. In genotype 2 and 3 infections, these correlations are less obvious. We studied the IL28B association to rapid viral response (RVR), SVR, first and second phase HCV RNA decline during treatment in 100 HCV mono-infected and 13 HCV/HIV co-infected patients. We found a significantly higher mean baseline HCV RNA level in IL28B SNP CC than non-CC mono-infected patients, 6.99 vs 6.30 log(10) IU/mL (P = 0.02), and a significantly larger median 1st phase decline in patients with CC than non-CC genotype, 2.03 vs 1.37 log(10) IU/mL, respectively. The overall SVR rate in HCV mono-infected patients was 87% vs 77% in HCV/HIV co-infected patients, with no correlation to IL28B SNP. In mono-infected patients with RVR, the SVR rate was high and independent of IL28B genotype. In mono-infected patients who failed to achieve RVR who had IL28B CC and non-CC genotype, 64% and 67% achieved SVR, respectively. In genotype 2 and 3 infected patients, the 1st phase HCV RNA decline was steeper in patients with IL28B CC vs non-CC genotype during SOC treatment. This did not translate into a higher frequency of RVR or SVR. Hence, the clinical relevance of pretreatment analysis of IL28B polymorphisms in genotype 2 and 3 infected patients can be questioned in patients with expected high SVR rate.

HIV-1 subtype is an independent predictor of reverse transcriptase mutation K65R in HIV-1 patients treated with combination antiretroviral therapy including tenofovir.

Subtype-dependent selection of HIV-1 reverse transcriptase resistance mutation K65R was previously observed in cell culture and small clinical investigations. We compared K65R prevalence across subtypes A, B, C, F, G, and CRF02_AG separately in a cohort of 3,076 patients on combination therapy including tenofovir. K65R selection was significantly higher in HIV-1 subtype C. This could not be explained by clinical and demographic factors in multivariate analysis, suggesting subtype sequence-specific K65R pathways.

European guidelines on the clinical management of HIV-1 tropism testing.

Viral tropism is the ability of viruses to enter and infect specific host cells and is based on the ability of viruses to bind to receptors on those cells. Testing for HIV tropism is recommended before prescribing a chemokine receptor blocker. In most European countries, HIV tropism is identified with tropism phenotype testing. New data support genotype analysis of the HIV third hypervariable loop (V3) for the identification of tropism. The European Consensus Group on clinical management of tropism testing was established to make recommendations to clinicians and clinical virologists. The panel recommends HIV-tropism testing for the following groups: drug-naive patients in whom toxic effects are anticipated or for whom few treatment options are available; patients who have poor tolerability to or toxic effects from current treatment or who have CNS pathology; and patients for whom therapy has failed and a change in treatment is considered. In general, an enhanced sensitivity Trofile assay and V3 population genotyping are the recommended methods. Genotypic methods are anticipated to be used more frequently in the clinical setting because of their greater accessibility, lower cost, and faster turnaround time than other methods. For the interpretation of V3 loop genotyping, clinically validated systems should be used when possible. Laboratories doing HIV tropism tests should have adequate quality assurance measures. Similarly, close collaboration between HIV clinicians and virologists is needed to ensure adequate diagnostic and treatment decisions.

Late presentation of HIV infection: a consensus definition.

OBJECTIVES: Across Europe, almost a third of individuals infected with HIV do not enter health care until late in the course of their infection. Surveillance to identify the extent to which late presentation occurs remains inadequate across Europe and is further complicated by the lack of a common clinical definition of late presentation. The objective of this article is to present a consensus definition of late presentation of HIV infection. METHODS: Over the past year, two initiatives have moved towards a harmonized definition. In spring 2009, they joined efforts to identify a common definition of what is meant by a 'late-presenting' patient. RESULTS: Two definitions were agreed upon, as follows. Late presentation: persons presenting for care with a CD4 count below 350 cells/µL or presenting with an AIDS-defining event, regardless of the CD4 cell count. Presentation with advanced HIV disease: persons presenting for care with a CD4 count below 200 cells/µL or presenting with an AIDS-defining event, regardless of the CD4 cell count. CONCLUSION: The European Late Presenter Consensus working group believe it would be beneficial if all national health agencies, institutions, and researchers were able to implement this definition (either on its own or alongside their own preferred definition) when reporting surveillance or research data relating to late presentation of HIV infection.

Overcoming obstacles to late presentation for HIV infection in Europe.

OBJECTIVE: The central goal of the HIV in Europe Initiative is to promote testing and treatment throughout Europe and Central Asia in order to decrease the number of people living with HIV presenting late for care. This article summarizes the results from the HIV in Europe 2009 Conference and the early results of the projects set up by the initiative, and discusses their implications for the future. METHODS: In November 2009, 100 key stakeholders from 25 countries met in Stockholm at the HIV in Europe Conference. The focus was to address five key issues that contribute to the barriers to testing identified in 2007 at an innovative HIV conference. The conference discussed barriers to testing and other reasons for late presentation and outlined concrete recommendations to address the problem. RESULTS: An early result of the initiative has been stimulation of the process of reaching a consensus definition of what is meant by a 'late presenter', with this definition to be implemented at the European level. Steps are being taken to advocate for appropriate health policies and surveillance data related to HIV throughout Europe. Also, the initiative has set up projects related to the barriers to testing, i.e. criminalization law, stigmatization and lack of offering of testing for people presenting with certain indicator diseases. CONCLUSIONS: The final results of ongoing projects will be published and widely disseminated in 2010 and beyond. The HIV in Europe Initiative will continue to reinforce collaboration, advocacy and networking activities in the field throughout Europe.

Prediction of response to antiretroviral therapy by human experts and by the EuResist data-driven expert system (the EVE study).

OBJECTIVES: The EuResist expert system is a novel data-driven online system for computing the probability of 8-week success for any given pair of HIV-1 genotype and combination antiretroviral therapy regimen plus optional patient information. The objective of this study was to compare the EuResist system vs. human experts (EVE) for the ability to predict response to treatment. METHODS: The EuResist system was compared with 10 HIV-1 drug resistance experts for the ability to predict 8-week response to 25 treatment cases derived from the EuResist database validation data set. All current and past patient data were made available to simulate clinical practice. The experts were asked to provide a qualitative and quantitative estimate of the probability of treatment success. RESULTS: There were 15 treatment successes and 10 treatment failures. In the classification task, the number of mislabelled cases was six for EuResist and 6-13 for the human experts [mean±standard deviation (SD) 9.1±1.9]. The accuracy of EuResist was higher than the average for the experts (0.76 vs. 0.64, respectively). The quantitative estimates computed by EuResist were significantly correlated (Pearson r=0.695, P<0.0001) with the mean quantitative estimates provided by the experts. However, the agreement among experts was only moderate (for the classification task, inter-rater κ=0.355; for the quantitative estimation, mean±SD coefficient of variation=55.9±22.4%). CONCLUSIONS: With this limited data set, the EuResist engine performed comparably to or better than human experts. The system warrants further investigation as a treatment-decision support tool in clinical practice.

Kinetics of plasma cytokines and chemokines during primary HIV-1 infection and after analytical treatment interruption.

BACKGROUND: There are strong theoretical arguments for initiating antiretroviral therapy (ART) during primary HIV-1 infection (PHI) to preserve HIV-1-specific T-cell responses and to decrease immune activation. METHODS: We assessed the degree of immune activation during PHI and after analytical treatment interruption (ATI) in plasma samples from 22 subjects by measuring 13 cytokines/chemokines with the Luminex system. Subjects initiated quadruple ART at PHI (the QUEST cohort) and were classified as responders or nonresponders according to their HIV-1 viral load (VL) 6 months post-ATI. RESULTS: During PHI, nonresponders had higher levels of HIV-1 RNA, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-10 and eotaxin than responders (P

Difference in drug resistance patterns between minor HIV-1 populations in cerebrospinal fluid and plasma.

OBJECTIVE: The aim of the study was to determine to what extent unique drug resistance patterns appear in minor and major HIV-1 quasispecies in cerebrospinal fluid (CSF) as compared with blood. METHODS: Forty-four plasma and CSF samples from 13 multi-treatment-experienced patients, seven of whom provided longitudinal samples, were included in the study. The subjects had failed antiretroviral therapy including lamivudine. The reverse transcriptase (RT) gene was examined by selective real-time polymerase chain reaction (SPCR), which can detect M184I/V mutants down to 0.2% of the viral population. RESULTS: SPCR revealed differences at amino acid position 184 in the plasma/CSF populations in 12 paired samples from eight patients. One plasma sample was positive by SPCR where direct sequencing showed wild-type M184. The other 11 paired samples showed quantitative differences in the mixed populations of the mutant or wild-type M184 quasispecies. Differences in other resistance-associated mutations between plasma and CSF viruses were also found by direct sequencing. CONCLUSIONS: In multi-treatment-experienced patients with therapy failure, differences in drug resistance patterns were found frequently between plasma and CSF in both minor and major viral populations. To what extent this was a true biological phenomenon remains to be established, and the clinical relevance of these findings is yet to be determined.

Virological Characterization of Dual HIV-1/HIV-2 Seropositivity and Infections in Southern Ghana.

SUMMARY BACKGROUND: Dual HIV-1/HIV-2 seropositivity (dual seropositivity) is common in West African countries including Ghana. The diagnosis of dual HIV-1/HIV-2 infections is however complicated as HIV-2 DNA is more often not detected in dual seropositive individuals. OBJECTIVES: To detect the presence of HIV-1 and HIV-2 pro-viral DNA in dual seropositives and to determine the correlation between HIV-2 antibody titers and presence of HIV-2 DNA. The growth kinetics of HIV-1 and HIV-2 in vitro were also determined using plasma and lymphocyte cultures. DESIGN: Cross-sectional study SETTING: Urban and semi-rural HIV/AIDS clinics PARTICIPANTS: 13 dual HIV-1/HIV-2 seropositives from Agomanya and Accra RESULTS: HIV-1 DNA was detected in uncultured peripheral blood mononuclear cells of all 13 patients but HIV-2 DNA in 4 (30.8%). HIV-2 antibody titres were not useful in determining the presence or absence of HIV-2 DNA (P=0.28, Mann-Whitney U test). HIV-2 specific antibody was detected in 12 of the 13 dual seropositives by peptide-inhibition, the only patient with an Innolia gp36 band rating of 1+ was shown not to be reactive. HIV-2 grew efficiently in the presence or HIV-1 in vitro. CONCLUSION: HIV-2 DNA may not be detected in all dual seropositives thus not all of such patients may need drugs effective against HIV-2. Peptide based assays will be useful for correctly diagnosing dual seropositivity. Since HIV-2 may grow efficiently in the presence of HIV-1 and no commercial HIV-2 HIV RNA tests are available, dual seropositives on HAART need to be monitored to determine if a lack of immune restoration may correspond to an efficient suppression of HIV-1 RNA levels.