Brief but Efficient: Acute HIV Infection and the Sexual Transmission of HIV

Background. We examined whether viral dynamics in the genital tract during the natural history of acute human immunodeficiency virus type 1 (HIV-1) infection could explain efficient heterosexual transmission of HIV. Methods. We measured HIV-1 concentration in blood and semen samples from patients with acute and long-term HIV-1 infection. We explored the effect of changes in viral dynamics in semen on the probability of transmission per coital act, using a probabilistic model published elsewhere. Results. Considered over time from infection, semen HIV-1 concentrations, in men with acute infection, increase and decrease in approximate parallel with changes occurring in blood. Modeling suggests that these acute dynamics alone are sufficient to increase probability of heterosexual transmission by 8-10-fold between peak (day 20 after infection, based on the model) and virologic set points (day 54 and later after infection). Depending on the frequency of coitus, men with average semen HIV-1 loads and without sexually transmitted diseases (STDs) would be expected to infect 7%-24% of susceptible female sex partners during the first 2 months of infection. The predicted infection rate would be much higher when either partner has an STD. Conclusions. Empirical biological data strongly support the hypothesis that sexual transmission by acutely infected individuals has a disproportionate effect on the spread of HIV-1 infection. Acute hyperinfectiousness may, in part, explain the current pandemic in heterosexual individual

Association of CD4 Cell Depletion and Elevated Blood and Seminal Plasma Human Immunodeficiency Virus Type 1 (HIV-1) RNA Concentrations with Genital Ulcer Disease in HIV-1-Infected Men in Malawi

CD4 cell counts and blood plasma and seminal plasma human immunodeficiency virus type 1 (HIV-1) concentrations were compared in HIV-1 RNA-seropositive men with urethritis and with or without genital ulcer disease (GUD). GUD was associated with lower CD4 cell counts (median, 258 vs. 348/μL) and increased blood plasma HIV-1 RNA (median, 240 × 103 vs. 79.4 × 103 copies/ mL). Men with nongonococcal urethritis and GUD shed significantly greater quantities of HIV-1 in semen (median, 195 × 103 vs. 4.0 × 103 copies/mL) than men with nongonococcal urethritis without GUD. These levels decreased ∽4-fold following antibiotic therapy. The results indicate an association between GUD and increased blood HIV-1 RNA levels. Increased HIV-1 in semen was demonstrated in some men with GUD; such an increase could lead to increased transmission, thus complicating interpretation of the role of the genital ulcer itself in the infectiousness of HIV. Reasons for increased HIV RNA in semen in men with GUD remain to be determine

High Levels of Human Immunodeficiency Virus Type 1 in Blood and Semen of Seropositive Men in Sub-Saharan Africa

High levels of human immunodeficiency virus type 1 (HIV-1) replication, as reflected in HIV-1 RNA concentrations in blood and semen, probably contribute to both rapid disease progression and enhanced sexual transmission. Semen and blood were collected from 49 Malawian and 61 US and Swiss (US/Swiss) HIV-1.seropositive men with similar CD4 cell counts and no urethritis or exposure to antiretroviral drugs. Median seminal plasma and blood plasma HIV-1 RNA concentrations were > 3-fold (P = .034) and 5-fold (P = .0003) higher, respectively, in the Malawian men. Similar differences were observed in subsets of the Malawian and US/Swiss study groups matched individually for CD4 cell count (P = .035 and P <.002, respectively). These observations may help explain the high rates of HIV-1 sexual transmission and accelerated HIV-1 disease progression in sub-Saharan Afric

Factors Associated with the Emergence of K65R in Patients with HIV-1 Infection Treated with Combination Antiretroviral Therapy Containing Tenofovir

Background. The human immunodeficiency virus type 1 reverse-transcriptase mutation K65R is a single-point mutation that has become more frequent after increased use of tenofovir disoproxil fumarate (TDF). We aimed to identify predictors for the emergence of K65R, using clinical data and genotypic resistance tests from the Swiss HIV Cohort Study. Methods. A total of 222 patients with genotypic resistance tests performed while receiving treatment with TDF-containing regimens were stratified by detectability of K65R (K65R group, 42 patients; undetected K65R group, 180 patients). Patient characteristics at start of that treatment were analyzed. Results. In an adjusted logistic regression, TDF treatment with nonnucleoside reverse-transcriptase inhibitors and/or didanosine was associated with the emergence of K65R, whereas the presence of any of the thymidine analogue mutations D67N, K70R, T215F, or K219E/Q was protective. The previously undescribed mutational pattern K65R/G190S/Y181C was observed in 6 of 21 patients treated with efavirenz and TDF. Salvage therapy after TDF treatment was started for 36 patients with K65R and for 118 patients from the wild-type group. Proportions of patients attaining human immunodeficiency virus type 1 loads <50 copies/mL after 24 weeks of continuous treatment were similar for the K65R group (44.1%; 95% confidence interval, 27.2%-62.1%) and the wild-type group (51.9%; 95% confidence interval, 42.0%-61.6%). Conclusions. In settings where thymidine analogue mutations are less likely to be present, such as at start of first-line therapy or after extended treatment interruptions, combinations of TDF with other K65R-inducing components or with efavirenz or nevirapine may carry an enhanced risk of the emergence of K65R. The finding of a distinct mutational pattern selected by treatment with TDF and efavirenz suggests a potential fitness interaction between K65R and nonnucleoside reverse-transcriptase inhibitor-induced mutation

Incidence of HIV-1 Drug Resistance Among Antiretroviral Treatment-Naive Individuals Starting Modern Therapy Combinations

By use of simulations we imputed human immunodeficiency virus type 1 drug resistance incidence to protease inhibitor-based or nonnucleoside reverse-transcriptase inhibitor-based combination therapy. We found that novel drugs such as tenofovir or boosted atazanavir lead to less drug resistance, most likely because of better tolerabilit

Long-Term Trends of HIV Type 1 Drug Resistance Prevalence among Antiretroviral Treatment-Experienced Patients in Switzerland

Background. Accurate quantification of the prevalence of human immunodeficiency virus type 1 (HIV-1) drug resistance in patients who are receiving antiretroviral therapy (ART) is difficult, and results from previous studies vary. We attempted to assess the prevalence and dynamics of resistance in a highly representative patient cohort from Switzerland. Methods. On the basis of genotypic resistance test results and clinical data, we grouped patients according to their risk of harboring resistant viruses. Estimates of resistance prevalence were calculated on the basis of either the proportion of individuals with a virologic failure or confirmed drug resistance (lower estimate) or the frequency-weighted average of risk group-specific probabilities for the presence of drug resistance mutations (upper estimate). Results. Lower and upper estimates of drug resistance prevalence in 8064 ART-exposed patients were 50% and 57% in 1999 and 37% and 45% in 2007, respectively. This decrease was driven by 2 mechanisms: loss to follow-up or death of high-risk patients exposed to mono- or dual-nucleoside reverse-transcriptase inhibitor therapy (lower estimates range from 72% to 75%) and continued enrollment of low-risk patients who were taking combination ART containing boosted protease inhibitors or nonnucleoside reverse-transcriptase inhibitors as first-line therapy (lower estimates range from 7% to 12%). A subset of 4184 participants (52%) had ⩾1 study visit per year during 2002-2007. In this subset, lower and upper estimates increased from 45% to 49% and from 52% to 55%, respectively. Yearly increases in prevalence were becoming smaller in later years. Conclusions. Contrary to earlier predictions, in situations of free access to drugs, close monitoring, and rapid introduction of new potent therapies, the emergence of drug-resistant viruses can be minimized at the population level. Moreover, this study demonstrates the necessity of interpreting time trends in the context of evolving cohort population

Improved Virological Outcome in White Patients Infected With HIV-1 Non-B Subtypes Compared to Subtype B

Patients infected with HIV type 1 non-B subtypes had a decreased probability for a virological failure while receiving combination antiretroviral therapy compared with individuals infected with subtype B. Subtypes A and CRF02_AG, in particular, revealed improved outcome

Costs and acceptability of simplified monitoring in HIV-suppressed patients switching to dual therapy: the SIMPL’HIV open-label, factorial randomised controlled trial

BACKGROUND: Clinical and laboratory monitoring of patients on antiretroviral therapy is an integral part of HIV care and determines whether treatment needs enhanced adherence or modification of the drug regimen. However, different monitoring and treatment strategies carry different costs and health consequences. MATERIALS AND METHODS: The SIMPL’HIV study was a randomised trial that assessed the non-inferiority of dual maintenance therapy. The co-primary outcome was a comparison of costs over 48 weeks of dual therapy with standard antiretroviral therapy and the costs associated with a simplified HIV care approach (patient-centred monitoring [PCM]) versus standard, tri-monthly routine monitoring. Costs included outpatient medical consultations (HIV/non-HIV consultations), non-medical consultations, antiretroviral therapy, laboratory tests and hospitalisation costs. PCM participants had restricted immunological and blood safety monitoring at weeks 0 and 48, and they were offered the choice to complete their remaining study visits via a telephone call, have medications delivered to a specified address, and to have blood tests performed at a location of their choice. We analysed the costs of both strategies using invoices for medical consultations issued by the hospital where the patient was followed, as well as those obtained from health insurance companies. Secondary outcomes included differences between monitoring arms for renal function, lipids and glucose values, and weight over 48 weeks. Patient satisfaction with treatment and monitoring was also assessed using visual analogue scales. RESULTS: Of 93 participants randomised to dolutegravir plus emtricitabine and 94 individuals to combination antiretroviral therapy (median nadir CD4 count, 246 cells/mm3; median age, 48 years; female, 17%),patient-centred monitoring generated no substantial reductions or increases in total costs (US$–421 per year [95$ –2620.4 [95% CI –2864.3 to –2331.4]) compared to standard triple-drug antiretroviral therapy costs. Approximately 50% of participants selected one monitoring option, one-third chose two, and a few opted for three. The preferred option was telephone calls, followed by drug delivery. The number of additional visits outside the study schedule did not differ by type of monitoring. Patient satisfaction related to treatment and monitoring was high at baseline, with no significant increase at week 48. CONCLUSIONS: Patient-centred monitoring did not reduce costs compared to standard monitoring in individuals switching to dual therapy or those continuing combined antiretroviral therapy. In this representative sample of patients with suppressed HIV, antiretroviral therapy was the primary factor driving costs, which may be reduced by using generic drugs to mitigate the high cost of lifelong HIV treatment. Trial registration: ClinicalTrials.gov NCT03160105

The Role of Migration and Domestic Transmission in the Spread of HIV-1 Non-B Subtypes in Switzerland

Background. By analyzing human immunodeficiency virus type 1 (HIV-1) pol sequences from the Swiss HIV Cohort Study (SHCS), we explored whether the prevalence of non-B subtypes reflects domestic transmission or migration patterns. Methods. Swiss non-B sequences and sequences collected abroad were pooled to construct maximum likelihood trees, which were analyzed for Swiss-specific subepidemics, (subtrees including ≥80% Swiss sequences, bootstrap >70%; macroscale analysis) or evidence for domestic transmission (sequence pairs with genetic distance <1.5%, bootstrap ≥98%; microscale analysis). Results. Of 8287 SHCS participants, 1732 (21%) were infected with non-B subtypes, of which A (n = 328), C (n = 272), CRF01_AE (n = 258), and CRF02_AG (n = 285) were studied further. The macroscale analysis revealed that 21% (A), 16% (C), 24% (CRF01_AE), and 28% (CRF02_AG) belonged to Swiss-specific subepidemics. The microscale analysis identified 26 possible transmission pairs: 3 (12%) including only homosexual Swiss men of white ethnicity; 3 (12%) including homosexual white men from Switzerland and partners from foreign countries; and 10 (38%) involving heterosexual white Swiss men and females of different nationality and predominantly nonwhite ethnicity. Conclusions. Of all non-B infections diagnosed in Switzerland, <25% could be prevented by domestic interventions. Awareness should be raised among immigrants and Swiss individuals with partners from high prevalence countries to contain the spread of non-B subtype