Single Tablet Regimen Usage and Efficacy in the Treatment of HIV Infection in Australia.

Single tablet regimens (STRs) for HIV infection improve patient satisfaction, quality of life, medication adherence, and virological suppression compared to multitablet regimens (MTRs). This is the first study assessing STR uptake and durability in Australia. This retrospective audit of all patients receiving an STR (n = 299) at a large Sydney HIV clinic (January 2012-December 2013) assessed patient demographics, treatment prior to STR, HIV RNA load and CD4 during MTR and STR dosing, and reasons for STR switch. 206 patients switched from previous antiretroviral treatment to an STR, of which 88% switched from an MTR. Reasons for switching included desire to simplify treatment (57%), reduced side effects or toxicity (18%), and cost-saving for the patient. There was no switching for virological failure. Compared to when on an MTR, patients switching to an STR had significantly lower HIV RNA counts (p < 0.001) and significantly higher CD4 counts (p < 0.001). The discontinuation rate from STR was very low and all patients who switched to an STR maintained virological suppression throughout the study duration, although the study is limited by the absence of a control group.

Can HIV-1 incidence be estimated from plasma viral load and sexual behaviour?

To estimate the impact of sexual practices and HIV-1 viral load status on HIV-1 incidence, we surveyed 38 men who have sex with men (MSM) on their sexual practices in the past three months. HIV-1 RNA load was measured in semen and blood contemporaneously. A Bernoulli model was developed incorporating seminal plasma viral load (SPVL), number and serostatus of partners, and number of protected and unprotected episodes of anal intercourse. Probability of transmission according to SPVL was determined by sensitivity analysis based on the correlation between blood plasma viral load (BPVL) and SPVL. There was a BPVL threshold below which SPVL was low or undetectable and above which SPVL increased geometrically. Seven subjects infected 0.93 HIV-1-negative partners and 13 subjects infected 4.28 unknown serostatus partners. Probability estimates were heavily skewed by a small number of subjects with high rates of unprotected sex and multiple sexual partners. We conclude that more HIV-1 infections may occur from increased episodes of unprotected sex with multiple partners of unknown HIV-1 serostatus. The model can be used to counsel individuals or predict epidemics, and to assess behaviour change or the impact of public health interventions.

Clinical experience with nevirapine combined with tenofovir plus emtricitabine or lamivudine-containing regimens in HIV-infected subjects.

We retrospectively evaluated the durability and reasons for discontinuation of nevirapine (NVP) in combination with a tenofovir (TDF) and emtricitabine (FTC) or lamivudine (3TC)-containing antiretroviral therapy (ART) regimen in an Australian outpatient setting. Between January 2003 and June 2009, 64 patients (29 naïve and 35 treatment-experienced) received NVP/TDF-based regimens. The median exposure was 13.0 months (interquartile range [IQR] 6.0-20.0 months). The two- and three-year probability of continuing a NVP/TDF with FTC or 3TC regimen was 76% and 70%, respectively. Thirteen (20.3%) patients discontinued their regimen during the observation period. Reasons for discontinuation included virological failure in four (6.3%), rash in three (4.7%), lost to follow-up in three (4.7%), liver toxicity in two (3.1%) and HIV-1-related encephalopathy in one (1.6%). Long-term follow-up with a NVP/TDF-based regimen showed a low rate of discontinuation and enabled physicians to extend the use of ART over a long period, often with simplified (once-daily) regimens.

Factors associated with unprotected anal intercourse between HIV-positive men and regular male partners in a Sydney cohort.

Blood plasma HIV-RNA load (BPVL) is the strongest predictor of HIV-1 transmission during sex. Unprotected anal intercourse (UAI) is the highest risk activity for transmission among men who have sex with men (MSM). Awareness of BPVL may influence rates of UAI. We assessed whether optimism towards antiretroviral therapy (ART) and/or biomedical factors influenced sexual activities with regular partners. Questionnaires were administered to 109 HIV-positive MSM participating in a cross-sectional study of BPVL and seminal viral load. The survey assessed HIV transmission beliefs and sexual practices with regular male partners in the past three months. Sixty-nine of 109 (63.3%) had been in a regular relationship and 42 reported having had anal sex. Unprotected receptive anal intercourse without ejaculation (URAI - e) was associated with awareness that their most recent BPVL was detectable (>50 RNA copies/mL) and not taking ART. Receptive UAI with ejaculation (URAI + e) was associated with not taking ART, having a sexually transmissible infection and having an HIV-positive partner; the latter was also associated with insertive UAI with ejaculation (UIAI + e). Treatment optimism was not associated with UAI. In this cohort, sexual practices were based more upon knowledge of biomedical factors rather than attitudes regarding transmission risks.

Fatal attraction: sex, sexually transmitted infections and HIV-1.

The predominant mode of HIV-1 transmission globally is from sexual practices. The risk of HIV-1 transmission by sexual means is a function of infectivity, susceptibility and mode of transmission (type of sexual practice). In addition, transmission may be enhanced by the presence of sexually transmissible infections (STIs). An understanding of the interplay between sexual practices, STIs and HIV-1 may facilitate the development of effective treatment and prevention strategies. These topics are the subject of this review.

Prevalence of antimicrobial resistance in Neisseria gonorrhoeae in an HIV/AIDS clinic.

Antimicrobial resistance in Neisseria gonorrhoeae is increasing in the Pacific region. The standard antibiotic used in urban Australia is intramuscular ceftriaxone. Isolates with reduced sensitivity are being isolated; however, resistance to ceftriaxone has yet to occur. Continued surveillance of antimicrobial resistance in the pathogen, with communication between clinic and laboratory, is needed to ensure optimal treatment of infection.

What's in a word? Case definitions in sexual health medicine.

In clinical medicine, establishing case definitions for diseases, including sexually transmitted infections, is often an inexact and arbitrary exercise. The definition is affected by the intended purpose, be it for disease surveillance, clinical care, service provision, research, or funding of services. A case must be defined precisely in order to monitor disease trends, detect outbreaks, and evaluate the effectiveness of interventions. The definition ensures consistent measurement of disease, specificity of reporting, and improves data standardization through time and across regions. The definition itself is one of the criteria used to evaluate the quality of a surveillance system. Designing definitions is fraught with problems relating to appropriate diagnostic criteria, sensitivity and specificity, context and relevance to current knowledge, and/or clinical practice. There is also the problem of reaching a consensus, especially for complex syndromes such as pelvic inflammatory disease.

Getting to the bottom of anal itch - a cautionary tale.

Peri-anal rash is common and may appear macroscopically benign. In HIV-positive men, however, more serious pathology may be revealed by a biopsy. The high prevalence of human papillomavirus infection in these men predisposes them to pre-cancerous lesions of the peri-anal and anal skin. We report an unusual case of dual pathology in the anal region, which highlights the need to thoroughly investigate peri-anal symptoms in HIV-positive men.

A sexual health strategy for Australia--time for action.

Australia still does not have a national sexual health strategy. Sexually transmissible infections such as chlamydia continue to plague the community, and the incidence of HIV is increasing. But a cohesive sexual health strategy cannot merely be disease-focussed, it must include the broader social and cultural aspects of sexual behaviour and sexuality. We propose a public health framework for the development of a national sexual health strategy that will bring Australia in line with the United Kingdom and New Zealand.