Physical and mental health of long-term users of HIV preexposure prophylaxis in Australia

INTRODUCTION

HIV preexposure prophylaxis (PrEP) is highly effective at preventing HIV. We aimed to assess mental and physical health among long-term PrEP users in Australia's X-PLORE cohort.

METHODS

In early 2021, 1485 X-PLORE participants were emailed a survey covering demographics, sexual practices, ongoing PrEP use, physical and psychological diagnoses received since commencing PrEP, substance use, and impacts of the COVID-19 pandemic. Current anxiety and depression were assessed using GAD-7 and PHQ-9 questionnaires.

RESULTS

Of 476 participants (completion rate 32.1%), 99.8% were cis-gender men. Median PrEP use duration was 48 months (2002 person-years), with 81.7% currently using PrEP. PrEP-related toxicity was uncommon: 2.9% reported bone fractures, 1.3% low bone density, and 4.0% reported kidney problems, largely not necessitating PrEP cessation. Most (92.0%) rated their health as 'good' to 'excellent', and 22.6% reported improved health since starting PrEP, often because of improved mental health. Only 6.2% reported deterioration in health since starting PrEP, largely unrelated to PrEP. The most common diagnoses were hypertension (9.9%), depression (13.2%) and anxiety (14.9%); 17% had PHQ-9 scores indicating current moderate-to-severe depression, which was associated with unemployment [adjusted odds ratio (aOR) 3.90], regular cannabis use (aOR 2.49), and having ceased PrEP (aOR 2.13).

CONCLUSION

Among long-term PrEP users, of which over 80% were currently using PrEP, self-reported PrEP toxicity was uncommon. With almost one in five PrEP users categorized as having depression, and with higher risk among those having ceased PrEP, we recommend routine screening for depression and anxiety in PrEP users and corresponding follow-up of patients no longer attending for PrEP.

Mpox (monkeypox) knowledge, concern, willingness to change behaviour, and seek vaccination: results of a national cross-sectional survey

BACKGROUND

In mid-2022, a global mpox (formerly 'monkeypox') outbreak affecting predominantly gay and bisexual men emerged in non-endemic countries. Australia had never previously recorded mpox cases and there was no prior research on knowledge or attitudes to mpox among gay and bisexual men across Australia.

METHODS

We conducted a national, online cross-sectional survey between August 2022 and September 2022. Participants were recruited through community organisation promotions, online advertising, and direct email invitations. Eligible participants were gay, bisexual or queer; identified as male (cisgender or transgender) or non-binary; aged 16years or older; and lived in Australia. The main outcome measures were: knowledge and concern about mpox; recognition of mpox symptoms and transmission routes; vaccination history; acceptability of behavioural changes to reduce mpox risk, and willingness to be vaccinated.

RESULTS

Of 2287 participants, most participants were male (2189/2287; 95.7%) and gay (1894/2287; 82.8%). Nearly all had heard about mpox (2255/2287; 98.6%), and the majority were concerned about acquiring it (1461/2287; 64.4%). Most of the 2268 participants not previously diagnosed with mpox correctly identified skin lesions (2087; 92%), rash (1977; 87.2%), and fever (1647; 72.6%) as potential symptoms, and prolonged and brief skin-to-skin contact as potential ways to acquire mpox (2124, 93.7%; and 1860, 82%, respectively). The most acceptable behavioural changes were reducing or avoiding attendance at sex parties (1494; 65.9%) and sex-on-premises venues (1503; 66.4%), and having fewer sexual partners (1466; 64.6%). Most unvaccinated and undiagnosed participants were willing to be vaccinated (1457/1733; 84.1%).

CONCLUSIONS

People at risk of mpox should be supported to adopt acceptable risk reduction strategies during outbreaks and to seek vaccination.

A cross-disciplinary view of current and emerging COVID-19 developments

The emergency phase of the coronavirus disease 2019 (COVID-19) pandemic is over. Still, the work goes on in understanding the SARS-CoV-2 virus and its evolution, infection impacts - acute and long term - as well as therapeutics and the lessons for preventing and responding to future pandemics. Research into the long-term post-infection effects and therapeutic interventions also expands as the post-infection period lengthens. We provide an overview of the leading edge of COVID-19 research across clinical, epidemiological and social domains.

Incidence and Prevalence of Hepatitis C Virus Among HIV-Negative Gay and Bisexual Men Using HIV Pre-exposure Prophylaxis (PrEP): A Systematic Review and Meta-analysis

Background

Gay and bisexual men using HIV pre-exposure prophylaxis (PrEP) are at increased risk for sexually transmissible infections. Hepatitis C virus (HCV) risk among PrEP users is less clear. We explored HCV prevalence and incidence among cohorts of gay and bisexual men using PrEP and sources of heterogeneity across studies.

Methods

This was a systematic review and meta-analysis of open-label PrEP studies to April 2022 reporting HCV prevalence at baseline or incidence during follow-up among gay and bisexual men using PrEP. Pooled prevalence and incidence estimates were calculated using random-effects meta-analysis, and subgroup analyses were performed by study- and country-level characteristics, including availability of HCV direct-acting antiviral (DAA) therapy at time of study.

Results

Twenty-four studies from 9 countries were included, with a total sample of 24 733 gay and bisexual men. Pooled HCV antibody baseline prevalence was 0.97% (95% CI, 0.63%-1.31%), and pooled HCV RNA baseline prevalence was 0.38% (95% CI, 0.19%-0.56%). Among 19 studies reporting HCV incidence, incidence ranged from 0.0 to 2.93/100 person-years (py); the pooled estimate was 0.83/100py (95% CI, 0.55-1.11). HCV incidence was higher in 12 studies that began follow-up before broad DAA availability (1.27/100py) than in 8 studies that began follow-up after broad DAA availability (0.34/100py) and higher in studies in Europe compared with North America and Australia.

Conclusions

Early reports of high HCV incidence among PrEP-using cohorts likely reflect enrollment of individuals based on specific risk-based eligibility criteria for smaller studies and enrollment before DAA scale-up. In contexts where both DAAs and PrEP have been implemented at scale, studies report lower HCV incidence. PrEP-specific HCV testing guidelines should be guided by local epidemiology.

"How PrEPared are you?": Knowledge of and attitudes toward PrEP among overseas-born and newly arrived gay, bisexual, and other men who have sex with men in Australia

Introduction

Overseas-born and newly arrived gay and bisexual men and men who have sex with men (GBMSM) are at higher risk of acquiring HIV in comparison to Australian-born GBMSM. Pre-exposure prophylaxis (PrEP) is subsidized by the Australian government under Medicare, Australia's universal health insurance scheme, however many members of this population are Medicare-ineligible, which could prevent them from accessing PrEP. We wanted to explore participants' knowledge of and attitudes toward PrEP and their opinions of new PrEP modalities, namely injectable PrEP and PrEP implants.

Methods

We conducted in-depth qualitative interviews between February 2021 to September 2021 with 22 overseas-born, newly arrived (<5 years in Australia) GBMSM of varying PrEP use. We asked their opinions of PrEP and their preferences of new PrEP modalities. Interviews were audio recorded and transcribed verbatim. We conducted a reflexive thematic analysis to interpret the data.

Results

Participants' views reflect the intersections between systemic factors, such as Medicare ineligibility and the high cost of PrEP, with socio-cultural factors, such as lack of knowledge about PrEP, internalized stigma stemming from homo- and sex-negativity, and stigmatizing attitudes toward PrEP and PrEP users. For participants who were on PrEP, being community connected, having a positive relationship with doctors and nurses, and being informed of the option to purchase PrEP from overseas pharmacies at a low cost helped them to overcome some of these barriers. Additionally, there was a strong preference for injectable PrEP but not PrEP implants. Participants stressed the importance of providing a comprehensive information about PrEP specific to this population and to make PrEP free for all.

Conclusions

We concluded that resources about PrEP specific to this population that address both systemic and socio-cultural factors are needed, and for these resources to be available in languages other than English. This is to coincide with on-going advocacy to increase the capacity of publicly funded sexual health clinics to provide multilingual PrEP services for people without Medicare, and to make PrEP free for all. These combined strategies have the potential to increase PrEP knowledge and uptake among this population.

Real-world trends in incidence of bacterial sexually transmissible infections among gay and bisexual men using HIV pre-exposure prophylaxis (PrEP) in Australia following nationwide PrEP implementation: an analysis of sentinel surveillance data

BACKGROUND

Although data from large implementation trials suggest that sexually transmissible infection (STI) risk increases among gay and bisexual men who initiate HIV pre-exposure prophylaxis (PrEP), there are few data on the trends in population-level STI incidence in the years following widespread PrEP implementation. We aimed to describe trends in bacterial STI incidence among gay and bisexual men using PrEP across Australia in the context of broad PrEP availability through Australia's subsidised medicines scheme.

METHODS

We analysed linked clinical data from HIV-negative gay and bisexual men aged 16 years or older who had been prescribed PrEP across a sentinel surveillance clinical network, including 37 clinics in Australia, between Jan 1, 2016, and Dec 31, 2019. Patients were included if they had STI testing at least twice during the observation period. Repeat testing methods were used to calculate chlamydia, gonorrhoea, syphilis, and any STI incidence rates during individuals' periods of PrEP use. Incidence rate ratios (IRRs) for estimated change in incidence per half calendar year (6-month) period were calculated using negative binomial regression. Secondary analyses compared STI incidence rates across individuals initiating PrEP in each year from 2016 to 2019, as well as by length of time using PrEP (per each additional 6 months of PrEP use).

FINDINGS

22 730 men were included in the analyses. During the observation period, 11 351 chlamydia infections were diagnosed in 6630 (30·1%) of 22 034 men over 25 991·2 person-years of PrEP use (incidence rate 43·7 cases [95% CI 42·9-44·5] per 100 person-years). Chlamydia incidence decreased from 48·7 cases per 100 person-years in July-December, 2016, to 42·0 cases per 100 person-years in July-December, 2019 (IRR for estimated change per 6-month period 0·98 [95% CI 0·97-0·99]; p=0·0031). 9391 gonorrhoea infections were diagnosed in 5885 (26·9%) of 21 845 men over 24 858·7 person-years of PrEP use (incidence rate 37·8 cases [95% CI 37·0-38·5] per 100 person-years). Gonorrhoea incidence decreased from 45·5 cases per 100 person-years in July-December, 2016, to 37·2 cases per 100 person-years in July-December, 2019 (IRR 0·97 [95% CI 0·96-0·98]; p<0·0001). Declines in chlamydia and gonorrhoea incidence were most prominent in the first 18 months of observation and incidence was stable thereafter. 2062 syphilis infections were diagnosed in 1488 (7·7%) of 19 262 men over 21 978·9 person-years of PrEP use (incidence rate 9·4 cases [95% CI 9·0-9·8] per 100 person-years). Syphilis incidence increased from 6·2 cases per 100 person-years in July-December, 2016, to 9·8 cases per 100 person-years in July-December, 2019 (IRR 1·08 [95% CI 1·05-1·10]; p<0·0001).

INTERPRETATION

Chlamydia and gonorrhoea incidence among gay and bisexual men using PrEP were highest in the early months of PrEP implementation in Australia and stabilised at slightly lower rates thereafter following wider PrEP uptake. Lower prospective STI risk among people initiating PrEP in later years contributed to the observed trends in STI incidence. Widespread PrEP implementation can contribute to increased STI screening and detection.

FUNDING

Australian Department of Health, National Health and Medical Research Council.

Latent Class Analysis of Sexual Behaviours and Attitudes to Sexually Transmitted Infections Among Gay and Bisexual Men Using PrEP

Gay and bisexual men (GBM) who use pre-exposure prophylaxis (PrEP) are at increased risk of sexually transmitted infections (STIs) compared to those who don't use PrEP. Since the implementation of PrEP in Australia, it is possible that attitudes towards STIs have shifted in line with changes in risk and transmission dynamics in the context of increased screening. As the extent to which GBM utilise STI prevention strategies likely depends on their attitudes towards STIs and STI prevention, the aims of this study were to use latent class analysis (LCA) to classify GBM using PrEP on the basis of their attitudes towards STIs and reported risk behaviours, and examine how these categorisations relate to risk of STI acquisition. 1225 GBM who were previously enrolled in a PrEP implementation study (The PrEPX Study) completed a survey focused on sexual behaviours and attitudes towards STIs 1 year post-study follow-up. Data on chlamydia, gonorrhoea and syphilis testing and positivity were available through a sentinel network of participating study clinics. Using LCA, participants were allocated into four classes; Class 1, "Some concern and lowest risk"; Class 2, "Low concern and lower risk"; Class 3, " High concern and higher risk"; and Class 4, "Low concern and highest risk". The majority (78%) of participants were classified into Class 3 or Class 4, two groups which were distinguished by highly disparate attitudes towards STIs but with a similar proportion of participants diagnosed with a bacterial STI in the last 12 months (48% and 57%, respectively). Findings suggest that attitudes towards STIs among GBM using PrEP in Australia vary considerably, and this will likely influence their receptivity to different STI prevention strategies.

Antiretroviral Initiation at ≥800 CD4+ Cells/mm3 Associated With Lower Human Immunodeficiency Virus Reservoir Size

BACKGROUND

Identifying factors that determine the frequency of latently infected CD4+ T cells on antiretroviral therapy (ART) may inform strategies for human immunodeficiency virus (HIV) cure. We investigated the role of CD4+ count at ART initiation for HIV persistence on ART.

METHODS

Among participants of the Strategic Timing of Antiretroviral Treatment Study, we enrolled people with HIV (PWH) who initiated ART with CD4+ T-cell counts of 500-599, 600-799, or ≥ 800 cells/mm3. After 36-44 months on ART, the levels of total HIV-DNA, cell-associated unspliced HIV-RNA (CA-US HIV-RNA), and two-long terminal repeat HIV-DNA in CD4+ T cells were quantified and plasma HIV-RNA was measured by single-copy assay. We measured T-cell expression of Human Leucocyte Antigen-DR Isotype (HLA-DR), programmed death-1, and phosphorylated signal transducer and activator of transcription-5 (pSTAT5). Virological and immunological measures were compared across CD4+ strata.

RESULTS

We enrolled 146 PWH, 36 in the 500-599, 60 in the 600-799, and 50 in the ≥ 800 CD4 strata. After 36-44 months of ART, total HIV-DNA, plasma HIV-RNA, and HLA-DR expression were significantly lower in PWH with CD4+ T-cell count ≥ 800 cells/mm3 at ART initiation compared with 600-799 or 500-599 cells/mm3. The median level of HIV-DNA after 36-44 months of ART was lower by 75% in participants initiating ART with ≥ 800 vs 500-599 cells/mm3 (median [interquartile range]: 16.3 [7.0-117.6] vs 68.4 [13.7-213.1] copies/million cells, respectively). Higher pSTAT5 expression significantly correlated with lower levels of HIV-DNA and CA-US HIV-RNA. Virological measures were significantly lower in females.

CONCLUSIONS

Initiating ART with a CD4+ count ≥ 800 cells/mm3 compared with 600-799 or 500-599 cells/mm3 was associated with achieving a substantially smaller HIV reservoir on ART.

The Presence or Absence of Symptoms Among Cases of Urethral Gonorrhoea Occurring in a Cohort of Men Taking Human Immunodeficiency Virus Pre-exposure Prophylaxis in the PrEPX Study

We aimed to estimate how often urethral gonorrhoea is symptomatic among men in the Pre-Exposure Prophylaxis Expanded Victoria study. Eighty-seven percent of 213 cases of urethral gonorrhoea were symptomatic. Ensuring men with urethral gonorrhoea both recognize and present early for treatment is critical to reduce transmission.

Evaluation of Preexposure (PrEP) Eligibility Criteria, Using Sexually Transmissible Infections as Markers of Human Immunodeficiency Virus (HIV) Risk at Enrollment in PrEPX, a Large Australian HIV PrEP Trial

Background

To determine participants' human immunodeficiency virus (HIV) risk, the Australian preexposure prophylaxis (PreEPX) trial used 6 eligibility criteria derived from the US Centers for Disease Control and Prevention PrEP guidelines. Participants who fulfilled no eligibility criteria could be enrolled if clinically assessed to need PrEP. This study evaluated whether PREPX eligibility criteria correlated with biological HIV risk markers-namely, syphilis, anorectal chlamydia, or anorectal gonorrhea (sexually transmitted infections [STIs]).

Methods

We calculated adjusted odds ratios (aORs) to assess whether eligibility criteria predicted STI diagnoses at enrollment.

Results

We included 1774 participants, of whom 10.2% tested positive for STIs. Eligibility criteria predicted STI diagnoses as follows: (1) aOR 2.5 (95% confidence interval [CI], 1.4-4.4) for condomless anal intercourse (CLAI) with an HIV-positive regular sexual partner (RSP) with detectable viral load; (2) aOR 1.8 (95% CI, 1.3-2.5) for receptive CLAI with casual sexual partners; (3) aOR 1.8 (95% CI, 1.3-2.5) for previous STIs; (4) aOR 2.1 (95% CI, 1.4-3.0) for methamphetamine use; (5) aOR 0.8 (95% CI, .6-1.1) for unsuccessful condom use; and (6) aOR 1.0 (95% CI, .7-1.4) for insertive CLAI when uncircumcised. Of participants enrolled outside eligibility criteria, 7.1% had STIs.

Conclusions

Eligibility criteria 1-4 predicted diagnoses of STIs, but eligibility criteria 5 and 6 did not. Our findings support the use of PrEP eligibility criteria recommended in current guidelines. Participants enrolled outside the eligibility criteria had substantial prevalence of STIs, suggesting that people who request PrEP but do not fulfill eligibility criteria may nonetheless need PrEP.

Transformation of Australian Community Pharmacies Into Good Clinical Practice Compliant Trial Pharmacies for HIV Pre-Exposure Prophylaxis

Background: In Australia, clinical trial drugs are conventionally dispensed through clinical trial pharmacies only, while community pharmacies dispense drugs approved by Australia’s regulatory body. A large HIV pre-exposure prophylaxis study aimed to deliver clinical trial drug through community pharmacies to improve convenience and mimic real world prescribing. This paper describes the process of making community trials compliant with good clinical practice and reports outcomes of delivering clinical trial drug through community pharmacies.

Methods: Eight community and four clinical trial pharmacies across three Australian states were approached to participate. A good clinical practice checklist was generated and pharmacies underwent a number of changes to meet clinical trial pharmacy requirements prior to study opening. Changes were made to community pharmacies to make them compliant with good clinical trial practice including; staff training, structural changes, and implementing monitoring of study drug and prescribing practices. Study drug was ordered through standard clinical trial processes and dispensed from study pharmacies by accredited pharmacists. Throughout the trial, record logs for training, prescriber signature and delegation, temperature, participant, and drug accountability were maintained at each pharmacy. The study team monitored each log and delivered on-site training to correct protocol variations.

Results: Each pharmacy that was approached agreed to participate. All community pharmacies achieved good clinical practice compliance prior to dispensing study drug. Over the course of the study, 20,152 dispensations of study drug occurred, 83% of these occurred at community pharmacies. Only 2.0% of dispensations had an error, and errors were predominantly minor. On five occasions a pharmacist who was not accredited dispensed study drug.

Conclusions: Community based pharmacies can undergo training and modifications to achieve good clinical practice compliance and dispense clinical trial study drug. Community based pharmacies recorded few variations from study protocol. Community based pharmacies offer a useful alternative to clinical trial pharmacies to increase convenience for study participants and expanded use of these pharmacies should be considered for large clinical trials, including HIV prevention trials.

Effects of Pre-exposure Prophylaxis for the Prevention of Human Immunodeficiency Virus Infection on Sexual Risk Behavior in Men Who Have Sex With Men: A Systematic Review and Meta-analysis

Background

Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) is effective in reducing HIV risk in men who have sex with men (MSM). However, concerns remain that risk compensation in PrEP users may lead to decreased condom use and increased incidence of sexually transmitted infections (STIs). We assessed the impact of PrEP on sexual risk outcomes in MSM.

Methods

We conducted a systematic review of open-label studies published to August 2017 that reported sexual risk outcomes in the context of daily oral PrEP use in HIV-negative MSM and transgender women. Pooled effect estimates were calculated using random-effects meta-analysis, and a qualitative review and risk of bias assessment were performed.

Results

Sixteen observational studies and 1 open-label trial met selection criteria. Eight studies with a total of 4388 participants reported STI prevalence, and 13 studies with a total of 5008 participants reported change in condom use. Pre-exposure prophylaxis use was associated with a significant increase in rectal chlamydia (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.19-2.13) and an increase in any STI diagnosis (OR, 1.24; 95% CI, .99-1.54). The association of PrEP use with STI diagnoses was stronger in later studies. Most studies showed evidence of an increase in condomless sex among PrEP users.

Conclusion

Findings highlight the importance of efforts to minimize STIs among PrEP users and their sexual partners. Monitoring of risk compensation among MSM in the context of PrEP scale-up is needed to assess the impact of PrEP on the sexual health of MSM and to inform preventive strategies.

Comparing non-occupational post-exposure prophylaxis drug regimens for HIV: insights from a linked HIV surveillance system

Background International non-occupational post-exposure prophylaxis (NPEP) guidelines recommend routine use of three drug NPEP regimens, despite absence of evidence for greater prevention efficacy compared with two drug regimens. This study examines the potential for excess HIV seroconversions among high-risk men who have sex with men (MSM) reporting receptive anal intercourse with a source of unknown HIV serostatus (RAIU) following a two-drug versus a three-drug NPEP regimen.

METHODS

Data for MSM in the Victorian NPEP service database between 10 August 2005 and 31 December 2012 were linked with all Victorian HIV notifications up to 31 December 2013. The primary outcome was NPEP failure following NPEP presentation among MSM reporting RAIU, stratified by the number of drugs prescribed.

RESULTS

Among 1482 MSM reporting 2002 episodes of RAIU and prescribed two- or three-drug NPEP, 70 seroconverted to HIV, but only 19 were considered possible NPEP failures. HIV diagnosis incidence among men reporting RAIU was 1.2/100 person years (PY) (95%CI=1.0-1.6); 1.1/100 PY (95%CI=0.8-1.4) among MSM prescribed two drugs and 2.2/100 PY (95%CI=1.4-3.7) among MSM prescribed three drugs (P<0.01). Of the 19 possible NPEP failures, 13 (0.7%) were prescribed two drugs and six (2.7%) three drugs (P<0.001).

CONCLUSIONS

This study suggests that two-drug NPEP regimens do not result in excess seroconversions compared with three-drug regimens when used following RAIU. Clinical services should carefully consider their use of three drug NPEP and whether resources might be better invested in other prevention strategies, particularly pre-exposure prophylaxis (PrEP).

Interest in Switching to On-Demand HIV Pre-Exposure Prophylaxis (PrEP) Among Australian Users of Daily PrEP: An Online Survey

We surveyed 970 PrEPX study participants to evaluate interest in switching from daily to on-demand PrEP in a study setting. Interested respondents (n = 469, 48%) more commonly reported PrEP cessation (adjusted odds ratio [aOR], 3.0; P < .001), difficulty with adherence (aOR, 1.6; P = .029), infrequent sex (aOR, 3.7; P < .001), and toxicity concerns (aOR, 2.7; P < .001).

Association of HIV Preexposure Prophylaxis With Incidence of Sexually Transmitted Infections Among Individuals at High Risk of HIV Infection

IMPORTANCE

Emerging evidence suggests that risk of bacterial sexually transmitted infections (STIs) increases among gay and bisexual men following initiation of HIV preexposure prophylaxis (PrEP).

OBJECTIVE

To describe STI incidence and behavioral risk factors among a cohort of predominantly gay and bisexual men who use PrEP, and to explore changes in STI incidence following PrEP commencement.

DESIGN, SETTING, AND PARTICIPANTS

The Pre-exposure Prophylaxis Expanded (PrEPX) Study, a multisite, open-label intervention study, was nested within the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance (ACCESS) clinic network. A total of 4275 participants were enrolled (July 26, 2016-April 1, 2018) in Victoria, Australia. Of these, 2981 enrolled at 5 ACCESS clinics (3 primary care, 1 sexual health, and 1 community-based HIV rapid testing service), had at least 1 follow-up visit, and were monitored until April 30, 2018.

EXPOSURES

Upon enrollment, participants received daily oral tenofovir disoproxil fumurate and emtricitabine for HIV PrEP, quarterly HIV and STI testing, and clinical monitoring.

MAIN OUTCOMES AND MEASURES

The primary outcome was incidence of chlamydia, gonorrhea, or syphilis. Incidence rates and hazard ratios describing behavioral risk factors of STI diagnosis were calculated. Incidence rate ratios (IRRs), adjusted for change in testing frequency, described changes in STI incidence from 1-year preenrollment to study follow-up among participants with preenrollment testing data (n = 1378).

RESULTS

Among the 2981 individuals (median age, 34 years [interquartile range, 28-42]), 98.5% identified as gay or bisexual males, 29% used PrEP prior to enrollment, 89 (3%) withdrew and were censored at date of withdrawal, leaving 2892 (97.0%) enrolled at final follow-up. During a mean follow-up of 1.1 years (3185.0 person-years), 2928 STIs were diagnosed among 1427 (48%) participants (1434 chlamydia, 1242 gonorrhea, 252 syphilis). STI incidence was 91.9 per 100 person-years, with 736 participants (25%) accounting for 2237 (76%) of all STIs. Among 2058 participants with complete data for multivariable analysis, younger age, greater partner number, and group sex were associated with greater STI risk, but condom use was not. Among 1378 participants with preenrollment testing data, STI incidence increased from 69.5 per 100 person-years prior to enrollment to 98.4 per 100 person-years during follow-up (IRR, 1.41 [95% CI, 1.29-1.56]). After adjusting for testing frequency, the increase in incidence from 1 year preenrollment to follow-up was significant for any STI (adjusted IRR, 1.12 [95% CI, 1.02-1.23]) and for chlamydia (adjusted IRR, 1.17 [95% CI, 1.04-1.33]).

CONCLUSIONS AND RELEVANCE

Among gay and bisexual men using PrEP, STIs were highly concentrated among a subset, and receipt of PrEP after study enrollment was associated with an increased incidence of STIs compared with preenrollment. These findings highlight the importance of frequent STI testing among gay and bisexual men using PrEP.

Sexual safety and HIV prevention in travel medicine: Practical considerations and new approaches

Travellers who engage in sexual contact with a new sexual partner abroad may be at high risk of HIV and other sexually transmitted infections (STIs), but these risks can be reduced through appropriate planning during the pre-travel clinic visit. Here we discuss strategies available to the clinician to maximise travellers' sexual safety during travel. Strategies may include immunizations, condoms, HIV pre-exposure prophylaxis (PrEP), HIV post-exposure prophylaxis (PEP), self-initiated treatment of symptomatic bacterial STIs, post-exposure prophylaxis for bacterial STIs and hormonal contraception. We discuss the role of these different strategies for travellers, and provide resources to assist clinicians in making clinical decisions and in educating travellers about sexual safety.

Protocol for an HIV Pre-exposure Prophylaxis (PrEP) Population Level Intervention Study in Victoria Australia: The PrEPX Study

Background: Pre-exposure prophylaxis (PrEP) is the use of HIV anti-retroviral therapy to prevent HIV transmission in people at high risk of HIV acquisition. PrEP is highly efficacious when taken either daily, or in an on-demand schedule. In Australia co-formulated tenofovir-emtricitabine is registered for daily use for PrEP, however, this co-formulation is not listed yet on the national subsidized medicines list. We describe a study protocol that aims to demonstrate if the provision of PrEP to up to 3800 individuals at risk of HIV in Victoria, Australia reduces HIV incidence locally by 25% generally and 30% among GBM.

Methods: PrEPX is a population level intervention study in Victoria, Australia in which generic PrEP will be delivered to 3800 individuals for up to 36 months. Study eligibility is consistent with the recently updated 2017 Australian PrEP guidelines. Participants will attend study clinics, shared care clinics, or outreach clinics for quarterly HIV/STI screening, biannual renal function tests and other clinical care as required. Study visits and STI diagnoses will be recorded electronically through the ACCESS surveillance system. At each study visit participants will be invited to complete behavioral surveys that collect demographics and sexual risk data. Diagnosis and behavioral data will be compared between PrEPX participants and other individuals testing within the ACCESS surveillance system. A subset of participants will complete in depth surveys and interviews to collect attitudes, beliefs and acceptability data. Participating clinics will provide clinic level data on implementation and management of PrEPX participants. The population level impact on HIV incidence will be assessed using Victorian HIV notification data.

Discussion: This study will collect evidence on the real world impact of delivery of PrEP to 3800 individuals at risk of acquiring HIV in Victoria. This study will provide important information for the broader implementation of PrEP planning upon listing of the tenofovir-emtricitabine on the national subsidized list of medicines. The study is registered on the Australian New Zealand Clinical Trials Registry (ACTRN12616001215415)

No neurocognitive advantage for immediate antiretroviral treatment in adults with greater than 500 CD4+ T-cell counts

OBJECTIVE

To compare the effect of immediate versus deferred antiretroviral treatment (ART) on neuropsychological test performance in treatment-naive HIV-positive adults with more than 500 CD4 cells/μl.

DESIGN

Randomized trial.

METHODS

The START parent study randomized participants to commence immediate versus deferred ART until CD4 less than 350 cells/μl. The START Neurology substudy used eight neuropsychological tests, at baseline, months 4, 8, 12 and annually, to compare groups for changes in test performance. Test results were internally standardized to z-scores. The primary outcome was the average of the eight test z-scores (QNPZ-8). Mean changes in QNPZ-8 from baseline were compared by intent-to-treat using longitudinal mixed models. Changes from baseline to specific time points were compared using ANCOVA models.

RESULTS

The 592 participants had a median age of 34 years; median baseline CD4 count was 629 cells/μl; the mean follow-up was 3.4 years. ART was used for 94 and 32% of accrued person-years in the immediate and deferred groups, respectively. There was no difference between the immediate and deferred ART groups in QNPZ-8 change through follow-up [-0.018 (95% CI -0.062 to 0.027, P = 0.44)], or at any visit. However, QNPZ-8 scores increased in both arms during the first year, by 0.22 and 0.24, respectively (P < 0.001 for increase from baseline).

CONCLUSION

We observed substantial improvement in neurocognitive test performance during the first year in both study arms, underlining the importance of using a control group in studies assessing neurocognitive performance over time. Immediate ART neither benefitted nor harmed neurocognitive performance in individuals with CD4 cell counts above 500 cells/μl.

Global developments in HIV neurology

Neurologic conditions associated with HIV remain major contributors to morbidity and mortality, and are increasingly recognized in the aging population on long-standing combination antiretroviral therapy (cART). Importantly, growing evidence suggests that the central nervous system (CNS) serves as a reservoir for viral replication with major implications for human immunodeficiency virus (HIV) eradication strategies. Though there has been major progress in the last decade in our understanding of the pathogenesis, burden, and impact of HIV-associated neurologic conditions, significant scientific gaps remain. In many low-income settings, second- and third-line cART regimens that carry substantial neurotoxicity remain treatment mainstays. Further, patients continue to present severely immunosuppressed with CNS opportunistic infections. Public health efforts should emphasize improvements in access and optimizing treatment of HIV-positive patients, specifically in resource-limited settings, to reduce the risk of neurologic sequelae.

Monitoring HIV-Associated Neurocognitive Disorder Using Screenings: a Critical Review Including Guidelines for Clinical and Research Use

Screening tools to identify HIV-associated neurocognitive disorder (HAND) are primarily devised to detect cognitive impairment on a single occasion. With the chronicity of HIV infection and the risk of HAND developing or progressing despite viral control, it may be pertinent to repeat HAND screening at more than one time point. Despite this, there are limited data on longitudinal use of such screening tools, particularly with regard to the role of practice effects. Additionally, no guidelines currently exist on the timeframe between testing intervals, or recommendation of the magnitude of baseline impairment that warrants follow-up testing. The aim of the current paper was to review existing evidence for longitudinal validity of HAND screening tools. Only those HAND screening tools previously found to have high cross-sectional criterion validity were included. Preliminary recommendations for clinical use and future research are proposed including in international settings.

Factors associated with neurocognitive test performance at baseline: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

We describe neuropsychological test performance (NP) in antiretroviral treatment (ART)-naïve HIV-positive individuals with CD4 cell counts above 500 cells/μL.

METHODS

In a neurology substudy of the International Network for Strategic Initiatives in Global HIV Trials (INSIGHT) Strategic Timing of AntiRetroviral Treatment (START) study, eight neurocognitive tests were administered. The primary measure of NP was the quantitative NP z-score (QNPZ-8), the average of the z-scores for the eight tests. Associations of baseline factors with QNPZ-8 scores were assessed by multiple regression. Mild neurocognitive impairment (NCI) was defined as z-scores < -1 in at least two of six cognitive domains.

RESULTS

A total of 608 participants had a median age of 34 years; 11% were women and 15% were black; the median time since HIV diagnosis was 0.9 years; the median CD4 cell count was 633 cells/μL; 19.9% had mild NCI. Better NP was independently associated with younger age, being white, higher body mass index (0.10 per 10 kg/m(2) higher), and higher haematocrit percentage (0.19 per 10% higher). Worse NP was associated with longer time since HIV diagnosis (-0.17 per 10 years), diabetes (-0.29) and higher Framingham risk score (-0.15 per 10 points higher). QNPZ-8 scores differed significantly between geographical locations, with the lowest scores in Brazil and Argentina/Chile.

CONCLUSIONS

This is the largest study of NP in ART-naïve HIV-positive adults with CD4 counts > 500 cells/μL. Demographic factors and diabetes were most strongly associated with NP. Unmeasured educational/sociocultural factors may explain geographical differences. Poorer NP was independently associated with longer time since HIV diagnosis, suggesting that untreated HIV infection might deleteriously affect NP, but the effect was small.

Evolving views and practices of antiretroviral treatment prescribers in Australia

OBJECTIVE

To examine whether there have been recent changes in Australian antiretroviral treatment (ART) prescribers' perceptions and practices relating to early ART initiation, which was defined as commencing ART when a patient's CD4+ T-cell count approaches 500 cells/mm3 or immediately after a patient is diagnosed with HIV.

DESIGN, PARTICIPANTS AND SETTING

Self-completed, anonymous, cross-sectional surveys, targeting all ART prescribers in Australia, were conducted online in 2012 and 2013. The surveys included questions on prescriber factors, CD4+ T-cell count at which prescribers would most strongly recommend ART initiation, and perceived patient characteristics that could change prescribers' practices of early initiation of ART.

MAIN OUTCOME MEASURES

Proportions of ART prescribers recommending early ART initiation.

RESULTS

We analysed responses from 108 participants in 2012 and 82 participants in 2013. In both years, more male than female prescribers participated. The median age of participants was 49 years in 2012 and 50 years in 2013. In both rounds, over 60% had more than 10 years' experience in treating HIV-positive patients. More prescribers in 2013 stated that they would most strongly recommend early ART initiation compared with those in 2012 (50.0% [95% CI, 38.7%-61.3%] v 26.9% [95% CI, 18.8%-36.2%]; P=0.001). The prescribers' primary concern was more about individual patient than public health benefit. Out of 824 patients for whom ART was initiated, as reported by prescribers in 2013, only 108 (13.1% [95% CI, 10.9%-15.6%]) were given ART primarily to prevent onward HIV transmission. The number of patients for whom ART was initiated was significantly associated with prescribers' HIV caseload even after adjusting for prescriber type (adjusted odds ratio, 1.73 [95% CI, 1.47-2.03]; P<0.001); of the 37 who had initiated ART for 10 or more patients, 29 had a high HIV caseload. In 2013, 60 prescribers (73.2% [95% CI, 62.2%-82.4%]) reported that they routinely recommended ART to treatment-naive, asymptomatic patients with a CD4+ T-cell count of 350-500 cells/mm3.

CONCLUSION

Our findings show increasing acceptance of and support for early ART initiation primarily as treatment and not as prevention.

Improved neurocognitive test performance in both arms of the SMART study: impact of practice effect

We evaluated factors associated with improvement in neurocognitive performance in 258 HIV-infected adults with baseline CD4 lymphocyte counts above 350 cells/mm³ randomized to intermittent, CD4-guided antiretroviral therapy (ART) (128 participants) versus continuous therapy (130) in the Neurology substudy of the Strategies for Management of Antiretroviral Therapy trial. Participants were enrolled in Australia, North America, Brazil, and Thailand, and neurocognitive performance was assessed by a five-test battery at baseline and month 6. The primary outcome was change in the quantitative neurocognitive performance z score (QNPZ-5), the average of the z scores of the five tests. Associations of the 6-month change in test scores with ART use, CD4 cell counts, HIV RNA levels, and other factors were determined using multiple regression models. At baseline, median age was 40 years, median CD4 cell count was 513 cells/mm³, 88 % had plasma HIV RNA ≤ 400 copies/mL, and mean QNPZ-5 was -0.68. Neurocognitive performance improved in both treatment groups by 6 months; QNPZ-5 scores increased by 0.20 and 0.13 in the intermittent and continuous ART groups, respectively (both P < 0.001 for increase and P = 0.26 for difference). ART was used on average for 3.6 and 5.9 out of the 6 months in the intermittent and continuous ART groups, respectively, but the increase in neurocognitive test scores could not be explained by ART use, changes in CD4, or plasma HIV RNA, which suggests a practice effect. The impact of a practice effect after 6 months emphasizes the need for a control group in HIV studies that measure intervention effects using neurocognitive tests similar to ours.

The Four Seasons approach to the management of modern HIV medicine in high-income countries

The Four Seasons and modern HIV medicine in high-income countries: a screening and management approach of non-AIDS illnesses.

Enhanced CD4+ T-cell recovery with earlier HIV-1 antiretroviral therapy

BACKGROUND

The relationship between the timing of the initiation of antiretroviral therapy (ART) after infection with human immunodeficiency virus type 1 (HIV-1) and the recovery of CD4+ T-cell counts is unknown.

METHODS

In a prospective, observational cohort of persons with acute or early HIV-1 infection, we determined the trajectory of CD4+ counts over a 48-month period in partially overlapping study sets: study set 1 included 384 participants during the time window in which they were not receiving ART and study set 2 included 213 participants who received ART soon after study entry or sometime thereafter and had a suppressed plasma HIV viral load. We investigated the likelihood and rate of CD4+ T-cell recovery to 900 or more cells per cubic millimeter within 48 months while the participants were receiving viral-load-suppressive ART.

RESULTS

Among the participants who were not receiving ART, CD4+ counts increased spontaneously, soon after HIV-1 infection, from the level at study entry (median, 495 cells per cubic millimeter; interquartile range, 383 to 622), reached a peak value (median, 763 cells per cubic millimeter; interquartile range, 573 to 987) within approximately 4 months after the estimated date of infection, and declined progressively thereafter. Recovery of CD4+ counts to 900 or more cells per cubic millimeter was seen in approximately 64% of the participants who initiated ART earlier (≤4 months after the estimated date of HIV infection) as compared with approximately 34% of participants who initiated ART later (>4 months) (P<0.001). After adjustment for whether ART was initiated when the CD4+ count was 500 or more cells per cubic millimeter or less than 500 cells per cubic millimeter, the likelihood that the count would increase to 900 or more cells per cubic millimeter was lower by 65% (odds ratio, 0.35), and the rate of recovery was slower by 56% (rate ratio, 0.44), if ART was initiated later rather than earlier. There was no association between the plasma HIV RNA level at the time of initiation of ART and CD4+ T-cell recovery.

CONCLUSIONS

A transient, spontaneous restoration of CD4+ T-cell counts occurs in the 4-month time window after HIV-1 infection. Initiation of ART during this period is associated with an enhanced likelihood of recovery of CD4+ counts. (Funded by the National Institute of Allergy and Infectious Diseases and others.).

Non-occupational post-exposure prophylaxis in Victoria, Australia: responding to high rates of re-presentation and low rates of follow-up

In Australia, the non-occupational post-exposure prophylaxis service in Victoria (VNPEPS) maintains a database of non-occupational post-exposure prophylaxis (NPEP) use throughout the state. Through the database the service can monitor and respond to patterns of NPEP presentation, re-presentation and follow-up as well as those who test positive for HIV. We describe a cohort of NPEP individuals from the commencement of the service to 31 December 2009. During this time, 1864 individuals presented for NPEP on 2396 occasions. The majority (85%) were men who have sex with men (MSM) presenting after receptive anal intercourse (56.1%). Repeat NPEP presentations were high (17.5%) and follow-up testing at week 12 post-NPEP was low (34%). Twenty-two patients (1.2%) tested positive for HIV at baseline presentation and six patients seroconverted to HIV during follow-up. The VNPEPS has initiated strategies to encourage behaviour change for those who re-present for NPEP, and to improve rates of week 12 follow-up.

Intra-operative 3-T MRI for paediatric brain tumours: challenges and perspectives

MRI is the ideal modality for imaging intracranial tumours. Intraoperative MRI (ioMRI) makes it possible to obtain scans during a neurosurgical operation that can aid complete macroscopic tumour resection—a major prognostic factor in the majority of brain tumours in children. Intraoperative MRI can also help limit damage to normal brain tissue. It therefore has the potential to improve the survival of children with brain tumours and to minimise morbidity, including neurological deficits. The use of ioMRI is also likely to reduce the need for second look surgery, and may reduce the need for chemotherapy and radiotherapy. Highfield MRI systems provide better anatomical information and also enable effective utilisation of advanced MRI techniques such as perfusion imaging, diffusion tensor imaging, and magnetic resonance spectroscopy. However, high-field ioMRI facilities require substantial capital investment, and careful planning is required for optimal benefit. Safe ioMRI requires meticulous attention to detail and rigorous application of magnetic field safety precautions. Interpretation of ioMRI can be challenging and requires experience and understanding of artefacts that are common in the intra-operative setting.

Nonoccupational post-exposure prophylaxis source tracing: is it really feasible in Australia?

OBJECTIVE

A Swiss nonoccupational post-exposure prophylaxis (NPEP) source-tracing study successfully reduced unnecessary NPEP prescriptions by recruiting and testing source partners of unknown HIV serostatus. The Victorian NPEP Service in Australia attempted to replicate this study with the addition of HIV rapid testing and a mobile service.

METHODS

Patients presenting to two busy NPEP sites who reported a source partner of unknown HIV status were routinely asked if their source could be traced. If the exposed person indicated that their source partner was traceable they were asked to contact them and discuss the possibility of having an HIV test.

RESULTS

No sources were enrolled and the study was terminated.

CONCLUSION

We hypothesize that there are a number of differences between Australia and Switzerland that make source tracing unfeasible in Australia.

HIV seroconversions among male non-occupational post-exposure prophylaxis service users: a data linkage study

BACKGROUND

Despite widespread prescription of non-occupational post-exposure prophylaxis (NPEP) in Victoria, little is known about subsequent HIV acquisition among NPEP users. We linked the Victorian NPEP Service (VNPEPS) database and the Victorian HIV Surveillance Registry to determine the number, incidence rate and predictive factors of HIV seroconversions among users of the VNPEPS.

METHODS

Records from male patients that received NPEP in the VNPEPS database (n = 1420) between January 2001 and February 2008 were linked with all entries in the Victorian HIV Surveillance Registry up to May 2008.

RESULTS

Sixty-one men who presented to the VNPEPS were identified as HIV seropositive; 16 of these were diagnosed at initial presentation for NPEP. The incidence of HIV seroconversion in males who were HIV seronegative at first presentation for NPEP was 1.27 (95% confidence interval 0.95-1.70) per 100 person-years. There was no association between HIV seroconversion and number of NPEP presentations or age. The median age of seroconversion was 34.6 years.

CONCLUSION

The incidence of HIV infection among men presenting to the VNPEPS is slightly lower than the HIV incidence in NPEP users in a recent Australian cohort study of men who have sex with men, but higher than HIV incidence in general gay male populations. Frequency of NPEP use was not associated with risk of HIV seroconversion. Examination of risk behaviour before and after NPEP use in this population is required to further assess the impact of NPEP availability and use on HIV incidence rates and risk behaviour in Australia.

Duffy-null-associated low neutrophil counts influence HIV-1 susceptibility in high-risk South African black women

BACKGROUND

The Duffy-null trait and ethnic netropenia are both highly prevalent in Africa. The influence of pre-seroconversion levels of peripheral blood cell counts (PBCs) on the risk of acquiring human immunodeficiency virus (HIV)-1 infection among Africans is unknown.

METHODS

The triangular relationship among pre-seroconversion PBC counts, host genotypes, and risk of HIV acquisition was determined in a prospective cohort of black South African high-risk female sex workers. Twenty-seven women had seroconversion during follow-up, and 115 remained HIV negative for 2 years, despite engaging in high-risk activity.

RESULTS

Pre-seroconversion neutrophil counts in women who subsequently had seroconversion were significantly lower, whereas platelet counts were higher, compared with those who remained HIV negative. Comprising 27% of the cohort, subjects with pre-seroconversion neutrophil counts of <2500 cells/mm(3) had a ∼3-fold greater risk of acquiring HIV infection. In a genome-wide association analyses, an African-specific polymorphism (rs2814778) in the promoter of Duffy Antigen Receptor for Chemokines (DARC -46T > C) was significantly associated with neutrophil counts (P = 7.9 × 10(-11)). DARC -46C/C results in loss of DARC expression on erthyrocytes (Duffy-null) and resistance to Plasmodium vivax malaria, and in our cohort, only subjects with this genotype had pre-seroconversion neutrophil counts of <2500 cells/mm(3). The risk of acquiring HIV infection was ∼3-fold greater in those with the trait of Duffy-null-associated low neutrophil counts, compared with all other study participants.

CONCLUSIONS

Pre-seroconversion neutrophil and platelet counts influence risk of HIV infection. The trait of Duffy-null-associated low neutrophil counts influences HIV susceptibility. Because of the high prevalence of this trait among persons of African ancestry, it may contribute to the dynamics of the HIV epidemic in Africa.

NeuroAIDS in the Asia Pacific Region

Over 8.3 million people living in the Asia Pacific region are human immunodeficiency virus (HIV) positive and up to 40% of these individuals have had prior acquired immunodeficiency syndrome (AIDS) illnesses. Recently endeavors have been made to better characterize the burden of HIV-related neurological disease within the Asia Pacific region and, with this in mind, the NeuroAIDS in Asia and the Pacific Rim workshop was held in Sydney, Australia, as an affiliated event of the 4th IAS Conference on HIV Pathogenesis, Treatment and Prevention. The workshop was supported by the National Institute of Neurological Disorders and Stroke (NINDS) and the National Institute of Mental Health (NIMH) of the United States National Institutes of Health and the Australian Government overseas AID program, AusAID. HIV neurologists, infectious disease physicians, pediatricians, psychiatrists, immunologists, virologists,and researchers from 12 countries of the Asia Pacific region (including Australia), the United States, and the United Kingdom attended the meeting. A broad range of topics were addressed, including common HIV neurological disorders, the lack of diagnostic, management, and research infrastructure, central nervous system (CNS) immune restoration disease, pediatric neuroAIDS, and current clinical and laboratory research projects being undertaken within the Asia Pacific region.

Cardiovascular risk factors associated with lower baseline cognitive performance in HIV-positive persons

OBJECTIVE

To determine factors associated with baseline neurocognitive performance in HIV-infected participants enrolled in the Strategies for Management of Antiretroviral Therapy (SMART) neurology substudy.

METHODS

Participants from Australia, North America, Brazil, and Thailand were administered a 5-test neurocognitive battery. Z scores and the neurocognitive performance outcome measure, the quantitative neurocognitive performance z score (QNPZ-5), were calculated using US norms. Neurocognitive impairment was defined as z scores <-2 in two or more cognitive domains. Associations of test scores, the QNPZ-5, and impairment with baseline factors including demographics and risk factors for HIV-associated dementia (HAD) and cardiovascular disease (CVD) were determined in multiple regression.

RESULTS

The 292 participants had a median CD4 cell count of 536 cells/mm(3), 88% had an HIV viral load < or =400 copies/mL, and 92% were taking antiretrovirals. Demographics, HIV, and clinical factors differed between locations. The mean QNPZ-5 score was -0.72; 14% of participants had neurocognitive impairment. For most tests, scores and z scores differed significantly between locations, with and without adjustment for age, sex, education, and race. Prior CVD was associated with neurocognitive impairment. Prior CVD, hypercholesterolemia, and hypertension were associated with poorer neurocognitive performance but conventional HAD risk factors and the CNS penetration effectiveness rank of antiretroviral regimens were not.

CONCLUSIONS

In this HIV-positive population with high CD4 cell counts, neurocognitive impairment was associated with prior CVD. Lower neurocognitive performance was associated with prior CVD, hypertension, and hypercholesterolemia, but not conventional HAD risk factors. The contribution of CVD and cardiovascular risk factors to the neurocognition of HIV-positive populations warrants further investigation.

Campylobacter lari: genotype and antibiotic resistance of isolates from cattle, wildlife and water in an area of mixed dairy farmland in the United Kingdom

Campylobacter lari is a rare human pathogen most commonly associated with birds and shellfish. Little information has been published regarding its prevalence in other environments, or on its potential role as a reservoir of antibiotic resistance. In this study, we characterized 109 C. lari isolated from a range of hosts using pulsed-field gel electrophoresis of macro-restricted chromosomal DNA, and by determining their susceptibility to a panel of four antibiotics. Pulsed-field gel electrophoresis analysis showed C. lari to be genetically diverse, particularly in isolates from wild birds and environmental water. The most common composite macro-restriction profile (cMRP) was found in multiple hosts (cattle, badgers, wild birds and rabbits), and seven other cMRPs were recovered from more than one host. All isolates were resistant to nalidixic acid and ciprofloxacin. Resistance to erythromycin and ampicillin was uncommon, but was observed in isolates from wild birds, cattle, wild mammals and water samples. The presence of the same cMRP in multiple hosts provides further evidence of transmission between livestock, wildlife and the environment, or for a common source of infection.

Human immunodeficiency virus-associated progressive multifocal leucoencephalopathy: epidemiology and predictive factors for prolonged survival

We performed a retrospective review of cases of human immunodeficiency virus-associated progressive multifocal leucoencephalopathy in four hospitals (three in Australia and one in Hong Kong) between 1987 and 2003 in order to describe the local experience with this disease and to evaluate parameters impacting upon survival. Eighty-seven cases were identified and demographic details, baseline parameters and treatment methods and response were described. Survival was substantially increased in the post-highly active antiretroviral therapy (HAART) era with a median survival increase from 14 to 64 weeks. On multivariate analysis, variables associated with prolonged survival included a CD4 count of >100 cells/mul at diagnosis and the use of HAART post-diagnosis, with no significant additional advantage from the use of neuroactive antiretrovirals.

Prevalence and genetic diversity of Campylobacter spp. in environmental water samples from a 100-square-kilometer predominantly dairy farming area

Water samples were taken systematically from a 100-km2 area of mainly dairy farmland in northwestern England and examined for Campylobacter spp. Pulsed-field gel electrophoresis-restriction fragment length polymorphism (PFGE-RFLP) and flaA strain typing of Campylobacter jejuni and Campylobacter coli isolates were done. Data on the water source and the adjacent environment were recorded and examined as explanatory variables. Campylobacter spp. were isolated from 40.5% (n = 119) of the water samples tested. C. jejuni was isolated from 14.3%, C. coli was isolated from 18.5%, and Campylobacter lari was isolated from 4.2% of the samples. Campylobacter hyointestinalis was not isolated from any water source. The difference in prevalence between water types (trough, running, and standing) was significant (P = 0.001). C. jejuni was the species most commonly isolated from trough-water and running-water sources, while C. coli was the most frequently isolated from standing water (P < 0.001). No association was found between the presence of Escherichia coli and that of Campylobacter spp. The final multivariable logistic regression model for Campylobacter spp. included the following variables: water source, soil type, aspect, and amount of cattle fecal material in the environment (fecal pat count). Strain typing demonstrated a diverse population of C. jejuni and the presence of a common C. coli flaA type that was widely distributed throughout the area. Most of the isolates within the common flaA type were discriminated by PFGE-RFLP. These findings suggest a possible role for environmental water in the epidemiology of Campylobacter spp. in a farming environment.

Intermittent and persistent shedding of Escherichia coli O157 in cohorts of naturally infected calves

AIMS

We conducted two short-term studies of cohorts of naturally infected calves to determine the prevalence and concentrations of Escherichia coli O157 shed in faeces.

METHODS AND RESULTS

Two cohorts of calves were sampled; in the first study 14 calves were sampled up to five times a day for 5 days; in the second study a group of 16 separate calves were sampled once or twice a day for 15 days. All cattle within the two cohorts shed E. coli O157 at some point during the respective studies. In 18% of samples, E. coli O157 could only be isolated using immunomagnetic separation after an enrichment period, suggesting concentrations <250 CFU g(-1). The highest concentrations recorded were 6.7 x 10(5) and 1.6 x 10(6) CFU g(-1) for studies 1 and 2 respectively.

CONCLUSIONS

Persistent, high shedders (shedding >10(3) CFU g(-1)) were evident in both studies but, in the majority of calves, the pathogen was isolated intermittently.

SIGNIFICANCE AND IMPACT OF THE STUDY

The variable patterns of shedding have important implications for the design of appropriate sampling protocols and for gaining meaningful estimates of parameters used in mathematical models of transmission.

Frequency and spatial distribution of environmental Campylobacter spp

Humans are exposed to Campylobacter spp. in a range of sources via both food and environmental pathways. For this study, we explored the frequency and distribution of thermophilic Campylobacter spp. in a 10- by 10-km square rural area of Cheshire, United Kingdom. The area contains approximately 70, mainly dairy, farms and is used extensively for outdoor recreational activities. Campylobacter spp. were isolated from a range of environmental samples by use of a systematic sampling grid. Livestock (mainly cattle) and wildlife feces and environmental water and soil samples were cultured, and isolates were presumptively identified by standard techniques. These isolates were further characterized by PCR. Campylobacter jejuni was the most prevalent species in all animal samples, ranging from 11% in samples from nonavian wildlife to 36% in cattle feces, and was isolated from 15% of water samples. Campylobacter coli was commonly found in water (17%) and sheep (21%) samples, but rarely in other samples. Campylobacter lari was recovered from all sample types, with the exception of sheep feces, and was found in moderate numbers in birds (7%) and water (5%). Campylobacter hyointestinalis was only recovered from cattle (7%) and birds (1%). The spatial distribution and determinants of C. jejuni in cattle feces were examined by the use of model-based spatial statistics. The distribution was consistent with very localized within-farm or within-field transmission and showed little evidence of any larger-scale spatial dependence. We concluded that there is a potentially high risk of human exposure to Campylobacter spp., particularly C. jejuni, in the environment of our study area. The prevalence and likely risk posed by C. jejuni-positive cattle feces in the environment diminished as the fecal material aged. After we took into account the age of the fecal material, the absence or presence of rain, and the presence of bird feces, there was evidence of significant variation in the prevalence of C. jejuni-positive cattle feces between grazing fields but no evidence of spatial clustering beyond this resolution. The spatial pattern of C. jejuni is therefore consistent with that for an organism that is ubiquitous in areas contaminated with cattle feces, with a short-scale variation in infection intensity that cannot be explained solely by variations in the age of the fecal material. The observed pattern is not consistent with large-scale transmission attributable to watercourses, wildlife territories, or other geographical features that transcend field and farm boundaries.

Development and application of a spiral plating method for the enumeration of Escherichia coli O157 in bovine faeces

AIM

To develop and validate a direct plating method applicable to epidemiological studies for enumerating Escherichia coli O157 in cattle faeces.

METHODS AND RESULTS

The spiral plate count method was used to enumerate E. coli O157 in faecal samples. The accuracy and variation of counts was then assessed using faecal samples inoculated with E. coli O157. There was good agreement between inoculated levels of E. coli O157 and those recovered from faeces, particularly when counts were > 10(2) CFU g(-1) of faeces. The method was applied to a small study assessing short-term survival of E. coli O157 in naturally infected cattle faeces. E. coli O157 was found to survive in faeces for over 10 days at concentrations above 10(3) CFU g(-1) of faeces. Populations of E. coli O157 were also found to increase 100-fold in the first few hours after defecation.

CONCLUSIONS

The enumeration method is easy to implement and enables a quick throughput of large numbers of samples. The method is accurate and reliable and enables the inherent variation in count data to be explored but needs to be used in combination with a more sensitive method for samples containing < 10(2) CFU g(-1) of faeces.

SIGNIFICANCE AND IMPACT OF THE STUDY

The method described is appropriate for enumeration of E. coli O157 in cattle faeces in large-scale epidemiological studies.

Genotypic and antibiotic susceptibility characteristics of a Campylobacter coli population isolated from dairy farmland in the United Kingdom

Campylobacter infections are the most common cause of bacterial enteritis in humans, and nearly 8% of such infections are caused by Campylobacter coli. Most studies have concentrated on Campylobacter jejuni, frequently isolated from intensively farmed poultry and livestock production units, and few studies have examined the spread and relatedness of Campylobacter across a range of geographical and host boundaries. Systematic sampling of a 100-km2 area of mixed farmland in northwest England yielded 88 isolates of C. coli from a range of sample types and locations, and water was heavily represented. Screening for antibiotic resistance revealed a very low prevalence of resistance, while genotyping performed by using three methods (flaA PCR restriction fragment length polymorphism [RFLP], pulsed-field gel electrophoresis [PFGE], and fluorescent amplified fragment length polymorphism [fAFLP]) provided insights into the genomic relatedness of isolates from different locations and hosts. Isolates were classified into 23 flaA groups, 34 PFGE groups, and five major fAFLP clusters. PFGE banding analysis revealed a high level of variability and no clustering by sample type. fAFLP and flaA analyses successfully grouped the isolates by sample type. We report preliminary findings suggesting that there is a strain of C. coli which may have become adapted to survival or persistence in water and that there is a group of mainly water-derived isolates from which unusual flaA PCR fragments were recovered.

Current status of fascia lata allograft slings treating urinary incontinence: effective or ephemeral?

PURPOSE

The aim of this article is to review the current state and technique of pubovaginal sling construction using cadaveric allograft fascia lata.

MATERIALS AND METHODS

A MEDLINE search was conducted to identify articles in the current literature addressing applications of cadaveric allograft fascia lata for surgical reconstructive procedures.

RESULTS

Current series evaluating cadaveric fascia lata allografts for pubovaginal sling find equivalent short-term outcomes when compared to autograft fascia. Long-term follow-up is not yet available for these series. Variability in tissue processing or host factors may account for some failures with cadaveric fascial slings.

CONCLUSIONS

Cadaveric fascia lata allografts are associated with reasonable efficacy and safety. Longer follow-up is needed. Further study of the relationship between tissue processing methods, surgical techniques, host factors, and outcome is indicated to better assess the long-term role of cadaveric fascia lata allograft for pubovaginal sling.