HIV eradication symposium: will the brain be left behind?

On 18 July 2014, the National Institute of Mental Health in collaboration with ViiV Health Care and Boehringer Ingelheim supported a symposium on HIV eradication and what it meant for the brain. The symposium was an affiliated event to the 20th International AIDS Conference. The meeting was held in Melbourne, Australia, and brought together investigators currently working on HIV eradication together with investigators who are working on the neurological complications of HIV. The purpose of the meeting was to bring the two fields of HIV eradication and HIV neurology together to foster dialogue and cross talk to move the eradication field forward in the context of issues relating to the brain as a potential reservoir of HIV. The outcomes of the symposium were that there was substantive but not definitive evidence for the brain as an HIV reservoir that will provide a challenge to HIV eradication. Secondly, the brain as a clinically significant reservoir for HIV is not necessarily present in all patients. Consequently, there is an urgent need for the development of biomarkers to identify and quantify the HIV reservoir in the brain. Lastly, when designing and developing eradication strategies, it is critical that approaches to target the brain reservoir be included.

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.

Symptoms of depression and rates of neurocognitive impairment in HIV positive patients in Beijing, China.

BACKGROUND: In China an estimated 780,000 people are living with HIV (PLWH). In high-income countries PLWH are at increased risk of depression, with subsequent adverse consequences for quality of life, and HIV-related morbidity and mortality. There are few data from low-and middle-income countries. The aims of this country-specific investigation of the Asia Pacific NeuroAIDS Consortium (APNAC) study were to establish the point prevalence, severity and HIV-related and non-HIV related correlates of depressive symptoms in PLWH, in Beijing, China. METHOD: PLWH attending an outpatient clinic at Ditan Hospital, Beijing were recruited consecutively. Data sources were: study-specific questions about demographic characteristics, and health behaviours, the Centre for Epidemiological Studies Depression Scale (CES-D), the World Health Organisation Self-Reporting Questionnaire (SRQ-20) translated into Mandarin and administered as structured individual interviews, and a screen battery of four standard neuropsychological tests. RESULTS: In total 50/51 (98%) eligible patients agreed to participate. Overall 28% scored CES-D≥16 or SRQ20≥10 and 18% in these clinical ranges on both measures; 69% were classified as being neuropsychologically impaired (scoring below 1 SD of the control value on at least two tests). Higher depressive symptom scores were associated with lower education, alcohol overuse and diminished motor ability (all p<0.05), but not neuropsychological impairment CONCLUSION: Clinically significant depressive symptoms among this cohort of PLWH in Beijing occurred at 5 times the rate reported among a general Chinese urban population. No participants had been assessed for depression prior to the study and none were treated, indicating that consideration of psychological morbidity and its consequences for health behaviours should be incorporated into routine HIV care in China.

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.

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 resection­a 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.

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.

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.

HCV treatment with pegylated interferon and ribavirin in patients with haemophilia and HIV/HCV co-infection.

Individuals with haemophilia are frequently infected with both human immunodeficiency virus (HIV) and hepatitis C virus (HCV); however, limited evidence is currently available regarding the efficacy of HCV treatment with pegylated interferon and ribavirin in this patient population. The aim of this study was to review HCV treatment outcomes in a cohort of patients with haemophilia and HIV/HCV co-infection. A retrospective, single centre review of 13 consecutive patients treated with pegylated interferon and ribavirin was performed. All patients were male with haemophilia A and a median age of 43 (range 27-62) at initiation of HCV therapy. Nine of 13 (69%) patients had genotype (gt1) 1 HCV (3 x gt3, 1 x gt4). Twelve of 13 (92%) were receiving ART, with a mean CD4+ count of 428 cells microL(-1) (range 175-928 cells microL(-1)) at initiation of HCV therapy. Six of 11 (55%) patients achieved EVR (3 x gt1, 2 x gt3, 1 x gt4) at 12 weeks, 4/13 (31%) had EOTR (2 x gt1, 2 x gt3) and 1/13 (8%) achieved sustained virological response (1 x gt1). Seven of 11 (64%) patients normalized ALT during therapy wherein mean ALT fell from 101 to 76 U L(-1). Only 1/13 (8%) patients discontinued therapy prematurely due to side effects. CD4+ cell counts and HIV viral load remained stable during HCV treatment, with a mean 437 cells microL(-1) and <50 copies mL(-1) at 48 weeks respectively. Patients in our cohort with haemophilia and HCV/HIV co-infection responded poorly to HCV treatment. Alternative HCV treatment strategies need to be considered in patients with haemophilia and HIV/HCV co-infection.

Quantifying within- and between-animal variation and uncertainty associated with counts of Escherichia coli O157 occurring in naturally infected cattle faeces.

Cattle faeces are considered the most important reservoir for human infection with Escherichia coli O157. We have previously described shedding of E. coli O157 in the faeces of naturally infected cattle cohorts. However, the data require further investigation to quantify the uncertainty and variability in the estimates previously presented. This paper proposes a method for analysing both the presence and the quantity of E. coli O157 in cattle faecal samples, using two isolation procedures, one of which enumerates E. coli O157. The combination of these two measurements, which are fundamentally different in nature and yet measuring a common outcome, has necessitated the development of a novel statistical model for ascertaining the contribution of the various components of variation (both natural and observation induced) and for judging the influence of explanatory variables. Most of the variation within the sampling hierarchy was attributable to multiple samples from the same animal. The contribution of laboratory-level variation was found to be low. After adjusting for fixed and random effects, short periods of increased intensity of shedding were identified in individual animals. We conclude that within-animal variation is greater than between animals over time, and studies aiming to elucidate the dynamics of shedding should focus resources, sampling more within than between animals. These findings have implications for the identification of persistent high shedders and for assessing their role in the epidemiology of E. coli O157 in cattle populations. The development of this non-standard statistical model may have many applications to other microbial count data.

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.

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.

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.

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.

Assessment of Australian Trichogramma species (Hymenoptera: Trichogrammatidae) as control agents of stored product moths.

Trichogramma species (T. brassicae, T. pretiosum and T. carverae) were assessed for their suitability as bio-control agents against Ephestia cautella and E. kuehniella which are important pests in food manufacturing and processing facilities in Australia. Parameters examined were longevity, fecundity on eggs of E. kuehniella, walking speed of adult wasps, reaction to moth scales, and host acceptance and host suitability of eggs of E. cautella and E. kuehniella. T. pretiosum and T. carverae performed better than T. brassicae in all traits examined apart from fecundity. T. pretiosum and T. carverae differ mainly in higher fecundity and host acceptance in T. pretiosum, and a better host-finding ability (walking speed, reaction to moth scales) in T. carverae. The suitability of the Trichogramma species for use as control agents is discussed with respect to these results.