Increased targeted HIV testing and reduced undiagnosed HIV infections among gay and bisexual men.

OBJECTIVES: To evaluate the impact of government HIV strategies that aimed to increase HIV testing uptake and frequency among gay and bisexual men (GBM) in New South Wales (NSW), Australia. DESIGN: We analysed HIV testing data from existing passive and sentinel surveillance systems between 2010 and 2018. METHODS: Six indicators were measured: (1) state-wide total HIV laboratory tests; (2) number of GBM attending publicly-funded clinics; (3) 12-monthly testing uptake; (4) annual testing frequency; (5) HIV testing with a STI diagnosis; and (6) HIV positivity. Mathematical modelling was used to estimate (7) the proportion of men with undiagnosed HIV. Indicators were stratified by Australian vs. overseas-born. RESULTS: Overall, 43,560 GBM attended participating clinics (22,662 Australian-born, 20,834 overseas-born) from 2010-2018. Attendees increased from 5,186 in 2010 to 16,507 in 2018. There were increasing trends (p<0.001 for all) in testing uptake (83.9% to 95.1%); testing with a STI diagnosis (68.7% to 94.0%); annual HIV testing frequency (1.4 to 2.7); and a decreasing trend (p<0.01) in HIV positivity (1.7% to 0.9%).Increases in testing were similar in Australian-born and overseas-born GBM. However, there were decreasing trends in the estimated undiagnosed HIV proportion overall (9.5% to 7.7%) and in Australian-born GBM (7.1% to 2.8%), but an increasing trend in overseas-born GBM (15.3% to 16.9%) (p<0.001 for all).

A longitudinal cohort study of HIV 'treatment as prevention' in gay, bisexual and other men who have sex with men: the Treatment with Antiretrovirals and their Impact on Positive And Negative men (TAIPAN) study protocol.

BACKGROUND: Australia has increased coverage of antiretroviral treatment (ART) over the past decade, reaching 73% uptake in 2014. While ART reduces AIDS-related deaths, accumulating evidence suggests that it could also bolster prevention efforts by reducing the risk of HIV transmission ('treatment as prevention'). While promising, evidence of community-level impact of treatment as prevention on reducing HIV incidence among gay and bisexual men is limited. We describe a study protocol that aims to determine if scale up of testing and treatment for HIV leads to a reduction in community viraemia and, in turn, if this reduction is temporally associated with a reduction in HIV incidence among gay and bisexual men in Australia's two most populous states. METHODS: Over the period 2009 to 2017, we will establish two cohorts making use of clinical and laboratory data electronically extracted retrospectively and prospectively from 73 health services and laboratories in the states of New South Wales and Victoria. The 'positive cohort' will consist of approximately 13,000 gay and bisexual men (>90% of all people living with HIV). The 'negative cohort' will consist of at least 40,000 HIV-negative gay and bisexual men (approximately half of the total population). Within the negative cohort we will use standard repeat-testing methods to calculate annual HIV incidence. Community prevalence of viraemia will be defined as the proportion of men with a viral load ≥200RNA copies/mm3, which will combine viral load data from the positive cohort and viraemia estimates among those with an undiagnosed HIV infection. Using regression analyses and adjusting for behavioural and demographic factors associated with infection, we will assess the temporal association between the community prevalence of viraemia and the incidence of HIV infection. Further analyses will make use of these cohorts to assess incidence and predictors of treatment initiation, repeat HIV testing, and viral suppression. DISCUSSION: This study will provide important information on whether 'treatment as prevention' is associated with a reduction in HIV incidence at a community level among gay and bisexual men.

Effect of testing experience and profession on provider acceptability of rapid HIV testing after implementation in public sexual health clinics in Sydney.

OBJECTIVES: Rapid HIV testing (RHT) is well established in many countries, but it is new in Australia since a policy change in 2011. We assessed service provider acceptability of RHT before and after its implementation in four Sydney public sexual health clinics. METHODS: Service providers were surveyed immediately after training in RHT and again 6-12 months later. Differences in mean scores between survey rounds were assessed via t-tests, with stratification by profession and the number of tests performed. RESULTS: RHT was rated as highly acceptable among staff at baseline and acceptability scores improved between survey rounds. Belief in being sufficiently skilled and experienced to perform RHT (P = 0.004) and confidence in the delivery of nonreactive results increased (P = 0.007), while the belief that RHT was disruptive declined (P = 0.001). Acceptability was higher for staff who had performed a greater number of tests regarding comfort with their role in RHT (P = 0.004) and belief that patients were satisfied with RHT (P = 0.007). Compared with nurses, doctors had a stronger preference for a faster rapid test (P = 0.027) and were more likely to agree that RHT interfered with consultations (P = 0.014). CONCLUSIONS: Differences in responses between professions may reflect differences in staff roles, the type of patients seen by staff and the model of testing used, all of which may affect the number of tests performed by staff. These findings may inform planning for how best to implement RHT in clinical services.

The acceptability of different HIV testing approaches: cross-sectional study among GMSM in Australia.

BACKGROUND: We explored the attitudes of Australian gay and other men who have sex with men (GMSM) about the current standard-of-care (non-rapid tests at healthcare settings) and alternative approaches (rapid tests and testing in non-healthcare settings) to better understand the acceptability of alternative testing approaches. METHODS: The Contemporary Norms in Networks and Communities of GMSM study enrolled GMSM in Sydney, Melbourne and Perth in 2011-2012 using peer referrals. We explored the self-reported preferences for testing: rapid versus non-rapid and in non-healthcare settings (community-based or home-based testing) versus in healthcare settings, and examined factors associated with preferences for these approaches. Analyses of associations used standard univariate and age-adjusted logistic regression models. RESULTS: Among 827 sexually active non-HIV-positive participants, 89% had been tested for HIV. Most preferred by participants was home rapid testing (46%), followed by standard-of-care (23%) and rapid testing in healthcare (20%) or community settings (7%). About 73% of participants preferred rapid over non-rapid testing, and 56% preferred testing in non-healthcare settings rather than in healthcare settings. Preference for rapid testing was associated with being fully employed (adjusted OR (aOR): 1.81; 95% CI 1.16 to 2.82), managerial/professional occupation (aOR: 2.03; 95% CI 1.19 to 3.46) and engaging in unprotected anal intercourse with casual partners (aOR: 1.89; 95% CI 1.29 to 2.78). The same factors were associated with preference for testing in non-healthcare settings. CONCLUSIONS: Australian GMSM prefer alternative testing approaches, possibly due to their convenience. The availability of new testing approaches may provide more options for GMSM at risk for HIV infection, improve access to HIV testing and potentially increase HIV testing rates.

Multi-centre field evaluation of the performance of the Trinity Biotech Uni-Gold HIV 1/2 rapid test as a first-line screening assay for gay and bisexual men compared with 4th generation laboratory immunoassays.

BACKGROUND: The Trinity Biotech Uni-Gold HIV test (Uni-Gold) is often used as a supplementary rapid test in testing algorithms. OBJECTIVE: To evaluate the operational performance of the Uni-Gold as a first-line screening test among gay and bisexual men (GBM) in a setting where 4th generation HIV laboratory assays are routinely used. STUDY DESIGN: We compared the performance of Uni-Gold with conventional HIV serology conducted in parallel among GBM attending 22 testing sites. Sensitivity was calculated separately for acute and established infection, defined using 4th generation screening Ag/Ab immunoassay (EIA) and Western blot results. Previous HIV testing history and results of supplementary 3rd generation HIV Ab EIA, and p24 antigen EIA were used to further characterise cases of acute infection. RESULTS: Of 10,793 specimens tested with Uni-Gold and conventional serology, 94 (0.90%, 95%CI:0.70-1.07) were confirmed as HIV-positive by conventional serology, and 37 (39.4%) were classified as acute infection. Uni-Gold sensitivity was 81.9% overall (77/94, 95%CI:72.6-89.1); 56.8% for acute infection (21/37, 95%CI:39.5-72.9) and 98.2% for established infection (56/57, 95%CI:90.6-100.0). Of 17 false non-reactive Uni-Gold results, 16 were acute infections, and of these seven were p24 antigen reactive but antibody negative. Uni-Gold specificity was 99.9% (10,692/10,699, 95%CI:99.9-100.0), PPV was 91.7% (95%CI:83.6-96.6) and NPV was 99.8% (95%CI:99.7-99.9), respectively. CONCLUSIONS: In this population, Uni-Gold had good specificity and sensitivity was high for established infections when compared to 4th generation laboratory assays, however sensitivity was lower in acute infections. Where rapid tests are used in populations with a high proportion of acute infections, additional testing strategies are needed to detect acute infections.

Deficient axonal transport of substance P in streptozocin-induced diabetic rats. Effects of sorbinil and insulin.

This study measured the accumulation of substance P-like immunoreactivity (SPLI) proximal and distal to 12-h constricting ligatures applied to rat sciatic nerves. There were three separate experiments, and the baseline for each consisted of control and age-matched rats with 3 wk of untreated streptozocin-induced diabetes. We compared the effects of twice-daily insulin treatment, daily sorbinil (25 mg.kg-1.day-1 p.o.), and a combination of both treatments. In untreated diabetic rats the anterograde accumulation of SPLI was reduced by 30-40%. This deficit was unaffected by sorbinil alone but was attenuated by insulin and prevented completely by insulin and sorbinil combined. There were also indications that diabetes caused reductions in retrograde accumulation of SPLI and its content in unconstricted nerve and the L4 dorsal root ganglion. The fraction of SPLI undergoing net anterograde or retrograde movement and the velocities of accumulation were unaffected by diabetes or the treatment regimens. These findings indicate a reduction in the amount of substance P moved by axonal transport in diabetic rats that is related partly to aldose reductase activity and partly to some other insulin-correctable consequence of experimental diabetes.

Regulation of phagolysosome pH in bovine and human neutrophils: the role of NADPH oxidase activity and an Na+/H+ antiporter.

Fluorescein-labelled Staphylococcus aureus were used to follow changes in phagolysosome (PL) pH of bovine and human neutrophils following phagocytosis. Under aerobic conditions there was an alkalinisation of the PL followed by a slow decline. Under anaerobic conditions no alkalinisation of the PL was seen, and pharmacological inhibition of the NADPH oxidase with diphenyleneiodonium (DPI) resulted in a rapid acidification of the PL following phagocytosis. The inclusion of amiloride, an inhibitor of Na+/H+ antiporter activity, produced a more rapid alkalinisation phase following phagocytosis under aerobic conditions and reduced, but did not abolish, the acidification phases seen under anaerobic conditions or following treatment of neutrophils with DPI. The results suggest that PL pH is influenced by NADPH oxidase activity and to a lesser extent by a Na+/H+ antiporter. The antibacterial effectiveness of neutrophil granule proteins may be affected under conditions that influence the functioning of these two systems.

Selective uptake of [3H]glutamine and [3H]glutamate into neurons and satellite cells of dorsal root ganglia in vitro.

The uptake of [3H]glutamate and [3H]glutamine into rat dorsal root ganglia has been examined by autoradiography and thin-layer chromatography. [3H]glutamate was selectively accumulated by satellite glial cells and after 10 min, 53% of this had been converted to [3H]glutamine. [3H]glutamine, on the other hand, entered neuronal perikarya and 40% was converted to [3H]glutamate. It is suggested that these selective uptake processes provide supporting evidence for the existence of a neuronal-glial glutamine cycle in dorsal root ganglia. Small dark (B) cells accumulated 6 times as much [3H]glutamine as did large light (A) cells. The reasons for this marked difference in the metabolism of the two main types of dorsal root ganglion neurone are discussed.

A quantitative analysis of the interrelationships between subpopulations of rat sensory neurons containing arginine vasopressin or oxytocin and those containing substance P, fluoride-resistant acid phosphatase or neurofilament protein.

In rat L5 dorsal root ganglia 50% of neurons contained arginine vasopressin-like immunoreactivity and 38% oxytocin-like immunoreactivity, the oxytocin entirely coexisting with the arginine vasopressin. Staining of alternate mirror-image sections with RT97 (an antibody to neurofilament protein, and a marker for large light neurons) and with arginine vasopressin antiserum showed that the two were entirely complementary, thus establishing arginine vasopressin as a marker for all small dark neurons. Mirror-image staining also showed that neurons containing substance P-like immunoreactivity and those containing fluoride-resistant acid phosphatase activity were each contained within the arginine vasopressin-positive population. Arginine vasopressin-like immunoreactivity was axonally transported in the dorsal root and (in greater quantity) in sciatic nerve. Arginine vasopressin-like immunoreactivity was present also in laminae I and II of the dorsal horn of the spinal cord and this reactivity was absent in animals which had been treated neonatally with capsaicin, suggesting that it was contained in primary afferent terminals. These results are discussed in terms of their implications for the classification of primary afferent neurons and of a possible physiological role for arginine vasopressin in these neurons.

Corneal sensitivity and substance P in experimental herpes simplex keratitis in mice.

Experimental herpes simplex keratitis in the mouse produced a rapid fall in both corneal sensitivity and levels of corneal substance P (SP). This finding supports the association of SP with sensory neurones and shows that such levels can be used as an indication of damage to neurones resulting, for example, from infection with HSV. However, the delay in recovery of SP compared to the more rapid and complete recovery of sensitivity suggests that SP in the cornea is not directly involved in mediation of the blink reflex.

The effect of nerve stimulation on the axonal transport of noradrenaline and dopamine-beta-hydroxylase.

1 A method for stimulating the lumbar sympathetic outflow from the spinal cord of the rat is described which does not require artificial respiration of the animal.2 In some, but not all experiments continuous stimulation at 2 Hz or intermittently at 10 Hz accelerated the rate at which noradrenaline and dopamine-beta-hydroxylase accumulated central to a ligature on the sciatic nerve by approximately 40%.3 It is concluded that, although nervous activity is not necessary for axonal transport of transmitter granules in sympathetic neurones, intense nervous activity may accelerate the rate of granule transport.

Morphine, but not sodium cromoglycate, modulates the release of substance P from capsaicin-sensitive neurones in the rat trachea in vitro.

1. Opioids have been shown to inhibit substance P (SP) release from primary afferent neurones (PAN). In addition, opioid receptors have been identified on PAN of the vagus nerves. Sodium cromoglycate (SCG) decreases the excitability of C-fibres in the lung of the dog in vivo. We have utilised a multi-superfusion system to investigate the effect of opioids and SCG on the release of SP from the rat trachea in vitro. 2. Pretreatment of newborn rats with capsaicin (50 mg kg-1 s.c. at day 1 and 2 of life) resulted in a 93.2 +/- 6.3% reduction in tracheal substance P-like immunoreactivity (SP-LI) content when determined by radioimmunoassay in the adult. 3. Exposure to isotonically elevated potassium concentrations (37-90 mM), capsaicin (100 nM-10 microM), and bradykinin (BK; 10nm-1 microM) but not des-Arg9-BK (1 microM) stimulated SP-LI release by a calcium-dependent mechanism. 4. SCG (1 microM and 100 microM) did not affect spontaneous, potassium (60 mM)- or BK (1 microM)-stimulated SP-LI release. 5. Morphine (0.1-100 microM) caused dose-related inhibition of potassium (60 mM)-stimulated SP-LI release with the greatest inhibition of 60.4 +/- 13.7% at 100 microM. The effect of morphine was not mimicked by the kappa-opioid receptor agonist, U50,488H (10 microM) or the delta-opioid receptor agonist, Tyr-(D-Pen)-Gly-Phe-(D-Pen) (DPDPE). 6. The effect of morphine was totally abolished by prior and concomitant exposure to naloxone (100 nM) which had no effect on control release values. 7. We conclude that opioid receptors, predominantly of the MM-opioid receptor subtype, inhibit SP-LI release from PAN in the rat trachea and suggest that centrally inactive MM-opioid receptor agonists may have therapeutic potential in the treatment of asthma.

GABAB receptor modulation of the release of substance P from capsaicin-sensitive neurones in the rat trachea in vitro.

1. The role of gamma-aminobutyric acid (GABA) as an inhibitory transmitter in the central nervous system is well documented. Recently, GABAA and GABAB receptors have been identified in the peripheral nervous system, notably on primary afferent neurones (PAN). We have utilised a multi-superfusion system to investigate the effect of selective GABA receptor agonists and antagonists on the release of substance P (SP) from the rat trachea in vitro. 2. GABA (1-100 microM) did not affect spontaneous release of SP-like immunoreactivity (LI) but caused dose-related inhibition of calcium-dependent potassium (60 mM)-stimulated SP-LI release. The greatest inhibition of 77.7 +/- 18.8% was observed at 100 microM. 3. The inhibitory effect of GABA was mimicked by the GABAB receptor agonist, (+/-)-baclofen (1-100 microM), but not the GABAA receptor agonist, 3-amino-1-propane-sulphonic acid (3-APS, 1-100 microM). Baclofen (100 microM) had no effect on SP-LI release stimulated by capsaicin (1 microM). 4. The inhibitory effect of baclofen (30 microM) was significantly reduced by prior and concomitant exposure to the GABAB receptor antagonist, phacolofen (100 microM) but not the GABAA receptor antagonist, bicuculline (10 microM). Neither antagonist, alone, affected spontaneous or potassium-stimulated SP-LI release. 5. We conclude that activation of pre-synaptic GABAB receptors on the peripheral termini of PANs in the rat trachea inhibits SP-LI release and suggest that GABAB receptor agonists may be of value in the therapeutic treatment of asthma.

Effect of cutting or crushing the rat sciatic nerve on synthesis of substance P by isolated L5 dorsal root ganglia.

Following cutting or crushing the rat sciatic nerve, synthesis of substance P by L5 dorsal root ganglia in vitro was reduced respectively to 20 and 40 per cent of control values. By day 64 the ability to synthesise substance P had been fully restored in crushed neurones but in cut neurones remained at a low level. We conclude that substance P synthesis is a more sensitive index of the effect of nerve injury than is substance P content and further that regenerating axons are able to support substance P synthesis before they reach their target tissue.

Chemical characterization of substance P-like immunoreactivity in primary afferent neurones.

Substance P-like immunoreactivity (SPLI) in rat dorsal root ganglia and dorsal spinal cord was characterized by high-performance liquid chromatography followed by radioimmunoassay. In spinal cord and ganglia, respectively, 87% and 64% of SPLI eluted with authentic SP. The remainder of the SPLI in ganglia eluted as a single peak which did not represent the sulphoxide of SP or any of its C-terminal fragments.

Synthesis, and central and peripheral axonal transport of substance P in a dorsal root ganglion-nerve preparation in vitro.

A preparation of the rat L5 dorsal root ganglion with 6 mm lengths of dorsal root and peripheral branch attached was incubated in vitro over a 9 h period. The substance P-like immunoreactivity (SPLI) of the preparation increased linearly with time and SPLI was transported down both branches. The turnover-time of ganglion SPLI was 3.6 h. Four times as much SPLI accumulated in the peripheral branch as in the dorsal root. When axonal transport was inhibited by demecolcine, SPLI was formed at the same rate but accumulated in the ganglion. Anisomycin inhibited SPLI synthesis after a delay of 2 h. It was apparent that the SPLI of the preparation was contained in two pools, only one of which underwent rapid axonal transport. The mobile pool of axonal SPLI comprised 30% of the total and moved with a velocity of 4.9 mm . h-1.

Reciprocal regulation of tachykinin- and vasoactive intestinal peptide-gene expression in rat sensory neurones following cut and crush injury.

The relative abundance of preprotachykinin- (PPT), actin- and vasoactive intestinal peptide- (VIP) mRNA's was measured in L5 dorsal root ganglia of rats after resecting or crushing the sciatic nerve. PPT-mRNA levels fell to 40% of control values 3, 6 and 9 days following nerve resection. Crushing produced a lesser fall at 3 and 6 days with a partial recovery at 9 days. Following resection actin-mRNA levels transiently rose to twice control values and had returned to normal by day 9. VIP-mRNA was not detectable in control ganglia but increasing amounts of VIP-mRNA were present 3, 6 and 9 days after nerve injury. The results are discussed in terms of the control mechanisms operating.

Regeneration of primary afferent neurons containing substance P-like immunoreactivity.

We compared changes in levels of substance P-like immunoreactivity (SPLI) in L4-6 dorsal root ganglia (DRG), L4-6 dorsal roots, sciatic nerve, tibial nerve and hind foot skin in rats following resection or crush injury of the sciatic nerve. The initial depletion of SPLI, which occurred in all areas sampled, was similar after either type of lesion. In DRG and dorsal roots, recovery to control values occurred in SPLI levels 35-45 days after sciatic crush, but not after resection. In sciatic nerve proximal to the injury, a partial recovery in SPLI content to about 60% of control occurred following crush injury, but not following resection. Distal to the injury, tibial nerve levels recovered rapidly following crush injury, consistent with the previously observed rapid regeneration of SPLI-containing axons. After resection, no recovery was observed until after 35 days, when it appeared that some axons succeeded in crossing the resection zone and regaining the distal nerve stump. Delayed and poor recovery of SPLI levels was observed in foot skin, even after crush injury. This correlated with the poor recovery of the plasma extravasation reaction, a functional index of SP-innervation of skin. In contrast, reinnervation by high-threshold mechanoreceptors was more rapid and complete, in agreement with a previous study. We conclude that although SPLI-containing axons regenerate rapidly, they appear to reinnervate skin less successfully than other afferents. Axon regeneration is associated with a recovery of SPLI levels which fell after axotomy: no recovery occurs if regeneration is prevented. Recovery was almost complete in DRG and roots, but incomplete in sciatic nerve. This peptide transmitter in afferent neurons thus behaves in a similar fashion to previously studied low-molecular weight transmitters and related materials in efferent neurons. Since recovery of SPLI levels begins before there is evidence for target reinnervation, it seems that axon regeneration is a sufficient condition for reversal of some axotomy-induced changes in these neurons. Further studies on substance P synthesis and on the response of individual DRG neurons to axotomy and regeneration will be required to explain fully the discrepancy between partial recovery of SPLI levels in sciatic nerve and full recovery in DRG and dorsal roots.

Axonal transport of substance P-like immunoreactivity in regenerating rat sciatic nerve.

Anterograde axonal transport of substance P-like immunoreactivity (SPLI) decreases after injury (crush or resection) to rat sciatic nerve. If the axons regenerate a partial recovery of transport occurs. If regeneration is impeded the decrease in transport is more severe and prolonged. No changes in the proportion of mobile SPLI (31%) or transport velocity (10.0 mm/h) occur. The decrease in SPLI transport largely accounts for the decline in SPLI content which occurs in nerve following injury and probably reflects decreased cell body synthesis.