Impact of multimorbidity and complex multimorbidity on healthcare utilisation in older Australian adults aged 45 years or more: a large population-based cross-sectional data linkage study

OBJECTIVES

As life expectancy increases, older people are living longer with multimorbidity (MM, co-occurrence of ≥2 chronic health conditions) and complex multimorbidity (CMM, ≥3 chronic conditions affecting ≥3 different body systems). We assessed the impacts of MM and CMM on healthcare service use in Australia, as little was known about this.

DESIGN

Population-based cross-sectional data linkage study.

SETTING

New South Wales, Australia.

PARTICIPANTS

248 496 people aged ≥45 years who completed the Sax Institute's 45 and Up Study baseline questionnaire.

PRIMARY OUTCOME

High average annual healthcare service use (≥2 hospital admissions, ≥11 general practice visits and ≥2 emergency department (ED) visits) during the 3-year baseline period (year before, year of and year after recruitment).

METHODS

Baseline questionnaire data were linked with hospital, Medicare claims and ED datasets. Poisson regression models were used to estimate adjusted and unadjusted prevalence ratios for high service use with 95% CIs. Using a count of chronic conditions (disease count) as an alternative morbidity metric was requested during peer review.

RESULTS

Prevalence of MM and CMM was 43.8% and 15.5%, respectively, and prevalence increased with age. Across three healthcare settings, MM was associated with a 2.02-fold to 2.26-fold, and CMM was associated with a 1.83-fold to 2.08-fold, increased risk of high service use. The association was higher in the youngest group (45-59 years) versus the oldest group (≥75 years), which was confirmed when disease count was used as the morbidity metric in sensitivity analysis.When comparing impact using three categories with no overlap (no MM/CMM, MM with no CMM, and CMM), CMM had greater impact than MM across all settings.

CONCLUSION

Increased healthcare service use among older adults with MM and CMM impacts on the demand for primary care and hospital services. Which of MM or CMM has greater impact on risk of high healthcare service use depends on the analytic method used. Ageing populations living longer with increasing burdens of MM and CMM will require increased Medicare funding and provision of integrated care across the healthcare system to meet their complex needs.

The acceptability and usability of two HIV self‐test kits among men who have sex with men: a randomised crossover trial

Objectives

Design

Setting, participants

Main outcome measures

Results

Conclusion

Impact of multimorbidity and complex multimorbidity on mortality among older Australians aged 45 years and over: a large population-based record linkage study

OBJECTIVES

Multimorbidity (MM, co-occurrence of two or more chronic conditions) and complex multimorbidity (CMM, three or more chronic conditions affecting three or more different body systems) are used in the assessment of complex healthcare needs and their impact on health outcomes. However, little is known about the impacts of MM and CMM on mortality in Australia.

DESIGN

Community-based prospective cohort study.

SETTING

New South Wales, Australia.

PARTICIPANTS

People aged 45 years and over who completed the baseline survey of the 45 and Up Study.

MEASURES

Baseline survey data from the 45 and Up Study were linked with deaths registry data. Deaths that occurred within 8 years from the baseline survey date were the study outcome. Eleven self-reported chronic conditions (cancer, heart disease, diabetes, stroke, Parkinson's disease, depression/anxiety, asthma, allergic rhinitis, hypertension, thrombosis and musculoskeletal conditions) from the baseline survey were included in the MM and CMM classifications. Cox proportional hazard models were used to estimate adjusted and unadjusted 8-year mortality hazard ratios (HRs).

RESULTS

Of 251 689 people (53% female and 54% aged ≥60 years) in the cohort, 111 084 (44.1%) were classified as having MM and 39 478 (15.7%) as having CMM. During the 8-year follow-up, there were 25 891 deaths. Cancer (34.7%) was the most prevalent chronic condition and the cardiovascular system (50.9%) was the body system most affected by a chronic condition. MM and CMM were associated with a 37% (adjusted HR 1.36, 95% CI 1.32 to 1.40) and a 22% (adjusted HR 1.22, 95% CI 1.18 to 1.25) increased risk of death, respectively. The relative impact of MM and CMM on mortality decreased as age increased.

CONCLUSION

MM and CMM were common in older Australian adults; and MM was a better predictor of all-cause mortality risk than CMM. Higher mortality risk in those aged 45-59 years indicates tailored, person-centred integrated care interventions and better access to holistic healthcare are needed for this age group.

The longer-term effects of access to HIV self-tests on HIV testing frequency in high-risk gay and bisexual men: follow-up data from a randomised controlled trial

Background

A wait-list randomised controlled trial in Australia (FORTH) in high-risk gay and bisexual men (GBM) showed access to free HIV self-tests (HIVSTs) doubled the frequency of HIV testing in year 1 to reach guideline recommended levels of 4 tests per year, compared to two tests per year in the standard-care arm (facility-based testing). In year 2, men in both arms had access to HIVSTs. We assessed if the effect was maintained for a further 12 months.

Methods

Participants included GBM reporting condomless anal intercourse or > 5 male partners in the past 3 months. We included men who had completed at least one survey in both year 1 and 2 and calculated the mean tests per person, based on the validated self-report and clinic records. We used Poisson regression and random effects Poisson regression models to compare the overall testing frequency by study arm, year and testing modality (HIVST/facility-based test).

Findings

Overall, 362 men completed at least one survey in year 1 and 343 in year 2. Among men in the intervention arm (access to HIVSTs in both years), the mean number of HIV tests in year 2 (3⋅7 overall, 2⋅3 facility-based tests, 1⋅4 HIVSTs) was lower compared to year 1 (4⋅1 overall, 1⋅7 facility-based tests, 2⋅4 HIVSTs) (RR:0⋅84, 95% CI:0⋅75-0⋅95, p=0⋅002), but higher than the standard-care arm in year 1 (2⋅0 overall, RR:1⋅71, 95% CI:1⋅48-1.97, p<0⋅001). Findings were not different when stratified by sociodemographic characteristics or recent high risk sexual history.

Interpretation

In year 2, fewer HIVSTs were used on average compared to year 1, but access to free HIVSTs enabled more men to maintain higher HIV testing frequency, compared with facility-based testing only. HIV self-testing should be a key component of HIV testing and prevention strategies.

Funding

This work was supported by grant 568971 from the National Health and Medical Research Council of Australia.

Rapid HIV testing increases testing frequency among gay and bisexual men: a controlled before-after study

Background Rapid HIV testing was introduced at 12 clinics in New South Wales (NSW) for routine testing and promoted with social marketing. The effect of the availability of rapid HIV testing on testing frequency among gay and bisexual men (GBM) was evaluated.

METHODS

An observational design using patient data from 12 clinics was used. The primary outcome was the mean number of HIV tests in 12 months. The intervention group comprised GBM who had one or more rapid tests from October 2013 to September 2014 and this was compared with two control groups; a concurrent group (no rapid test in the same period) and a historical group (attended between July 2011 and June 2012). Independent sample t-tests were conducted to compare mean number of tests among men in the intervention, concurrent and historical groups. Multivariate logistic regression was used to assess the association between rapid HIV testing and testing frequency.

RESULTS

Men in the intervention group (n = 3934) had a mean of 1.8 HIV tests in 12 months, compared with 1.4 in the concurrent group (n = 5063; P < 0.001) and 1.4 in the historical group (n = 5904; P < 0.001); testing frequency was higher among men at increased risk of HIV in the intervention group compared with the other two groups (mean 2.2, 1.6 and 1.5 respectively; P < 0.001). Membership of the intervention group was associated with increased odds of having two or more HIV tests in 12 months (AOR = 2.5, 95%CI 2.2-2.8; P < 0.001) compared with the concurrent group, after controlling for demographic and behavioural factors.

CONCLUSION

Introducing and promoting rapid HIV testing in clinics in NSW was associated with increased HIV testing frequency among GBM.

HIV testing self-efficacy is associated with higher HIV testing frequency and perceived likelihood to self-test among gay and bisexual men

Background Regular testing of individuals at higher-risk of HIV is central to current prevention strategies. The aim of the present study was to examine the extent to which confidence in one's perceived ability to undertake various aspects of HIV testing and self-testing (self-efficacy) affected HIV testing outcomes. We assessed factors, including self-efficacy, associated with HIV testing frequency and the likelihood to self-test among gay and bisexual men (GBM).

METHODS

Participants were HIV-negative GBM at an increased risk of HIV (more than five partners or condomless anal intercourse in the previous 3 months) enrolled in a randomised controlled trial of HIV self-testing. The baseline questionnaire captured data regarding sociodemographic characteristics, HIV and/or sexually transmissible infection testing history, sexual behaviour, beliefs and attitudes towards HIV and eight items capturing confidence in HIV testing ability that were combined as a single broad measure of HIV testing self-efficacy (α=0.81). Factors associated with three or more HIV tests in the past year and the likelihood of self-testing in the future were determined using logistic regression.

RESULTS

Of 354 GBM, 34% reported three or more HIV tests in the past year, and 64% reported being 'very likely' to self-test. Factors independently associated with three or more HIV tests in the past year were: higher self-efficacy (adjusted odds ratio (aOR) 1.08 per unit increase; 95% confidence interval (CI) 1.02-1.14; P=0.004); >10 male partners in the past 6 months (aOR 1.79; 95% CI 1.05-3.04; P=0.031) and higher optimism regarding the effects of HIV treatments on HIV transmission (aOR 1.14; 95% CI 1.00-1.29; P=0.044). Only higher self-efficacy was independently associated with reporting a greater likelihood to self-test in the future (aOR 1.10; 95% CI 1.05-1.15; P < 0.001).

CONCLUSIONS

Improving self-efficacy by enhancing GBM's knowledge and experience may lead to higher testing frequency. The self-efficacy measure used in the present study could be useful in identifying GBM likely to face difficulties with HIV testing and self-testing.

Validation of participant eligibility for pre-exposure prophylaxis: Baseline data from the PRELUDE demonstration project

BACKGROUND

In Australia, pre-exposure prophylaxis (PrEP) is targeted to individuals at high risk for HIV infection. We describe the HIV risk profile and characteristics of PRELUDE participants, and evaluate the population validity of the sample in representing high-risk gay and bisexual men (GBM) eligible for PrEP.

METHODS

PRELUDE is an on-going, open-label, single-arm observational study. Participants were identified in clinics and screened for eligibility using a paper-based risk assessment tool which followed the New South Wales (NSW) PrEP guidelines. Selection was validated using an independent online behavioural survey, completed by study participants upon enrolment. Demographic information was analysed using descriptive statistics, and kappa tests were used to determine agreement between reporting of high-risk practices in the risk assessment and behavioural survey.

RESULTS

During 2014-15, 471 individuals were targeted for enrolment; 341 were assessed for PrEP eligibility and 313 were enrolled. Of these, 303 (97%) identified as GBM. Overall, 85% of GBM met at least one high-risk criterion; 68% reported receptive intercourse with an HIV-positive or unknown status casual male partner, and 37% reported methamphetamine use in the three months preceding enrolment. The remaining 15% were enrolled based on medium-risk behaviours, or at the clinicians' discretion. We found an 82% total agreement between self-reported high-risk behaviour and clinicians' categorisation of GBM as being at high risk for HIV based on PrEP eligibility criteria.

CONCLUSIONS

Behavioural eligibility criteria used by clinicians successfully identified individuals at high risk for HIV infection. This targeted approach ensures that the greatest public health and HIV prevention benefits can be derived in a setting without universal access to PrEP.

Effect of availability of HIV self-testing on HIV testing frequency in gay and bisexual men at high risk of infection (FORTH): a waiting-list randomised controlled trial

BACKGROUND

Frequent testing of individuals at high risk of HIV is central to current prevention strategies. We aimed to determine if HIV self-testing would increase frequency of testing in high-risk gay and bisexual men, with a particular focus on men who delayed testing or had never been tested before.

METHODS

In this randomised trial, HIV-negative high-risk gay and bisexual men who reported condomless anal intercourse or more than five male sexual partners in the past 3 months were recruited at three clinical and two community-based sites in Australia. Enrolled participants were randomly assigned (1:1) to the intervention (free HIV self-testing plus facility-based testing) or standard care (facility-based testing only). Participants completed a brief online questionnaire every 3 months, which collected the number of self-tests used and the number and location of facility-based tests, and HIV testing was subsequently sourced from clinical records. The primary outcome of number of HIV tests over 12 months was assessed overall and in two strata: recent (last test ≤2 years ago) and non-recent (>2 years ago or never tested) testers. A statistician who was masked to group allocation analysed the data; analyses included all participants who completed at least one follow-up questionnaire. After the 12 month follow-up, men in the standard care group were offered free self-testing kits for a year. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12613001236785.

FINDINGS

Between Dec 1, 2013, and Feb 5, 2015, 182 men were randomly assigned to self-testing, and 180 to standard care. The analysis population included 178 (98%) men in the self-testing group (174 person-years) and 165 (92%) in the standard care group (162 person-years). Overall, men in the self-testing group had 701 HIV tests (410 self-tests; mean 4·0 tests per year), and men in the standard care group had 313 HIV tests (mean 1·9 tests per year); rate ratio (RR) 2·08 (95% CI 1·82-2·38; p<0·0001). Among recent testers, men in the self-testing group had 627 tests (356 self-tests; mean 4·2 per year), and men in the standard care group had 297 tests (mean 2·1 per year); RR 1·99 (1·73-2·29; p<0·0001). Among non-recent testers, men in the self-testing group had 74 tests (54 self-tests; mean 2·8 per year), and men in the standard care group had 16 tests (mean 0·7 per year); RR 3·95 (2·30-6·78; p<0·0001). The mean number of facility-based HIV tests per year was similar in the self-testing and standard care groups (mean 1·7 vs 1·9 per year, respectively; RR 0·86, 0·74-1·01; p=0·074). No serious adverse events were reported during follow-up.

INTERPRETATION

HIV self-testing resulted in a two times increase in frequency of testing in gay and bisexual men at high risk of infection, and a nearly four times increase in non-recent testers, compared with standard care, without reducing the frequency of facility-based HIV testing. HIV self-testing should be made more widely available to help increase testing and earlier diagnosis.

FUNDING

The National Health and Medical Research Council, Australia.

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.

Rationale and design of FORTH: a randomised controlled trial assessing the effectiveness of HIV self-testing in increasing HIV testing frequency among gay and bisexual men

BACKGROUND

Gay and bisexual men (GBM) are a major risk group for HIV acquisition, yet the majority of higher-risk GBM test for HIV less often than recommended (3-6 monthly). HIV self-testing has the potential to increase testing frequency and improve awareness of personal HIV status. HIV self-tests have been approved in some countries, however there are concerns whether self-testing would increase HIV testing frequency enough to compensate for the reduced sensitivity of self-tests in early infection. We describe here a randomised controlled trial to assess the effectiveness of self-testing in increasing HIV testing frequency among higher-risk GBM, and its acceptability.

METHODS/DESIGN

Participants are higher-risk HIV negative GBM (>5 partners or condomless anal intercourse in previous 3 months; n = 350), including 50 GBM who tested for HIV over two years ago or never tested before ('infrequent-testers'). Participants are recruited from sexual health clinics and community-based organisations, and randomised 1:1 to either self-testing or standard-care (routine clinic-based testing) arms. The trial employs a wait-list control design: participants in the standard-care arm switch to self-testing arm in the second year, and gain access to self-test kits. Participants in the self-testing arm receive four oral-fluid self-test kits at enrolment, with additional kits provided on request. Demographics, sexual behaviour and HIV testing preferences are collected at baseline, and the frequency and pattern of HIV and sexually transmissible infection (STI) testing is collected via online 3-monthly questionnaires. The acceptability of self-testing is assessed at 12 months via an online questionnaire and in-depth interviews. A 24-h telephone support is provided, with expedited follow-up of those with reactive self-test results. The primary outcome is HIV testing frequency (mean number of HIV tests per person) over 12 months, and the secondary outcomes are: mean number of STI tests (chlamydia, gonorrhoea, syphilis) per person; reasons for HIV testing; and acceptability of HIV self-testing.

DISCUSSION

This is the first trial to evaluate the use of self-testing among GBM in Australia, and the first internationally among infrequent testers. The study will provide evidence on whether self-testing increases HIV testing frequency, and its acceptability among GBM. The findings will improve our understanding of self-testing patterns, and whether GBM supplement or replace their existing testing routine.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trial Registration number: ACTRN12613001236785 , registered on November 12, 2013.

Potential public health benefits of HIV testing occurring at home in Australia

In many countries, including Australia, policies have recently changed to support HIV self-testing. The decision has created much debate about the public health benefits of the strategy versus the risks. Self-testing for HIV was approved in the US on the basis that it would facilitate greater HIV testing uptake, despite having a lower sensitivity than laboratory HIV immunoassays. We calculated the frequency of self-testing that would be required among Australian gay and bisexual men at high-risk for there to be a public health benefit (detection of HIV infections that would have otherwise remained undiagnosed). At a population level, if access to HIV self-testing led to men supplementing their usual sexual health check-ups (involving a laboratory HIV immunoassay) with one or more self-tests at home, or self-tests led to untested gay and bisexual men having an HIV test for the first time, there would be a public health benefit. If men replaced their average of one laboratory HIV immunoassay per year with self-testing at home, then three self-tests would be needed to counteract the lower sensitivity of the self-test (so zero infections would be missed). If four self-tests were undertaken then additional infections would be detected (ie, there would be a public health benefit). Additional public health benefits include a reduction in the period of undiagnosed infection, which is known to be a period of relatively high infectiousness.

An evaluation of a novel dual treponemal/nontreponemal point-of-care test for syphilis as a tool to distinguish active from past treated infection

BACKGROUND

Most syphilis point-of-care (POC) tests detect treponemal antibodies, which persist after successful treatment. Subsequent POC tests are positive, despite no active infection, and can lead to unnecessary treatment. We evaluated a new POC test, incorporating a nontreponemal component, to distinguish active from past infection.

METHODS

Sera stored at 2 Australian laboratories were tested with DPP Screen and Confirm Assay. Treponemal and nontreponemal test lines were compared to corresponding conventional treponemal and nontreponemal reference test results: immunoassays and rapid plasma reagin (RPR), respectively, with RPR quantification by endpoint titration. POC test outcome concordance with conventional test results was assessed according to serological and clinical categories.

RESULTS

Among 1005 serum samples tested, DPP treponemal line sensitivity was 89.8% (95% confidence interval [CI], 87.3%-91.9%) and specificity was 99.3% (95% CI, 97.0%-99.9%). DPP nontreponemal line sensitivity was 94.2% (95% CI, 91.8%-96.0%) and specificity was 62.2% (95% CI, 57.5%-66.6%). DPP test outcome (pair of test lines) was concordant with both reference test results for 94.3% of 404 high-titer infections, 90.1% of 121 low-titer infections, 27.5% of 211 past/treated infections, and 78.1% of 242 infections classified as not syphilis. Among 211 past/treated infections, 49.8% were incorrectly identified as active infection and a further 22.8% as not syphilis.

CONCLUSIONS

DPP test use would result in identification of >93% of active syphilis infections, whereas just over half of past infections would be diagnosed as past or not syphilis, avoiding unnecessary treatment compared with other POC tests. This may be at the expense of missing some active infections; thus, its potential benefits will depend on the prevalence of past vs active infection in a population.

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.

Multi-centre evaluation of the Determine HIV Combo assay when used for point of care testing in a high risk clinic-based population

Background

Determine HIV Combo (DHC) is the first point of care assay designed to increase sensitivity in early infection by detecting both HIV antibody and antigen. We conducted a large multi-centre evaluation of DHC performance in Sydney sexual health clinics.

Methods

We compared DHC performance (overall, by test component and in early infection) with conventional laboratory HIV serology (fourth generation screening immunoassay, supplementary HIV antibody, p24 antigen and Western blot tests) when testing gay and bisexual men attending four clinic sites. Early infection was defined as either acute or recent HIV infection acquired within the last six months.

Results

Of 3,190 evaluation specimens, 39 were confirmed as HIV-positive (12 with early infection) and 3,133 were HIV-negative by reference testing. DHC sensitivity was 87.2% overall and 94.4% and 0% for the antibody and antigen components, respectively. Sensitivity in early infection was 66.7% (all DHC antibody reactive) and the DHC antigen component detected none of nine HIV p24 antigen positive specimens. Median HIV RNA was higher in false negative than true positive cases (238,025 vs. 37,591 copies/ml; p = 0.022). Specificity overall was 99.4% with the antigen component contributing to 33% of false positives.

Conclusions

The DHC antibody component detected two thirds of those with early infection, while the DHC antigen component did not enhance performance during point of care HIV testing in a high risk clinic-based population.

A laboratory-based evaluation of four rapid point-of-care tests for syphilis

Background

Syphilis point-of-care tests may reduce morbidity and ongoing transmission by increasing the proportion of people rapidly treated. Syphilis stage and co-infection with HIV may influence test performance. We evaluated four commercially available syphilis point-of-care devices in a head-to-head comparison using sera from laboratories in Australia.

Methods

Point-of-care tests were evaluated using sera stored at Sydney and Melbourne laboratories. Sensitivity and specificity were calculated by standard methods, comparing point-of-care results to treponemal immunoassay (IA) reference test results. Additional analyses by clinical syphilis stage, HIV status, and non-treponemal antibody titre were performed. Non-overlapping 95% confidence intervals (CI) were considered statistically significant differences in estimates.

Results

In total 1203 specimens were tested (736 IA-reactive, 467 IA-nonreactive). Point-of-care test sensitivities were: Determine 97.3%(95%CI:95.8–98.3), Onsite 92.5%(90.3–94.3), DPP 89.8%(87.3–91.9) and Bioline 87.8%(85.1–90.0). Specificities were: Determine 96.4%(94.1–97.8), Onsite 92.5%(90.3–94.3), DPP 98.3%(96.5–99.2), and Bioline 98.5%(96.8–99.3). Sensitivity of the Determine test was 100% for primary and 100% for secondary syphilis. The three other tests had reduced sensitivity among primary (80.4–90.2%) compared to secondary syphilis (94.3–98.6%). No significant differences in sensitivity were observed by HIV status. Test sensitivities were significantly higher among high-RPR titre (RPR≥8) (range: 94.6–99.5%) than RPR non-reactive infections (range: 76.3–92.9%).

Conclusions

The Determine test had the highest sensitivity overall. All tests were most sensitive among high-RPR titre infections. Point-of-care tests have a role in syphilis control programs however in developed countries with established laboratory infrastructures, the lower sensitivities of some tests observed in primary syphilis suggest these would need to be supplemented with additional tests among populations where syphilis incidence is high to avoid missing early syphilis cases.

Which gay men would increase their frequency of HIV testing with home self-testing?

Many Australian gay men do not get tested for HIV at the recommended frequency. Barriers to HIV testing may be reduced by the availability of home HIV self-testing (HHST). An online cross-sectional questionnaire was conducted with 2,306 Australian gay men during 2009. Multivariate logistic regression identified factors associated with being likely to increase testing frequency if HHST was available, among previously-tested and never-tested men. Among 2,018 non-HIV-positive men, 83.9% had been tested. Two-thirds indicated they would test more often if HHST was available irrespective of previous testing history. In multivariate analysis, independent predictors of increased testing frequency with HHST included preferences for more convenient testing, not having to see a doctor when testing and wanting immediate results among all men, as well as not being from an Anglo-Australian background and recent unprotected anal sex with casual partners among previously-tested men only. The majority of gay men report that being able to test themselves at home would increase their frequency of HIV testing.

Providing HIV-negative results to low-risk clients by telephone

Background In Australia, Health Department policies differ on the recommended method of providing HIV results. Traditionally, all results have been provided in person. Our aim was to trial provision of HIV-negative test results by telephone to low-risk clients attending sexual health services and to assess clients’ preferences for delivery method. Methods: During 4 months in 2009 at two sexual health services in Sydney, all clients assessed as low-risk for HIV infection were invited to receive their HIV result by telephone. Non-receipt of results was defined as failure to receive results within 30 days of the test being performed. Results: Of 763 clients tested, 328 (43%) were excluded following risk assessment, 30 (4%) declined to participate and 405 (53%) were enrolled. Among enrolled clients, 86% received their HIV result by telephone within 30 days, 97% were satisfied with delivery of the result by telephone and 93% preferred telephone delivery for their next HIV result. Only one enrolled client returned a positive HIV result. Independent predictors of receiving results within the 30-day timeframe were clinic attendance for sexually transmissible infection screening (P = 0.021), lack of anogenital symptoms (P = 0.015) and not being a sex worker (P = 0.001). Conclusions: In this study of telephone provision of HIV results to low HIV-risk clients, there were no adverse events and clients expressed satisfaction with the process plus a strong preference for telephone delivery of future results. There was a decreased rate of failure to receive HIV results compared with other Australian studies.

The efficacy of TAMUS 2032 in preventing a natural outbreak of colibacillosis in broiler chickens in floor pens

A 42-d floor pen study was conducted with broiler chickens comparing the effects on bird performance of 12 ppm TAMUS 2032 (also known as BT) and 55 ppm bacitracin methylene disalicyclate (BMD) when fed alone or in combination with 99 ppm monensin (MON). Unmedicated and 99 ppm MON treatments were included in the study design. Beginning on d 22 of study, birds in all 6 treatments were subjected to a modulated house temperature and airflow to mimic conditions conducive to outbreaks of colibacillosis. A natural outbreak of colibacillosis developed beginning on d 27. Primary lesions in dead birds included airsacculitis and pericarditis with occasional findings of perihepatitis. At d 42 of study, means for weight gain in the TAMUS 2032 and TAMUS 2032 + MON treatments were greater in comparison with the unmedicated and BMD treatments, and means for feed conversion for both treatments were improved in comparison with the unmedicated treatment. Mean feed conversion in the TAMUS 2032 + MON treatment was also improved in comparison with BMD treatment. Mortality due to colibacillosis was reduced in the TAMUS 2032 (0.051%), TAMUS 2032 + MON (0.642%), and MON + BMD (1.515%) treatments in comparison with the unmedicated treatment (13.402%) and the BMD treatment (11.159%). The results of improved performance and reduced mortality indicated that 12 ppm TAMUS 2032 was highly efficacious against colibacillosis in growing chickens. The reduced mortality percentages in the MON + BMD treatment indicated that this combination also provided a good level of protection against the natural outbreak of colibacillosis.

World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the efficacy of anticoccidial drugs in chickens and turkeys

These guidelines have been written to aid in the design, implementation and interpretation of studies for the assessment of drug efficacy against Eimeria species in chickens and turkeys. The information provided deals with many aspects of how to conduct controlled studies in battery cages (dose determination), floor pens (dose confirmation), and commercial facilities (field effectiveness studies), the selection of birds, housing, feeding, preparation of medicated rations, record keeping, diagnostic techniques, and methods for the preparation, maintenance and use of parasites. These guidelines are also intended to assist investigators in conducting specific studies, provide specific information for registration authorities involved in the decision-making process, assist in the approval and registration of new anticoccidial drugs, and facilitate the world-wide adoption of standard procedures.

The use of diclazuril in extended withdrawal anticoccidial programs: 2. Immunity to Eimeria tenella challenge after drug withdrawal

The effect of diclazuril medication on the development of natural immunity to Eimeria tenella was determined. Birds in two treatments, nonexposed, non-challenged (NENC) and nonexposed, challenged (NEC), were from a holding group raised under conditions designed to prevent coccidial infection. Birds in five other treatments, from the same hatch and source as birds in the first two treatments, were from a floor pen study involving a natural exposure to Eimeria spp. These birds were assigned to the current study based on their respective treatments in the original floor pen study as follows: unmedicated (UNM), 66 ppm salinomycin (SAL) + 50 ppm roxarsone in the starter and grower diets to Day 28 (SAL 28), 66 ppm SAL + 50 ppm roxarsone in the starter diet and 1 ppm diclazuril (DIC) in the grower diet to Day 28 (DIC 28) or to Day 35 (DIC 35), or in the grower and finisher diets to Day 42 (DIC 42). Each treatment comprised three floor pens of 10 birds (female) in a randomized complete block design. All birds were fed an UNM finisher diet during the 7-d challenge study. Birds in each treatment, except NENC, were individually inoculated (p.o.) with 1 x 10(5) Eimeria tenella sporulated oocysts on Day 1. Based on bird performance and cecal lesion scores, birds in the DIC 35 and 42 treatments had a low immunity to the challenge infection, birds in the DIC 28 treatment were partially immunized, and the highest levels of immunity were observed in the UNM and SAL 28 treatments.

The use of diclazuril in extended withdrawal anticoccidial programs: 1. Efficacy against Eimeria spp. in broiler chickens in floor pens

A 49-d floor pen study was conducted with broiler chickens to compare the effects of different anticoccidial withdrawal times on the efficacy of 1 ppm diclazuril. The starter diet in three treatments contained 66 ppm salinomycin + 50 ppm roxarsone (3-nitro-4-hydroxyphenylarsonic acid), followed by 1 ppm diclazuril in the grower diet commencing on Day 17. Diclazuril was withdrawn from these treatments on Day 28, 35, or 42 (finisher diet), respectively. Two other treatments in the study were given 66 ppm salinomycin + 50 ppm roxarsone in the starter and grower diets to Day 28 or no anticoccidial (unmedicated). The starter (Days 0 to 16), grower (Days 17 to 35), and finisher (Days 36 to 49) diets in each treatment included 55 ppm bacitracin methylene disalicylate for growth promotion. Fifty 1-d-old chicks were randomly allotted to each of 10 pens per treatment using a randomized complete block design. Birds in each pen were raised on litter naturally contaminated with a mixture of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. The results demonstrated that some performance loss occurred in the salinomycin Day 28 treatment. Means for weight gain and feed conversion on Day 49 were improved (P < 0.05) in each diclazuril treatment in comparison with the salinomycin and unmedicated treatments. Feed conversion means in the diclazuril Day 35 and Day 42 treatments were improved (P < 0.05) in comparison with the diclazuril Day 28 treatment, indicating that shorter withdrawal times provided further benefit.

Efficacy of diclazuril in comparison with chemical and ionophorous anticoccidials against Eimeria spp. in broiler chickens in floor pens

Two 42-d floor pen studies were conducted with commercial broiler chickens to measure the efficacy of 1 ppm diclazuril in the starter or grower diet in shuttle programs with 66 ppm salinomycin. Study 1 compared a salinomycin to diclazuril (starter to grower diet) shuttle treatment with salinomycin to salinomycin, salinomycin to 100 ppm monensin, salinomycin to 99.8 ppm lasalocid, and unmedicated treatments. Study 2 compared a diclazuril to salinomycin (starter to grower) shuttle treatment with 125 ppm nicarbazin to salinomycin, 79.2 ppm narasin + nicarbazin to salinomycin, 125 ppm zoalene to salinomycin, and unmedicated treatments. Fifty 1-d-old chicks were randomly allotted to each of 10 pens per treatment in each study using a randomized complete block design. Starter (Days 0 to 21) and grower (Days 22 to 37) diets in each study contained 55 ppm bacitracin methylene disalicylate. The finisher diet (Days 38 to 42) in each study was unmedicated. Birds were inoculated via their feed on Day 22 (Study 1) or Day 15 (Study 2) with a mixed inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Four birds per pen (two male and two female) were randomly selected in each study for coccidial lesion scores on Day 6 postinoculation. These studies demonstrated that the use of 1 ppm diclazuril in shuttle programs was highly efficacious against a mixed inoculum of Eimeria spp. in comparison with nicarbazin, narasin + nicarbazin, and zoalene in starter diets and salinomycin, monensin, and lasalocid in grower diets.

Comparative testing of anticoccidials in broiler chickens: the role of coccidial lesion scores

The relationship between oocyst dose and lesion score was evaluated in trials involving five field isolates each of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Each trial included an uninfected, unmedicated treatment, and at least three treatments of unmedicated birds given different doses of oocysts from a single isolate. In four trials each with E. acervulina and E. tenella, and all five trials with E. maxima, infected, salinomycin-medicated (60 ppm) treatments were included. Each treatment consisted of five cages with eight male broiler birds per cage using a randomized complete block design. The relationship between oocyst dose and lesion score was examined within each coccidial species using the linear model: Y = beta0 + beta1(log(n) oocyst dose + 1). The results demonstrated that in unmedicated birds, low oocyst doses caused mean lesion scores up to 2.0, but the numbers required to cause higher mean scores were many times greater. Second, the estimated oocyst dose in salinomycin-medicated birds for any given mean lesion score was substantially more than the corresponding estimate for unmedicated birds. These results indicated that there could be wide differences in levels of oocyst dose between unmedicated and medicated birds that lesion scores failed to measure. If lesion scores are used in trials comparing anticoccidial drugs, an alternative design may be to include three infected, unmedicated treatments each given a different level of inoculum (e.g., low, medium, and high). Medicated treatments, given the highest oocyst dose only, would then be compared to each of the infected, unmedicated treatments.

Effect of semduramicin, salinomycin, and monensin on performance, shank pigmentation, and coccidial lesions in broiler chickens in floor pens

The effects of 25 ppm semduramicin, 66 ppm salinomycin, 110 ppm monensin, and unmedicated treatments on performance, shank pigmentation, and coccidial lesion scores in broiler chickens were evaluated in two floorpen trials in the United States. On day 24 of each test, birds in each treatment were inoculated via the feed with a mixture of recent field isolates of Eimeria spp. at a dose rate calculated to provide 2 x 10(5) E. acervulina, 3 x 10(4) E. maxima, and 2 x 10(4) E. tenella sporulated oocysts per bird. Weight gain and feed conversion were significantly (P < or = 0.05) improved in the semduramicin-treated broilers in comparison with the monensin-treated and unmedicated broilers. These performance variables for the salinomycin-treated birds were intermediate between the semduramicin- and monensin-treated birds. Shank pigmentation scores were significantly (P < or = 0.05) improved in the three anticoccidial treatments compared with unmedicated birds, with the highest scores (P < or = 0.05) occurring in the semduramicin-treated broilers. Semduramicin was more efficacious (P < or = 0.05) than salinomycin in controlling upper intestinal lesions and more efficacious than monensin in controlling mid-intestinal lesions. All three drugs were comparable in controlling lesions in the ceca.

Efficacy of semduramicin and salinomycin against Eimeria maxima in a laboratory test using two levels of oocyst inocula

The anticoccidial efficacies of semduramicin and salinomycin against five field isolates of Eimeria maxima in broiler chickens were compared in five trials. Uninfected, unmedicated; infected, unmedicated; infected, 25 ppm semduramicin; and infected, 66 ppm salinomycin treatments were assigned to battery cages using a randomized, complete block design. Two levels of inocula, 10(3) and 10(4) oocysts per bird, were used in each trial in the infected treatments, creating a total of seven treatments per trial. Each treatment consisted of five replicate cages of eight broiler cockerels each. Medications were given in the feed continuously for 7 d beginning 24 h before inoculation. Response variables measured included bird weight gain by pen, feed consumption, feed conversion, plasma carotenoid concentrations, and coccidial lesion score. By using two levels of inocula it was demonstrated that the efficacy of each anticoccidial was equal to or greater than 90% in controlling these E. maxima isolates. It was also demonstrated that 25 ppm semduramicin was more efficacious than 66 ppm salinomycin based on improvements in weight gain, feed conversion, plasma carotenoid concentrations, and coccidial lesion control.

Anticoccidial efficacy of semduramicin. 2. Evaluation against field isolates including comparisons with salinomycin, maduramicin, and monensin in battery tests

The efficacy of semduramicin (AVIAX), a novel polyether ionophore, was profiled in a series of 57 battery tests conducted in the United States and the United Kingdom. The studies employed mixed and monospecific infections of Eimeria acervulina, Eimeria mivati/Eimeria mitis, Eimeria brunetti, Eimeria maxima, Eimeria necatrix, and Eimeria tenella derived from North American and European field isolates. Ten-day-old broiler cockerels in pens of 8 to 10 birds were continuously medicated in feed beginning 24 h before challenge in tests of 6 to 8 days' duration. At the use level of 25 ppm, semduramicin effectively controlled mortality, lesions, and weight gain depression that occurred in unmedicated, infected controls for all species. In comparison with 60 ppm salinomycin, semduramicin significantly (P < .05) improved weight gain against E. brunetti and E. tenella, lesion control against E. brunetti and E. maxima, and the control of coccidiosis mortality against E. tenella. Salinomycin was superior (P < .05) to all treatments in maintenance of weight gain and control of lesions for E. acervulina. Maduramicin at 5 ppm was inferior (P < .05) to semduramicin in control of E. acervulina and E. maxima lesions, but was superior (P < .05) to all treatments in maintenance of weight gain and control of lesions in E. tenella infections. The data indicate that semduramicin at 25 ppm is well tolerated in broilers and possesses broad spectrum anticoccidial activity.

Anticoccidial efficacy of semduramicin. 1. Evaluation against field isolates by dose titration in battery tests

Semduramicin (AVIAX), a novel polyether ionophore, was titrated in a series of five battery tests at 20, 25, and 30 ppm in feed to determine the optimum level for use. Twelve-day-old broiler chicks were medicated for 48 h prior to inoculation in each 9-day test. The inocula included monospecific field isolates of Eimeria tenella, Eimeria brunetti, Eimeria necatrix, and Eimeria maxima, and a mixture of these species with Eimeria acervulina and Eimeria mitis. The numbers of oocysts inoculated were selected after titration of each species and the mixture of species. All three concentrations of semduramicin significantly (P < .05) reduced coccidiosis mortality and lesion scores and achieved lower feed:gain ratios and greater weight gains than the infected, unmediated treatments. A concentration of 25 ppm semduramicin was determined to be optimal based on improved lesion control compared with 20 ppm and improved weight gain compared with 30 ppm.

"Spencer splint" for metacarpalphalangeal joint sprains

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Efficacy of semduramicin and salinomycin against different stages of Eimeria tenella and E. acervulina in the chicken

The efficacy of a new ionophore, semduramicin, was compared with salinomycin in a series of in ovo and in vivo trials. Semduramicin was more efficacious than salinomycin against Eimeria tenella sporozoites as judged by oocyst production in embryonated eggs. When the two drugs were given in ovo at 93 h post inoculation (PI), both drugs exerted some effect against late schizogonous stages of E. tenella. In three battery studies, semduramicin (25 ppm) and salinomycin (60 and 66 ppm) were tested against E. tenella and E. acervulina. Medicated feed was withdrawn at 24-h intervals PI to study the stage of action of the anticoccidials. In E. tenella infected chickens, both anticoccidials exerted their maximum effect on weight gain and feed:gain ratio through the first 72 h PI. Semduramicin was more effective than salinomycin in controlling E. tenella lesions and coccidiosis mortality. With E. acervulina, both drugs acted similarly on early life cycle stages and no improvement in performance was recorded when medicated feed was given for longer than 72 h. Semduramicin was more effective than salinomycin in controlling E. acervulina lesions.

Effects of different levels of oocyst inocula of Eimeria acervulina, E. tenella, and E. maxima on plasma constituents, packed cell volume, lesion scores, and performance in chickens

The effects of different levels of oocyst inocula of Eimeria acervulina, E. tenella, or E. maxima on plasma carotenoids, total plasma lipids, total plasma proteins, packed cell volume (PCV), bird performance, and coccidial lesion scores were determined in male Hubbard chickens. Each test consisted of an uninfected treatment and either four levels (E. tenella and E. maxima) or five levels (E. acervulina) of inocula. Carotenoids and lipids were significantly (P < or = 0.05) depressed by E. acervulina starting at 10(2) oocysts per bird, whereas 10(4) and higher inoculum levels significantly depressed plasma protein. Carotenoids and lipids were significantly depressed by E. tenella beginning at 10(4) oocysts per bird, whereas 10(2) oocysts per bird and greater levels significantly depressed plasma protein. E. maxima significantly depressed carotenoids and lipids beginning at 6.7 x 10(2) oocysts per bird and plasma protein at 6.7 x 10(4) oocysts per bird. PCV was depressed by E. acervulina and E. tenella starting at 10(4) oocysts per bird but was not affected by E. maxima. Weight gain was significantly depressed by E. acervulina beginning at 10(5) oocysts per bird, by E. tenella at 10(4) oocysts per bird, and by E. maxima at 6.7 x 10(4) oocysts per bird. Coefficients of determination (R2) were highest for carotenoids (0.96-0.99), followed by lipids (0.93-0.96), weight gain (0.89-0.91), feed:weight gain ratio (0.89-0.91), and protein and PCV (0.65-0.92). Results demonstrated that plasma carotenoids and lipids were excellent response variables for measuring the effects on broiler chickens of each of the Eimeria spp. tested.

Prophylactic medication with pyrantel to prevent liver condemnation in pigs naturally exposed to Ascaris infections

The use of pyrantel tartrate (106 mg/kg of feed) as a continuous feed medication was evaluated in 848 finishing hogs for efficacy in preventing Ascaris suum infections, and in reducing liver fibrosis and liver condemnation at slaughter, associated with A suum infections. Liver condemnations due to Ascaris damage were reduced 100% in all pigs given pyrantel, when compared with condemnation in non-medicated controls. None of the livers from any of the medicated animals was condemned, whereas livers from 101 (21%) of 479 nonmedicated pigs were condemned due to extensive hepatic scarring. Pyrantel medication administered for 62, 45, or 28 to 31 days resulted in reductions of total number of livers lesions at slaughter by 93.4%, 80.5%, and 68.6%, respectively. In nearly all cases, hepatic lesions remaining at slaughter of pigs given pyrantel in the feed were less distinct than were lesions found on livers from nonmedicated pigs.

The distribution of nematode eggs when using a dilution-egg-count procedure

By combining a number of well-known but scattered results, a theoretical model has been constructed to explain the observed quadratic increase in sample variance of egg counts over sample mean with increasing egg concentration. Our contention is that the over-dispersion arises because of inherent variation in volumetric deliveries of faecal suspension onto the counting slide. Even though the observed variation of volumetric deliveries appears to be small, we have shown that it is adequate to cause a considerable increase in egg count variance over mean at not unreasonably high concentrations.