Sensitivity and specificity of pooled faecal culture and serology as flock-screening tests for detection of ovine paratuberculosis in Australia

The flock-level sensitivity of pooled faecal culture and serological testing using AGID for the detection of ovine Johne's disease-infected flocks were estimated using non-gold-standard methods. The two tests were compared in an extensive field trial in 296 flocks in New South Wales during 1998. In each flock, a sample of sheep was selected and tested for ovine Johne's disease using both the AGID and pooled faecal culture. The flock-specificity of pooled faecal culture also was estimated from results of surveillance and market-assurance testing in New South Wales. The overall flock-sensitivity of pooled faecal culture was 92% (95% CI: 82.4 and 97.4%) compared to 61% (50.5 and 70.9%) for serology (assuming that both tests were 100% specific). In low-prevalence flocks (estimated prevalence

Methadone maintenance treatment reduces heroin injection in New South Wales prisons

The purpose of this study was to examine whether methadone maintenance treatment reduces injecting risk behaviour land therefore transmission of blood-borne viral infections) among prisoners in New South Wales (NSW), using comparison of retrospective reports of drug use in prisons for people who received standard drug treatment, time-limited methadone treatment and methadone maintenance treatment, The setting for the study was the NSW prison system. One hundred and eighty-five injecting drug users who had been recently released from NSW prisons were recruited in 1993, Self-reported drug use and injecting risk behaviour were compared in inmates who received standard drug treatment (counselling), time-limited methadone treatment and methadone maintenance treatment. HIV status was determined by serology, Intervention comprised high and low dose methadone treatment and counselling. The groups were similar in terms of most basic demographic characteristics but subjects who had been maintained on methadone reported a significantly lower prevalence of heroin injection, syringe sharing and scored lower on an HIV Risk-taking Behavioural Scale than subjects who received standard drug treatment and time-limited methadone treatment, This study suggests that methadone treatment is associated with reduced injecting risk behaviour in prison with adequate (greater than 60 mg) dose and duration in treatment. These treatment conditions are known to increase effectiveness in community-based methadone programmes. Prospective studies are required to evaluate the effectiveness of methadone programmes in the prevention of HIV and other blood-borne viral infections among IDU prisoners.

Epizootic activity of Murray Valley encephalitis virus in an aboriginal community in the southeast Kimberley region of western Australia: Results of cross-sectional and longitudinal serologic studies

Murray Valley encephalitis (MVE) virus is a mosquito-borne flavivirus causing severe encephalitis with a resultant high morbidity and mortality. In the period 1989-1993. we undertook a cross-sectional and longitudinal studs by annually screening members of a small remote Aboriginal community in northwestern Australia for MVE virus antibodies. Of the estimated 250-300 people in the community. 249 were tested, and 52.6% had positive serology to MVE. The proportion testing positive increased with increasing age group. and males were slightly more likely to be positive than females. During the study period. a high proportion of the population seroconverted to MVE: the clinical/subclinical ratio seems to be lower than previously reported. Although MVE is mostly asymptomatic, the devastating consequences of clinical illness indicate that advice should be provided regarding the avoidance of mosquito bites. Our longitudinal study showed that the risk of seroconversion was similar for each age group. not just the young.

Toxoplasmosis in Indo-Pacific humpbacked dolphins (Sousa chinensis), from Queensland

Objective To describe the clinical signs, gross pathology, serology, bacteriology, histopathology, electron microscopy and immunohistochemistry findings associated with toxoplasmosis in four Indo-Pacific humpbacked dolphins (Sousa chinensis) that stranded in Queensland in 2000 and 2001. Design Clinical assessment, gross necropsy, and laboratory examinations. Procedure Necropsies were performed on four S chinensis to determine cause of death. Laboratory tests including serology, bacteriology, histopathology and transmission electron microscopy were done on the four dolphins. Immunohistochemistry was done on the brain, heart, liver, lung, spleen and adrenal gland from various dolphins to detect Toxoplasma gondii antigens. Results Necropsies showed all of four S chinensis that stranded in Queensland in 2000 and 2001 had evidence of predatory shark attack and three were extremely emaciated. Histopathological examinations showed all four dolphins had toxoplasmosis with tissue cysts resembling T gondii in the brain. Tachyzoite stages of T gondii were detected in the lungs, heart, liver, spleen and adrenal gland, variously of all four dolphins. Electron microscopy studies and immunohistochemistry confirmed the tissues cysts were those of T gondii. All four dolphins also had intercurrent disease including pneumonia, three had peritonitis and one had pancreatitis. Conclusion Four S chinensis necropsied in Queensland in 2000 and 2001 were found to be infected with toxoplasmosis. It is uncertain how these dolphins became infected and further studies are needed to determine how S chinensis acquire toxoplasmosis. All four dolphins stranded after periods of heavy rainfall, and coastal freshwater runoff may be a risk factor for T gondii infection in S chinensis. This disease should be of concern to wildlife managers since S chinensis is a rare species and its numbers appear to be declining.

Polymerase chain reaction tests for the identification of Ross River, Kunjin and Murray Valley encephalitis virus infections in horses

Objective To develop and validate specific, sensitive and rapid diagnostic tests using RT-PCR for the detection of Ross River virus (RRV), Kunjin virus (KV) and Murray Valley encephalitis virus (MVEV) infections in horses. Methods Primer sets based on nucleotide sequence encoding the envelope glycoprotein E2 of RRV and on the nonstructural protein 5 (NS5) of KV and MVEV were designed and used in single round PCRs to test for the respective viruses in infected cell cultures and, in the case of RRV, in samples of horse blood and synovial fluid. Results The primer pairs designed for each of the three viruses amplified a product of expected size from prototype viruses that were grown in cell culture. The identity of each of the products was confirmed by nucleotide sequencing indicating that in the context used the RT-PCRs were specific. RRV was detected in serums from 8 horses for which there were clinical signs consistent with RRV infection such that an acute-phase serum sample was taken and submitted for RRV serology testing. The RRV RT-PCR was analytically sensitive in that it was estimated to detect as little as 50 TCID50 of RRV per mL of serum and was specific in that the primer pairs did not amplify other products from the 8 serum samples. The RRV primers also detected virus in three independent mosquito pools known to contain RRV by virus isolation in cell culture. Samples from horses suspected to be infected with KV and MVEV were not available. Conclusion Despite much anecdotal and serological evidence for infection of horses with RRV actual infection and associated clinical disease are infrequently confirmed. The availability of a specific and analytically sensitive RT-PCR for the detection of RRV provides additional opportunities to confirm the presence of this virus in clinical samples. The RTPCR primers for the diagnosis of KV and MVEV infections were shown to be specific for cell culture grown viruses but the further validation of these tests requires the availability of appropriate clinical samples from infected horses.

A randomised controlled trial of methadone maintenance treatment versus wait list control in an Australian prison system

Objectives: The aim was to determine whether methadone maintenance treatment reduced heroin use, syringe sharing and HIV or hepatitis C incidence among prisoners. Methods: All eligible prisoners seeking drug treatment were randomised to methadone or a waitlist control group from 1997 to 1998 and followed up after 4 months. Heroin use was measured by hair analysis and self report; drugs used and injected and syringe sharing were measured by self report. Hepatitis C and HIV incidence was measured by serology. Results: Of 593 eligible prisoners, 382 (64%) were randomised to MMT (n = 191) or control (n = 191). 129 treated and 124 control subjects were followed up at 5 months. Heroin use was significantly lower among treated than control subjects at follow up. Treated subjects reported lower levels of drug injection and syringe sharing at follow up. There was no difference in HIV or hepatitis C incidence. Conclusions: Consideration should be given to the introduction of prison methadone programs particular where community based programs exist. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Diagnosis of Helicobacter pylori infection in adults with intellectual disability

Helicobacter pylori infection is common among adults with intellectual disability. The acceptabilities and accuracies of different diagnostic tests in this population are unknown. We aimed to determine (i) patient acceptability and (ii) performance characteristics of serology, fecal-antigen, and urea breath tests among adults with intellectual disability. One hundred sixty-eight such adults underwent H. pylori testing with serology and fecal-antigen tests, and a portion underwent treatment. One year later, the participants were retested with fecal-antigen, serology, and urea breath tests. The numbers of specimens obtained and difficulties in collection reported by caregivers were noted. Test performance characteristics were assessed among participants and 65 of their caregivers, using serology as the reference. All participants provided at least one specimen, despite reported collection difficulties for 23% of fecal and 27% of blood specimens. Only 25% of the participants provided breath specimens; failure to perform this test was associated with lower intellectual ability and higher maladaptive behavior. The sensitivity, specificity, and positive and negative predictive values of the fecal test (baseline and 12 months versus caregivers) were 70 and 63 versus 81, 93 and 95 versus 98, 96 and 92 versus 93, and 53 and 74 versus 93%, respectively; those of the urea breath test (12 months versus caregivers) were 86 versus 100, 88 versus 95, 75 versus 89, and 94 versus 100%, respectively. With assistance, fecal or blood specimens for H. pylori assessment can be provided by most patients with intellectual disability regardless of their level of function or behavior. Only those with greater ability can perform the urea breath test. Using serology as the reference test, the limitations of performance characteristics of the fecal-antigen and urea breath tests are similar to those among a control group of caregivers.

Study of knowledge of genital herpes infection and attitudes to testing for genital herpes among antenatal clinic attendees

A descriptive survey of knowledge of genital herpes and attitudes to testing was conducted among antenatal clinic attendees at the Gold Coast Hospital, Australia. The study subjects showed a good knowledge of genital herpes, to a level that appears sufficient for an informed choice regarding herpes serology testing to be made. A preference for testing for genital herpes was suggested. Although serological testing is not routinely required, the results of the study indicate that discussion of genital herpes should be considered in the antenatal clinic, setting.

Determining virological, serological and immunological parameters of EBV infection in the development of PTLD

Post-transplant lymphoproliferative disease (PTLD) in Epstein-Barr virus (EBV) seronegative solid organ transplant recipients remains a significant problem, particularly in the first year post-transplant. Immune monitoring of a cohort of high-risk patients indicated that four EBV seronegative transplant recipients developed early-onset PTLD prior to evidence of an EBV humoral response. EBV status has been classically defined serologically, however these patients demonstrated multiple parameters of EBV infection, including the generation of EBV-specific CTL, outgrowth of spontaneous lymphoblastoid cell lines, and elevated EBV DNA levels, despite the absence of a classic EBV antibody response. As EBV serology is influenced by both immunosuppression and cytomegalovirus immunoglobulin treatment, both the EBV-specific CTL response and elevated EBV levels are more reliable indicators of EBV infection post-transplant.

Treatment of maternal syphilis in rural South Africa: effect of multiple doses of benzathine penicillin on pregnancy loss

OBJECTIVES Despite few data, the treatment of syphilis in pregnant women using a single dose of benzathine penicillin is the standard of care in many resource-poor settings. We examined the effect of various doses of benzathine penicillin on pregnancy loss among women with a positive Rapid Plasma Reagin (RPR) test result in a rural South African district. METHODS All pregnant women making their first antenatal care visit during pregnancy were screened for syphilis using the RPR test. Those testing positive were counselled to receive three weekly doses of benzathine penicillin, and received a partner notification card. Pregnancy outcomes were determined from facility records or home visits where necessary. RESULTS Of 8917 women screened, 1043 (12%) had reactive syphilis serology; of those with titre data available, 30% had titres of 1:8 or greater. While 41% (n = 430) of women received all three doses as counselled, 30% (n = 312) received only one dose, and 20% (n = 207) did not return to the clinic to receive treatment. Among the 947 women with pregnancy outcome data available, there were 17 miscarriages and 48 perinatal deaths observed. There was a strong trend towards reduced risk of pregnancy loss among women receiving multiple doses of penicillin (adjusted OR for perinatal mortality for each additional dose received, 0.63; 95% CI, 0.48-0.84). CONCLUSIONS While this association requires further investigation, these results suggest that there may be substantial benefit to providing multiple doses of benzathine penicillin to treat maternal syphilis in this setting.

Effects of Helicobacter pylori eradication among adults with intellectual disability

Background Compared to the general population, Helicobacter pylori infection is more common among adults with intellectual disability (ID) and is associated with greater levels of disability, maladaptive behaviour, and institutionalization. Little information exists about the effects of eradication therapy in this group, so we aimed to evaluate: (1) success of a standard H. pylori eradication protocol; (2) frequency of side-effects; and (3) impact of eradication on level of functional ability and maladaptive behaviour. Method A cohort of adults with ID underwent assessment of their levels of function and maladaptive behaviour, medical history, physical examination, and H. pylori testing using serology and faecal antigen tests. Some received standard H. pylori eradication therapy. Twelve months later, participants underwent repeat assessment, were grouped by change in H. pylori status and compared. Results Of 168 participants, 117 (70%) were currently infected with H. pylori at baseline, and 96 (82%) of the 117 were given standard H. pylori eradication therapy. The overall eradication rate was 61% but 31% reported side-effects. Institutional status of the participants, their level of behaviour or function, and number of comorbid medical conditions were not associated with failure of eradication. There were no statistically significant differences in level of behaviour or function, ferritin, or weight between the groups in whom H. pylori was eradicated or stayed positive. Conclusion Adults with ID have lower H. pylori eradication and higher side-effect rates than the general population. Levels of maladaptive behaviour and disability did not improve with eradication and thus greater levels of maladaptive behaviour or disability appear to be risk factors for, rather than consequences of, H. pylori infection.

Parvovirus B19 infection presenting as 'bathing trunk' erythema with pustules

A 7-year-old girl presented with acute vulval erythema and pustules, associated with a petechial eruption in her flexures and over her feet. There was a mild prodromal illness and the patient was afebrile. There were minimal symptoms associated with the rash. Skin and throat swabs were negative and blood examination showed mild neutrophilia and lymphopaenia. Parvovirus B19 IgM was detected on serology and cutaneous features resolved within 4 days. This is a further case of parvovirus B19 infection presenting as a 'bathing trunk' exanthem that has unique dermatologic features, including the presence of pustules and distant petechiae. © 2006 The Australasian College of Dermatologists.

Utility of serological follow-up of chronic strongyloidiasis after anthelminthic chemotherapy

The difficulty of establishing a diagnosis and confirming cure of strongyloidiasis is widely appreciated. As parasitological diagnosis is often unsatisfactory, serodiagnosis is frequently relied upon. The aim of this study was to investigate changes in Strongyloides-specific antibody levels among a group of 79 seropositive Indigenous Australians living in a Strongyloides-endemic region. Testing before and after treatment revealed that seroreversion occurred most commonly after multiple courses of ivermectin therapy, with antibody titres of 35/42 (83%) subjects becoming negative. Seroreversion was also common following a single course of ivermectin or multiple courses of a 3-day regimen of albendazole, with seroreversion occurring in 13/19 (68%) and 7/10 (70%) subjects respectively. One 3-day course of albendazole was less effective with 4/10 (40%) subjects seroreverting, whereas none of the five subjects receiving a single dose of albendazole and 1/10 (10%) of subjects receiving no therapy seroreverted. These results support the use of serological follow-up for strongyloidiasis, and indicate that reversion to negative serostatus after ivermectin therapy is frequent.

Serologic response to human papillomavirus 16 among Australian women with high-grade cervical intraepithelial neoplasia

This study evaluated the detection of human papillomavirus (HPV) 16 antibody in HPV 16-associated cervical intraepithelial neoplasia (CIN) in Australian women. Seroreactivity to HPV 16 L1 virus-like particles was assessed in patients with CIN 2 (n = 169) and CIN 3 (n = 229) lesions previously tested for the presence of HPV DNA. Seropositivity was significantly commoner in women with HPV 16 DNA-positive lesions (98/184) than in women with no HPV DNA in the lesion (15/47) or with HPV of types other than 16 in the lesion (43/167) (P = 0.0004). In addition, seropositivity was observed in 33% (55/169) of women with CIN 2 and 46% (106/229) of women with CIN 3, in keeping with the lower fraction of CIN 2 (57/169) than CIN 3 (127/229) biopsies positive for HPV 16 DNA. HPV 16 seropositivity is most common in women with HPV 16-associated CIN, but many patients with HPV-associated CIN 3 are seronegative, and HPV 16 seropositivity is common in women with CIN associated with other HPV types. Overall, HPV 16 serology is a poor predictor of presence of HPV 16-associated CIN 3 in patient population studied.