Differences in climatic factors between Ross River virus disease outbreak and nonoutbreak years

Ross River virus is a common mosquito-borne arbovirus responsible for outbreaks of polyarthritic disease throughout Australia. To better understand climatic factors preceding outbreaks, we compared seasonal and monthly rainfall and temperature trends in outbreak and nonoutbreak years at four epidemic-prone locations. Our analyses showed that rainfall in outbreak years tended to be above average and higher than rainfall in nonoutbreak years. Overall temperatures were warmer during outbreak years. However, there were a number of distinct deviations in temperature, which seem to play a role in either promoting or inhibiting outbreaks. These preliminary findings show that climatic differences occur between outbreak and nonoutbreak years; however, seasonal and monthly trends differed across geo-climatic regions of the country. More detailed research is imperative if we are to optimize the surveillance and control of epidemic polyarthritic disease in Australia.

Ross River virus transmission, infection, and disease: a cross-disciplinary review

Ross River virus (RRV) is a fascinating, important arbovirus that is endemic and enzootic in Australia and Papua New Guinea and was epidemic in the South Pacific in 1979 and 1980. Infection with RRV may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. RRV disease notificatïons in Australia average 5,000 per year. The first well-described outbreak occurred in 1928. During World War II there were more outbreaks, and the name epidemic polyarthritis was applied. During a 1956 outbreak, epidemic polyarthritis was linked serologically to a group A arbovirus (Alphavirus). The virus was subsequently isolated from Aedes vigilax mosquitoes in 1963 and then from epidemic polyarthritis patients. We review the literature on the evolutionary biology of RRV, immune response to infection, pathogenesis, serologic diagnosis, disease manifestations, the extraordinary variety of vertebrate hosts, mosquito vectors, and transmission cycles, antibody prevalence, epidemiology of asymptomatic and symptomatic human infection, infection risks, and public health impact. RRV arthritis is due to joint infection, and treatment is currently based on empirical anti-inflammatory regimens. Further research on pathogenesis may improve understanding of the natural history of this disease and lead to new treatment strategies. The burden of morbidity is considerable, and the virus could spread to other countries. To justify and design preventive programs, we need accurate data on economic costs and better understanding of transmission and behavioral and environmental risks.

Detection of West Nile Virus Infection in birds in the United States by blocking ELISA and immunohistochemistry

A blocking ELISA targeting an immunodominant West Nile epitope on the West Nile Virus NS1 protein was assessed for the detection of West Nile-specific antibodies in blood samples collected from 584 sentinel chickens and 238 wild birds collected in-New Jersey from May-December 2000. Ten mallard ducks (Anas platyrhynchos) experimentally infected with West Nile virus and six uninfected controls were also tested. The ELISA proved specific in detecting WNV antibodies in 9/10 chickens and 4/4 wild birds previously confirmed as positive by Plaque Reduction Neutralization test (PRNT) at the Center for Disease Control, Division of Vector Borne Diseases, Fort Collins, CO, USA (CDC). Nine out of the ten experimentally infected mallard ducks also tested positive for WN antibodies in the blocking ELISA, while 6/6 uninfected controls did not. Additionally, 1705 wild birds, collected in New Jersey from December 2000-November 2001 and Long Island, New York between November 1999 and August 2001 were also tested for WN antibodies by the blocking ELISA. These tests identified 30 positive specimens, 12 of which had formalin-fixed tissues available to allow detection of WN specific viral antigen in various tissues by WNV-specific immunohistochemistry. Our results indicate that rapid and specific detection of antibodies to WN virus in sera from a range of avian species by blocking ELISA is an effective strategy for WN Virus surveillance in avian hosts. In combination with detection of WN-specific antigens in tissues by immunohistochemistry (IHC) the blocking ELISA will also be useful for confirming WN infection in diseased birds.

Passive smoking and Parkinson disease

This is the first report of an inverse relationship between passive smoking exposure and Parkinson's disease.

The effects of pregnancy on myelin basic protein-induced experimental autoimmune encephalomyelitis in Lewis rats: Suppression of clinical disease, modulation of cytokine expression in the spinal cord inflammatory infiltrate and suppression of lymphocyte p

Problem: The present study was performed to explore the effects of pregnancy on experimental autoimmune encephalomyelitis (EAE) induced in Lewis rats by inoculation with myelin basic protein (MBP) (MBP-EAE). Method of study: MBP-EAE was induced in pregnant and non-pregnant rats and severity of disease evaluated. Serum from pregnant and non-pregnant rats was used in standard lymphocyte proliferation assays. Real-time polymerase chain reaction (PCR) was used to investigate the expression of cytokine mRNA in the inflammatory cells obtained from the spinal cord of rats on day 15 after inoculation. Results: Pregnant rats developed less severe disease than non-pregnant rats. Serum from pregnant rats suppressed the proliferation of T lymphocytes in response to MBP. There was significantly increased expression of IL-4. IL-10 and TNF-alpha mRNA in the spinal cord infiltrate of pregnant rats. Conclusion: Circulating humoral factors and alteration in cytokine production by inflammatory cells may contribute to the suppression of EAE in pregnant rats.

Oral disease in animals: The Australian perspective. Isolation and characterisation of black-pigmented bacteria from the oral cavity of marsupials

A wide range of animals suffer from periodontal disease. However, there is very little reported on disease and oral micro-biota of Australian animals. Therefore, the oral cavity of 90 marsupials was examined for oral health status. Plaque samples were collected from the subgingival margins using curettes; or swabs. Plaque samples were plated onto. non-selective trypticase soy agar plates, selective trypticase soy agar, non-selective and selective Wilkens Chalgrens, Agar. Plates were incubated in an anaerobic atmosphere and examined after 7-14 days for the presence of black-brown-pigmented colonies. A combination of morphological and biochemical tests were used (colonial morphology, pigmentation, aerobic growth, Gram reaction, fluorescence under long-wave UV light (360 nm), production of catalase, enzymatic activity with fluorogenic substrates and haemagglutination of sheep red cells) to identify these organisms. Black-pigmented bacteria were cultivated from the plaque of 32 animals including six eastern grey kangaroos, a musky rat kangaroo, a whiptail and a red-necked wallaby, 18 koalas, a bandicoot and five brushtail possums. No black-pigmented colonies were cultivated from squirrel or sugar gliders or quokkas or from marsupial mice. The majority of isolates were identified as Porphyromonas gingivalis-like species with the higher prevalence of isolation from the oral cavity of macropods (the kangaroos and wallabies). Oral diseases, such as gingivitis can be found in native Australian animals with older koalas having an increase in disease indicators and black-pigmented bacteria. Non-selective Wilkens Chalgren Agar was the medium of choice for the isolation of black-pigmented bacteria. (C) 2002 Elsevier Science Ltd. All rights reserved.

Walking performance, oxygen uptake kinetics and resting muscle pyruvate dehydrogenase complex activity in peripheral arterial disease

In the present study, we tested the hypothesis that walking intolerance in intermittent claudication (IC) is related to both slowed whole body oxygen uptake (Vo(2)) kinetics and altered activity of the active fraction of the pyruvate dehydrogenase complex (PDCa) in skeletal muscle. Ten patients with IC and peripheral arterial disease [ankle/brachial index (ABI) = 0.73 +/- 0.13] and eight healthy controls (ABI = 1. 17 +/- 0.13) completed three maximal walking tests. From these tests, averaged estimates of walking time, peak Vo(2) and the time constant of Vo(2) (tau) during submaximal walking were obtained. A muscle sample was taken from the gastrocnemius medialis muscle at rest and analysed for PDCa and several other biochemical variables. Walking time and peak Vo(2) were approx. 50 % lower in patients with IC than controls, and tau was 2-fold higher (P < 0.05). r was significantly correlated with walking time (r = -0.72) and peak Vo(2) (r = -0.66) in patients with IC, but not in controls. PDCa was not significantly lower in patients with IC than controls; however, PDCa tended to be correlated with tau (r = -0.56, P = 0.09) in patients with IC, but not in controls (r = -0.14). A similar correlation was observed between resting ABI and tau (r = -0.63, P = 0.05) in patients with IC. These data suggest that the impaired Vo(2) kinetics contributes to walking intolerance in IC and that, within a group of patients with IC, differences in Vo(2) kinetics might be partly linked to differences in muscle carbohydrate oxidation.

Wolbachia-induced cytoplasmic incompatibility as a means for insect pest population control

Biological control is the purposeful introduction of parasites, predators, and pathogens to reduce or suppress pest populations. Wolbachia are inherited bacteria of arthropods that have recently attracted attention for their potential as new biocontrol agents. Wolbachia manipulate host reproduction by using several strategies, one of which is cytoplasmic incompatibility (CI) [Stouthamer, R., Breeuwer, J. A. J. & Hurst, G. D. D. (1999) Annu. Rev. Microbiol. 53,71-102]. We established Wolbachia-infected lines of the medfly Ceratitis capitata using the infected cherry fruit fly Rhagoletis cerasi as donor. Wolbachia induced complete CI in the novel host. Laboratory cage populations were completely suppressed by single releases of infected males, suggesting that Wolbachia-induced CI could be used as a novel environmentally friendly tool for the control of medfly populations. The results also encourage the introduction of Wolbachia into pest and vector species of economic and hygenic relevance to suppress or modify natural populations.

Development time and survival of Verrallina funerea (Theobald) (Diptera : Culicidae) immatures and other brackish water mosquito species in southeast Queensland, Australia

Verrallina funerea (Theobald) is a brackish water mosquito that is recognised as an important pest and vector in southeast Queensland, Australia. Immature development time and survival of Ve. funerea was defined in the laboratory in response to a range of temperatures (17-34 degrees C) and salinities (0-35 parts per thousand (p.p.t)). The expression of autogeny in this species was also assessed. Salinity only had a slight effect on mean development time from hatching to adult emergence (7.0-7.4 d at salinities of 0, 17.5 and 31.5 p.p.t) and survival was uniformly high (97.5-99.0%). Mean development times were shorter at 26, 29 and 32 degrees C (7.0, 6.8 and 6.8 d, respectively) and longest at 17 degrees C (12.2 d). The threshold temperature (t) was 5.8 degrees C and the thermal constant (K) was 142.9 degree-days above t. Survival to adulthood decreased from > 95% (at 17-29 degrees C) to 78% (at 32 degrees C) and 0% (at 34 degrees C). No expression of autogeny was observed. Immature development times of Ve. funerea, Ochlerotatus vigilax (Skuse) and Oc. procax (Skuse) were then determined under field conditions at Maroochy Shire. Following tide and rain inundation, cohorts of newly hatched larvae were monitored daily by dipping, and time until pupation was noted. Tidal inundation triggered hatching of Ve. funerea and Oc. vigilax larvae whereas Oc. procax larvae were found only after rain inundation. Estimates of Ve. funerea and Oc. vigilax field development times were similar (8-9 d) while Oc. procax development time was slightly longer (9-10 d). Based on these survey results, control activities targeting Ve. funerea must be initiated 4 d (if using Bacillus thuringiensis var. israelensis de Barjac) or 5 d (if using s-methoprene) after inundation. However, Casuarina glauca Sieber canopy and branchlets covering breeding habitats may present a problem for the penetration of such treatments.

Lymphoproliferative disease of the ocular adnexa: A clinical and pathologic study with statistical analysis of 69 patients

Purpose: To evaluate the clinical features, treatment, and outcomes of a cohort of patients with ocular adnexal lymphoproliferative disease classified according to the World Health Organization modification of the Revised European-American Classification of Lymphoid neoplasms and to perform a robust statistical analysis of these data. Methods: Sixty-nine cases of ocular adnexal lymphoproliferative disease, seen in a tertiary referral center from 1992 to 2003, were included in the study. Lesions were classified by using the World Health Organization modification of the Revised European-American Classification of Lymphoid neoplasms classification. Outcome variables included disease-specific Survival, relapse-free survival, local control, and distant control. Results: Stage IV disease at presentation, aggressive lymphoma histology, the presence of prior or concurrent systemic lymphoma at presentation, and bilateral adnexal disease were significant predictors for reduced disease-specific survival, local control, and distant control. Multivariate analysis found that aggressive histology and bilateral adnexal disease had significantly reduced disease-specific Survival. Conclusions: The typical presentation of adnexal lymphoproliferative disease is with a painless mass, swelling, or proptosis; however, pain and inflammation occurred in 20% and 30% of patients, respectively. Stage at presentation, tumor histology, primary or secondary status, and whether the process was unilateral or bilateral were significant variables for disease outcome. In this study, distant spread of lymphoma was lower in patients who received greater than 20 Gy of orbital radiotherapy.