Are insect frugivores always plant pests? The impact of fruit fly (Diptera: Tephritidae) larvae on host plant fitness

Herbivory is generally regarded as negatively impacting on host plant fitness. Frugivorous insects, which feed directly on plant reproductive tissues, are predicted to be particularly damaging to hosts. We tested this prediction with the fruit fly, Bactrocera tryoni, by recording the impact of larval feeding on two direct (seed number and germination) and two indirect (fruit decay rate and attraction/deterrence of vertebrate frugivores) measures of host plant fitness. Experiments were done in the laboratory, glasshouse and tropical rainforest. We found no negative impact of larval feeding on seed number or germination for three test plants: tomato, capsicum and eggplant. Further, larval feeding accelerated the initiation of decay and increased the final level of fruit decay in tomatoes, apples, pawpaw and pear, a result considered to be beneficial to the fruit. In rainforest studies, native rodents preferred infested apple and pears compared to uninfested control fruit; however, there were no differences observed between treatments for tomato and pawpaw. For our study fruits, these results demonstrate that fruit fly larval infestation has neutral or beneficial impacts on the host plant, an outcome which may be largely influenced by the physical properties of the host. These results may contribute to explaining why fruit flies have not evolved the same level of host specialization generally observed for other herbivore groups.

Diabetes foot disease : the Cinderella of Australian diabetes management?

Diabetes is one of the greatest public health challenges to face Australia. It is already Australia’s leading cause of kidney failure, blindness (in those under 60 years) and lower limb amputation, and causes significant cardiovascular disease. Australia’s diabetes amputation rate is one of the worst in the developed world, and appears to have significantly increased in the last decade, whereas some other diabetes complication rates appear to have decreased. This paper aims to compare the national burden of disease for the four major diabetes-related complications and the availability of government funding to combat these complications, in order to determine where diabetes foot disease ranks in Australia. Our review of relevant national literature indicates foot disease ranks second overall in burden of disease and last in evidenced-based government funding to combat these diabetes complications. This suggests public funding to address foot disease in Australia is disproportionately low when compared to funding dedicated to other diabetes complications. There is ample evidence that appropriate government funding of evidence-based care improves all diabetes complication outcomes and reduces overall costs. Numerous diverse Australian peak bodies have now recommended similar diabetes foot evidence-based strategies that have reduced diabetes amputation rates and associated costs in other developed nations. It would seem intuitive that “it’s time” to fund these evidence-based strategies for diabetes foot disease in Australia as well.

Striving to achieve best practice in heart failure disease management

Based on a national audit of chronic heart failure (CHF) management programmes (CHF-MPs) conducted in 2006, Driscoll et al identified a disproportionate distribution ranging from 0 to 4.2 programmes/million population in the various states of Australia with many programmes not following best practice.1 We welcome their proposal to develop national benchmarks for CHF management and acknowledge the contributions of the Heart Foundation and health professionals in finalising these recommendations.2 We would like to share the Queensland experience in striving towards best practice with the number of CHF-MPs increasing from four (at the time of the 2006 survey) to 23, equating to 5.0 programmes/million population. Queensland now has a state-wide heart failure service steering committee with a focus on the development of CHF-MPs supported by a central coordinator...

Dalcetrapib restoring belief in modulating CETP as a beneficial mechanism in cardiovascular disease

Abstract Background: As low HDL cholesterol levels are a risk factor for cardiovascular disease, raising HDL cholesterol substantially by inhibiting or modulating cholesteryl ester transfer protein (CETP) may be useful in coronary artery disease. The first CETP inhibitor that went into clinical trial, torcetrapib, was shown to increase the levels of HDL cholesterol, but it also increased cardiovascular outcomes, probably due to an increase in blood pressure and aldosterone secretion, by an off-target mechanism/s. Objective/methods: Dalcetrapib is a new CETP modulator that increases the levels of HDL cholesterol, but does not increase blood pressure or aldosterone secretion. The objective was to evaluate a paper describing the effects of dalcetrapib on carotid and aortic wall thickness in subjects with, or at high risk, of coronary artery disease; the dal-PLAQUE study. Results: dal-PLAQUE showed that dalcetrapib reduced the progression of atherosclerosis and may also reduce the vascular inflammation associated with this, in subjects with, or with high risk of, coronary heart disease, who were already taking statins. Conclusions: These results suggest that modulating CETP with dalcetrapib may be a beneficial mechanism in cardiovascular disease. The results of the dal-HEART series, which includes dal-PLAQUE 1 and 2, and dal-OUTCOMES, when complete, will provide more definitive information about the benefit, or not, of dalcetrapib in coronary artery disease.

The utility of serum CA-125 in predicting extra-uterine disease in apparent early stage endometrial cancer

Objectives: To evaluate the clinical value of pre-operative serum CA125 in predicting the presence of extra-uterine disease in patients with apparent early stage endometrial cancer. Methods: Between October 6, 2005 and June 17, 2010, 760 patients were enrolled in an international, multicentre, prospective randomized trial (LACE) comparing laparotomy with laparoscopy in the management of endometrial cancer apparently confined to the uterus. This study is based on data from 657 patients with endometrial adenocarcinoma who had a pre-operative serum CA125 value, and was undertaken to correlate pre-operative serum CA125 with final stage. Results: Using a pre-operative CA-125 cutpoint of 30U/ml was associated with the smallest misclassification error (14.5%) using a multiple cross-validation method. Median pre-operative serum CA-125 was 14U/ml, and using a cutpoint of 30U/ml, 14.9% of patients had elevated CA-125 levels. Of 98 patients with elevated CA-125 level, 36 (36.7%) had evidence of extra-uterine disease. Of the 116 patients (17.7%) with evidence of extra-uterine disease, 31.0% had elevated CA-125 level. In univariate and multivariate logistic regression analysis, only pre-operative CA-125 level was found to be associated with extra-uterine spread of disease. Utilising a cutpoint of 30U/ml achieved a sensitivity, specificity, positive predictive value and negative predictive value of 31.0%, 88.5%, 36.7% and 85.7% respectively. Overall, 326/657 (49.6%) of patients had full surgical staging involving lymph node dissection. When analysis was limited to patients that had undergone full surgical staging, the outcomes remained essentially unchanged. Conclusions: Elevated CA-125 above 30U/ml in patients with apparent early stage disease is associated with a sensitivity of 31.0% and specificity of 88.5% in detecting extra-uterine disease. Pre-operative identification of this risk factor may assist to triage patients to tertiary centres and comprehensive surgical staging.

Evidence of unique genotypes of Beak and feather disease virus in Southern Africa

Psittacine beak and feather disease (PBFD), caused by Beak and feather disease virus (BFDV), is the most significant infectious disease in psittacines. PBFD is thought to have originated in Australia but is now found worldwide; in Africa, it threatens the survival of the indigenous endangered Cape parrot and the vulnerable black-cheeked lovebird. We investigated the genetic diversity of putative BFDVs from southern Africa. Feathers and heparinized blood samples were collected from 27 birds representing 9 psittacine species, all showing clinical signs of PBFD. DNA extracted from these samples was used for PCR amplification of the putative BFDV coat protein (CP) gene. The nucleotide sequences of the CP genes of 19 unique BFDV isolates were determined and compared with the 24 previously described sequences of BFDV isolates from Australasia and America. Phylogenetic analysis revealed eight BFDV lineages, with the southern African isolates representing at least three distinctly unique genotypes; 10 complete genome sequences were determined, representing at least one of every distinct lineage. The nucleotide diversity of the southern African isolates was calculated to be 6.4% and is comparable to that found in Australia and New Zealand. BFDVs in southern Africa have, however, diverged substantially from viruses found in other parts of the world, as the average distance between the southern African isolates and BFDV isolates from Australia ranged from 8.3 to 10.8%. In addition to point mutations, recombination was found to contribute substantially to the level of genetic variation among BFDVs, with evidence of recombination in all but one of the genomes analyzed.

The capsid protein of beak and feather disease virus binds to the viral DNA and is responsible for transporting the replication-associated protein into the nucleus

Circoviruses lack an autonomous DNA polymerase and are dependent on the replication machinery of the host cell for de novo DNA synthesis. Accordingly, the viral DNA needs to cross both the plasma membrane and the nuclear envelope before replication can occur. Here we report on the subcellular distribution of the beak and feather disease virus (BFDV) capsid protein (CP) and replication-associated protein (Rep) expressed via recombinant baculoviruses in an insect cell system and test the hypothesis that the CP is responsible for transporting the viral genome, as well as Rep, across the nuclear envelope. The intracellular localization of the BFDV CP was found to be directed by three partially overlapping bipartite nuclear localization signals (NLSs) situated between residues 16 and 56 at the N terminus of the protein. Moreover, a DNA binding region was also mapped to the N terminus of the protein and falls within the region containing the three putative NLSs. The ability of CP to bind DNA, coupled with the karyophilic nature of this protein, strongly suggests that it may be responsible for nuclear targeting of the viral genome. Interestingly, whereas Rep expressed on its own in insect cells is restricted to the cytoplasm, coexpression with CP alters the subcellular localization of Rep to the nucleus, strongly suggesting that an interaction with CP facilitates movement of Rep into the nucleus. Copyright © 2006, American Society for Microbiology. All Rights Reserved.

A unique isolate of beak and feather disease virus isolated from budgerigars (Melopsittacus undulatus) in South Africa

Beak and feather disease virus (BFDV), the causative agent of psittacine beak and feather disease (PBFD) infects psittaciformes worldwide. We provide an annotated sequence record of three full-length unique genomes of BFDV isolates from budgerigars (Melopsittacus undulatus) from a breeding farm in South Africa. The isolates share >99% nucleotide sequence identity with each other and ~96% nucleotide sequence identity to two recent isolates (Melopsittacus undulatus) from Thailand but only between 91. 6 and 86. 6% identity with all other full-length BFDV sequences. Maximum-likelihood analysis and recombination analysis suggest that the South African budgerigar BFDV isolates are unique to budgerigars, are non-recombinant in origin, and represent a new genotype of BFDV. © 2010 Springer-Verlag.

Global genetic diversity and geographical and host-species distribution of beak and feather disease virus isolates

Psittacine beak and feather disease (PBFD) has a broad host range and is widespread in wild and captive psittacine populations in Asia, Africa, the Americas, Europe and Australasia. Beak and feather disease circovirus (BFDV) is the causative agent. BFDV has an ~2 kb single stranded circular DNA genome encoding just two proteins (Rep and CP). In this study we provide support for demarcation of BFDV strains by phylogenetic analysis of 65 complete genomes from databases and 22 new BFDV sequences isolated from infected psittacines in South Africa. We propose 94% genome-wide sequence identity as a strain demarcation threshold, with isolates sharing > 94% identity belonging to the same strain, and strain subtypes sharing> 98% identity. Currently, BFDV diversity falls within 14 strains, with five highly divergent isolates from budgerigars probably representing a new species of circovirus with three strains (budgerigar circovirus; BCV-A, -B and -C). The geographical distribution of BFDV and BCV strains is strongly linked to the international trade in exotic birds; strains with more than one host are generally located in the same geographical area. Lastly, we examined BFDV and BCV sequences for evidence of recombination, and determined that recombination had occurred in most BFDV and BCV strains. We established that there were two globally significant recombination hotspots in the viral genome: the first is along the entire intergenic region and the second is in the C-terminal portion of the CP ORF. The implications of our results for the taxonomy and classification of circoviruses are discussed. © 2011 SGM.

Spatial and temporal analysis of Barmah Forest virus disease in Queensland, Australia

Barmah Forest virus (BFV) disease is one of the most widespread mosquito-borne diseases in Australia. The number of outbreaks and the incidence rate of BFV in Australia have attracted growing concerns about the spatio-temporal complexity and underlying risk factors of BFV disease. A large number of notifications has been recorded continuously in Queensland since 1992. Yet, little is known about the spatial and temporal characteristics of the disease. I aim to use notification data to better understand the effects of climatic, demographic, socio-economic and ecological risk factors on the spatial epidemiology of BFV disease transmission, develop predictive risk models and forecast future disease risks under climate change scenarios. Computerised data files of daily notifications of BFV disease and climatic variables in Queensland during 1992-2008 were obtained from Queensland Health and Australian Bureau of Meteorology, respectively. Projections on climate data for years 2025, 2050 and 2100 were obtained from Council of Scientific Industrial Research Organisation. Data on socio-economic, demographic and ecological factors were also obtained from relevant government departments as follows: 1) socio-economic and demographic data from Australian Bureau of Statistics; 2) wetlands data from Department of Environment and Resource Management and 3) tidal readings from Queensland Department of Transport and Main roads. Disease notifications were geocoded and spatial and temporal patterns of disease were investigated using geostatistics. Visualisation of BFV disease incidence rates through mapping reveals the presence of substantial spatio-temporal variation at statistical local areas (SLA) over time. Results reveal high incidence rates of BFV disease along coastal areas compared to the whole area of Queensland. A Mantel-Haenszel Chi-square analysis for trend reveals a statistically significant relationship between BFV disease incidence rates and age groups (ƒÓ2 = 7587, p<0.01). Semi-variogram analysis and smoothed maps created from interpolation techniques indicate that the pattern of spatial autocorrelation was not homogeneous across the state. A cluster analysis was used to detect the hot spots/clusters of BFV disease at a SLA level. Most likely spatial and space-time clusters are detected at the same locations across coastal Queensland (p<0.05). The study demonstrates heterogeneity of disease risk at a SLA level and reveals the spatial and temporal clustering of BFV disease in Queensland. Discriminant analysis was employed to establish a link between wetland classes, climate zones and BFV disease. This is because the importance of wetlands in the transmission of BFV disease remains unclear. The multivariable discriminant modelling analyses demonstrate that wetland types of saline 1, riverine and saline tidal influence were the most significant risk factors for BFV disease in all climate and buffer zones, while lacustrine, palustrine, estuarine and saline 2 and saline 3 wetlands were less important. The model accuracies were 76%, 98% and 100% for BFV risk in subtropical, tropical and temperate climate zones, respectively. This study demonstrates that BFV disease risk varied with wetland class and climate zone. The study suggests that wetlands may act as potential breeding habitats for BFV vectors. Multivariable spatial regression models were applied to assess the impact of spatial climatic, socio-economic and tidal factors on the BFV disease in Queensland. Spatial regression models were developed to account for spatial effects. Spatial regression models generated superior estimates over a traditional regression model. In the spatial regression models, BFV disease incidence shows an inverse relationship with minimum temperature, low tide and distance to coast, and positive relationship with rainfall in coastal areas whereas in whole Queensland the disease shows an inverse relationship with minimum temperature and high tide and positive relationship with rainfall. This study determines the most significant spatial risk factors for BFV disease across Queensland. Empirical models were developed to forecast the future risk of BFV disease outbreaks in coastal Queensland using existing climatic, socio-economic and tidal conditions under climate change scenarios. Logistic regression models were developed using BFV disease outbreak data for the existing period (2000-2008). The most parsimonious model had high sensitivity, specificity and accuracy and this model was used to estimate and forecast BFV disease outbreaks for years 2025, 2050 and 2100 under climate change scenarios for Australia. Important contributions arising from this research are that: (i) it is innovative to identify high-risk coastal areas by creating buffers based on grid-centroid and the use of fine-grained spatial units, i.e., mesh blocks; (ii) a spatial regression method was used to account for spatial dependence and heterogeneity of data in the study area; (iii) it determined a range of potential spatial risk factors for BFV disease; and (iv) it predicted the future risk of BFV disease outbreaks under climate change scenarios in Queensland, Australia. In conclusion, the thesis demonstrates that the distribution of BFV disease exhibits a distinct spatial and temporal variation. Such variation is influenced by a range of spatial risk factors including climatic, demographic, socio-economic, ecological and tidal variables. The thesis demonstrates that spatial regression method can be applied to better understand the transmission dynamics of BFV disease and its risk factors. The research findings show that disease notification data can be integrated with multi-factorial risk factor data to develop build-up models and forecast future potential disease risks under climate change scenarios. This thesis may have implications in BFV disease control and prevention programs in Queensland.

Food insecurity among adults residing in disadvantaged urban areas : potential health and dietary consequences

Objective: Food insecurity is the limited or uncertain availability or access to nutritionally-adequate, culturally-appropriate and safe foods. Food insecurity may result in inadequate dietary intakes, overweight or obesity and the development of chronic disease. Internationally, few studies have focused on the range of potential health outcomes related to food insecurity among adults residing in disadvantaged locations and no such Australian studies exist. The objective of this study was to investigate associations between food insecurity, socio-demographic and health factors and dietary intakes among adults residing in disadvantaged urban areas. Design: Data were collected by mail survey (n= 505, 53% response rate), which ascertained information about food security status, demographic characteristics (such as age, gender, household income, education) fruit and vegetable intakes, take-away and meat consumption, general health, depression and chronic disease. Setting: Disadvantaged suburbs of Brisbane city, Australia, 2009. Subjects: Individuals aged ≥ 20 years. Results: Approximately one-in-four households (25%) were food insecure. Food insecurity was associated with lower household income, poorer general health, increased healthcare utilisation and depression. These associations remained after adjustment for age, gender and household income. Conclusion: Food insecurity is prevalent in urbanised disadvantaged areas in developed countries such as Australia. Low-income households are at high risk of experiencing food insecurity. Food insecurity may result in significant health burdens among the population, and this may be concentrated in socioeconomically-disadvantaged suburbs.

Potential dietary consquences of food insecurity among Australian adults residing in urbanised disadvantaged areas

Introduction: Food insecurity is the limited/uncertain availability, access to or ability to acquire nutritionally-adequate, culturallyrelevant and safe foods. Adults suffering from food insecurity are at risk of inadequate nutrient intakes or, paradoxically, overweight/ obesity and the development of chronic disease. Despite the global financial crisis and rising costs of living, there are few studies investigating the potential dietary consequences of food insecurity among the Australian population. This study examined whether food insecurity was associated with weight status and poorer intakes of fruits, vegetable and takeaway foods among adults residing in socioeconomically-disadvantaged urbanised areas. Methods: In this cross-sectional study, a random sample of residents (n=1000) were selected from the most disadvantaged suburbs of Brisbane city (response rate 51%). Data were collected by postal questionnaire which ascertained information on sociodemographic information, household food security status, height, weight, fruit and vegetable intakes and takeaway consumption. Data were analysed using chi-square and logistic regression. Results: The overall prevalence of food insecurity was 31%. Food insecurity was not associated with weight status among men or women. Associations between food security status and potential dietary consequences differed for men and women. Among women, food security was not associated with intakes of fruit, vegetable or takeaway consumption. Contrastingly, among men food security was associated with vegetable intakes and consumption of takeaway food: men reporting food insecurity had lower intakes of vegetables and were more likely to consume takeaway foods compared to those that were food secure. Conclusion: Food security is an important public health issue in Australia and has potential dietary consequences that may adversely affect the health of food-insecure groups, most notably men residing in food-insecure households.

Potential health and dietary consequences of food insecurity among Australian adults residing in urbanised disadvantaged areas

Purpose: Food insecurity is the limited/uncertain availability or ability to acquire nutritionally-adequate, culturally-relevant and safe foods. Adults suffering from food insecurity are at risk of inadequate nutrient intakes or, paradoxically, overweight/obesity and the development of chronic disease. Despite the global financial crisis and rising costs of living, few studies have investigated the potential dietary and health consequences of food insecurity among the Australian population. This study examined whether food insecurity was associated with health behaviours and dietary intakes among adults residing in socioeconomically-disadvantaged urbanised areas. Methods: In this cross-sectional study, a random sample of residents (n = 1000) were selected from the most disadvantaged suburbs of Brisbane city (response rate 51%). Data were collected by postal questionnaire which ascertained information on socio-demographic information, household food security, height, weight, frequency of healthcare utilisation, presence of chronic disease and intakes of fruit, vegetables and take-away. Data were analysed using logistic regression. Results/Findings: The prevalence of food insecurity was 25%. Those reporting food insecurity were two-to-three times more likely to have seen a general practitioner or been hospitalised within the previous 6 months. Furthermore, food insecurity was associated with a three-to-six-fold increase in the likelihood of experiencing depression. Food insecurity was associated with higher intakes of some take-away foods, however was not significantly associated with weight status or intakes of fruits or vegetables among this disadvantaged sample. Conclusion: Food insecurity has potential adverse health consequences that may result in significant health burdens among the population, and this may be concentrated in socioeconomically-disadvantaged suburbs.

Smoking status as a moderator of the association between food insecurity and decreased fruit and vegetable consumption

Food insecurity is the inadequate access to, or availability of, sufficient amounts of nutritious, culturally-appropriate and safe foods, or the inability to acquire such foods by socially acceptable means. Food insecurity has been shown to be associated with poor dietary intakes and poor health status. Recently, evidence has emerged suggesting increased rates of food insecurity among those with substance abuse problems, including those who smoke. This cross-sectional study investigates the potential moderating effect of smoking on the association between food insecurity and fruit and vegetable intakes among the Australian population, using regression analyses. Participants were adults 18 years and older participating in the 2004/05 National Health Survey (n = 19,500). Those from food insecure households were up to two-times more likely to report inadequate fruit and vegetable intakes compared to those who were food secure. Those who smoked were nearly six times more likely to report being food insecure, and up to three-times more likely to report inadequate fruit and vegetable intakes, compared to their non-smoking counterparts. Further analyses revealed a marked decline in the strength of the association between food insecurity and fruit consumption with the addition of smoking status into a regression model. These findings have important implications for the development of policy and interventions to address food insecurity, suggesting that those from food insecure households are less likely to comply with national dietary recommendations, and that this may in part be moderated by smoking status.

Associations exist between food insecurity, poor diet, chronic illness and obesity among an Australian population

Food insecurity is the limited availability of, or access to, sufficient amounts of nutritious, culturally-appropriate and safe foods, or the inability to access such foods by socially-acceptable means. Evidence from the United States and Canada suggests that food insecurity may be associated with poor dietary intakes, obesity, and chronic disease including depression and diabetes, thus constituting a significant public health issue. Currently, no existing studies have investigated the dietary and health factors associated with food insecurity among the general Australian population. The current study investigated the potential associations between food insecurity, diet and health among Australian adults (18 years and over) participating in the cross-sectional National Health Survey (n = 19,500). Data were analysed by logistic regression adjusting for sociodemographic covariates. Those from food insecure households were 50% less likely to consume the recommended number of servings of fruit, 60% more likely to report poor health and experienced a 6-fold increase in the risk of severe depressive disorders, compared to their food secure counterparts. Furthermore, food insecurity was associated with a 50% increase in the risk of being diagnosed with ‘high sugar levels’. Finally, women from food insecure households were 30% more likely to be obese compared to their food secure counterparts. These findings suggest that food insecurity may play an important role in preventing adherence with national dietary recommendations, and may increase the risk of obesity and chronic illness. This has important implications for both clinical practice, and the development of interventions and policy to address food insecurity.