ORCID Profile
0000-0002-7952-4581
Current Organisations
University of Tasmania
,
University of Newcastle Australia
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Publisher: Elsevier BV
Date: 05-2019
Publisher: Wiley
Date: 07-09-2016
DOI: 10.1111/AJR.12316
Publisher: Oxford University Press (OUP)
Date: 17-12-2015
DOI: 10.1093/CID/CIV1018
Abstract: Knowledge of relationships between antibiotic susceptibility of Shigella isolates and travel destination or other risk factors can assist clinicians in determining appropriate antibiotic therapy prior to susceptibility testing. We describe relationships between resistance patterns and risk factors for acquisition in Shigella isolates using routinely collected data for notified cases of shigellosis between 2008 and 2012 in Victoria, Australia. We included all shigellosis patients notified during the study period, where Shigella isolates were tested for antimicrobial sensitivity using Clinical and Laboratory Standards Institute breakpoints. Cases were interviewed to collect data on risk factors, including recent travel. Data were analyzed using Stata 13.1 to examine associations between risk factors and resistant strains. Of the 500 cases of shigellosis, 249 were associated with overseas travel and 210 were locally acquired. Forty-six of 51 isolates of Indian origin displayed decreased susceptibility or resistance to ciprofloxacin. All isolates of Indonesian origin were susceptible to ciprofloxacin. Twenty-six travel-related isolates were resistant to all tested oral antimicrobials. Male-to-male sexual contact was the primary risk factor for 80% (120/150) of locally acquired infections among adult males, characterized by distinct periodic Shigella sonnei outbreaks. Clinicians should consider travel destination as a marker for resistance to common antimicrobials in returning travelers, where severe disease requires empirical treatment prior to receipt of in idual sensitivity testing results. Repeated outbreaks of locally acquired shigellosis among men who have sex with men highlight the importance of prevention and control measures in this high-risk group.
Publisher: Informa UK Limited
Date: 05-2011
DOI: 10.2147/RMHP.S12710
Publisher: Cambridge University Press (CUP)
Date: 28-03-2013
DOI: 10.1017/S095026881300068X
Abstract: Mycobacterium tuberculosis is primarily a pathogen of humans. Infections have been reported in animal species and it is emerging as a significant disease of elephants in the care of humans. With the close association between humans and animals, transmission can occur. In November 2010, a clinically healthy Asian elephant in an Australian zoo was found to be shedding M. tuberculosis in September 2011, a sick chimpanzee at the same zoo was diagnosed with tuberculosis caused by an indistinguishable strain of M. tuberculosis. Investigations included staff and animal screening. Four staff had tuberculin skin test conversions associated with spending at least 10 hours within the elephant enclosure none had disease. Six chimpanzees had suspected infection. A pathway of transmission between the animals could not be confirmed. Tuberculosis in an elephant can be transmissible to people in close contact and to other animals more remotely. The mechanism for transmission from elephants requires further investigation.
Publisher: American Society for Microbiology
Date: 11-2011
DOI: 10.1128/AEM.00616-11
Abstract: Cryptosporidiosis is one of the most common waterborne diseases reported worldwide. Outbreaks of this gastrointestinal disease, which is caused by the Cryptosporidium parasite, are often attributed to public swimming pools and municipal water supplies. Between the months of January and April in 2009, New South Wales, Australia, experienced the largest waterborne cryptosporidiosis outbreak reported in Australia to date. Through the course of the contamination event, 1,141 in iduals became infected with Cryptosporidium . Health authorities in New South Wales indicated that public swimming pool use was a contributing factor in the outbreak. To identify the Cryptosporidium species responsible for the outbreak, fecal s les from infected patients were collected from hospitals and pathology companies throughout New South Wales for genetic analyses. Genetic characterization of Cryptosporidium oocysts from the fecal s les identified the anthroponotic Cryptosporidium hominis IbA10G2 subtype as the causative parasite. Equal proportions of infections were found in males and females, and an increased susceptibility was observed in the 0- to 4-year age group. Spatiotemporal analysis indicated that the outbreak was primarily confined to the densely populated coastal cities of Sydney and Newcastle.
Publisher: Oxford University Press (OUP)
Date: 14-07-2020
DOI: 10.1093/CID/CIAA972
Abstract: Multiresistant organisms (MROs) pose a critical threat to public health. Population-based programs for control of MROs such as carbapenemase-producing Enterobacterales (CPE) have emerged and evaluation is needed. We assessed the feasibility and impact of a statewide CPE surveillance and response program deployed across Victoria, Australia (population 6.5 million). A prospective multimodal intervention including active screening, carrier isolation, centralized case investigation, and comparative pathogen genomics was implemented. We analyzed trends in CPE incidence and clinical presentation, risk factors, and local transmission over the program’s first 3 years (2016–2018). CPE case ascertainment increased over the study period to 1.42 cases/100 000 population, linked to increased screening without a concomitant rise in active clinical infections (0.45–0.60 infections/100 000 population, P = .640). KPC-2 infection decreased from 0.29 infections/100 000 population prior to intervention to 0.03 infections/100 000 population in 2018 (P = .003). Comprehensive case investigation identified instances of overseas community acquisition. Median time between isolate referral and genomic and epidemiological assessment for local transmission was 11 days (IQR, 9–14). Prospective surveillance identified numerous small transmission networks (median, 2 range, 1–19 cases), predominantly IMP and KPC, with median pairwise distance of 8 (IQR, 4–13) single nucleotide polymorphisms low ersity between clusters of the same sequence type suggested genomic cluster definitions alone are insufficient for targeted response. We demonstrate the value of centralized CPE control programs to increase case ascertainment, resolve risk factors, and identify local transmission through prospective genomic and epidemiological surveillance methodologies are transferable to low-prevalence settings and MROs globally.
Publisher: Elsevier BV
Date: 04-2023
Publisher: Elsevier BV
Date: 09-2023
Publisher: Australian Government Department of Health and Aged Care
Date: 17-11-2022
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/SH14201
Abstract: Background Chlamydia remains Australia’s most frequently notified communicable disease however, interpretation of notification data is difficult without knowledge of testing practices. This study examined the value of reporting positivity trends. Methods: Tasmanian population-level chlamydia laboratory tests and notification data from 2001 to 2010 were compared. Results: Notifications, tests and positivity increased, most significantly in males and females aged 15–29 years. Conclusions: Analysis of chlamydia positivity trends can inform the development, monitoring and evaluation of prevention and control activities and improves the interpretation of notification trends. After allowing for testing effort, an increase in chlamydia infections in young people was found.
Publisher: Wiley
Date: 14-11-2023
DOI: 10.5694/MJA2.51778
Abstract: To assess associations between SARS-CoV-2 infection and the incidence of hospitalisation with selected respiratory and non-respiratory conditions in a largely SARS-CoV-2 vaccine-naïve population . Self-control case series analysis of population-wide surveillance and administrative data for all laboratory-confirmed COVID-19 cases notified to the Victorian Department of Health (onset, 23 January 2020 - 31 May 2021 ie, prior to widespread vaccination rollout) and linked hospital admissions data (admission dates to 30 September 2021). Hospitalisation of people with acute COVID-19 incidence rate ratios (IRRs) comparing incidence of hospitalisations with defined conditions (including cardiac, cerebrovascular, venous thrombo-embolic, coagulative, and renal disorders) from three days before to within 89 days of onset of COVID-19 with incidence during baseline period (60-365 days prior to COVID-19 onset). A total of 20 594 COVID-19 cases were notified 2992 people (14.5%) were hospitalised with COVID-19. The incidence of hospitalisation within 89 days of onset of COVID-19 was higher than during the baseline period for several conditions, including myocarditis and pericarditis (IRR, 14.8 95% CI, 3.2-68.3), thrombocytopenia (IRR, 7.4 95% CI, 4.4-12.5), pulmonary embolism (IRR, 6.4 95% CI, 3.6-11.4), acute myocardial infarction (IRR, 3.9 95% CI, 2.6-5.8), and cerebral infarction (IRR, 2.3 95% CI, 1.4-3.9). SARS-CoV-2 infection is associated with higher incidence of hospitalisation with several respiratory and non-respiratory conditions. Our findings reinforce the value of COVID-19 mitigation measures such as vaccination, and awareness of these associations should assist the clinical management of people with histories of SARS-CoV-2 infection.
Publisher: Frontiers Media SA
Date: 10-03-2022
DOI: 10.3389/FPUBH.2022.837504
Abstract: The Inter-Agency Standing Committee (IASC), created by the United Nations (UN) General Assembly in 1991, serves as the global humanitarian coordination forum of the UN s system. The IASC brings 18 agencies together, including the World Health Organization (WHO), for humanitarian preparedness and response policies and action. Early in the COVID-19 pandemic, the IASC recognized the importance of providing intensified support to countries with conflict, humanitarian, or complex emergencies due to their weak health systems and fragile contexts. A Global Humanitarian Response Plan (GHRP) was rapidly developed in March 2020, which reflected the international support needed for 63 target countries deemed to have humanitarian vulnerability. This paper assessed whether WHO provided intensified technical, financial, and commodity inputs to GHRP countries ( n = 63) compared to non-GHRP countries ( n = 131) in the first year of the COVID-19 pandemic. The analysis showed that WHO supported all 194 countries regardless of humanitarian vulnerability. Health commodities were supplied to most countries globally (86%), and WHO implemented most (67%) of the $1.268 billion spent in 2020 at country level. However, proportionally more GHRP countries received health commodities and nearly four times as much was spent in GHRP countries per capita compared to non-GHRP countries ($232 vs. $60 per 1,000 capita). In countries with WHO country offices ( n = 149), proportionally more GHRP countries received WHO support for developing national response plans and monitoring frameworks, training of technical staff, facilitating logistics, publication of situation updates, and participation in research activities prior to the characterization of the pandemic or first in-country COVID-19 case. This affirms WHO's capacity to scale country support according to its humanitarian mandate. Further work is needed to assess the impact of WHO's inputs on health outcomes during the COVID-19 pandemic, which will strengthen WHO's scaled support to countries during future health emergencies.
Publisher: Elsevier BV
Date: 2022
DOI: 10.2139/SSRN.4267519
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/SH16146
Abstract: Background Clinical guidelines recommend annual chlamydia tests for all sexually active people aged 15–29 years. This study measured adherence to these guidelines and compared testing rates to the projected levels required to reduce chlamydia prevalence. Methods: All chlamydia tests conducted in Tasmania during 2012–13, for residents aged 15–29 years, were linked. Data linkage allowed in iduals who had multiple tests across different healthcare settings to be counted only once each year in analyses. Rates of testing and test positivity by age, sex, rebate status and socioeconomic indicators were measured. Results: There were 31 899 eligible tests conducted in 24 830 in iduals. Testing coverage was higher in females (21%, 19 404/92 685) than males (6%, 5426/98 123). Positivity was higher in males (16%, 862/5426) than females (10%, 1854/19 404). Most tests (81%, 25 803/31 899) were eligible for a rebate. Positivity was higher in females with non-rebatable tests (12%, 388/3116 compared with those eligible for a rebate (9%, 1466/16 285). More testing occurred in areas of middle disadvantage (10%, 9688/93 678) compared with least (8%, 1680/21 670) and most (10%, 7284/75 460) (both P 0.001) disadvantaged areas. Higher test positivity was found in areas of most-disadvantage (11%, 822/7284) compared with middle- (10%, 983/9688) and least- (8%, 139/1680) disadvantaged areas. Conclusions: Chlamydia testing rates are lower than recommended levels. Sustaining the current testing rates in females aged 20–24 years may reduce population prevalence within 10 years. This study meets key priorities of national strategies for chlamydia control by providing a method of monitoring testing coverage and evidence to evaluate prevention programs.
Publisher: Elsevier BV
Date: 02-2018
Abstract: To review the use of data linkage by Australian state and territory communicable disease control units, and to identify barriers to and enablers of data linkage to inform communicable disease surveillance and control activities. Semi-structured telephone interviews were carried out with one key informant from communicable disease control units in all eight Australian states and territories between October 2017 and January 2018. Key informants from all Australian states and territories participated in the interview. A variety of existing practices were identified, with few jurisdictions making systematic use of available data linkage infrastructure. Key barriers identified from the review included: a lack of perceived need system factors and resources. Existing regulatory tools enable data linkage to enhance communicable disease surveillance and control. We identified considerable variation in the use of data linkage to inform communicable disease surveillance and control activities between jurisdictions. We suggest that routinely collected, disparate data are systematically integrated into existing surveillance and response policy cycle to improve communicable disease prevention and control efforts. Implications for public health: Existing gaps in communicable disease surveillance data may affect prevention and control efforts. Data linkage is recognised as a valuable method to close surveillance gaps and should be used to enhance the value of publicly held health data.
Publisher: Elsevier BV
Date: 02-2007
Publisher: American Academy of Pediatrics (AAP)
Date: 09-2021
Abstract: Infant influenza and pertussis disease causes considerable morbidity and mortality worldwide. We examined the effectiveness of maternal influenza and pertussis vaccines in preventing these diseases in infants. This inception cohort study comprised women whose pregnancies ended between September 1, 2015, and December 31, 2017, in Victoria, Australia. Maternal vaccination status was sourced from the Victorian Perinatal Data Collection and linked to 5 data sets to ascertain infant outcomes and vaccination. The primary outcome of interest was laboratory-confirmed influenza or pertussis disease in infants aged & months, 2 to & months, and & months combined. Secondary outcomes included infant hospitalization (emergency presentation or admission) and death. Risk ratios and 95% confidence intervals (CIs) were estimated by Poisson regression. Vaccine effectiveness (VE) was estimated as (1 minus the risk ratio) x 100%. Among 186 962 pregnant women, 85 830 (45.9%) and 128 060 (68.5%) were vaccinated against influenza and pertussis, respectively. There were 175 and 51 infants with laboratory-confirmed influenza and pertussis disease, respectively. Influenza VE was 56.1% (95% CI, 23.3% to 74.9%) for infants aged & months and 35.7% (2.2% to 57.7%) for infants aged 2 to & months. Pertussis VE was 80.1% (95% CI, 37.1% to 93.7%) for infants aged & months and 31.8% (95% CI, −39.1% to 66.6%) for infants aged 2 to & months. Our study provides evidence of the direct effectiveness of maternal influenza and pertussis vaccination in preventing these diseases in infants aged & months. The findings strengthen the importance of maternal vaccination to prevent these diseases in infants.
Publisher: AMPCo
Date: 08-2017
DOI: 10.5694/MJA17.00195
Publisher: Cambridge University Press (CUP)
Date: 22-05-2017
DOI: 10.1017/S095026881700098X
Abstract: Identification of priority populations such as men who have sex with men (MSM) is important in surveillance systems to monitor trends of sexually transmitted infections (STIs). We explored using routinely collected non-behavioural data as a means to establish MSM status in surveillance by assessing anorectal swab as a marker of male-to-male sexual exposure. We used chlamydia testing data from a sexual health clinic, 2007–2012. Men reporting any male sexual partner(s) in the previous 12 months were considered MSM. The dataset was split into development and validation s les to develop a univariate predictive model and assess the model fit. The dataset included 30 358 in idual men and 48 554 episodes of STI testing 45% were among reported MSM and an anorectal swab was performed in 40% of testing episodes. Anorectal swabbing had good diagnostic performance as a marker for MSM status (sensitivity = 87%, specificity = 99%, positive predictive value = 98·6%, negative predictive value = 90·3%). The model showed good fit against the internal validation s le (area under the curve = 0·93). Anorectal swabs are a valid marker of MSM behaviour in surveillance data from sexual health clinics, and they are likely to be particularly useful for monitoring STI trends among MSM with higher risk behaviour.
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.ENVRES.2022.112969
Abstract: While the relationship between outdoor particulate matter (PM) and lower respiratory tract infections in children and adolescents is accepted, we know little about the impacts of outdoor PM on the risk of developing or aggravating upper respiratory tract infections (URTIs). We aimed to review the literature examining the relationship between outdoor PM exposure and URTIs in children and adolescents. A systematic search of EMBASE, MEDLINE, PubMed, Scopus, CINAHL and Web of Science databases was undertaken on April 3, 2020 and October 27, 2021. Comparable short-term studies of time-series or case-crossover designs were pooled in meta-analyses using random-effects models, while the remainder of studies were combined in a narrative analysis. Quality, risk of bias and level of evidence for health effects were appraised using a combination of emerging frameworks in environmental health. Out of 1366 articles identified, 34 were included in the systematic review and 16 of these were included in meta-analyses. Both PM This study found some evidence of associations between PM and URTIs in children and adolescents, the relationship strength increased with PM
Publisher: Wiley
Date: 02-2017
DOI: 10.5694/MJA16.00614
Abstract: Traditional herbal products are widely used in Australia to treat a broad range of conditions and diseases. It is popularly believed that these products are safer than prescribed drugs. While many may be safe, it is worrying that the specific effects and harmful interactions of a number of their components with prescription medications is not well understood. Some traditional herbal preparations contain heavy metals and toxic chemicals, as well as naturally occurring organic toxins. The effects of these substances can be dire, including acute hepatic and renal failure, exacerbation of pre-existing conditions and diseases, and even death. The content and quality of herbal preparations are not tightly controlled, with some ingredients either not listed or their concentrations recorded inaccurately on websites or labels. Herbal products may also include illegal ingredients, such as ephedra, Asarum europaeum (European wild ginger) and endangered animal species (eg, snow leopard). An additional problem is augmentation with prescription medications to enhance the apparent effectiveness of a preparation. Toxic substances may also be deliberately or inadvertently added: less expensive, more harmful plants may be substituted for more expensive ingredients, and processing may not be adequate. The lack of regulation and monitoring of traditional herbal preparations in Australia and other Western countries means that their contribution to illness and death is unknown. We need to raise awareness of these problems with health care practitioners and with the general public.
Publisher: Cambridge University Press (CUP)
Date: 30-08-2016
DOI: 10.1017/S0950268816001734
Abstract: Immigrants and their children who return to their country of origin to visit friends and relatives (VFR) are at increased risk of acquiring infectious diseases compared to other travellers. VFR travel is an important disease control issue, as one quarter of Australia's population are foreign-born and one quarter of departing Australian international travellers are visiting friends and relatives. We conducted a 1-year prospective enhanced surveillance study in New South Wales and Victoria, Australia to determine the contribution of VFR travel to notifiable diseases associated with travel, including typhoid, paratyphoid, measles, hepatitis A, hepatitis E, malaria and chikungunya. Additional data on characteristics of international travel were collected. Recent international travel was reported by 180/222 (81%) enhanced surveillance cases, including all malaria, chikungunya and paratyphoid cases. The majority of cases who acquired infections during travel were immigrant Australians (96, 53%) or their Australian-born children (43, 24%). VFR travel was reported by 117 (65%) travel-associated cases, highest for typhoid (31/32, 97%). Cases of children (aged years) (86%) were more frequently VFR travellers compared to adult travellers (57%, P 0·001). VFR travel is an important contributor to imported disease in Australia. Communicable disease control strategies targeting these travellers, such as targeted health promotion, are likely to impact importation of these travel-related infections.
Publisher: Wiley
Date: 21-04-2019
DOI: 10.5694/MJA2.50125
Abstract: To assess variations by time of year and hospital in the uptake of influenza and pertussis vaccinations by pregnant women in Victoria to identify factors associated with vaccination uptake. Retrospective analysis of data in the Victorian Perinatal Data Collection (VPDC), a population surveillance system for obstetric conditions, procedures, and pregnancy and birth outcomes. Women whose pregnancies ended in a live or stillbirth during July 2015 - June 2017. Influenza and pertussis vaccinations during pregnancy. 153 980 pregnancies in 67 hospitals ended during July 2015 - June 2017 59 968 pregnant women (39.0%) were vaccinated against influenza and 98 583 (64.0%) against pertussis. Coverage varied by pregnancy end date, rising for influenza during winter and spring, but for pertussis rising continuously across the two years from 37.5% to 82.2%. Differences between hospitals in coverage were marked. Factors associated with vaccination included greater maternal age, primigravidity, early antenatal care, and GP-led care. The odds of vaccination were statistically significantly lower for women born overseas and those who smoked during pregnancy the odds of vaccination were also lower for Aboriginal and Torres Strait Islander women. Pertussis vaccination of pregnant women in Victoria has increased, but influenza vaccination rates remain moderate and variable. Structural changes at the system level may improve maternal vaccination rates. Embedding the delivery of maternal vaccination programs in antenatal care pathways should be a priority.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 07-2023
Publisher: Cambridge University Press (CUP)
Date: 16-02-2012
DOI: 10.1017/S0950268812000180
Abstract: Twenty-two confirmed cases of Salmonella Infantis were identified in 70 residents of high-level care areas of a residential aged care facility in Sydney in April 2010 during an outbreak of gastroenteritis. A retrospective cohort study was conducted to identify a possible cause. Consuming a soft diet, puréed diet, or thickened fluid were each independently associated with illness. A logistic regression showed consumption of thickened fluid to be the only significant exposure associated with illness (adjusted odds ratio 11·8, 95% confidence interval 1·9–75·9). It was postulated that the thickened fluid had been contaminated by chicken mince, a s le of which also cultured S . Infantis. This finding reinforces the need to educate food-handlers on the risk of potential cross-contamination it also highlights the need to consider all dietary components, such as thickened fluids, as potential vehicles for transmission in an outbreak.
Publisher: Springer Science and Business Media LLC
Date: 22-01-2013
Publisher: Research Square Platform LLC
Date: 23-06-2023
DOI: 10.21203/RS.3.RS-3045254/V1
Abstract: BACKGROUND Evidence on the relationship between air pollution and allergic sensitisation in childhood is inconsistent, and this relationship has not been investigated in the context of smoke events that are predicted to increase with climate change. Thus, we aimed to evaluate associations between exposure in two early life periods to severe levels of particulate matter with an aerodynamic diameter 2.5µm (PM 2.5 ) from a mine fire, background PM 2.5 , and allergic sensitisation later in childhood. METHODS We measured specific immunoglobulin E (IgE) levels for seven common aeroallergens as well as total IgE levels in a cohort of children who had been exposed to the Hazelwood coal mine fire, either in utero or during their first two years of life, in a regional area of Australia where ambient levels of PM 2.5 are generally low. We estimated personal exposure to fire-specific emissions of PM 2.5 based on a high-resolution meteorological and pollutant dispersion model and detailed reported movements of pregnant mothers and young children during the fire. We also estimated the usual background exposure to PM 2.5 at the residential address at birth using a national satellite-based land-use regression model. Associations between both sources of PM 2.5 and sensitisation to dust, cat, fungi, and grass seven years after the fire were estimated with logistic regression, while associations with total IgE levels were estimated with linear regression. RESULTS No association was found between the levels of exposure at either developmental stage to fire-related PM 2.5 and allergic sensitisation seven years after the event. However, levels of background exposure were positively associated with sensitisation to dust (OR = 1.89, 95%CI = 1.11,3.20 per 1 µg/m 3 ). CONCLUSIONS Chronic but low exposure to PM 2.5 in early life could be more strongly associated with allergic sensitisation in childhood than time-limited high exposure levels, such as the ones experienced during landscape fires.
Publisher: Elsevier BV
Date: 02-2019
Abstract: To assess the impact of an enhanced viral hepatitis surveillance program on data completeness and on epidemiological assessment of affected populations. Notified cases of non-acute hepatitis B and C were analysed to determine demographic characteristics and risk factors during the period prior to July 2015-June 2016, and during enhanced surveillance of the period July 2016-June 2017, during which time doctors were contacted for information about new diagnoses. During the enhanced period, completeness for country of birth and Indigenous status doubled for both hepatitis B and hepatitis C, from 18-37% to 48-65%. The incidence ratio of hepatitis C among Aboriginal and Torres Strait Islander people increased from eight-fold to 11.4-fold, and the proportion of hepatitis B cases reported as born in China and Vietnam relative to other countries increased. New data fields identified that 12% of hepatitis C diagnoses occurred in a correctional facility, and 2% of hepatitis B cases were healthcare workers. Improved data completeness highlighted the underlying epidemiology of chronic viral hepatitis, demonstrating the increased burden of infection among specific priority populations. Implications for public health: Enhanced surveillance provides greater insight into the epidemiology of chronic viral hepatitis, identifying groups at risk and opportunities for public health action.
Publisher: Wiley
Date: 17-10-2016
DOI: 10.1002/CAM4.929
Publisher: Elsevier BV
Date: 2022
DOI: 10.2139/SSRN.4025054
Publisher: Environmental Health Perspectives
Date: 02-2018
Publisher: Environmental Health Perspectives
Date: 18-09-2022
Publisher: Environmental Health Perspectives
Date: 18-09-2022
Publisher: Oxford University Press (OUP)
Date: 23-03-2006
DOI: 10.1093/IJE/DYL044
Abstract: The population-based case-control study is not suited to the evaluation of rare genetic (or environmental) factors. The use of a novel case-control design in which cases have second primaries and controls are cancer survivors has been proposed for this purpose. We report results from an international study of melanoma that involved population-based ascertainment of incident cases of second or subsequent primary melanoma as the 'case' group and incident cases of first primary melanoma as the 'control' group. We evaluate the validity of the study design by comparing the results obtained for phenotypic factors that have been shown consistently to be associated with melanoma in previous conventional studies with the results from a conventional case-control study conducted in Connecticut and from literature reviews. All but one of the known risk factors for melanoma were shown to be significantly associated with melanoma in our study, though the in idual odds ratios appear to be somewhat attenuated relative to the magnitudes typically observed in the literature. Patients with a second or subsequent primary cancer of a single type represent a potentially valuable and under-utilized resource for the study of cancer aetiology.
Publisher: Oxford University Press (OUP)
Date: 19-10-2005
DOI: 10.1093/JNCI/DJI312
Abstract: Germline mutations in the CDKN2A gene have been linked to melanoma incidence in many families with multiple cases of the disease. Previous studies of multiple-case families have indicated that the lifetime risk (i.e., penetrance) of melanoma in CDKN2A mutation carriers is very high, ranging from 58% in Europe to 91% in Australia by age 80 years. In this study, we examined lifetime melanoma risk among CDKN2A mutation carriers using carriers who were identified in a population-based study of melanoma. Probands for the study were incident case patients with either first or subsequent melanoma who were identified in nine geographic regions in Australia, Canada, the United States, and Italy. A total of 3626 probands (53% participation rate) with adequate DNA for analysis were recruited and genotyped for CDKN2A mutations. From the 3550 probands whose DNA could be lified by polymerase chain reaction of CDKN2A exons 1alpha, 2, and 3 and surrounding regions, 65 mutation carriers were identified. Melanoma histories in first-degree relatives of these probands were used to calculate the lifetime risk in CDKN2A mutation carriers using the kin-cohort method. The risk of melanoma in CDKN2A mutation carriers was approximately 14% (95% CI = 8% to 22%) by age 50 years, 24% (95% CI = 15% to 34%) by age 70 years, and 28% (95% CI = 18% to 40%) by age 80 years. Eighteen probands had three or more first-degree relatives with melanoma, but only one was a carrier of a CDKN2A mutation. CDKN2A mutation carriers in the general population have a much lower risk of melanoma than that suggested by estimates obtained from multiple-case families. The preponderance of familial clustering of melanoma occurs in families without identifiable mutations in CDKN2A.
Publisher: Elsevier BV
Date: 04-2010
DOI: 10.1111/J.1753-6405.2010.00494.X
Abstract: To investigate trends in notification rates of Chlamydia trachomatis in Tasmania, Australia, by population sub-groups, from 1 January 2001 to 31 December 2007. An enhanced surveillance dataset was used to supplement case notifications. Rates based on age group were analysed by sex, geographic region, indigenous status, sexual exposure, reason for testing and healthcare provider. In all age groups, the notification rate increased steeply. The highest rates were seen in the ages 15-24 years this age group represented 15% of the population but accounted for 74% of the chlamydial notifications. The increased rates in females aged 15-24 years and males 15-19 years in Tasmania were larger than the increases observed nationally. Rates were consistently higher in urban areas. Females were more likely to have been tested as a result of screening, and males were more likely to have been tested when presenting with symptoms or as a result of contact tracing. The majority of cases reported sexual exposure with opposite sex partners only. This study highlights the increasing significance of chlamydial infection as a public health issue, the gender differences in health-seeking behaviour, and the discrepancies in testing patterns. These findings will assist with the design of health promotion programs.
Publisher: AMPCo
Date: 02-2014
DOI: 10.5694/MJA12.11750
Publisher: Elsevier BV
Date: 02-2007
Publisher: Elsevier BV
Date: 08-2016
Abstract: The proportion of positive chlamydia tests in young people in Tasmania increased significantly between 2001 and 2010. While female positivity rates increased steadily, male positivity rose steeply to 2005 then stabilised. Crude positivity rates can be influenced by a variety of factors making interpretation difficult. Unique Tasmanian datasets were used to explore whether symptom status, reason for testing or sexual exposure could explain the observed positivity trends. Population-level chlamydia positivity rates in Tasmania over a 10-year period were compared with surveillance data collected on people aged 15 to 29 years notified with chlamydia. The proportion of asymptomatic chlamydia cases increased, with the largest increase in males aged 15 to 19 years (28%). Opportunistic testing of cases increased (greatest in males, range 17-32%). Sexual exposure remained consistent. After allowing for any changes in sexual exposure, symptom status and reason for testing, an increase in chlamydia positivity occurred over the 10 years. Healthcare providers have increased chlamydia testing in high-risk groups. Monitoring chlamydia testing patterns and positivity rates at a population level is a step forward in surveillance practices. Targeted surveys provide valuable information to supplement routine surveillance data.
Publisher: Elsevier BV
Date: 02-2018
Abstract: Recent studies have used Bayesian methods to predict timing of influenza epidemics many weeks in advance, but there is no documented evaluation of how such forecasts might support the day-to-day operations of public health staff. During the 2015 influenza season in Melbourne, Australia, weekly forecasts were presented at Health Department surveillance unit meetings, where they were evaluated and updated in light of expert opinion to improve their accuracy and usefulness. Predictive capacity of the model was substantially limited by delays in reporting and processing arising from an unprecedented number of notifications, disproportionate to seasonal intensity. Adjustment of the predictive algorithm to account for these delays and increased reporting propensity improved both current situational awareness and forecasting accuracy. Collaborative engagement with public health practitioners in model development improved understanding of the context and limitations of emerging surveillance data. Incorporation of these insights in a quantitative model resulted in more robust estimates of disease activity for public health use. Implications for public health: In addition to predicting future disease trends, forecasting methods can quantify the impact of delays in data availability and variable reporting practice on the accuracy of current epidemic assessment. Such evidence supports investment in systems capacity.
Publisher: Australian Government Department of Health and Aged Care
Date: 19-01-2023
Abstract: Introduction Healthcare facilities are high-risk settings for coronavirus disease 2019 (COVID-19) transmission. Early in the COVID-19 pandemic, the first large healthcare-associated outbreak within Australia occurred in Tasmania. Several operational research studies were conducted amongst workers from the implicated hospital c us, to learn more about COVID-19 transmission. Methods Healthcare workers (HCWs) from the implicated hospital c us were invited to complete an online survey and participate in a serology study. Blood s les for serological testing were collected at approximately 12 weeks (round one) and eight months (round two) after the outbreak. A descriptive analysis was conducted of participant characteristics, serology results, and longevity of antibodies. Results There were 261 HCWs in round one, of whom 44 (17%) were polymerase chain reaction (PCR) confirmed outbreak cases 129 of the 261 (49%) participated in round two, of whom 34 (27%) were outbreak cases. The prevalence of positive antibodies at round one was 15% (n = 38) and at round two was 12% (n = 15). There were 15 participants (12%) who were seropositive in both rounds, with a further 9% (n = 12) of round two participants having equivocal results after previously being seropositive. Six HCWs not identified as cases during the outbreak were seropositive in round one, with three still seropositive in round two. Of those who participated in both rounds, 68% (n = 88) were seronegative at both time points. Discussion Our findings demonstrate that serological testing after this large healthcare-associated COVID-19 outbreak complemented the findings of earlier diagnostic testing, with evidence of additional infections to those diagnosed when use of PCR testing had been restricted. The results also provide evidence of persisting SARS-CoV-2 antibody response eight months after an outbreak in an unvaccinated population. The high proportion of HCWs who remained seronegative is consistent with low community transmission in Tasmania after this outbreak.
Publisher: Oxford University Press (OUP)
Date: 07-01-2019
DOI: 10.1093/CID/CIZ005
Abstract: In urban Australia, the burden of shigellosis is either in returning travelers from shigellosis-endemic regions or in men who have sex with men (MSM). Here, we combine genomic data with comprehensive epidemiological data on sexual exposure and travel to describe the spread of multidrug-resistant Shigella lineages. A population-level study of all cultured Shigella isolates in the state of Victoria, Australia, was undertaken from 1 January 2016 through 31 March 2018. Antimicrobial susceptibility testing, whole-genome sequencing, and bioinformatic analyses of 545 Shigella isolates were performed at the Microbiological Diagnostic Unit Public Health Laboratory. Risk factor data on travel and sexual exposure were collected through enhanced surveillance forms or by interviews. Rates of antimicrobial resistance were high, with 17.6% (95/541) and 50.6% (274/541) resistance to ciprofloxacin and azithromycin, respectively. There were strong associations between antimicrobial resistance, phylogeny, and epidemiology. Specifically, 2 major MSM-associated lineages were identified: a Shigellasonnei lineage (n = 159) and a Shigella flexneri 2a lineage (n = 105). Of concern, 147/159 (92.4%) of isolates within the S. sonnei MSM-associated lineage harbored mutations associated with reduced susceptibility to recommended oral antimicrobials: namely, azithromycin, trimethoprim-sulfamethoxazole, and ciprofloxacin. Long-read sequencing demonstrated global dissemination of multidrug-resistant plasmids across Shigella species and lineages, but predominantly associated with MSM isolates. Our contemporary data highlight the ongoing public health threat posed by resistant Shigella, both in Australia and globally. Urgent multidisciplinary public health measures are required to interrupt transmission and prevent infection.
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.VACCINE.2018.02.094
Abstract: During a pertussis epidemic in 2009, the Department of Health, Victoria, Australia, implemented a cocoon program offering parents of new babies a funded-dose of pertussis-containing vaccine. We assessed vaccine effectiveness (VE) of the program in reducing pertussis infection in infants. Using a matched case-control design, infants aged <12 months that were notified with pertussis between 1 January 2010 and 31 December 2011, and born during the time that the cocoon program was in place, were identified. Controls were matched by area of residence and date of birth. Telephone interviews we conducted to ascertain parents' vaccination status, and if vaccinated, timing of vaccination receipt relative to the birth of their baby. Odds ratios (ORs) were calculated for the association between vaccination and pertussis infection, with VE calculated as (1 - OR) × 100%. The study recruited 215 cases and 240 controls (response rates 67% and 25% of eligible participants, respectively). Vaccination of both parents after delivery of the infant and ≥28 days prior to illness onset reduced pertussis infection by 77% (Vaccine Effectiveness [VE] = 77% (confidence interval [95% CI], 18-93%). After adjusting for maternal education, presence of a sibling within the household, and the infants' primary course vaccination status, the adjusted VE was 64% (95% CI, -58-92%). Although not reaching statistical significance, our results demonstrated that cocoon immunisation - where both parents are vaccinated in the post-partum period - may offer some protection again infant pertussis infection. Cocoon immunisation could be considered in circumstances where antenatal vaccination of the mother has not occurred.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/SH09010
Abstract: Background: To examine the relationship between genital chlamydia testing by healthcare providers and patient demographic characteristics in Tasmania, Australia, from 2001 to 2007. Methods: Analysis of enhanced surveillance data for genital Chlamydia trachomatis infections notified to the Tasmanian Communicable Diseases Prevention Unit between 1 January 2001 and 31 December 2007. Results: General practitioners identify most cases of genital chlamydia infection, irrespective of patient age, gender, indigenous status or urban status. Tests that are performed for screening purposes identify the largest number of cases in females, particularly in very young females. In males, tests performed due to the presence of clinical symptoms identify the majority of cases. However, tests performed for the purposes of contact tracing also identify a substantial burden of genital chlamydia infection, particularly in males. Conclusions: The present study demonstrates the critical role the general practitioner has in the identification of genital chlamydia infection. Opportunistic screening for genital chlamydia, including in the context of contact tracing, is an essential clinical activity that results in the identification of substantial numbers of cases of infection. Policy makers and public health practitioners should support general practice screening initiatives and remove the barriers to genital chlamydia screening in general practice.
Publisher: American Association for Cancer Research (AACR)
Date: 11-2010
DOI: 10.1158/1055-9965.EPI-10-0686
Abstract: Background: Solar elastosis adjacent to melanomas in histologic sections is regarded as an indicator of sun exposure, although the associations of UV exposure and phenotype with solar elastosis are yet to be fully explored. Methods: The study included 2,589 incident primary melanoma patients with assessment of histologic solar elastosis in the population-based Genes, Environment, and Melanoma study. Ambient erythemal UV (UVE) at places of residence and sun exposure hours, including body site–specific exposure, were collected. We examined the association of cumulative site-specific and non–site-specific sun exposure hours and ambient UVE with solar elastosis in multivariable models adjusted for age, sex, center, pigmentary characteristics, nevi, and, where relevant, body site. Results: Solar elastosis was associated most strongly with site-specific UVE [odds ratio (OR) for top exposure quartile, 5.20 95% confidence interval (95% CI), 3.40-7.96 P for trend & .001] and also with site-specific sun exposure (OR for top quartile, 5.12 95% CI, 3.35-7.83 P for trend & .001). Older age (OR at & years, 7.69 95% CI, 5.14-11.52 P for trend & 0.001) and having more than 10 back nevi (OR, 0.77 95% CI, 0.61-0.97 P = 0.03) were independently associated with solar elastosis. Conclusion: Solar elastosis had a strong association with higher site-specific UVE dose, older age, and fewer nevi. Impact: Solar elastosis could be a useful biomarker of lifetime site-specific UV. Future research is needed to explore whether age represents more than simple accumulation of sun exposure and to determine why people with more nevi may be less prone to solar elastosis. Cancer Epidemiol Biomarkers Prev 19(11) 2932–41. ©2010 AACR.
Publisher: Frontiers Media SA
Date: 11-08-2022
DOI: 10.3389/FIMMU.2022.945021
Abstract: Autoantibodies to multiple targets are found during acute COVID-19. Whether all, or some, persist after 6 months, and their correlation with sustained anti-SARS-CoV-2 immunity, is still controversial. Herein, we measured antibodies to multiple SARS-CoV-2 antigens (Wuhan-Hu-1 nucleoprotein (NP), whole spike (S), spike subunits (S1, S2 and receptor binding domain (RBD)) and Omicron spike) and 102 human proteins with known autoimmune associations, in plasma from healthcare workers 8 months post-exposure to SARS-CoV-2 (n=31 with confirmed COVID-19 disease and n=21 uninfected controls (PCR and anti-SARS-CoV-2 negative) at baseline). IgG antibody responses to SARS-CoV-2 antigens were significantly higher in the convalescent cohort than the healthy cohort, highlighting lasting antibody responses up to 8 months post-infection. These were also shown to be cross-reactive to the Omicron variant spike protein at a similar level to lasting anti-RBD antibodies (correlation r=0.89). In iduals post COVID-19 infection recognised a common set of autoantigens, specific to this group in comparison to the healthy controls. Moreover, the long-term level of anti-Spike IgG was associated with the breadth of autoreactivity post-COVID-19. There were further moderate positive correlations between anti-SARS-CoV-2 responses and 11 specific autoantigens. The most commonly recognised autoantigens were found in the COVID-19 convalescent cohort. Although there was no overall correlation in self-reported symptom severity and anti-SARS-CoV-2 antibody levels, anti-calprotectin antibodies were associated with return to healthy normal life 8 months post infection. Calprotectin was also the most common target for autoantibodies, recognized by 22.6% of the overall convalescent cohort. Future studies may address whether, counter-intuitively, such autoantibodies may play a protective role in the pathology of long-COVID-19.
Publisher: The Sax Institute
Date: 2013
DOI: 10.1071/NB13003
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/SH16137
Abstract: Background Chlamydia re-infection increases the likelihood of adverse long-term sequelae. Clinical guidelines recommend retesting at 3–12 months for in iduals with positive results, to detect re-infections. Retesting and test positivity levels were measured in young people who previously tested positive for chlamydia infection. Methods: All chlamydia tests conducted during 2012–13 in Tasmanian residents aged 15–29 years were linked. Retesting and retest positivity rates were calculated by sex, age, socioeconomic indicators and test timeframe. Results: Retesting rates were higher in females than males at 3 months (14.5%, n = 242/1673 vs 10%, n = 71/721) (P 0.01) and 12 months (27%, 265/968 vs 24%, 98/410) (P = 0.24). The retesting rate was higher in females living in areas of most disadvantage (35.5%, 154/434) compared with areas of middle and least disadvantage (26% 139/534) (P 0.01). Males were more likely than females to retest positive at 3 months (35%, 25/71 vs 23%, 55/242) (P 0.01) retest positivity at 12 months was 32% in both sexes (males 98/140 females 265/968). Retest positivity was higher in males living in areas of least disadvantage (43%, 3/7) compared with middle (24%, 16/67) (P = 0.27) and most (27%, 10/37) (P = 0.09) and higher in females living in areas of least disadvantage (39%, 7/18) compared with middle (24%, 29/121) (P 0.01) and most (31%, 48/154) (P = 0.02). Conclusions: Retesting rates are low in Tasmania and retest positivity is high, reinforcing the importance of promoting safer sex practices, partner notification and treatment, and retesting.
No related grants have been discovered for Nicola Stephens.