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1.  Bioluminescence in the ghost fungus Omphalotus nidiformis does not attract potential spore dispersing insects 
IMA Fungus  2016;7(2):229-234.
Bioluminescence has been known from fungi since ancient times, but little work has been done to establish its potential role. There is evidence that some bioluminescent fungi differentially attract potential spore-dispersing insects, and we aimed to establish if this was the case for the ghost fungus, Omphalotus nidiformis (Agaricales, Marasmiaceae), a widespread Australian temperate zone species. We examined three corroborative lines of evidence: circadian rhythmicity of bioluminescence; field-recorded insect abundance at the time of basidiome production; and attractiveness of glowing fungi to flying insects. Basidiomes glowed continuously day and night, and were present in winter (June-July) when insect abundance was low. To assess attractiveness, we deployed sticky-traps in open woodland in the absence of light pollution, in Treatment (baited with fresh bioluminescent O. nidiformis) and Control pairs, for 480 trap-hours on moonless nights. There was no statistical difference in mean insect abundance between Treatment and Control traps (mean 0.33 and 0.54 individuals per trap night, respectively). To interpret these results, we provide a brief review of competing hypotheses for fungal bioluminescence, and conclude that for some fungi, bioluminescence may be an incidental by-product of metabolism rather than conferring any selective advantage. It is possible that the role of bioluminescence differs among evolutionary lineages of fungi and/or with attributes of their growth environments that could affect spore dispersal, such as wind and insect abundance.
PMCID: PMC5159592  PMID: 27990328
Agaricales; fungal physiology; insect-fungal interactions; Kangaroo Island; spore dispersal
2.  Dental Attendance Among Low-Income Women and Their Children Following a Brief Motivational Counseling Intervention: A Community Randomized Trial 
This study tested a behavioral intervention to increase dental attendance among rural Oregonian low-income women and their children. It utilized a multi-site, single-blind, randomized trial design. Four hundred women were randomized into one of four conditions to receive prenatal or postpartum motivational interviewing/counseling (MI) or prenatal or postpartum health education (HE). Counselors also functioned as patient navigators. Primary outcomes were dental attendance during pregnancy for the mother and for the child by age 18 months. Attendance was obtained from the Oregon Division of Medical Assistance Programs and participant self-report. Statewide self-reported utilization data were obtained from the Oregon Pregnancy Risk Assessment Monitoring System (PRAMS). Maternal attendance was 92% in the prenatal MI group and 94% in the prenatal HE group (RR = 0.98; 95% CI = 0.93–1.04). Children’s attendance was 54% in postpartum MI group and 52% in the postpartum HE group (RR = 1.03; 95% CI = 0.82–1.28). Compared to statewide PRAMS, attendance was higher during pregnancy for study mothers (45% statewide; 95% CI = 40–50%) and for their children by 24 months (36% statewide; 95% CI = 27–44%). MI did not lead to greater attendance when compared to HE alone and cost more to implement. High attendance may be attributable to the counselors’ patient navigator function.
Trial Registration: Identifier NCT01120041
PMCID: PMC4610142  PMID: 26372934
motivational interviewing; oral health; RCT; community; pregnancy; PRAMS
3.  Comparative Sensitivity of Intraoperative Motor Evoked Potential Monitoring in Predicting Postoperative Neurologic Deficits: Nondegenerative versus Degenerative Myelopathy 
Global Spine Journal  2015;6(5):452-458.
Study Design
 Retrospective review.
 Intraoperative motor evoked potential (MEP) monitoring in spine surgery may assist surgeons in taking corrective measures to prevent neurologic deficits. The efficacy of monitoring MEPs intraoperatively in patients with myelopathy from nondegenerative causes has not been quantified. We compared the sensitivity and specificity of intraoperative MEP monitoring in patients with myelopathy caused by nondegenerative processes to patients with degenerative cervicothoracic spondylotic myelopathy (CSM).
 We retrospectively reviewed our myelopathy surgical cases during a 1-year period to identify patients with degenerative CSM and CSM of nondegenerative causes and collected data on intraoperative MEP changes and postoperative new deficits. Categorical variables were analyzed by Fisher exact test. Receiver operator curves assessed intraoperative MEP monitoring performance in the two groups.
 In all, 144 patients were identified: 102 had degenerative CSM and 42 had CSM of nondegenerative causes (24 extra-axial tumors, 12 infectious processes, 5 traumatic fractures, and 1 rheumatoid arthritis). For degenerative CSM, there were 11 intraoperative MEP alerts and 7 new deficits (p < 0.001). The corresponding sensitivity was 71% and the specificity was 94%. In the nondegenerative group, there were 11 intraoperative MEP alerts and 3 deficits, which was not significant (p > 0.99). The sensitivity (33%) and specificity (74%) were lower. Among patients with degenerative CSM, the model performed well for predicting postoperative deficits (area under the curve [AUC] 0.826), which appeared better than the nondegenerative group, although it did not reach statistical significance (AUC 0.538, p = 0.16).
 Based on this large retrospective analysis, intraoperative MEP monitoring in surgery for nondegenerative CSM cases appears to be less sensitive to cord injury and less predictive of postoperative deficits when compared with degenerative CSM cases.
PMCID: PMC4947397  PMID: 27433429
MEP; neuromonitoring; myelopathy; tumor; infection
4.  Risk factors of direct heat-related hospital admissions during the 2009 heatwave in Adelaide, Australia: a matched case–control study 
BMJ Open  2016;6(6):e010666.
The extreme heatwave of 2009 in South Australia dramatically increased morbidity, with a 14-fold increase in direct heat-related hospitalisation in metropolitan Adelaide. Our study aimed to identify risk factors for the excess morbidity.
A matched case–control study of risk factors was conducted.
Patients and matched community controls were interviewed to gather data on demographics, living environment, social support, health status and behaviour changes during the heatwave.
Cases were all hospital admissions with heat-related diagnoses during the 5-day heatwave in 2009. Controls were randomly selected from communities.
Outcome measures
Descriptive analyses, simple and multiple conditional logistic regressions were performed. Adjusted ORs (AORs) were estimated.
In total, 143 hospital patients and 143 matched community controls were interviewed, with a mean age of 73 years (SD 21), 96% European ethnicity, 63% retired, 36% with high school or higher education, and 8% institutional living. The regression model indicated that compared with the controls, cases were more likely to have heart disease (AOR=13.56, 95% CI 1.27 to 144.86) and dementia (AOR=26.43, 95% CI 1.99 to 350.73). The protective factors included higher education level (AOR=0.48, 95% CI 0.23 to 0.99), having air-conditioner in the bedroom (AOR=0.12, 95% CI 0.02 to 0.74), having an emergency button (AOR=0.09, 95% CI 0.01 to 0.96), using refreshment (AOR=0.10, 95% CI 0.01 to 0.84), and having more social activities (AOR=0.11, 95% CI 0.02 to 0.57).
Pre-existing heart disease and dementia significantly increase the risk of direct heat-related hospitalisations during heatwaves. The presence of an air-conditioner in the bedroom, more social activities, a higher education level, use of emergency buttons and refreshments reduce the risk during heatwaves.
PMCID: PMC4893849  PMID: 27256088
5.  Resource Limitation, Controphic Ostracod Density and Larval Mosquito Development 
PLoS ONE  2015;10(11):e0142472.
Aquatic environments can be restricted with the amount of available food resources especially with changes to both abiotic and biotic conditions. Mosquito larvae, in particular, are sensitive to changes in food resources. Resource limitation through inter-, and intra-specific competition among mosquitoes are known to affect both their development and survival. However, much less is understood about the effects of non-culicid controphic competitors (species that share the same trophic level). To address this knowledge gap, we investigated and compared mosquito larval development, survival and adult size in two experiments, one with different densities of non-culicid controphic conditions and the other with altered resource conditions. We used Aedes camptorhynchus, a salt marsh breeding mosquito and a prominent vector for Ross River virus in Australia. Aedes camptorhynchus usually has few competitors due to its halo-tolerance and distribution in salt marshes. However, sympatric ostracod micro-crustaceans often co-occur within these salt marshes and can be found in dense populations, with field evidence suggesting exploitative competition for resources. Our experiments demonstrate resource limiting conditions caused significant increases in mosquito developmental times, decreased adult survival and decreased adult size. Overall, non-culicid exploitation experiments showed little effect on larval development and survival, but similar effects on adult size. We suggest that the alterations of adult traits owing to non-culicid controphic competition has potential to extend to vector-borne disease transmission.
PMCID: PMC4641740  PMID: 26558896
6.  Infectious Diseases, Urbanization and Climate Change: Challenges in Future China 
China is one of the largest countries in the world with nearly 20% of the world’s population. There have been significant improvements in economy, education and technology over the last three decades. Due to substantial investments from all levels of government, the public health system in China has been improved since the 2003 severe acute respiratory syndrome (SARS) outbreak. However, infectious diseases still remain a major population health issue and this may be exacerbated by rapid urbanization and unprecedented impacts of climate change. This commentary aims to explore China’s current capacity to manage infectious diseases which impair population health. It discusses the existing disease surveillance system and underscores the critical importance of strengthening the system. It also explores how the growing migrant population, dramatic changes in the natural landscape following rapid urbanization, and changing climatic conditions can contribute to the emergence and re-emergence of infectious disease. Continuing research on infectious diseases, urbanization and climate change may inform the country’s capacity to deal with emerging and re-emerging infectious diseases in the future.
PMCID: PMC4586659  PMID: 26371017
climate change; urbanization; infectious disease; disease surveillance; challenges; disease control and prevention
7.  Antibodies to Leptospira among blood donors in higher-risk areas of Australia: possible implications for transfusion safety 
Blood Transfusion  2015;13(1):32-36.
Leptospirosis is one of the most common bacterial zoonoses worldwide, and clinical manifestations range from asymptomatic infection to acute febrile illness, multi-organ failure and death. Asymptomatic, acute bacteraemia in a blood donor provides a potential for transfusion-transmission, although only a single such case from India has been recorded. Human leptospirosis is uncommon in developed countries; however, the state of Queensland in Australia has one of the highest rates among developed countries, especially after increased rainfall. This study examined the prevalence of antibodies to Leptospira spp. in blood donors residing in higher-risk areas of Australia, to evaluate the appropriateness of current blood safety guidelines.
Materials and methods
Plasma samples collected from blood donors residing in higher-risk areas of Australia during 2009 and 2011 were included in the study. All samples were tested for the presence of antibodies to 22 leptospiral serovars using the microscopic agglutination test.
No sample had antibody titres suggestive of a current or recent infection, however, seven samples (1.44%, 95% CI: 0.38–2.50%) had titres suggestive of a past infection.
This study provides data that may support the appropriateness of current relevant donor selection policies in Australia. Given that the risk profile for leptospirosis is expanding and that the infection is likely to become more prevalent with climate change, this disease may become more of a concern for transfusion safety in the future.
PMCID: PMC4317087  PMID: 24960651
emerging pathogen; climate; rainfall
8.  Are the Dietary Guidelines for Meat, Fat, Fruit and Vegetable Consumption Appropriate for Environmental Sustainability? A Review of the Literature 
Nutrients  2014;6(6):2251-2265.
This paper reviews the current literature around the environmental impacts of dietary recommendations. The focus of the review is on collating evidence relating to environmental impacts of the dietary advice found in the World Health Organisation guidelines, and environmental impact literature: reducing the consumption of fat, reducing the consumption of meat-based protein and animal-based foods, and increasing the consumption of fruit and vegetables. The environmental impact of reducing dietary fat intake is unclear, although reducing consumption of the food category of edible fats and oils appears to have little impact. However most, but not all, studies support environmental benefits of a reduced consumption of animal-based foods and increased consumption of fruit and vegetables. In general, it appears that adhering to dietary guidelines reduces impact on the environment, but further study is required to examine the environmental impacts of animal-based foods, and fruit and vegetable intake in depth.
PMCID: PMC4073148  PMID: 24926526
environmental impact; diet; food; red meat; animal protein; fat; fruit; vegetables
9.  Using Mathematical Transmission Modelling to Investigate Drivers of Respiratory Syncytial Virus Seasonality in Children in the Philippines 
PLoS ONE  2014;9(2):e90094.
We used a mathematical transmission model to estimate when ecological drivers of respiratory syncytial virus (RSV) transmissibility would need to act in order to produce the observed seasonality of RSV in the Philippines. We estimated that a seasonal peak in transmissibility would need to occur approximately 51 days prior to the observed peak in RSV cases (range 49 to 67 days). We then compared this estimated seasonal pattern of transmissibility to the seasonal patterns of possible ecological drivers of transmissibility: rainfall, humidity and temperature patterns, nutritional status, and school holidays. The timing of the seasonal patterns of nutritional status and rainfall were both consistent with the estimated seasonal pattern of transmissibility and these are both plausible drivers of the seasonality of RSV in this setting.
PMCID: PMC3937436  PMID: 24587222
10.  An evidence-based framework to measure quality of allied health care 
There is no standard way of describing the complexities of allied health (AH) care, or its quality. AH is an umbrella term which excludes medicine and nursing, and variably includes disciplines which provide therapy, diagnostic, or scientific services. This paper outlines a framework for a standard approach to evaluate the quality of AH therapy services.
A realist synthesis framework describing what AH does, how it does it, and what is achieved, was developed. This was populated by the findings of a systematic review of literature published since 1980 reporting concepts of quality relevant to AH. Articles were included on quality measurement concepts, theories, debates, and/or hypothetical frameworks.
Of 139 included articles, 21 reported on descriptions of quality potentially relevant to AH. From these, 24 measures of quality were identified, with 15 potentially relating to what AH does, 17 to how AH delivers care, 8 relating to short term functional outcomes, and 9 relating to longer term functional and health system outcomes.
A novel evidence-based quality framework was proposed to address the complexity of AH therapies. This should assist in better evaluation of AH processes and outcomes, costs, and evidence-based engagement of AH providers in healthcare teams.
PMCID: PMC4015500  PMID: 24571857
Allied health; Therapy; Quality constructs
11.  Treatment fidelity of brief motivational interviewing and health education in a randomized clinical trial to promote dental attendance of low-income mothers and children: Community-Based Intergenerational Oral Health Study “Baby Smiles” 
BMC Oral Health  2014;14:15.
Fidelity assessments are integral to intervention research but few published trials report these processes in detail. We included plans for fidelity monitoring in the design of a community-based intervention trial.
The study design was a randomized clinical trial of an intervention provided to low-income women to increase utilization of dental care during pregnancy (mother) or the postpartum (child) period. Group assignment followed a 2 × 2 factorial design in which participants were randomly assigned to receive either brief Motivational Interviewing (MI) or Health Education (HE) during pregnancy (prenatal) and then randomly reassigned to one of these groups for the postpartum intervention. The study setting was four county health departments in rural Oregon State, USA. Counseling was standardized using a step-by-step manual. Counselors were trained to criteria prior to delivering the intervention and fidelity monitoring continued throughout the implementation period based on audio recordings of counselor-participant sessions. The Yale Adherence and Competence Scale (YACS), modified for this study, was used to code the audio recordings of the counselors’ delivery of both the MI and HE interventions. Using Interclass Correlation Coefficients totaling the occurrences of specific MI counseling behaviors, ICC for prenatal was .93, for postpartum the ICC was .75. Participants provided a second source of fidelity data. As a second source of fidelity data, the participants completed the Feedback Questionnaire that included ratings of their satisfaction with the counselors at the completion of the prenatal and post-partum interventions.
Coding indicated counselor adherence to MI protocol and variation among counselors in the use of MI skills in the MI condition. Almost no MI behaviors were found in the HE condition. Differences in the length of time to deliver intervention were found; as expected, the HE intervention took less time. There were no differences between the overall participants’ satisfaction ratings of the HE and MI sessions by individual counselor or overall (p > .05).
Trial design, protocol specification, training, and continuous supervision led to a high degree of treatment fidelity for the counseling interventions in this randomized clinical trial and will increase confidence in the interpretation of the trial findings.
Trial registration NCT01120041
PMCID: PMC3996055  PMID: 24559035
Dental health; Motivational interviewing; Clinical competence; Postpartum care; Prenatal care
12.  Design of a community-based intergenerational oral health study: “Baby Smiles” 
BMC Oral Health  2013;13:38.
Rural, low-income pregnant women and their children are at high risk for poor oral health and have low utilization rates of dental care. The Baby Smiles study was designed to increase low-income pregnant women’s utilization of dental care, increase young children’s dental care utilization, and improve home oral health care practices.
Baby Smiles was a five-year, four-site randomized intervention trial with a 2 × 2 factorial design. Four hundred participants were randomly assigned to one of four treatment arms in which they received either brief Motivational Interviewing (MI) or health education (HE) delivered during pregnancy and after the baby was born. In the prenatal study phase, the interventions were designed to encourage dental utilization during pregnancy. After childbirth, the focus was to utilize dental care for the infant by age one. The two primary outcome measures were dental utilization during pregnancy or up to two months postpartum for the mother, and preventive dental utilization by 18 months of age for the child. Medicaid claims data will be used to assess the primary outcomes. Questionnaires were administered at enrollment and 3, 9 and 18 months postpartum (study end) to assess mediating and moderating factors.
This trial can help define the most effective way to provide one-on-one counseling to pregnant women and new mothers regarding visits to the dentist during pregnancy and after the child is born. It supports previous work demonstrating the potential of reducing mother-to-child transmission of Streptococcus mutans and the initiation of dental caries prevention in early childhood.
Trial registration Identifier NCT01120041
PMCID: PMC3751087  PMID: 23914908
Counseling; Motivation; Dental caries; Early childhood caries; Health Education; Dental; Mothers; Infant
13.  Poor Growth and Pneumonia Seasonality in Infants in the Philippines: Cohort and Time Series Studies 
PLoS ONE  2013;8(6):e67528.
Children with poor nutrition are at increased risk of pneumonia. In many tropical settings seasonal pneumonia epidemics occur during the rainy season, which is often a period of poor nutrition. We have investigated whether seasonal hunger may be a driver of seasonal pneumonia epidemics in children in the tropical setting of the Philippines. In individual level cohort analysis, infant size and growth were both associated with increased pneumonia admissions, consistent with findings from previous studies. A low weight for age z-score in early infancy was associated with an increased risk of pneumonia admission over the following 12 months (RR for infants in the lowest quartile of weight for age z-scores 1.28 [95% CI 1.08 to 1.51]). Poor growth in smaller than average infants was also associated with an increased risk of pneumonia (RR for those in the lowest quartile of growth in early infancy 1.31 [95%CI 1.02 to 1.68]). At a population level, we found that seasonal undernutrition preceded the seasonal increase in pneumonia and respiratory syncytial virus admissions by approximately 10 weeks (pairwise correlation at this lag was −0.41 [95%CI −0.53 to −0.27] for pneumonia admissions, and −0.63 [95%CI −0.72 to −0.51] for respiratory syncytial virus admissions). This lag appears biologically plausible. These results suggest that in addition to being an individual level risk factor for pneumonia, poor nutrition may act as a population level driver of seasonal pneumonia epidemics in the tropics. Further investigation of the seasonal level association, in particular the estimation of the expected lag between seasonal undernutrition and increased pneumonia incidence, is recommended.
PMCID: PMC3695907  PMID: 23840731
14.  Geographical Information Systems for Dengue Surveillance 
This review provides details on the role of Geographical Information Systems (GIS) in current dengue surveillance systems and focuses on the application of open access GIS technology to emphasize its importance in developing countries, where the dengue burden is greatest. It also advocates for increased international collaboration in transboundary disease surveillance to confront the emerging global challenge of dengue.
PMCID: PMC3335676  PMID: 22556070
15.  Leptospirosis in American Samoa 2010: Epidemiology, Environmental Drivers, and the Management of Emergence 
Leptospirosis has recently been reported as an emerging disease worldwide, and a seroprevalence study was undertaken in American Samoa to better understand the drivers of transmission. Antibodies indicative of previous exposure to leptospirosis were found in 15.5% of 807 participants, predominantly against three serovars that were not previously known to occur in American Samoa. Questionnaires and geographic information systems data were used to assess behavioral factors and environmental determinants of disease transmission, and logistic regression was used to identify factors associated with infection. Many statistically significant factors were consistent with previous studies, but we also showed a significant association with living at lower altitudes (odds ratio [OR] = 1.53, 95% confidence interval [CI]: 1.03–2.28), and having higher numbers of piggeries around the home (OR = 2.63, 95% CI: 1.52–4.40). Our findings support a multifaceted approach to combating the emergence of leptospirosis, including modification of individual behavior, but importantly also managing the evolving environmental drivers of risk.
PMCID: PMC3269286  PMID: 22302868
16.  Seroprevalence of Dengue in American Samoa, 2010 
Emerging Infectious Diseases  2013;19(2):324-326.
PMCID: PMC3559036  PMID: 23343610
dengue; dengue virus; viruses; seroprevalence; IgG; American Samoa
18.  Prevention of Both Neutrophil and Monocyte Recruitment Promotes Recovery after Spinal Cord Injury 
Journal of Neurotrauma  2011;28(9):1893-1907.
Strategies that block infiltration of leukocytes into the injured spinal cord improve sparing of white matter and neurological recovery. In this article, we examine the dependency of recovery on hematogenous depletion of neutrophils and monocytes. Mice were depleted of neutrophils or monocytes by systemic administration of anti-Ly6G or clodronate-liposomes. A third group was depleted of both subsets. Neurological improvement, based on a battery of tests of performance, and white matter sparing, occurred only in animals depleted of both neutrophils and monocytes. We also attempted to define the nature of the environment that was favorable to recovery. Hemeoxygenase-1 and malondialdehyde, markers of oxidative stress and lipid peroxidation, respectively, were reduced to similar levels in animals depleted of both neutrophils and monocytes, or only monocytes, but remained elevated in the group only depleted of neutrophils. Matrix metalloproteinase-9, a protease involved in early damage, was most strongly reduced in animals depleted of both leukocyte subsets. Finally, disruption of the blood–spinal cord barrier and abnormal nonheme iron accumulation were reduced only in animals depleted of both neutrophils and monocytes. Together, these findings indicate cooperation between neutrophils and monocytes in mediating early pathogenesis in the contused spinal cord and defining long-term neurological recovery.
PMCID: PMC3172879  PMID: 21657851
functional recovery; monocytes; mouse; neutrophils; spinal cord injury
19.  Leptospirosis in American Samoa – Estimating and Mapping Risk Using Environmental Data 
The recent emergence of leptospirosis has been linked to many environmental drivers of disease transmission. Accurate epidemiological data are lacking because of under-diagnosis, poor laboratory capacity, and inadequate surveillance. Predictive risk maps have been produced for many diseases to identify high-risk areas for infection and guide allocation of public health resources, and are particularly useful where disease surveillance is poor. To date, no predictive risk maps have been produced for leptospirosis. The objectives of this study were to estimate leptospirosis seroprevalence at geographic locations based on environmental factors, produce a predictive disease risk map for American Samoa, and assess the accuracy of the maps in predicting infection risk.
Methodology and Principal Findings
Data on seroprevalence and risk factors were obtained from a recent study of leptospirosis in American Samoa. Data on environmental variables were obtained from local sources, and included rainfall, altitude, vegetation, soil type, and location of backyard piggeries. Multivariable logistic regression was performed to investigate associations between seropositivity and risk factors. Using the multivariable models, seroprevalence at geographic locations was predicted based on environmental variables. Goodness of fit of models was measured using area under the curve of the receiver operating characteristic, and the percentage of cases correctly classified as seropositive. Environmental predictors of seroprevalence included living below median altitude of a village, in agricultural areas, on clay soil, and higher density of piggeries above the house. Models had acceptable goodness of fit, and correctly classified ∼84% of cases.
Conclusions and Significance
Environmental variables could be used to identify high-risk areas for leptospirosis. Environmental monitoring could potentially be a valuable strategy for leptospirosis control, and allow us to move from disease surveillance to environmental health hazard surveillance as a more cost-effective tool for directing public health interventions.
Author Summary
Leptospirosis is the most common bacterial infection transmitted from animals to humans. Infected animals excrete the bacteria in their urine, and humans can become infected through contact with animals or a contaminated environment such as water and soil. Environmental factors are important in determining the risk of human infection, and differ between ecological settings. The wide range of risk factors include high rainfall and flooding; poor sanitation and hygiene; urbanisation and overcrowding; contact with animals (including rodents, livestock, pets, and wildlife); outdoor recreation and ecotourism; and environmental degradation. Predictive risk maps have been produced for many infectious diseases to identify high-risk areas for transmission and guide allocation of public health resources. Maps are particularly useful where disease surveillance and epidemiological data are poor. The objectives of this study were to estimate leptospirosis seroprevalence at geographic locations based on environmental factors, produce a predictive disease risk map for American Samoa, and assess the accuracy of the maps in predicting infection risk. This study demonstrated the value of geographic information systems and disease mapping for identifying environmental risk factors for leptospirosis, and enhancing our understanding of disease transmission. Similar principles could be used to investigate the epidemiology of leptospirosis in other areas.
PMCID: PMC3362644  PMID: 22666516
20.  Emergence of new leptospiral serovars in American Samoa - ascertainment or ecological change? 
Leptospirosis has recently been discussed as an emerging infectious disease in many contexts, including changes in environmental drivers of disease transmission and the emergence of serovars. In this paper, we report the epidemiology of leptospiral serovars from our study of human leptospirosis in American Samoa in 2010, present evidence of recent serovar emergence, and discuss the potential epidemiological and ecological implications of our findings.
Serovar epidemiology from our leptospirosis seroprevalence study in 2010 was compared to findings from a study in 2004. The variation in geographic distribution of the three most common serovars was explored by mapping sero-positive participants to their place of residence using geographic information systems. The relationship between serovar distribution and ecological zones was examined using geo-referenced data on vegetation type and population distribution.
Human leptospirosis seroprevalence in American Samoa was 15.5% in 2010, with serological evidence that infection was caused by three predominant serovars (Hebdomadis, LT 751, and LT 1163). These serovars differed from those identified in an earlier study in 2004, and were not previously known to occur in American Samoa. In 2010, serovars also differed in geographic distribution, with variations in seroprevalence between islands and different ecological zones within the main island.
Our findings might indicate artefactual emergence (where serovars were long established but previously undetected), but we believe the evidence is more in favour of true emergence (a result of ecological change). Possibilities include changes in interactions between humans and the environment; introduction of serovars through transport of animals; evolution in distribution and/or abundance of animal reservoirs; and environmental changes that favour transmission of particular serovars.
Future research should explore the impact of ecological change on leptospirosis transmission dynamics and serovar emergence, and investigate how such new knowledge might better target environmental monitoring for disease control at a public health level.
PMCID: PMC3305655  PMID: 22273116
21.  Chikungunya Virus: A Novel and Potentially Serious Threat to New Zealand and the South Pacific Islands 
There has never been a locally transmitted outbreak of mosquito-borne disease in New Zealand, but the risk of an outbreak occurring is increasing with on-going interceptions of exotic mosquito vectors across its border, increasing traffic of goods and passengers, higher numbers of viremic travelers arriving, and local, regional, and global environmental change. The risk posed to New Zealand by chikungunya virus is potentially high because of the transmissibility of this virus in subtropical climates, compounded by a population that is predominantly immunologically naive to exotic arboviruses. However, risk reduction in New Zealand should not be considered in isolation but must be viewed within a wider South Pacific context. In this report, we discuss the potential threat posed by chikungunya to the region, focusing in particular on New Zealand, and re-emphasizing the need for a South Pacific–wide approach towards mosquito-borne disease prevention.
PMCID: PMC2946738  PMID: 20889861
22.  Empowering Head Start to Improve Access to Good Oral Health for Children from Low Income Families 
Maternal and child health journal  2008;15(7):876-882.
Surveys over 20 years have documented worsening in the dental health of preschoolers. Healthy People 2010 Midcourse Review reports the country moving away from oral health goals for young children; the slip is 57%. Exacerbating this is the inability of Medicaid to provide for those in need. Most children receive examinations only: few receive comprehensive care. We urge Head Start grantees to adopt a new approach to oral health goals and in this paper offer: (1) a review of the problem and premises preventing a solution; (2) a proposal that Head Start adopt a public health perspective; and (3) specific roles staff and dental personnel can take to mount aggressive strategies to arrest tooth decay at the grantee site.
PMCID: PMC2914140  PMID: 18246416
oral health; preschool children; Head Start; tooth decay
23.  A Review of Frameworks for Developing Environmental Health Indicators for Climate Change and Health 
The role climate change may play in altering human health, particularly in the emergence and spread of diseases, is an evolving area of research. It is important to understand this relationship because it will compound the already significant burden of diseases on national economies and public health. Authorities need to be able to assess, anticipate, and monitor human health vulnerability to climate change, in order to plan for, or implement action to avoid these eventualities. Environmental health indicators (EHIs) provide a tool to assess, monitor, and quantify human health vulnerability, to aid in the design and targeting of interventions, and measure the effectiveness of climate change adaptation and mitigation activities. Our aim was to identify the most suitable framework for developing EHIs to measure and monitor the impacts of climate change on human health and inform the development of interventions. Using published literature we reviewed the attributes of 11 frameworks. We identified the Driving force-Pressure-State-Exposure-Effect-Action (DPSEEA) framework as the most suitable one for developing EHIs for climate change and health. We propose the use of EHIs as a valuable tool to assess, quantify, and monitor human health vulnerability, design and target interventions, and measure the effectiveness of climate change adaptation and mitigation activities. In this paper, we lay the groundwork for the future development of EHIs as a multidisciplinary approach to link existing environmental and epidemiological data and networks. Analysis of such data will contribute to an enhanced understanding of the relationship between climate change and human health.
PMCID: PMC3155333  PMID: 21845162
climate change; DPSEEA; environmental health; frameworks; indicators; monitoring; policy
24.  Use of a total traffic count metric to investigate the impact of roadways on asthma severity: a case-control study 
Environmental Health  2011;10:52.
This study had two principal objectives: (i) to investigate the relationship between asthma severity and proximity to major roadways in Perth, Western Australia; (ii) to demonstrate a more accurate method of exposure assessment for traffic pollutants using an innovative GIS-based measure that fully integrates all traffic densities around subject residences.
We conducted a spatial case-control study, in which 'cases' were defined as individuals aged under 19 years of age with more severe asthma (defined here as two or more emergency department contacts with asthma in a defined 5-year period) versus age- and gender-matched 'controls' with less severe asthma (defined here as one emergency department contact for asthma). Traffic exposures were measured using a GIS-based approach to determine the lengths of the roads falling within a buffer area, and then multiplying them by their respective traffic counts.
We examined the spatial relationship between emergency department contacts for asthma at three different buffer sizes: 50 metres, 100 metres and 150 metres. No effect was noted for the 50 metre buffer (OR = 1.07; 95% CI: 0.91-1.26), but elevated odds ratios were observed with for crude (unadjusted) estimates OR = 1.21 (95% CI: 1.00-1.46) for 100 metre buffers and OR = 1.25 (95% CI: 1.02-1.54) for 150 metre buffers. For adjusted risk estimates, only the 150 metre buffer yielded a statistically significant finding (OR = 1.24; 95% CI:1.00-1.52).
Our study revealed a significant 24% increase in the risk of experiencing multiple emergency department contacts for asthma for every log-unit of traffic exposure. This study provides support for the hypothesis that traffic related air pollution increases the frequency of health service contacts for asthma. This study used advanced GIS techniques to establish traffic-weighted buffer zones around the geocoded residential location of subjects to provide an accurate assessment of exposure to traffic emissions, thereby providing a quantification of the ranges over which pollutants may exert a health effect.
PMCID: PMC3127974  PMID: 21631953
25.  Environmental monitoring to enhance comprehension and control of infectious diseases† 
In a world of emerging and resurging infectious diseases, dominated by zoonoses, environmental monitoring plays a vital role in our understanding their dynamics and their spillover to humans. Here, we critically review the ecology, epidemiology and need for monitoring of a variety of directly transmitted (Sin Nombre virus, Avian Influenza) and vector-borne (Ross River virus, West Nile virus, Lyme disease, anaplasmosis and babesiosis) zoonoses. We focus on the valuable role that existing monitoring plays in the understanding of these zoonoses, the demands for new monitoring, and how improvements can be made to existing monitoring. We also identify the fruitful outcomes which would result from implementation of the monitoring demands we have highlighted. This review aims to promote improvements in our understanding of zoonoses, their management, and public health by encouraging discussion among researchers and public health officials.
PMCID: PMC2990948  PMID: 20957286

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