Environmental plastics in the context of UV radiation, climate change, and the Montreal Protocol.

There are close links between solar UV radiation, climate change, and plastic pollution. UV-driven weathering is a key process leading to the degradation of plastics in the environment but also the formation of potentially harmful plastic fragments such as micro- and nanoplastic particles. Estimates of the environmental persistence of plastic pollution, and the formation of fragments, will need to take in account plastic dispersal around the globe, as well as projected UV radiation levels and climate change factors.

Plastics in the environment in the context of UV radiation, climate change and the Montreal Protocol: UNEP Environmental Effects Assessment Panel, Update 2023.

This Assessment Update by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) considers the interactive effects of solar UV radiation, global warming, and other weathering factors on plastics. The Assessment illustrates the significance of solar UV radiation in decreasing the durability of plastic materials, degradation of plastic debris, formation of micro- and nanoplastic particles and accompanying leaching of potential toxic compounds. Micro- and nanoplastics have been found in all ecosystems, the atmosphere, and in humans. While the potential biological risks are not yet well-established, the widespread and increasing occurrence of plastic pollution is reason for continuing research and monitoring. Plastic debris persists after its intended life in soils, water bodies and the atmosphere as well as in living organisms. To counteract accumulation of plastics in the environment, the lifetime of novel plastics or plastic alternatives should better match the functional life of products, with eventual breakdown releasing harmless substances to the environment.

The immune cell transcriptome is modulated by vitamin D3 supplementation in people with a first demyelinating event participating in a randomized placebo-controlled trial.

Vitamin D deficiency is a risk factor for developing multiple sclerosis. The PrevANZ trial was conducted to determine if vitamin D3 supplementation can prevent recurrent disease activity in people with a first demyelinating event. As a sub-study of this trial, we investigated the effect of supplementation on peripheral immune cell gene expression. Participants were randomized to 1000, 5000 or 10,000 international units daily of vitamin D3 or placebo. Peripheral blood was collected at baseline and 12 weeks and sent for ribonucleic acid sequencing. Datasets from 55 participants were included. Gene expression was modulated by high dose supplementation. Antigen presentation and viral response pathways were upregulated. Oxidative phosphorylation and immune signaling pathways, including tumor necrosis factor-alpha and interleukin-17 signaling, were downregulated. Overall, vitamin D3 supplementation for 12 weeks modulated the peripheral immune cell transcriptome with induction of anti-inflammatory gene expression profiles. Our results support a dose-dependent effect of vitamin D3 supplementation on immune gene expression.

Relative risks of childhood developmental vulnerabilities in three Australian communities with exposure to per- and polyfluoroalkyl substances: data linkage study.

Background: Aqueous film forming foams (AFFF) containing per- and polyfluoroalkyl substances (PFAS) caused local environmental contamination in three Australian residential areas: Katherine in the Northern Territory (NT), Oakey in Queensland (Qld) and Williamtown in New South Wales (NSW). We examined whether children who lived in these areas had higher risks of developmental vulnerabilities than children who lived in comparison areas without known contamination. Methods: All children identified in the Medicare Enrolment File-a consumer directory for Australia's universal healthcare insurance scheme-who ever lived in exposure areas, and a sample of children who ever lived in selected comparison areas, were linked to the Australian Early Development Census (AEDC). The AEDC data were available from four cycles: 2009, 2012, 2015 and 2018. For each exposure area, we estimated relative risks (RRs) of developmental vulnerability on each of five AEDC domains and a summary measure, adjusting for sociodemographic characteristics and other potential confounders. Findings: We included 2,429 children from the NT, 2,592 from Qld and 510 from NSW. We observed lower risk of developmental vulnerability in the Communication skills and general knowledge domain in Katherine (RR = 0.74, 95% confidence interval (CI) 0.57 to 0.97), and higher risks of developmental vulnerability in the same domain (RR = 1.49, 95% CI 1.18 to 1.87) and in the Physical health and wellbeing domain in Oakey (RR = 1.31, 95% CI 1.06 to 1.61). Risks of developmental vulnerabilities on other domains were not different from those in the relevant comparison areas or were uncertain due to small numbers of events. Conclusion: There was inadequate evidence for increased risks of developmental vulnerabilities in children who ever lived in three PFAS-affected areas in Australia.

Balancing the risks and benefits of sun exposure: A revised position statement for Australian adults.

OBJECTIVE: To describe the development of a new position statement regarding balancing the risks and benefits of sun exposure for Australian adults. METHODS: We conducted a Sun Exposure Summit in March 2021, with presentations from invited experts and a workshop including representation from academic, clinical, policy, and patient stakeholder organisations. The group considered advice about balancing the risks and benefits of sun exposure for Australian adults and developed a revised consensus position statement. RESULTS: The balance of risks and benefits of sun exposure is not the same for everybody. For people at very high risk of skin cancer, the risks of exposure likely outweigh the benefits; sun protection is essential. Conversely, people with deeply pigmented skin are at low risk of skin cancer but at high risk of vitamin D deficiency; routine sun protection is not recommended. For those at intermediate risk of skin cancer, sun protection remains a priority, but individuals may obtain sufficient sun exposure to maintain adequate vitamin D status. CONCLUSIONS: The new position statement provides sun exposure advice that explicitly recognises the differing needs of Australia's diverse population. IMPLICATIONS FOR PUBLIC HEALTH: Mass communication campaigns should retain the focus on skin cancer prevention. The new position statement will support the delivery of personalised advice.

Vitamin D did not reduce multiple sclerosis disease activity after a clinically isolated syndrome.

Low serum levels of 25-hydroxyvitamin D [25(OH)D] and low sunlight exposure are known risk factors for the development of multiple sclerosis. Add-on vitamin D supplementation trials in established multiple sclerosis have been inconclusive. The effects of vitamin D supplementation to prevent multiple sclerosis is unknown. We aimed to test the hypothesis that oral vitamin D3 supplementation in high-risk clinically isolated syndrome (abnormal MRI, at least three T2 brain and/or spinal cord lesions), delays time to conversion to definite multiple sclerosis, that the therapeutic effect is dose-dependent, and that all doses are safe and well tolerated. We conducted a double-blind trial in Australia and New Zealand. Eligible participants were randomized 1:1:1:1 to placebo, 1000, 5000 or 10 000 international units (IU) of oral vitamin D3 daily within each study centre (n = 23) and followed for up to 48 weeks. Between 2013 and 2021, we enrolled 204 participants. Brain MRI scans were performed at baseline, 24 and 48 weeks. The main study outcome was conversion to clinically definite multiple sclerosis based on the 2010 McDonald criteria defined as either a clinical relapse or new brain MRI T2 lesion development. We included 199 cases in the intention-to-treat analysis based on assigned dose. Of these, 116 converted to multiple sclerosis by 48 weeks (58%). Compared to placebo, the hazard ratios (95% confidence interval) for conversion were 1000 IU 0.87 (0.50, 1.50); 5000 IU 1.37 (0.82, 2.29); and 10 000 IU 1.28 (0.76, 2.14). In an adjusted model including age, sex, latitude, study centre and baseline symptom number, clinically isolated syndrome onset site, presence of infratentorial lesions and use of steroids, the hazard ratios (versus placebo) were 1000 IU 0.80 (0.45, 1.44); 5000 IU 1.36 (0.78, 2.38); and 10 000 IU 1.07 (0.62, 1.85). Vitamin D3 supplementation was safe and well tolerated. We did not demonstrate reduction in multiple sclerosis disease activity by vitamin D3 supplementation after a high-risk clinically isolated syndrome.

Relative Risks of Adverse Perinatal Outcomes in Three Australian Communities Exposed to Per- and Polyfluoroalkyl Substances: Data Linkage Study.

INTRODUCTION: Firefighting foams containing per- and polyfluoroalkyl substances (PFAS) have caused environmental contamination in several Australian residential areas, including Katherine in the Northern Territory (NT), Oakey in Queensland (Qld), and Williamtown in New South Wales (NSW). We examined whether the risks of adverse perinatal outcomes were higher in mothers living in these exposure areas than in selected comparison areas without known contamination. METHODS: We linked residential addresses in exposure areas to addresses collected in the jurisdictional Perinatal Data Collections of the NT (1986-2017), Qld (2007-2018), and NSW (1994-2018) to select all pregnancies from mothers who gave birth while living in these areas. We also identified one comparison group for each exposure area by selecting pregnancies where the maternal address was in selected comparison areas. We examined 12 binary perinatal outcomes and three growth measurements. For each exposure area, we estimated relative risks (RRs) of adverse outcomes and differences in means of growth measures, adjusting for sociodemographic characteristics and other potential confounders. RESULTS: We included 16,970 pregnancies from the NT, 4654 from Qld, and 7475 from NSW. We observed elevated risks of stillbirth in Oakey (RR = 2.59, 95% confidence interval (CI) 1.25 to 5.39) and of postpartum haemorrhage (RR = 1.94, 95% CI 1.13 to 3.33) and pregnancy-induced hypertension (RR = 1.88, 95% CI 1.30 to 2.73) in Williamtown. The risks of other perinatal outcomes were not materially different from those in the relevant comparison areas or were uncertain due to small numbers of events. CONCLUSIONS: There was limited evidence for increased risks of adverse perinatal outcomes in mothers living in areas with PFAS contamination from firefighting foams. We found higher risks of some outcomes in individual areas, but these were not consistent across all areas under study and could have been due to chance, bias, or confounding.

Risk of a first clinical diagnosis of central nervous system demyelination in relation to human herpesviruses in the context of Epstein-Barr virus.

BACKGROUND AND PURPOSE: Epstein-Barr virus (EBV) is implicated in multiple sclerosis (MS) risk; evidence for other herpesviruses is inconsistent. Here, we test blood markers of infection with human herpesvirus 6 (HHV-6), varicella zoster virus (VZV), and cytomegalovirus (CMV) as risk factors for a first clinical diagnosis of central nervous system demyelination (FCD) in the context of markers of EBV infection. METHODS: In the Ausimmune case-control study, cases had an FCD, and population controls were matched on age, sex, and study region. We quantified HHV-6- and VZV-DNA load in whole blood and HHV-6, VZV, and CMV antibodies in serum. Conditional logistic regression tested associations with FCD risk, adjusting for Epstein-Barr nuclear antigen (EBNA) IgG, EBV-DNA load, and other covariates. RESULTS: In 204 FCD cases and 215 matched controls, only HHV-6-DNA load (positive vs. negative) was associated with FCD risk (adjusted odds ratio = 2.20, 95% confidence interval = 1.08-4.46, p = 0.03). Only EBNA IgG and HHV-6-DNA positivity were retained in a predictive model of FCD risk; the combination had a stronger association than either alone. CMV-specific IgG concentration modified the association between an MS risk-related human leucocyte antigen gene and FCD risk. Six cases and one control had very high HHV-6-DNA load (>1.0 × 106 copies/mL). CONCLUSIONS: HHV-6-DNA positivity and high load (possibly due to inherited HHV-6 chromosomal integration) were associated with increased FCD risk, particularly in association with markers of EBV infection. With growing interest in prevention/management of MS through EBV-related pathways, there should be additional consideration of the role of HHV-6 infection.

Liver and cardiometabolic markers and conditions in a cross-sectional study of three Australian communities living with environmental per- and polyfluoroalkyl substances contamination.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) have been associated with higher cholesterol and liver function markers in some studies, but the evidence for specific cardiometabolic conditions has been inconclusive. OBJECTIVES: We quantified the associations of single and combined PFAS with cardiometabolic markers and conditions in a cross-sectional study of three Australian communities with PFAS-contaminated water from the historical use of aqueous film-forming foam in firefighting activities, and three comparison communities. METHODS: Participants gave blood samples for measurement of nine PFAS, four lipids, six liver function markers, and completed a survey on sociodemographic characteristics and eight cardiometabolic conditions. We estimated differences in mean biomarker concentrations per doubling in single PFAS concentrations (linear regression) and per interquartile range increase in the PFAS mixture (Bayesian kernel machine regression). We estimated prevalence ratios of biomarker concentrations outside reference limits and self-reported cardiometabolic conditions (Poisson regression). RESULTS: We recruited 881 adults in exposed communities and 801 in comparison communities. We observed higher mean total cholesterol with higher single and mixture PFAS concentrations in blood serum (e.g., 0.18 mmol/L, 95% credible interval -0.06 to 0.42, higher total cholesterol concentrations with an interquartile range increase in all PFAS concentrations in Williamtown, New South Wales), with varying certainty across communities and PFAS. There was less consistency in direction of associations for liver function markers. Serum perfluorooctanoic acid (PFOA) concentrations were positively associated with the prevalence of self-reported hypercholesterolemia in one of three communities, but PFAS concentrations were not associated with self-reported type II diabetes, liver disease, or cardiovascular disease. DISCUSSION: Our study is one of few that has simultaneously quantified the associations of blood PFAS concentrations with multiple biomarkers and cardiometabolic conditions in multiple communities. Our findings for total cholesterol were consistent with previous studies; however, substantial uncertainty in our estimates and the cross-sectional design limit causal inference.

Vitamin D and Sun Exposure: A Community Survey in Australia.

Sun exposure carries both harms and benefits. Exposing the skin to the sun is the main modifiable cause of skin cancers, which exert a considerable health and economic burden in Australia. The most well-established benefit of exposure to ultraviolet (UV) radiation is vitamin D production. Australia has the highest incidence of skin cancer in the world but, despite the high ambient UV radiation, approximately one quarter of the population is estimated to be vitamin D deficient. Balancing the risks and benefits is challenging and requires effective communication. We sought to provide a snapshot of public knowledge and attitudes regarding sun exposure and vitamin D and to examine the associations between these factors and sun protective behaviors. In 2020 we administered an online survey; 4824 participants with self-reported fair or medium skin color were included in this analysis. Only 25% and 34% of participants were able to identify the amount of time outdoors needed to maintain adequate vitamin D status in summer and winter, respectively and 25% were concerned that sunscreen use inhibits vitamin D synthesis. This lack of knowledge was associated with suboptimal sun protection practices. Public education is warranted to prevent over-exposure, while supporting natural vitamin D production.

Conjunctival ultraviolet autofluorescence area decreases with age and sunglasses use.

BACKGROUND: Conjunctival ultraviolet autofluorescence (CUVAF) is a method of detecting conjunctival damage related to ultraviolet radiation exposure. In cross-sectional studies, CUVAF area is positively associated with self-reported time spent outdoors and pterygium and negatively associated with myopia; however, longitudinal studies are scarce. AIMS: To use a novel deep learning-based tool to assess 8-year change in CUVAF area in young adults, investigate factors associated with this change and identify the number of new onset pterygia. METHODS: A deep learning-based CUVAF tool was developed to measure CUVAF area. CUVAF area and pterygium status were assessed at three study visits: baseline (participants were approximately 20 years old) and at 7-year and 8-year follow-ups. Participants self-reported sun protection behaviours and ocular history. RESULTS: CUVAF data were available for 1497 participants from at least one study visit; 633 (43%) participants had complete CUVAF data. Mean CUVAF areas at baseline and the 7-year and 8-year follow-ups were 48.4, 39.3 and 37.7 mm2, respectively. There was a decrease in mean CUVAF area over time (change in total CUVAF area=-0.96 mm2 per year (95% CI: -1.07 to -0.86)). For participants who wore sunglasses ≥1/2 of the time, CUVAF area decreased by an additional -0.42 mm2 per year (95% CI: -0.72 to -0.12) on average. Fourteen (1.5%) participants developed a pterygium. CONCLUSIONS: In this young adult cohort, CUVAF area declined over an 8-year period. Wearing sunglasses was associated with a faster reduction in CUVAF area. Deep learning-based models can assist in accurate and efficient measurement of CUVAF area.

Predictors of progression from a first demyelinating event to clinically definite multiple sclerosis.

Understanding the predictors of progression from a first to a second demyelinating event (and formerly, a diagnosis of clinically definite multiple sclerosis) is important clinically. Previous studies have focused on predictors within a single domain, e.g. radiological, lacking prospective data across multiple domains. We tested a comprehensive set of personal, environmental, neurological, MRI and genetic characteristics, considered together, as predictors of progression from a first demyelinating event to clinically definite multiple sclerosis. Participants were aged 18-59 years and had a first demyelinating event during the study recruitment period (1 November 2003-31 December 2006) for the Ausimmune Study (n = 216) and had follow-up data to 2-3 years post-initial interview. Detailed baseline data were available on a broad range of demographic and environmental factors, MRI, and genetic and viral studies. Follow-up data included confirmation of clinically definite multiple sclerosis (or not) and changes in environmental exposures during the follow-up period. We used multivariable logistic regression and Cox proportional hazards regression modelling to test predictors of, and time to, conversion to clinically definite multiple sclerosis. On review, one participant had an undiagnosed event prior to study recruitment and was excluded (n = 215). Data on progression to clinically definite multiple sclerosis were available for 91.2% (n = 196); 77% were diagnosed as clinically definite multiple sclerosis at follow-up. Mean (standard deviation) duration of follow-up was 2.7 (0.7) years. The set of predictors retained in the best predictive model for progression from a first demyelinating event to clinically definite multiple sclerosis were as follows: younger age at first demyelinating event [adjusted odds ratio (aOR) = 0.92, 95% confidence interval (CI) = 0.87-0.97, per additional year of age); being a smoker at baseline (versus not) (aOR = 2.55, 95% CI 0.85-7.69); lower sun exposure at age 6-18 years (aOR = 0.86, 95% CI 0.74-1.00, per 100 kJ/m2 increment in ultraviolet radiation dose), presence (versus absence) of infratentorial lesions on baseline magnetic resonance imaging (aOR = 7.41, 95% CI 2.08-26.41); and single nucleotide polymorphisms in human leukocyte antigen (HLA)-B (rs2523393, aOR = 0.25, 95% CI 0.09-0.68, for any G versus A:A), TNFRSF1A (rs1800693, aOR = 5.82, 95% CI 2.10-16.12, for any C versus T:T), and a vitamin D-binding protein gene (rs7041, aOR = 3.76, 95% CI 1.41-9.99, for any A versus C:C). The final model explained 36% of the variance. Predictors of more rapid progression to clinically definite multiple sclerosis (Cox proportional hazards regression) were similar. Genetic and magnetic resonance imaging characteristics as well as demographic and environmental factors predicted progression, and more rapid progression, from a first demyelinating event to a second event and clinically definite multiple sclerosis.

Multiple sclerosis incidence: A systematic review of change over time by geographical region.

BACKGROUND: The incidence of multiple sclerosis (MS) has reportedly increased over time; however, change in MS incidence has not been rigorously assessed globally. METHODS: We followed the guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Two independent reviewers systematically searched Scopus, PubMed and Web of Science for peer-reviewed publications in English from 1 January 1985 to 24 September 2020 reporting MS incidence for at least two contiguous five-year periods with clearly-defined case ascertainment. The outcome was change in MS incidence rate according to geographical region. RESULTS: We identified 64 papers providing 65 regional estimates (including three paediatric-onset MS) across 24 countries covering ∼3% of the world's population (in 2000/1 or closest available total population for the entire country), with quality (adapted Newcastle-Ottawa Scale) ranging from sufficient to good. Studies were mainly from Italy (n=14 including San Marino), Norway (n=10) or Canada (n=9), with no studies in the Africa or South-East Asia regions. Of the 62 whole-of-population estimates, MS incidence rates: significantly increased in 38 (61%), significantly decreased in 13 (21%) and remained stable in 11 (18%). In the paediatric-onset studies, MS incidence was stable in two (67%) and increased in one (33%). Many estimates derived from only selected (often small) regions of a country. For 42 (68%) of the whole-of-population estimates (and two of the paediatric-onset estimates) a consistent case definition or diagnostic criteria over the entire study period was explicitly reported. Across the n=9 whole-of-population estimates based on a consistent case definition for the duration of the study period, and including a substantial proportion of the population of a country (≥one-third), incidence rates were stable in n=3, increased in n=3 and decreased in n=3. Studies using a consistent case definition covered ∼2.7% of the global population; incidence rates were stable in 0.9% of the global population, decreased in studies covering 1%, and increased in those covering 0.8% of the global population. CONCLUSION: The studies reporting change in MS incidence rate over time were limited by world region and the proportion of the global population covered. Although by number of studies, the predominant pattern was increasing MS incidence, in studies where a consistent case definition was used across the duration of the study and with high population coverage, no predominant pattern of MS incidence was evident.

Total Dairy Consumption Is Not Associated With Likelihood of a First Clinical Diagnosis of Central Nervous System Demyelination.

Background: The evidence associating consumption of dairy products and risk of MS is contradictory and inconclusive. Objective: To test associations between dairy consumption and the likelihood of a first clinical diagnosis of central nervous system demyelination (FCD), a common precursor to MS. Methods: We used data from the 2003-2006 Ausimmune Study, a population-based Australian, multicentre, matched case-control study (272 cases, 519 controls). Total dairy consumption (servings/day) was calculated by summing consumption of milk, cheese and yogurt. Covariate-adjusted treatment effects using augmented inverse probability weighting was used to test for associations with FCD. We conducted sensitivity analyses in the subset of participants who had had a classic first demyelinating event (FDE), defined as a single, first episode of symptoms suggestive of CNS demyelination. Results: There were no statistically significant associations between total dairy consumption (per one serving/day) and FCD (adjusted OR 1.00; 95% CI 0.93, 1.07; p = 0.979). However, yogurt consumption (vs. no yogurt consumption) was associated with an 11% decreased likelihood of FDE (adjusted OR 0.89; 95% CI 0.89, 0.79; p = 0.046). Conclusion: While total dairy consumption was not associated with FCD in this Australian case-control study, yogurt consumption was associated with reduced likelihood of FDE.

Vitamin D composition of Australian game products.

The vitamin D content of many Australian game products is unknown. These foods are potential sources of vitamin D for remote-dwelling Aboriginal and Torres Strait Islander people, of whom 39% are vitamin D deficient (serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations < 50 nmol/L). Vitamin D3, 25(OH)D3, vitamin D2 and 25(OH)D2 were measured by liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ) in raw meat (camel, crocodile, emu, kangaroo), emu eggs and emu oil. Vitamin D3 (range, 0.5-14.5 µg/100 g) was found in all products except camel and kangaroo. All samples except kangaroo contained 25(OH)D3; some camel samples contained relatively high concentrations (range, 0.4-5.2 µg/100 g). Vitamin D2 was found in emu products and some kangaroo samples. We detected trace amounts of 25(OH)D2 in some camel and kangaroo samples. This study provides valuable insight into foods with a paucity of data on vitamin D content, showing that some are potentially useful sources of vitamin D.

Smokers Increasingly Motivated and Able to Quit as Smoking Prevalence Falls: Umbrella and Systematic Review of Evidence Relevant to the "Hardening Hypothesis," Considering Transcendence of Manufactured Doubt.

INTRODUCTION: The "hardening hypothesis" proposes that as the prevalence of smoking in a population declines, there will be a "hardening" of the remaining smoker population. This review examines the evidence regarding smokers' motivation, dependence, and quitting behavior as smoking prevalence declines, to assess whether population "hardening" (decreasing propensity to quit) or "softening" (the converse) is occurring. METHODS: MEDLINE, PsychINFO, Scopus, Web of Science, and Cochrane Library were searched to July 2019, using terms related to smoking and hardening, for reviews and large, population-based repeat cross-sectional studies. There were additional searches of reference lists and citations of key research articles. Two reviewers screened half the titles and abstracts each, and two reviewers screened full texts independently using tested criteria. Four reviewers independently and systematically extracted data from eligible publications, with one reviewer per study, checked by another reviewer. RESULTS: Of 265 titles identified, three reviews and ten repeat cross-sectional studies were included. Reviews concluded that hardening has not occurred among the general smoking population over time. Among repeated cross-sectional studies, five examined motivation, nine examined dependence, five examined hardcore smoking, and two examined quit outcomes. All but one study found a lack of hardening. Most found softening within the smoking population, consistent across hardening indicators, definitions, countries (and tobacco control environments), and time periods examined. CONCLUSIONS: Tobacco control reduces smoking prevalence and fosters a smoking population more amenable to evidence-based interventions. Based on the weight of the available evidence, the "hardening hypothesis" should be rejected and the reality of softening accepted. IMPLICATIONS: This umbrella review and systematic review provides a critical consideration of evidence from epidemiology and psychology and other fields regarding the "hardening hypothesis"-a persistent myth undermining tobacco control. It reaches the conclusion that the sum-total of the worldwide evidence indicates either "softening" of the smoking population, or a lack of hardening. Hence, tobacco control reduces smoking prevalence and fosters a smoking population more amenable to evidence-based interventions. The review indicates that the time has come to take active steps to combat the myth of hardening and to replace it with the reality of "softening."

Australian vaccine preventable disease epidemiological review series: Pertussis, 2013-2018.

INTRODUCTION: Significant recent changes in Australian pertussis immunisation policy include the progressive introduction of funded pertussis immunisation programs for pregnant women, from late 2014 to mid-2015 at jurisdictional level and then under the National Immunisation Program from July 2018, and reintroduction of the 18-month booster dose in 2016. This study analyses pertussis notification, hospitalisation, and mortality data from 2013 to 2018 in the context of trends since 1995. METHODS: This study used data from the National Notifiable Diseases Surveillance System, the National Hospital Morbidity Database, and the Australian Coordinating Registry, for descriptive analysis of pertussis notifications, hospitalisations and deaths in Australia by Aboriginal and Torres Strait Islander (Indigenous) status from 2013 to 2018, examining trends between 1995 and 2012 at both the national and jurisdictional level. Incidence rate ratios (IRR) were utilised to compare pertussis incidence in infants aged < 2 months and 6-11 months for each year from the 2015-2018 (post-maternal-vaccination) period against the 2010-2013 (pre-maternal-vaccination) period. RESULTS AND DISCUSSION: Annual national all-age incidence of pertussis notifications between 2013 and 2018 was 63.6 per 100,000 population, 40% less than between 2006 and 2012. Between 2016 and 2018, infants aged < 2 months had the lowest notification rates of age groups < 5 years old, with the highest notification rates in pre-adolescents aged 9-11 years. Compared with the baseline period (2010-2013), the IRR for infants aged < 2 months decreased in each year during the post-maternal-vaccination period from 0.4 (95% confidence interval [95% CI]: 0.3-0.5) in 2015 to 0.1 (95% CI: 0.1-0.2) in 2018. For infants aged 6-11 months, the IRR was 0.9 (95% CI: 0.8-1.0) in 2015, 1.1 (95% CI: 1.0-1.2) in 2016 and declined to 0.7 (95% CI: 0.6-0.8) in 2017 and 2018. Notification and hospitalisation rates in Indigenous children were 3-8 times as high as rates in non-Indigenous children across all age groups < 5 years old. CONCLUSION: Pertussis remains the second most frequently notified vaccine preventable disease in Australia, after influenza, but dramatic decreases in incidence have been observed in infants too young to receive any doses of pertussis-containing vaccine.

Vitamin D metabolites and risk of first clinical diagnosis of central nervous system demyelination.

Low 25-hydroxyvitamin D (25(OH)D) concentration is a recognised risk factor for multiple sclerosis (MS). Associations with vitamin D metabolites and vitamin D binding globulin (VDBG) have not been widely studied. We assessed the association between vitamin D metabolites (25(OH)D2, 25(OH)D3, c3-epimer 25(OH)D3, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3)) measured by liquid chromatography-tandem mass spectrometry assays, VDBG measured using a polyclonal immunoassay, and calculated free and bioavailable 25(OH)D, free 1,25(OH)2D3, and the 24,25(OH)2D3: total 25(OH)D and total 1,25(OH)2D: total 25(OH)D ratios with risk of a first clinical diagnosis of CNS demyelination (FCD) in an Australian case-control study (n = 196 cases, n = 241 controls, matched on age, sex and study region). Higher 25(OH)D (adjusted odds ratio (AOR) = 0.94 (95 % confidence interval (CI) 0.85-1.03) per 10 nmol/L increment) and 24,25(OH)2D3 (AOR = 0.81 (95 %CI 0.65-1.00) per 1 nmol/L increment) concentrations were associated with reduced FCD risk. Our results were compatible with no association for the other vitamin D metabolites, ratios, or VDBG with FCD risk. Thus, using standardised assays, and a comprehensive range of vitamin D metabolites, we confirmed the association of higher 25(OH)D and reduced FCD risk, and describe a similar effect for 24,25(OH)2D3; free or bioavailable 25(OH)D were not associated with FCD risk.

Changes in serum neurofilament light chain levels following narrowband ultraviolet B phototherapy in clinically isolated syndrome.

OBJECTIVE: To determine whether serum neurofilament light chain (sNfL) levels are suppressed in patients with the clinically isolated syndrome (CIS) following narrowband ultraviolet B phototherapy (UVB-PT). METHODS: sNfL levels were measured using a sensitive single-molecule array assay at baseline and up to 12 months in 17 patients with CIS, 10 of whom received UVB-PT, and were compared with healthy control (HC) and early relapsing remitting multiple sclerosis (RRMS) group. sNfL levels were correlated with magnetic resonance imaging total lesion volume (LV) determined using icobrain version 4.4.1 and with clinical outcomes. RESULTS: Baseline median sNfL levels were significantly higher in the CIS (20.6 pg/mL, interquartile range [IQR] 13.7-161.4) and RRMS groups (36.6 pg/ml [IQR] 16.2-212.2) than in HC (10.7 pg/ml [IQR] 4.9-21.5) (p = .012 and p = .0002, respectively), and were strongly correlated with T2 and T1 LV at 12 months (r = .800; p = .014 and r = .833; p = .008, respectively) in the CIS group. Analysis of changes in sNfL levels over time in the CIS group showed a significant cumulative suppressive effect of UVB-PT in the first 3 months (UVB-PT -10.6% vs non-UVB-PT +58.3%; p = .04) following which the levels in the two groups converged and continued to fall. CONCLUSIONS: Our findings provide the basis for further studies to determine the utility of sNfL levels as a marker of neuro-axonal damage in CIS and early MS and for assessing the efficacy of new therapeutic interventions such as UVB-PT.