The gout epidemic in French Polynesia: a modelling study of data from the Ma'i u'u epidemiological survey.

BACKGROUND: Gout is the most common cause of inflammatory arthritis worldwide, particularly in Pacific regions. We aimed to establish the prevalence of gout and hyperuricaemia in French Polynesia, their associations with dietary habits, their comorbidities, the prevalence of the HLA-B*58:01 allele, and current management of the disease. METHODS: The Ma'i u'u survey was epidemiological, prospective, cross-sectional, and gout-focused and included a random sample of adults from the general adult population of French Polynesia. It was conducted and data were collected between April 13 and Aug 16, 2021. Participants were randomly selected to represent the general adult population of French Polynesia on the basis of housing data collected during the 2017 territorial census. Each selected household was visited by a research nurse from the Ma'i u'u survey who collected data via guided, 1-h interviews with participants. In each household, the participant was the individual older than 18 years with the closest upcoming birthday. To estimate the frequency of HLA-B*58:01, we estimated HLA-B haplotypes on individuals who had whole-genome sequencing to approximately 5× average coverage (mid-pass sequencing). A subset of individuals who self-reported Polynesian ancestry and not European, Chinese, or other ancestry were used to estimate Polynesian-ancestry specific allele frequencies. Bivariate associations were reported for weighted participants; effect sizes were estimated through the odds ratio (OR) of the association calculated on the basis of a logistic model fitted with weighted observations. FINDINGS: Among the random sample of 2000 households, 896 participants were included, 140 individuals declined, and 964 households could not be contacted. 22 participants could not be weighted due to missing data, so the final weighted analysis included 874 participants (449 [51·4%] were female and 425 [48·6%] were male) representing the 196 630 adults living in French Polynesia. The estimated prevalence of gout was 14·5% (95% CI 9·9-19·2), representing 28 561 French Polynesian adults, that is 25·5% (18·2-32·8) of male individuals and 3·5% (1·0-6·0) of female individuals. The prevalence of hyperuricaemia was estimated at 71·6% (66·7-76·6), representing 128 687 French Polynesian adults. In multivariable analysis, age (OR 1·5, 95% CI 1·2-1·8 per year), male sex (10·3, 1·8-60·7), serum urate (1·6, 1·3-2·0 per 1 mg/dL), uraturia (0·8, 0·8-0·8 per 100 mg/L), type 2 diabetes (2·1, 1·4-3·1), BMI more than 30 kg/m2 (1·1, 1·0-1·2 per unit), and percentage of visceral fat (1·7, 1·1-2·7 per 1% increase) were associated with gout. There were seven heterozygous HLA-B*58:01 carriers in the full cohort of 833 individuals (seven [0·4%] of 1666 total alleles) and two heterozygous carriers in a subset of 696 individuals of Polynesian ancestry (two [0·1%]). INTERPRETATION: French Polynesia has an estimated high prevalence of gout and hyperuricaemia, with gout affecting almost 15% of adults. Territorial measures that focus on increasing access to effective urate-lowering therapies are warranted to control this major public health problem. FUNDING: Variant Bio, the French Polynesian Health Administration, Lille Catholic University Hospitals, French Society of Rheumatology, and Novartis.

SARS-CoV-2 seroprevalence and associated factors of infection before and after the Delta wave in French Polynesia: a cross-sectional study.

BACKGROUND: French Polynesia (FP) comprises 75 inhabited islands scattered across five archipelagos. Between July and October 2021, the SARS-CoV-2 Delta variant triggered a much stronger second epidemic wave in FP than the original Wuhan strain, which was dominant from August 2020 to March 2021. Although previous seroprevalence surveys made it possible to determine the proportion of the population infected by SARS-CoV-2 on the two most populated islands (Tahiti and Moorea) after the first (20.6% in Tahiti and 9.4% in Moorea) and second (57.7% in Tahiti) epidemic waves, no data are available for more remote islands. We used blood samples and personal data collected before, during, and after the second wave from inhabitants of several islands within the five archipelagos to assess the prevalence of SARS-CoV-2 infections and identify associated factors. METHODS: Blood samples and personal data were collected between April and December 2021 as part of the MATAEA study, a cross-sectional survey conducted on a random sample of the adult population representative of the five FP archipelagos and stratified by age and gender. IgG antibodies targeting the SARS-CoV-2 nucleocapsid (N) protein were detected using a recombinant antigen-based microsphere immunoassay. Factors associated with anti-SARS-CoV-2-N seropositivity were identified using logistic regression models. RESULTS: Of 1,120 participants, 503 (44.9%) tested positive for anti-SARS-CoV-2-N antibodies, corresponding to a weighted prevalence of 56.8% for the FP population aged 18-69 years. The seroprevalence increased from 21.9% to 62.1% before and during/after the Delta wave. Of these infections, only 28.4% had been diagnosed by health professionals. The odds of being seropositive were lower in males, participants recruited before the Delta wave, those who had never been married, those with a diagnosed respiratory allergy, smokers, and those vaccinated against COVID-19. CONCLUSIONS: Our results confirm the high impact of the Delta wave in FP. By the end of 2021, 56.8% of the FP population aged 18-69 years had been infected by SARS-CoV-2; the majority of these infections went undetected. Individuals with respiratory allergies were found to be less susceptible to SARS-CoV-2 infection.

Ciguatera poisoning in French Polynesia: A review of the distribution and toxicity of Gambierdiscus spp., and related impacts on food web components and human health.

Ciguatera Poisoning (CP) is a seafood poisoning highly prevalent in French Polynesia. This illness results from the consumption of seafood contaminated with ciguatoxins (CTXs) produced by Gambierdiscus, a benthic dinoflagellate. Ciguatera significantly degrades the health and economic well-being of local communities largely dependent on reef fisheries for their subsistence. French Polynesia has been the site of rich and active CP research since the 1960's. The environmental, toxicological, and epidemiological data obtained in the frame of large-scale field surveys and a country-wide CP case reporting program conducted over the past three decades in the five island groups of French Polynesia are reviewed. Results show toxin production in Gambierdiscus in the natural environment may vary considerably at a temporal and spatial scale, and that several locales clearly represent Gambierdiscus spp. "biodiversity hotspots". Current data also suggest the "hot" species G. polynesiensis could be the primary source of CTXs in local ciguateric biotopes, pending formal confirmation. The prevalence of ciguatoxic fish and the CTX levels observed in several locales were remarkably high, with herbivores and omnivores often as toxic as carnivores. Results also confirm the strong local influence of Gambierdiscus spp. on the CTX toxin profiles characterized across multiple food web components including in CP-prone marine invertebrates. The statistics, obtained in the frame of a long-term epidemiological surveillance program established in 2007, point towards an apparent decline in the number of CP cases in French Polynesia as a whole; however, incidence rates remain dangerously high in some islands. Several of the challenges and opportunities, most notably those linked to the strong cultural ramifications of CP among local communities, that need to be considered to define effective risk management strategies are addressed.

Impact of vaccinations, boosters and lockdowns on COVID-19 waves in French Polynesia.

Estimating the impact of vaccination and non-pharmaceutical interventions on COVID-19 incidence is complicated by several factors, including successive emergence of SARS-CoV-2 variants of concern and changing population immunity from vaccination and infection. We develop an age-structured multi-strain COVID-19 transmission model and inference framework to estimate vaccination and non-pharmaceutical intervention impact accounting for these factors. We apply this framework to COVID-19 waves in French Polynesia and estimate that the vaccination programme averted 34.8% (95% credible interval: 34.5-35.2%) of 223,000 symptomatic cases, 49.6% (48.7-50.5%) of 5830 hospitalisations and 64.2% (63.1-65.3%) of 1540 hospital deaths that would have occurred in a scenario without vaccination up to May 2022. We estimate the booster campaign contributed 4.5%, 1.9%, and 0.4% to overall reductions in cases, hospitalisations, and deaths. Our results suggest that removing lockdowns during the first two waves would have had non-linear effects on incidence by altering accumulation of population immunity. Our estimates of vaccination and booster impact differ from those for other countries due to differences in age structure, previous exposure levels and timing of variant introduction relative to vaccination, emphasising the importance of detailed analysis that accounts for these factors.

Diabetes in the Cook Islands: a clinical audit.

Introduction The global burden of diabetes mellitus (diabetes) is significant and of increasing concern with more pregnant women being diagnosed with gestational diabetes mellitus (GDM). The Cook Islands face mounting pressures to address diabetes alongside competing population health needs and priorities. Cook Islands residents frequently travel to New Zealand to access health services. Inadequate information systems also make it difficult for countries to prioritise preventative measures for investment. In the absence of good data to inform effective diabetes preventative and treatment measures, people with diabetes are likely to progress to complications which will burden society and health systems in the Cook Islands and New Zealand. Aim To determine the prevalence of diabetes and prediabetes, and incidence of GDM, in the Cook Islands. Methods We analysed two Te Marae Ora Cook Islands Ministry of Health datasets, the Non-Communicable Diseases (NCD) register examining demographic data for the period 1967 to December 2018 and same for the GDM register from January 2009 to December 2018. Results Of the 1270 diabetes cases, 53% were female and half were aged 45-64 years. There were 54 pre-diabetes cases and 146 GDM. Of the 20 GDM cases who developed type 2 diabetes, 80% were diagnosed before the age of 40 years. Data quality was poor. Discussion The Cook Islands diabetes registers provide important data to inform priorities for diabetes-related preventative and treatment measures. A data analyst has been employed to ensure quality, regularly audited data and information systems.

Detection of Mycobacterium angelicum in Human Urinary Tract, French Polynesia.

We definitively characterized Mycobacterium angelicum, an aquatic zoonotic opportunistic pathogen of the M. szulgai complex, using a polyphasic approach that included whole-genome sequencing. The sequence was obtained on the island of Tahiti, French Polynesia, from a urine specimen collected from a patient experiencing a urinary tract infection.

Assessment of Differentiated Thyroid Carcinomas in French Polynesia After Atmospheric Nuclear Tests Performed by France.

Importance: Due to the amount of iodine 131 released in nuclear tests and its active uptake by the thyroid, differentiated thyroid carcinoma (DTC) is the most serious health risk for the population living near sites of nuclear tests. Whether low doses to the thyroid from nuclear fallout are associated with increased risk of thyroid cancer remains a controversial issue in medicine and public health, and a misunderstanding of this issue may be associated with overdiagnosis of DTCs. Design, Setting, and Participants: This case-control study was conducted by extending a case-control study published in 2010 that included DTCs diagnosed between 1984 and 2003 by adding DTCs diagnosed between 2004 and 2016 and improving the dose assessment methodology. Data on 41 atmospheric nuclear tests conducted by France between 1966 and 1974 in French Polynesia (FP) were assessed from original internal radiation-protection reports, which the French military declassified in 2013 and which included measurements in soil, air, water, milk, and food in all FP archipelagos. These original reports led to an upward reassessment of the nuclear fallout from the tests and a doubling of estimates of the mean thyroid radiation dose received by inhabitants from 2 mGy to nearly 5 mGy. Included patients were diagnosed from 1984 to 2016 with DTC at age 55 years or younger and were born in and resided in FP at diagnosis; 395 of 457 eligible cases were included, and up to 2 controls per case nearest by birthdate and matched on sex were identified from the FP birth registry. Data were analyzed from March 2019 through October 2021. Exposure: The radiation dose to the thyroid gland was estimated using recently declassified original radiation-protection service reports, meteorological reports, self-reported lifestyle information, and group interviews of key informants and female individuals who had children at the time of these tests. Main Outcomes and Measures: The lifetime risk of DTC based on Biological Effects of Ionizing Radiation (BEIR) VII models was estimated. Results: A total of 395 DTC cases (336 females [85.1%]; mean [SD] age at end of follow-up, 43.6 [12.9] years) and 555 controls (473 females [85.2%]; mean [SD] age at end of follow-up, 42.3 [12.5] years) were included. No association was found between thyroid radiation dose received before age 15 years and risk of DTC (excess relative risk [ERR] per milligray, 0.04; 95% CI, -0.09 to 0.17; P = .27). When excluding unifocal noninvasive microcarcinomas, the dose response was significant (ERR per milligray, 0.09; 95% CI, -0.03 to 0.02; P = .02), but several incoherencies with the results of the initial study reduce the credibility of this result. The lifetime risk for the entire FP population was 29 cases of DTC (95% CI, 8-97 cases), or 2.3% (95% CI, 0.6%-7.7%) of 1524 sporadic DTC cases in this population. Conclusions and Relevance: This case-control study found that French nuclear tests were associated with an increase in lifetime risk of PTC in FP residents of 29 cases of PTC. This finding suggests that the number of thyroid cancer cases and the true order of magnitude of health outcomes associated with these nuclear tests were small, which may reassure populations of this Pacific territory.

Chikungunya virus (CHIKV) seroprevalence in the South Pacific populations of the Cook Islands and Vanuatu with associated environmental and social factors.

BACKGROUND: Arthropod-borne diseases pose a significant and increasing risk to global health. Given its rapid dissemination, causing large-scale outbreaks with severe human infections and economic loss, the Chikungunya virus (CHIKV) is one of the most important arboviruses worldwide. Despite its significance, the real global impact of CHIKV remains underestimated as outbreak data are often incomplete and based solely on syndromic surveillance. During 2011-2016, the South Pacific Region was severely affected by several CHIKV-epidemics, yet the area is still underrepresented in arboviral research. METHODS: 465 outpatient serum samples collected between 08/2016 and 04/2017 on three islands of the island states Vanuatu (Espiritu Santo) and the Cook Islands (Rarotonga, Aitutaki) were tested for anti-CHIKV specific antibodies using Enzyme-linked immunosorbent Assays. RESULTS: A total of 30% (Cook Islands) and 8% (Vanuatu) of specimens were found positive for anti-CHIKV specific antibodies with major variations in national and intranational immunity levels. Seroprevalence throughout all age groups was relatively constant. Four potential outbreak-protective factors were identified by comparing the different study settings: presence of Ae. albopictus (in absence of ECSA E1-A226V-mutation CHIKV), as well as low levels of human population densities, residents' travel activity and tourism. CONCLUSION: This is the first seroprevalence study focussing on an arboviral disease in the Cook Islands and Vanuatu. It highlights the impact of the 2014/2015 CHIKV epidemic on the Cook Islands population and shows that a notable part of the Vanuatu test population was exposed to CHIKV although no outbreaks were reported. Our findings supplement the knowledge concerning CHIKV epidemics in the South Pacific Region and contribute to a better understanding of virus dissemination, including outbreak modifying factors. This study may support preventive and rapid response measures in affected areas, travel-related risk assessment and infection identification in returning travellers. TRIAL REGISTRATION: ClinicalTrials.gov Aachen: 051/16_09/05/2016 Cook Islands Ref.: #16-16 Vanuatu Ref.: MOH/DG 10/1/1-GKT/lr.

Reconstructing long-term dengue virus immunity in French Polynesia.

BACKGROUND: Understanding the underlying risk of infection by dengue virus from surveillance systems is complicated due to the complex nature of the disease. In particular, the probability of becoming severely sick is driven by serotype-specific infection histories as well as age; however, this has rarely been quantified. Island communities that have periodic outbreaks dominated by single serotypes provide an opportunity to disentangle the competing role of serotype, age and changes in surveillance systems in characterising disease risk. METHODOLOGY: We develop mathematical models to analyse 35 years of dengue surveillance (1979-2014) and seroprevalence studies from French Polynesia. We estimate the annual force of infection, serotype-specific reporting probabilities and changes in surveillance capabilities using the annual age and serotype-specific distribution of dengue. PRINCIPAL FINDINGS: Eight dengue epidemics occurred between 1979 and 2014, with reporting probabilities for DENV-1 primary infections increasing from 3% to 5%. The reporting probability for DENV-1 secondary infections was 3.6 times that for primary infections. We also observed heterogeneity in reporting probabilities by serotype, with DENV-3 having the highest probability of being detected. Reporting probabilities declined with age after 14 y.o. Between 1979 and 2014, the proportion never infected declined from 70% to 23% while the proportion infected at least twice increased from 4.5% to 45%. By 2014, almost half of the population had acquired heterotypic immunity. The probability of an epidemic increased sharply with the estimated fraction of susceptibles among children. CONCLUSION/SIGNIFICANCE: By analysing 35 years of dengue data in French Polynesia, we characterised key factors affecting the dissemination profile and reporting of dengue cases in an epidemiological context simplified by mono-serotypic circulation. Our analysis provides key estimates that can inform the study of dengue in more complex settings where the co-circulation of multiple serotypes can greatly complicate inference.

Mathematical modelling of the mosquito Aedes polynesiensis in a heterogeneous environment.

BACKGROUND: The mosquito Aedes polynesiensis inhabits Pacific islands and territories and transmits arboviruses and parasites. In the context of rapid environmental change, understanding the effects of environmental heterogeneity on mosquitoes is crucial. METHODS: First, empirical field data and remote sensing data were combined to model spatial heterogeneity in the environmental suitability for Ae. polynesiensis. Second, a model of mosquito population dynamics was applied to predict mosquito distributions over a heterogeneous landscape assuming different dispersal behaviours. Motu Tautau, French Polynesia, was used as a case study of the utility of this methodological approach. Ae. polynesiensis use land crab Cardisoma carnifex burrows for oviposition in French Polynesia; environmental suitability was therefore quantified using C. carnifex burrow density. RESULTS: Micro-regions with large Ae. polynesiensis populations facilitated by high C. carnifex burrow density were accurately captured by our methodology. Preferential dispersal towards oviposition sites promoted larger population sizes than non-preferential dispersal but did not offer greater resilience to environmental change. Reduced environmental suitability for Ae. polynesiensis resulted in spatially non-linear effects upon the mosquito distribution. CONCLUSIONS: Environmental change has complex spatial effects upon mosquito populations. Mosquito control strategies must carefully balance spatial effects with net effects.

[Intercontinental Multidisciplinary Oncology Videoconferencing between the South Pacific and the French mainland: Results after one year and 323 cases of rare or complex cancers discussed]. / RCP Pacifique : bilan après un an et 323 cancers rares et/ou complexes discutés.

INTRODUCTION: Overseas France represents 18 % of French territory and is home to 4 % of its population for whom there is unequal treatment in the field of rare/complex cancer. AIM: To report our experience of intercontinental multidisciplinary videoconferencing between the French mainland and Pacific territories. METHODS: Every other friday, three centers located in Papeete, Nouméa and Paris-Villejuif connected between 6:30 AM and 8:00 AM GMT to discuss cases of rare/complex cancers. RESULTS: Between November 2019 and December 2020, 323 presentations implicating 233 patients involved sarcoma (n=93), digestive pathology (n=60), neuroendocrine tumors (n=35), urology (n=24), gynecology (n=24), neurology (n=16), thyroid pathology (n=14), dermatology (n=14), senology (n=11), hematology (n=11), ENT pathology (n=10), pathology thoracic (n=10) and pediatrics (n=1). Of the 233 patients, 134 (57.5 %) living in New Caledonia and 99 (42.5 %) in French Polynesia, 117 (50.5 %) had metastatic disease. 39 patients (16.7 %) were transferred to French mainland (EVASAN), for surgery (n=25), vectorized radiotherapy (n=7), biopsy (n=5), chemotherapy (n=1) or inclusion in a clinical trial (n=1). 195 patients (83.7 %) were treated at home, 15 (6.4 %) are still awaiting a decision and 4 (1.7 %) lost to follow-up. CONCLUSION: The use of videoconferencing to discuss rare/complex cancer cases was effective in guaranteeing French overseas population access to innovative therapies and clinical trials, limiting the need for intercontinental transfer to 16.7 %.

Self-collection and pooling of samples as resources-saving strategies for RT-PCR-based SARS-CoV-2 surveillance, the example of travelers in French Polynesia.

In French Polynesia, the first case of SARS-CoV-2 infection was detected on March 10th, 2020, in a resident returning from France. Between March 28th and July 14th, international air traffic was interrupted and local transmission of SARS-CoV-2 was brought under control, with only 62 cases recorded. The main challenge for reopening the air border without requiring travelers to quarantine on arrival was to limit the risk of re-introducing SARS-CoV-2. Specific measures were implemented, including the obligation for all travelers to have a negative RT-PCR test for SARS-CoV-2 carried out within 3 days before departure, and to perform another RT-PCR testing 4 days after arrival. Because of limitation in available medical staff, travelers were provided a kit allowing self-collection of oral and nasal swabs. In addition to increase our testing capacity, self-collected samples from up to 10 travelers were pooled before RNA extraction and RT-PCR testing. When a pool tested positive, RNA extraction and RT-PCR were performed on each individual sample. We report here the results of COVID-19 surveillance (COV-CHECK PORINETIA) conducted between July 15th, 2020, and February 15th, 2021, in travelers using self-collection and pooling approaches. We tested 5,982 pools comprising 59,490 individual samples, and detected 273 (0.46%) travelers positive for SARS-CoV-2. A mean difference of 1.17 Ct (CI 95% 0.93-1.41) was found between positive individual samples and pools (N = 50), probably related to the volume of samples used for RNA extraction (200 µL versus 50 µL, respectively). Retrospective testing of positive samples self-collected from October 20th, 2020, using variants-specific amplification kit and spike gene sequencing, found at least 6 residents infected by the Alpha variant. Self-collection and pooling approaches allowed large-scale screening for SARS-CoV-2 using less human, material and financial resources. Moreover, this strategy allowed detecting the introduction of SARS-CoV-2 variants of concern in French Polynesia.

Screening for Predictors of Chronic Ciguatera Poisoning: An Exploratory Analysis among Hospitalized Cases from French Polynesia.

Ciguatera poisoning is a globally occurring seafood disease caused by the ingestion of marine products contaminated with dinoflagellate produced neurotoxins. Persistent forms of ciguatera, which prove to be highly debilitating, are poorly studied and represent a significant medical issue. The present study aims to better understand chronic ciguatera manifestations and identify potential predictive factors for their duration. Medical files of 49 patients were analyzed, and the post-hospitalization evolution of the disease assessed through a follow-up questionnaire. A rigorous logistic lasso regression model was applied to select significant predictors from a list of 37 patient characteristics potentially predictive of having chronic symptoms. Missing data were handled by complete case analysis, and a survival analysis was implemented. All models used standardized variables, and multiple comparisons in the survival analyses were handled by Bonferroni correction. Among all studied variables, five significant predictors of having symptoms lasting ≥3 months were identified: age, tobacco consumption, acute bradycardia, laboratory measures of urea, and neutrophils. This exploratory, hypothesis-generating study contributes to the development of ciguatera epidemiology by narrowing the list from 37 possible predictors to a list of five predictors that seem worth further investigation as candidate risk factors in more targeted studies of ciguatera symptom duration.

Dengue fever outbreak in Cook Island: A rising concern, efforts, challenges, and future recommendations.

The Cook Island government has made several efforts to ensure zero confirmed cases and transmission of COVID-19, especially among visiting travelers. However, the Cook Island ministry of health has to deal with the new strain of dengue fever outbreak, known as dengue fever type 2 (DEN-2), by adopting several measures to control its spread, especially in the affected parts of the subtropical country. This paper aims to describe the dengue fever response taken in Cook Island and suggest recommendations to control the risk of transmission in endemic parts of the world.

Assessing the Status of Diabetes Associations in the Pacific: A Starting Point for Strengthening Associations to Manage Diabetes.

This study aimed to assess the status of national diabetes associations in the Pacific Island Countries and Territories as a starting point for strengthening their development and effectiveness in the prevention and control of diabetes. This cross-sectional study was conducted in 21 Pacific Island Countries and Territories using a structured questionnaire that gathered information from national non-communicable diseases prevention and control focal persons on diabetes associations, organizational structure, funding sources, and ongoing activities to address diabetes. The overall status of national diabetes associations was assessed using standardized criteria. Of the 21 countries surveyed, 18 (86%) responded. Of these, 12 (67%; American Samoa, Northern Mariana Islands, Federated States of Micronesia, French Polynesia, Fiji, Guam, Nauru, Papua New Guinea, Marshall Islands, Solomon Islands, Tonga, and Vanuatu) have a national diabetes association. Half of the existing associations are fully functioning, while the remainder is either partially functioning or not functioning. Only 50% of existing associations have a regular funding source, and many lack clear visions and workable governance structures. This study fills a knowledge gap on the current status of associations and forms a baseline from which associations can be strengthened. It also draws attention to the need for Pacific leaders to invest and engage more in civil societies for better and effective diabetes care for all.

Stochastic Epidemic Models inference and diagnosis with Poisson Random Measure Data Augmentation.

We present a new Bayesian inference method for compartmental models that takes into account the intrinsic stochasticity of the process. We show how to formulate a SIR-type Markov jump process as the solution of a stochastic differential equation with respect to a Poisson Random Measure (PRM), and how to simulate the process trajectory deterministically from a parameter value and a PRM realization. This forms the basis of our Data Augmented MCMC, which consists of augmenting parameter space with the unobserved PRM value. The resulting simple Metropolis-Hastings sampler acts as an efficient simulation-based inference method, that can easily be transferred from model to model. Compared with a recent Data Augmentation method based on Gibbs sampling of individual infection histories, PRM-augmented MCMC scales much better with epidemic size and is far more flexible. It is also found to be competitive with Particle MCMC for moderate epidemics when using approximate simulations. PRM-augmented MCMC also yields a posteriori estimates of the PRM, that represent process stochasticity, and which can be used to validate the model. A pattern of deviation from the PRM prior distribution will indicate that the model underfits the data and help to understand the cause. We illustrate this by fitting a non-seasonal model to some simulated seasonal case count data. Applied to the Zika epidemic of 2013 in French Polynesia, our approach shows that a simple SEIR model cannot correctly reproduce both the initial sharp increase in the number of cases as well as the final proportion of seropositive. PRM augmentation thus provides a coherent story for Stochastic Epidemic Model inference, where explicitly inferring process stochasticity helps with model validation.

SARS-CoV-2 Wave Two Surveillance in East Asia and the Pacific: Longitudinal Trend Analysis.

BACKGROUND: The COVID-19 pandemic has had a profound global impact on governments, health care systems, economies, and populations around the world. Within the East Asia and Pacific region, some countries have mitigated the spread of the novel coronavirus effectively and largely avoided severe negative consequences, while others still struggle with containment. As the second wave reaches East Asia and the Pacific, it becomes more evident that additional SARS-CoV-2 surveillance is needed to track recent shifts, rates of increase, and persistence associated with the pandemic. OBJECTIVE: The goal of this study is to provide advanced surveillance metrics for COVID-19 transmission that account for speed, acceleration, jerk, persistence, and weekly shifts, to better understand country risk for explosive growth and those countries who are managing the pandemic successfully. Existing surveillance coupled with our dynamic metrics of transmission will inform health policy to control the COVID-19 pandemic until an effective vaccine is developed. We provide novel indicators to measure disease transmission. METHODS: Using a longitudinal trend analysis study design, we extracted 330 days of COVID-19 data from public health registries. We used an empirical difference equation to measure the daily number of cases in East Asia and the Pacific as a function of the prior number of cases, the level of testing, and weekly shift variables based on a dynamic panel model that was estimated using the generalized method of moments approach by implementing the Arellano-Bond estimator in R. RESULTS: The standard surveillance metrics for Indonesia, the Philippines, and Myanmar were concerning as they had the largest new caseloads at 4301, 2588, and 1387, respectively. When looking at the acceleration of new COVID-19 infections, we found that French Polynesia, Malaysia, and the Philippines had rates at 3.17, 0.22, and 0.06 per 100,000. These three countries also ranked highest in terms of jerk at 15.45, 0.10, and 0.04, respectively. CONCLUSIONS: Two of the most populous countries in East Asia and the Pacific, Indonesia and the Philippines, have alarming surveillance metrics. These two countries rank highest in new infections in the region. The highest rates of speed, acceleration, and positive upwards jerk belong to French Polynesia, Malaysia, and the Philippines, and may result in explosive growth. While all countries in East Asia and the Pacific need to be cautious about reopening their countries since outbreaks are likely to occur in the second wave of COVID-19, the country of greatest concern is the Philippines. Based on standard and enhanced surveillance, the Philippines has not gained control of the COVID-19 epidemic, which is particularly troubling because the country ranks 4th in population in the region. Without extreme and rigid social distancing, quarantines, hygiene, and masking to reverse trends, the Philippines will remain on the global top 5 list of worst COVID-19 outbreaks resulting in high morbidity and mortality. The second wave will only exacerbate existing conditions and increase COVID-19 transmissions.

Thyroid Doses to French Polynesians Resulting from Atmospheric Nuclear Weapons Tests: Estimates Based on Radiation Measurements and Population Lifestyle Data.

Thyroid doses were estimated for the subjects of a population-based case-control study of thyroid cancer in a population exposed to fallout after atmospheric nuclear weapons tests conducted in French Polynesia between 1966 and 1974. Thyroid doses due to (1) intake of I and of short-lived radioiodine isotopes (I, I, I) and Te, (2) external irradiation from gamma-emitting radionuclides deposited on the ground, and (3) ingestion of long-lived Cs with foodstuffs were reconstructed for each study subject. The dosimetry model that had been used in 2008 in Phase I of the study was substantially improved with (1) results of radiation monitoring of the environment and foodstuffs, which became available in 2013 for public access, and (2) historical data on population lifestyle related to the period of the tests, which were collected in 2016-2017 using focus-group discussions and key informant interviews. The mean thyroid dose among the study subjects was found to be around 5 mGy while the highest dose was estimated to be around 36 mGy. Doses from I intake ranged up to 27 mGy, while those from intake of short-lived iodine isotopes (I, I, I) and Te ranged up to 14 mGy. Thyroid doses from external exposure ranged up to 6 mGy, and those from internal exposure due to Cs ingestion did not exceed 1 mGy. Intake of I was found to be the main pathway for thyroid exposure accounting for 72% of the total dose. Results of this study are being used to evaluate the risk of thyroid cancer among the subjects of the epidemiologic study of thyroid cancer among French Polynesians.

Evidence for the Range Expansion of Ciguatera in French Polynesia: A Revisit of the 2009 Mass-Poisoning Outbreak in Rapa Island (Australes Archipelago).

Ciguatera poisoning (CP) results from the consumption of seafood contaminated with ciguatoxins (CTXs). This disease is highly prevalent in French Polynesia with several well-identified hotspots. Rapa Island, the southernmost inhabited island in the country, was reportedly free of CP until 2007. This study describes the integrated approach used to investigate the etiology of a fatal mass-poisoning outbreak that occurred in Rapa in 2009. Symptoms reported in patients were evocative of ciguatera. Several Gambierdiscus field samples collected from benthic assemblages tested positive by the receptor binding assay (RBA). Additionally, the toxicity screening of ≈250 fish by RBA indicated ≈78% of fish could contain CTXs. The presence of CTXs in fish was confirmed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The potential link between climate change and this range expansion of ciguatera to a subtropical locale of French Polynesia was also examined based on the analysis of temperature time-series data. Results are indicative of a global warming trend in Rapa area. A five-fold reduction in incidence rates was observed between 2009 and 2012, which was due in part to self-regulating behavior among individuals (avoidance of particular fish species and areas). Such observations underscore the prominent role played by community outreach in ciguatera risk management.