Health Challenges of the Pacific Region: Insights From History, Geography, Social Determinants, Genetics, and the Microbiome

Traumatic Brain Injury and Gut Microbiome: The Role of the Gut-Brain Axis in Neurodegenerative Processes

PURPOSE OF REVIEW

A deeper understanding of the communication network between the gut microbiome and the central nervous system, termed the gut-brain axis (GBA), has revealed new potential targets for intervention to prevent the development of neurodegenerative disease associated with tramatic brain injury (TBI). This review aims to comprehensively examine the role of GBA post-traumatic brain injury (TBI).

RECENT FINDINGS

The GBA functions through neural, metabolic, immune, and endocrine systems, creating bidirectional signaling pathways that modulate brain and gastrointestinal (GI) tract physiology. TBI perturbs these signaling pathways, producing pathophysiological feedback loops in the GBA leading to dysbiosis (i.e., a perturbed gut microbiome, impaired brain-blood barrier, impaired intestinal epithelial barrier (i.e., "leaky gut"), and a maladaptive, systemic inflammatory response. Damage to the CNS associated with TBI leads to GI dysmotility, which promotes small intestinal bacterial overgrowth (SIBO). SIBO has been associated with the early stages of neurodegenerative conditions such as Parkinson's and Alzheimer's disease. Many of the bacteria associated with this overgrowth promote inflammation and, in rodent models, have been shown to compromise the structural integrity of the intestinal mucosal barrier, causing malabsorption of essential nutrients and further exacerbating dysbiosis. TBI-induced pathophysiology is strongly associated with an increased risk of neurodegenerative diseases, including Parkinson's and Alzheimer's diseases, which represents a significant public health burden and challenge for patients and their families. A healthy gut microbiome has been shown to promote improved recovery from TBI and prevent the development of neurodegenerative disease, as well as other chronic complications. The role of the gut microbiome in brain health post-TBI demonstrates the potential for microbiome-targeted interventions to mitigate TBI-associated comorbidities. Promising new evidence on prebiotics, probiotics, diet, and fecal microbiota transplantation may lead to new therapeutic options for improving the quality of life for patients with TBI. Still, many of these preliminary findings must be explored further in clinical settings. This review covers the current understanding of the GBA in the setting of TBI and how the gut microbiome may provide a novel therapeutic target for treatment in this patient population.

Palau: Non-Communicable Disease Off-Island Treatment Referrals 2020-2022

Background: The Republic of Palau is a small island nation with limited healthcare resources and a lack of onsite subspecialty medical care services such as orthopedic surgery, cardiology, and oncology. Palauans receive sub-specialty healthcare during medical missions from other countries or when they are referred off-island to surrounding countries by the Palau Medical Referral Program. The goal of this study is to identify patterns in costs, locations, and types of cases to elucidate potential areas of improvement to the Palauan healthcare system. Methods: This study utilized the 2020-2022 referral data to analyze the frequency of medical conditions that result in off-island referrals and the associated economic burden. Data is presented in a descriptive analysis. Results: We found that oncology and cardiology are the two most common types of medical conditions requiring off-island medical referrals and that Palau is spending over 2 million dollars annually for referrals on subspecialty medical care. Cardiology and oncology are the most frequent cases and have the highest costs. The results of this study provide insight into the current state of medical care in Palau. Discussion/Conclusions: There is a need for a systematic, timely, and economically feasible approach to subspecialty medical sub-care for Palau, especially cardiology and oncology, to reduce the economic burden for Palau. This approach should be linked with appropriate prevention, risk reduction, and early intervention efforts for these non-communicable diseases.

Chemical Characterization of Alphitonia neocaledonica (Schltr.) Guillaumin Bark Extract and Its Anti-Inflammatory Activities

Alphitonia neocaledonica (Schltr.) Guillaumin is a small forest tree endemic of New Caledonia traditionally used to treat rheumatic pain and dermatoses. Very few studies described biological activities and phytochemical composition of this plant. This study aims to investigate the anti-inflammatory and anti-gout activities of A. neocaledonica bark extract (ANBE) and its chemical composition. Lipopolysaccharide (LPS)-induced phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages and LPS/monosodium urate (MSU)-treated THP-1 model reproducing gout in vitro were used. Chemical analyses were undertaken using liquid chromatography-high resolution mass spectrometry (LC-HRMS) approaches. Dose-dependent inhibitory effects of ANBE on inflammatory cytokines interleukin-(IL-)1β, IL-6, and tumor necrosis factor-α (TNF-α) were observed. Inhibition of LPS/MSU-dependent IL-1β at 1 and 10 µg/mL was also reported. Chemical analyses by LC-HRMS allowed us to putatively identify some features such as epigallocatechin, iridoid- and flavonoid-glycosides, oligopeptides, and triterpenoids in ANBE. These results provide some cues in favor of traditional uses of ANBE and support the need of further bioactivities and chemical investigations.

A Quantitative Analysis of Human and Material Resources for Endoscopy Services in Pacific Island Countries

Aims

This study aims to evaluate the current state of endoscopy services in Pacific Island Countries (PICs) by quantifying human and material resources, including the number of trained endoscopists and nurses, the types of procedures performed, and the availability and maintenance of endoscopic equipment.

Methods and Results

A mixed methods survey was conducted in 2023, targeting doctors and nurses who participated in the WGO-FNU-ANZGITA endoscopy training program as well as non-participants. Survey invitations were sent through email, WhatsApp, and Facebook Messenger. Data were collected from 16 sites across 12 PICs, achieving an 85% response rate. Survey results indicated a total of 58 endoscopists (2.1/100000 population) and 52 nurses (1.9/100000 population), with a majority having received training through international partnerships. Basic endoscopy services, such as gastroscopy and colonoscopy, were widely available, but advanced procedures were limited to a few sites. Most sites reported using donated equipment, with significant challenges in equipment maintenance and repair. The availability of functional endoscopes averaged four per site. Common issues included outdated equipment, lack of qualified personnel, and insufficient funding for new equipment.

Conclusion

Despite efforts to enhance endoscopy services in PICs through international collaborations, significant gaps remain, particularly in terms of advanced procedural capacity and equipment maintenance. Recommendations include expanding training programs, improving equipment maintenance infrastructure, securing funding for new equipment, and fostering stronger partnerships to support the sustainability of endoscopy services. Addressing these areas can enhance the quality and availability of endoscopy services, ultimately improving healthcare outcomes for populations in PICs.

"I've yet to meet anyone who's not keen for simulation" - a qualitative study of simulation-based education in the Pacific Islands

BACKGROUND

Simulation-based education (SBE) has been increasingly used to train healthcare workers in low-resource settings and has been endorsed by the World Health Organization (WHO). Consideration of the educational and cultural context is important to maximize the effectiveness of SBE. Despite its demonstrable benefits, there have been no studies of the general approach in the Pacific Islands. This study aimed to determine the factors that influence the uptake and success of SBE in the Pacific Islands.

METHODS

In this qualitative study, participants were recruited via professional networks to contribute to focus groups. Questions focused on participants' previous experiences and perspectives on SBE. Data were manually transcribed before thematic analysis. The reporting of the research was guided by the Standards for Reporting Qualitative Research (SRQR). Human Research Ethics Committee approval was obtained.

RESULTS

Two focus groups were conducted with 16 participants from six Pacific Island countries. Six themes and 15 subthemes were conceptualized from the data. Uptake of SBE is challenged by resource availability, clinical workloads and geographic remoteness. However, locally-driven solutions and positive attitudes towards SBE facilitate its success.

CONCLUSION

This study reveals the complexity of factors affecting the uptake and success of SBE in the Pacific Islands. These findings can serve to optimize the impact of existing and future SBE programmes and may be considered by educators prior to programme implementation.

Temporal trends in cross-country inequalities of stroke and subtypes burden from 1990 to 2021: a secondary analysis of the global burden of disease study 2021

Background

Stroke remains a significant global health challenge, with persistent disparities in burden across different countries and regions. This study aimed to assess the temporal trends in cross-country inequalities of stroke and its subtypes burden from 1990 to 2021.

Methods

We conducted a secondary analysis of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. The age-standardised disability-adjusted life years (DALYs) rate (ASDR) was used to assess the burden of stroke and its subtypes (ischemic stroke, intracerebral haemorrhage, and subarachnoid haemorrhage) across 21 GBD regions and 204 countries. The slope index of inequality (SII) and the concentration index were calculated to quantify the absolute and relative cross-country inequalities in the burden of stroke and its subtypes, with negative values indicating a higher burden in lower socio-demographic index (SDI) countries, and positive values indicating a higher burden in higher SDI countries. Estimated annual percentage change (EAPC) was used to illustrate temporal trends at global and regional levels from 1990 to 2021. The inequality changing patterns from 1990 to 2021 were classified as worsening, improving, and shifting to higher burdens among higher or lower SDI countries.

Findings

From 1990 to 2021, the ASDR of total stroke decreased from 3078.95 (95% uncertainty interval [UI]: 2893.58, 3237.34) to 1886.20 (95% UI: 1738.99, 2017.90) per 100,000 population globally. While both absolute and relative inequalities increased, with a disproportionately higher burden shouldered by countries with lower SDI. The SII of total stroke exhibited a worsening inequality among lower SDI countries, increasing by 286.97 units from -2329.47 (95% confidence interval [CI]: -2857.50, -1801.43) in 1990 to -2616.44 (95% CI: -2987.33, -2245.56) in 2021. Similarly, the concentration index of total stroke increased by 0.03 from -0.0819 (95% CI: -0.1143, -0.0495) in 1990 to -0.1119 (95% CI: -0.1478, -0.0759) in 2021. The changing patterns from 1990 to 2021 were diverse across regions, yet most regions exhibited a worsening inequality among lower SDI countries in both SII and concentration index. Southern Sub-Saharan Africa showed the largest worsening inequality in SII (EAPC: -2.15, 95% CI: -2.71, -1.57) while Central Europe showed the largest worsening inequality in concentration index (EAPC: -0.51, 95% CI: -0.58, -0.44). In 2021, the highest negative SII was observed in Oceania and the highest negative concentration index was in the Caribbean. In terms of subtypes, ischemic stroke reported a worsening inequality among lower SDI countries in SII (EAPC: -2.13, 95% CI: -2.20, -2.05) while intracerebral haemorrhage showed an improving inequality in SII (EAPC: 0.44, 95% CI: 0.40, 0.47). SII in subarachnoid haemorrhage (EAPC: -0.18, 95% CI: -0.19, -0.17) and concentration index in ischemic stroke (EAPC: -0.25, 95% CI: -0.27, -0.23) presented a shift to higher burden among lower SDI countries from 1990 to 2021.

Interpretation

Although the burden of stroke and its subtypes decreased from 1990 to 2021, inequalities have persisted and even widened in some regions. Timely and effective prevention and management strategies for stroke and its subtypes are needed in specific areas to reduce the stroke burden and achieve equity in health outcomes.

Funding

None.

Native Hawaiian and Pacific Islander populations in genomic research

The role of genomic research and medicine in improving health continues to grow significantly, highlighting the need for increased equitable inclusion of diverse populations in genomics. Native Hawaiian and Pacific Islander (NHPI) communities are often missing from these efforts to ensure that the benefits of genomics are accessible to all individuals. In this article, we analyze the qualities of NHPI populations relevant to their inclusion in genomic research and investigate their current representation using data from the genome-wide association studies (GWAS) catalog. A discussion of the barriers NHPI experience regarding participating in research and recommendations to improve NHPI representation in genomic research are also included.

Levels and functionality of Pacific Islanders' hybrid humoral immune response to BNT162b2 vaccination and delta/omicron infection: A cohort study in New Caledonia

BACKGROUND

Pacific Islanders are underrepresented in vaccine efficacy trials. Few studies describe their immune response to COVID-19 vaccination. Yet, this characterization is crucial to re-enforce vaccination strategies adapted to Pacific Islanders singularities.

METHODS AND FINDINGS

We evaluated the humoral immune response of 585 adults, self-declaring as Melanesians, Europeans, Polynesians, or belonging to other communities, to the Pfizer BNT162b2 vaccine. Anti-spike and anti-nucleoprotein IgG levels, and their capacity to neutralize SARS-CoV-2 variants and to mediate antibody-dependent cellular cytotoxicity (ADCC) were assessed across communities at 1 and 3 months post-second dose or 1 and 6 months post-third dose. All sera tested contained anti-spike antibodies and 61.3% contained anti-nucleoprotein antibodies, evidencing mostly a hybrid immunity resulting from vaccination and SARS-CoV-2 infection. At 1-month post-immunization, the 4 ethnic communities exhibited no significant differences in their anti-spike IgG levels (p value = 0.17, in an univariate linear regression model), in their capacity to mediate omicron neutralization (p value = 0.59 and 0.60, in an univariate logistic regression model at 1-month after the second and third dose, respectively) and in their capacity to mediate ADCC (p value = 0.069 in a multivariate linear regression model), regardless of the infection status. Anti-spike IgG levels and functionalities of the hybrid humoral immune response remained equivalent across the 4 ethnic communities during follow-up and at 6 months post-third dose.

CONCLUSIONS

Our study evidenced Pacific Islander's robust humoral immune response to Pfizer BNT162b2 vaccine, which is pivotal to re-enforce vaccination deployment in a population at risk for severe COVID-19.

TRIAL REGISTRATION

This trial has been register in ClinicalTrials.gov (ID: NCT05135585).

High seropositivity against NDO-LID in a group of household contacts of leprosy patients. Are we close to leprosy elimination in Colombia?

INTRODUCTION

Leprosy is a chronic infectious disease caused by two mycobacteria (Mycobacterium leprae and Mycobacterium lepromatosis). The household contacts (HHC) of leprosy index cases are at higher risk of being infected with these mycobacteria. Therefore, serological testing in HHC would be an effective strategy to eliminate leprosy in Colombia.

OBJECTIVE

To determine the seroprevalence and factors associated with the infection by M. leprae in HHC.

METHODS

An observational study was conducted in 428 HHC located in the Colombian Caribbean, Andean, Pacific, and Amazonian regions. We evaluated the seropositivity and titrations of IgM, IgG, and protein A against NDO-LID.

RESULTS

The evaluated HHC showed high seropositivity, precisely 36.9% anti-NDO-LID IgM, 28.3% anti-NDO-LID IgG, and 47.7% protein A. Furthermore, Protein A showed a greater capacity to detect infected individuals than other anti-NDO-LID conjugates (p < 0.0001). This study did not show differences in the seropositivity according to sex or age of the HHC (p > 0.05). Higher seropositivity for IgM was evidenced mainly in HHC located in the Colombian Pacific region (p 0.001). This research did not show differences in the seropositivity for these serological tests between HHC of PB or MB leprosy patients (p > 0.05).

CONCLUSION

Leprosy transmission is still active between Colombian HHC. Consequently, controlling leprosy transmission in this population is fundamental to eradicating this disease.

Unravelling the determinants of human health in French Polynesia: the MATAEA project

Background

French Polynesia is a French overseas collectivity in the Southeast Pacific, comprising 75 inhabited islands across five archipelagoes. The human settlement of the region corresponds to the last massive migration of humans to empty territories, but its timeline is still debated. Despite their recent population history and geographical isolation, inhabitants of French Polynesia experience health issues similar to those of continental countries. Modern lifestyles and increased longevity have led to a rise in non-communicable diseases (NCDs) such as obesity, diabetes, hypertension, and cardiovascular diseases. Likewise, international trade and people mobility have caused the emergence of communicable diseases (CDs) including mosquito-borne and respiratory diseases. Additionally, chronic pathologies including acute rheumatic fever, liver diseases, and ciguatera, are highly prevalent in French Polynesia. However, data on such diseases are scarce and not representative of the geographic fragmentation of the population.

Objectives

The present project aims to estimate the prevalence of several NCDs and CDs in the population of the five archipelagoes, and identify associated risk factors. Moreover, genetic analyses will contribute to determine the sequence and timings of the peopling history of French Polynesia, and identify causal links between past genetic adaptation to island environments, and present-day susceptibility to certain diseases.

Methods

This cross-sectional survey is based on the random selection of 2,100 adults aged 18-69 years and residing on 18 islands from the five archipelagoes. Each participant answered a questionnaire on a wide range of topics (including demographic characteristics, lifestyle habits and medical history), underwent physical measurements (height, weight, waist circumference, arterial pressure, and skin pigmentation), and provided biological samples (blood, saliva, and stool) for biological, genetic and microbiological analyses.

Conclusion

For the first time in French Polynesia, the present project allows to collect a wide range of data to explore the existence of indicators and/or risk factors for multiple pathologies of public health concern. The results will help health authorities to adapt actions and preventive measures aimed at reducing the incidence of NCDs and CDs. Moreover, the new genomic data generated in this study, combined with anthropological data, will increase our understanding of the peopling history of French Polynesia.

Clinical trial registration

https://clinicaltrials.gov/, identifier: NCT06133400.

Influence of an oral health promotion program on the evolution of dental status in New Caledonia: A focus on health inequities

New Caledonia is a sui generis collectivity of overseas France situated in the south Pacific Ocean. Geographical and social inequalities are superimposed on ethnic disparities with high prevalence of chronic diseases such as oral diseases. In 2012, the health agency has evaluated the children's health status. Then, an oral health promotion program was developed in 2014. Another study was conducted in 2019 in New Caledonia to appreciate the evolution of children's oral health. A sample of 488 9-years-old children was randomly selected. Dental status was clinically recorded, families and children answered questionnaires about oral health determinants. The methodology (sampling, study variables…) was similar to the one used in the 2012 study. Multivariate mixed-models were conducted to compare 2012 and 2019 dental status and to explore the determinants of caries experience in 2019. Results indicated that caries prevalence and experience decreased between 2012 and 2019, with nonetheless various trends depending on the province or type of indexes. The number of carious lesions (d3t + D3T) in 2019 was used as an outcome variable in four models. Model 1 integrated social variables; ethnicity was found to be the only significant determinant. Model 2 was related to oral health care; participation in the program & and access to oral health care was found to be significant. For oral health behaviours (model 3), tooth brushing frequency and consumption of sugary snacks were significant risk factors. In a final model with significant variables from the previous models, ethnicity, accessibility of oral health care, number of sealed molars, consumption of sugary snacks remained explanatory factors. Five years after the implementation of the oral health promotion program, positive changes in oral health have been observed. However, health equity is still an issue with varying health status depending on ethnicity, behavioural factors and accessibility to oral health care.

Indigenous communities and influenza: protocol for a systematic review and meta-analysis

BACKGROUND

Several studies have documented that specific Indigenous groups have been disproportionately affected by previous pandemics. The objective of this paper is to describe the protocol to be used in a review and meta-analysis of the literature on Indigenous groups and influenza. Using this protocol as a guide, a future study will provide a comprehensive historical overview of pre-COVID impact of influenza on Indigenous groups by combining data from the last five influenza pandemics and seasonal influenza up to date.

METHODS/PRINCIPLE FINDINGS

The review will include peer-reviewed original studies published in English, Spanish, Portuguese, Swedish, Danish, and Norwegian. Records will be identified through systematic literature search in eight databases: Embase, MEDLINE, CINAHL, Web of Science, Academic Search Ultimate, SocINDEX, ASSIA, and Google Scholar. Results will be summarized narratively and using meta-analytic strategies.

DISCUSSION

To our knowledge, there is no systematic review combining historical data on the impact of both seasonal and pandemic influenza on Indigenous populations. By summarizing results within and across Indigenous groups, different countries, and historical periods, as well as research in six different languages, we aim to provide information on how strong the risk for influenza is among Indigenous groups and how consistent this risk is across groups, regions, time, and seasonal versus the specific pandemic influenza strains.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021246391.

Global, Regional, and National Advances Toward the Management of Rheumatic Heart Disease Based on the Global Burden of Disease Study 2019

Background Population growth, aging, and major alterations in epidemiologic trends inadvertently modulate the status of rheumatic heart disease (RHD) epidemiology. This investigation predicted RHD burden pattern and temporal trends to provide epidemiologic evidence. Methods and Results Prevalence, mortality, and disability-adjusted life-years data for RHD were obtained from the GBD (Global Burden of Disease) study. We performed decomposition analysis and frontier analysis to assess variations and burden in RHD from 1990 to 2019. In 2019, there were >40.50 million RHD cases worldwide, along with nearly 0.31 million RHD-related deaths and 10.67 million years of healthy life lost to RHD. The RHD burden was commonly concentrated within lower sociodemographic index regions and countries. RHD primarily affects women (22.52 million cases in 2019), and the largest age-specific prevalence rate was at 25 to 29 years in women and 20 to 24 years in men. Multiple reports demonstrated prominent downregulation of RHD-related mortality and disability-adjusted life-years at the global, regional, and national levels. Decomposition analysis revealed that the observed improvements in RHD burden were primarily due to epidemiological alteration; however, it was negatively affected by population growth and aging. Frontier analysis revealed that the age-standardized prevalence rates were negatively linked to sociodemographic index, whereas Somalia and Burkina Faso, with lower sociodemographic index, showed the lowest overall difference from the frontier boundaries of mortality and disability-adjusted life-years. Conclusions RHD remains a major global public health issue. Countries such as Somalia and Burkina Faso are particularly successful in managing adverse outcomes from RHD and may serve as a template for other countries.

The Gut Microbiome of an Indigenous Agropastoralist Population in a Remote Area of Colombia with High Rates of Gastrointestinal Infections and Dysbiosis

An Indigenous agropastoralist population called the Wiwa from the Sierra Nevada de Santa Marta, in North-East Colombia, shows high rates of gastrointestinal infections. Chronic gut inflammatory processes and dysbiosis could be a reason, suggesting an influence or predisposing potential of the gut microbiome composition. The latter was analyzed by 16S rRNA gene amplicon next generation sequencing from stool samples. Results of the Wiwa population microbiomes were associated with available epidemiological and morphometric data and compared to control samples from a local urban population. Indeed, locational-, age-, and gender-specific differences in the Firmicutes/Bacteriodetes ratio, core microbiome, and overall genera-level microbiome composition were shown. Alpha- and ß-diversity separated the urban site from the Indigenous locations. Urban microbiomes were dominated by Bacteriodetes, whereas Indigenous samples revealed a four times higher abundance of Proteobacteria. Even differences among the two Indigenous villages were noted. PICRUSt analysis identified several enriched location-specific bacterial pathways. Moreover, on a general comparative scale and with a high predictive accuracy, we found Sutterella associated with the abundance of enterohemorrhagic Escherichia coli (EHEC), Faecalibacteria associated with enteropathogenic Escherichia coli (EPEC) and helminth species Hymenolepsis nana and Enterobius vermicularis. Parabacteroides, Prevotella, and Butyrivibrio are enriched in cases of salmonellosis, EPEC, and helminth infections. Presence of Dialister was associated with gastrointestinal symptoms, whereas Clostridia were exclusively found in children under the age of 5 years. Odoribacter and Parabacteroides were exclusively identified in the microbiomes of the urban population of Valledupar. In summary, dysbiotic alterations in the gut microbiome in the Indigenous population with frequent episodes of self-reported gastrointestinal infections were confirmed with epidemiological and pathogen-specific associations. Our data provide strong hints of microbiome alterations associated with the clinical conditions of the Indigenous population.

Diversity of Leptospira spp. in bats and rodents from Papua New Guinea

Leptospirosis is the most common bacterial zoonosis globally. The pathogen, Leptospira spp., is primarily associated with rodent reservoirs. However, a wide range of other species has been implicated as reservoirs or dead-end hosts. We conducted a survey for Leptospira spp. in bats and rodents from Papua New Guinea. Kidney samples were collected from 97 pteropodid bats (five species), 37 insectivorous bats from four different families (six species) and 188 rodents (two species). Leptospires were detected in a high proportion of pteropodid bats, including Nyctimene cf. albiventer (35%), Macroglossus minimus (34%) and Rousettus amplexicaudatus (36%). Partial sequencing of the secY gene from rodent and bat leptospires showed host species clustering, with Leptospira interrogans and L. weilii detected in rodents and L. kirschneri and a potential novel species of Leptospira detected in bats. Further research is needed in Papua New Guinea and other locales in the Pacific region to gain a better understanding of the circulation dynamics of leptospires in reservoir species and the risks to public and veterinary health.

Dynamics of the gut microbiota in rats after hypobaric hypoxia exposure

Background

Gut microbiota plays an important role in host health and is influenced by multiple factors. Hypobaric hypoxia usually existing at high altitude conditions can adversely affect normal physiological functions. However, the dynamic changes of gut microbiota influenced by hypobaric hypoxia have not been elucidated.

Methods

In this study, we collected fecal samples from seven rats at 14 time points from entering the hypobaric chamber (eight time points) to leaving the chamber (six time points) and five rats served as normoxic controls. Metagenome sequencing was performed on all samples and the dynamics of taxa and functions were analyzed.

Results

We found that the α-diversity was changed in the first 5 days after entering or leaving the hypobaric chamber. The β-diversity analysis revealed that gut microbiota structure was significantly separated among 14 time points. After entering the chamber, the relative abundance of Bacteroides decreased and the most abundant genus turned into Prevotella. The abundance of Firmicutes and Bacteroidetes showed an opposite trend and both have a significant change within 5 days after entering or leaving the hypobaric hypoxia chamber. Some obligate anaerobic bacteria belonging to Desulfovibrio and Alistipes were significantly enriched after entering the chamber for 5 weeks, whereas Probiotics like Bifidobacterium and Lactococcus, and short-chain fatty acids producers like Butyrivibrio and Pseudobutyrivibrio were significantly enriched after leaving the chamber for 3 weeks. Microbial functions like 'Two-component regulatory system', 'beta-carotene biosynthesis' and 'Fatty acid biosynthesis' were significantly enriched after entering the chamber for 5 weeks. Hypobaric hypoxia conditions could deeply affect the diversity and structure of gut microbiota. The alterations of abundance of dominant taxa (Firmicutes and Bacteroidetes), increased anaerobes and decreased probiotics induced by hypobaric hypoxia conditions might affect the host health.

A fusidic acid-resistant (PVL+) clone is associated with the increase in methicillin-resistant Staphylococcus aureus in New Caledonia

OBJECTIVES

Since 2014, Staphylococcus aureus methicillin resistance is rapidly increasing in New Caledonia and is associated with potential serious clinical repercussions. In the present study, we investigated the epidemiology of Methicillin-Resistant S. aureus (MRSA) in New Caledonia and the possible emergence of a particular clonal strain.

METHODS

An overview of the distribution of MRSA in New Caledonia in 2019 is presented. We collected and analysed 171 clinical MRSA isolates from New Caledonia medical laboratories during August and September 2019. Among this collection, 49 representative isolates were analyzed by the French National Reference Center for Staphylococci using StaphyType DNA microarray allowing genetic characterization of the isolates.

RESULTS

Among the 1144 S. aureus isolated over the year 2019, 442 isolates (39%) were resistant to methicillin and 62% of these isolates were resistant to fusidic acid (FA). During the inclusion period, FA resistance rate was similar (60%). Genetic characterization evidenced CC6 as the predominant clonal complex (70%) with 26 isolates (53%) identified as CC6-MRSA-[IV+fus] (PVL+).

CONCLUSIONS

These findings demonstrated a low diversity of MRSA in New Caledonia with the dominance of a clonal complex not reported previously. The frequent fusidic acid (FA) resistance in MRSA was associated with a high prevalence of fusC, suggesting that FA misuse contributed to driving the selection of this clone. Our findings suggest the recommendation to stop the topical use of FA to control the emergence of this severe MRSA clone and decrease the rate of MRSA in New Caledonia.

Rheumatic Heart Disease Is a Neglected Disease Relative to Its Burden Worldwide: Findings From Global Burden of Disease 2019

Background

Rheumatic heart disease (RHD) takes a heavy toll in low‐ and middle‐income countries. We aimed to present worldwide estimates for the burden of the RHD during 1990 to 2019 using the GBD (Global Burden of Disease) study.

Methods and Results

Sociodemographic index (SDI) and age‐period‐cohort analysis were used to assess inequity. The age‐standardized death, disability‐adjusted life years, incidence, and prevalence rates of RHD were 3.9 (95% uncertainty interval, 3.3–4.3), 132.9 (95% uncertainty interval, 115.0–150.3), 37.4 (28.6–46.7), and 513.7 (405.0–636.3) per 100 000 in 2019, respectively. The age‐standardized incidence and prevalence rates increased by 14.4% and 13.8%, respectively. However, disability‐adjusted life years and death rates decreased by 53.1% and 56.9%, respectively. South Asia superregion had the highest age‐standardized disability‐adjusted life years and deaths. Sub‐Saharan Africa had the highest age‐standardized incidence and prevalence rates. There was a steep decline in RHD burden among higher‐SDI countries. However, only age‐standardized deaths and disability‐adjusted life years rates decreased in lower‐SDI countries. The age‐standardized years of life lost and years lived with disability rates for RHD significantly declined as countries' SDI increased. The coefficients of birth cohort effect on the incidence of RHD showed an increasing trend from 1960 to 1964 to 2015 to 2019; however, the birth cohort effect on deaths attributable to RHD showed unfailingly decreasing trends from 1910 to 1914 to 2015 to 2019.

Conclusions

There was a divergence in the burden of RHD among countries based on SDI levels, which calls for including RHD in global assistance and funding. Indeed, many countries are still dealing with an unfinished infectious disease agenda, and there is an urgency to act now to prevent an increase in future RHD burden.

Geographically diverse canid sampling provides novel insights into pre-industrial microbiomes

Canine microbiome studies are often limited in the geographic and temporal scope of samples studied. This results in a paucity of data on the canine microbiome around the world, especially in contexts where dogs may not be pets or human associated. Here, we present the shotgun sequences of fecal microbiomes of pet dogs from South Africa, shelter and stray dogs from India, and stray village dogs in Laos. We additionally performed a dietary experiment with dogs housed in a veterinary medical school, attempting to replicate the diet of the sampled dogs from Laos. We analyse the taxonomic diversity in these populations and identify the underlying functional redundancy of these microbiomes. Our results show that diet alone is not sufficient to recapitulate the higher diversity seen in the microbiome of dogs from Laos. Comparisons to previous studies and ancient dog fecal microbiomes highlight the need for greater population diversity in studies of canine microbiomes, as modern analogues can provide better comparisons to ancient microbiomes. We identify trends in microbial diversity and industrialization in dogs that mirror results of human studies, suggesting future research can make use of these companion animals as substitutes for humans in studying the effects of industrialization on the microbiome.

Not the great equalizers: Covid-19, 1918-20 influenza, and the need for a paradigm shift in pandemic preparedness

Despite common perceptions to the contrary, pandemic diseases do not affect populations indiscriminately. In this paper, we review literature produced by demographers, historians, epidemiologists, and other researchers on disparities during the 1918-20 influenza pandemic and the Covid-19 pandemic. Evidence from these studies demonstrates that lower socio-economic status and minority/stigmatized race or ethnicity are associated with higher morbidity and mortality. However, such research often lacks theoretical frameworks or appropriate data to explain the mechanisms underlying these disparities fully. We suggest using a framework that considers proximal and distal factors contributing to differential exposure, susceptibility, and consequences as one way to move this research forward. Further, current pandemic preparedness plans emphasize medically defined risk groups and epidemiological approaches. Therefore, we conclude by arguing in favour of a transdisciplinary paradigm that recognizes socially defined risk groups, includes input from the social sciences and humanities and other diverse perspectives, and contributes to the reduction of health disparities before a pandemic hits.

Adherence to Mediterranean diet impacts gastrointestinal microbial diversity throughout pregnancy

Background

Consumption of a diet with high adherence to a Mediterranean diet pattern (MDP) has been associated with a favorable gastrointestinal tract (GIT) microbiome. A healthy GIT microbiome in pregnancy, as defined by increased alpha diversity, is associated with lower chance of adverse perinatal outcomes. This study aimed to evaluate the impact of adherence to an MDP on GIT microbial diversity longitudinally throughout pregnancy.

Methods

Adherence to MDP was scored by the Alternate Mediterranean (aMED) Diet Quality Score, after being applied to a validated Food Frequency Questionnaire. Association of aMED Scores with GIT alpha diversity profiles were compared linearly and across time using a linear mixed model, including covariates of age, body mass index (BMI), ethnicity, and parity.

Results

Forty-one participants of Filipino, Japanese, Native Hawaiian, and Non-Hispanic White descent provided dietary information and microbiome samples during each trimester of pregnancy. Alpha diversity profiles changed over gestation, with decreased microbial diversity in the third trimester. aMED scores positively correlated with Chao1 Index and Observed Species Number (r = 0.244, p = 0.017, and r = 0.233, p = 0.023, respectively). The strongest association was detected in the third trimester (Chao 1: r = 0.43, p = 0.020, Observed Species Number: r = 0.41, p = 0.026). Participants with higher aMED scores had higher relative abundance of Acidaminoacaeae at the family level (p = 0.0169), as well as higher abundance of several species known to increase production of short chain fatty acids within the GIT.

Conclusions

Adherence to MDP pattern is associated with increased maternal GIT microbial diversity, and promotes the abundance of bacteria that produce short chain fatty acids. Increased consumption of fruits, vegetables and legumes with low red meat consumption were key components driving this association. The effect of nutrition however, was less of an effect than pregnancy itself. Further studies are needed to determine if adherence to a Mediterranean diet translates not only into microbial health, but also into reduced risk of adverse pregnancy outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04033-8.

Gut microbiota composition in obese and non-obese adult relatives from the highlands of Papua New Guinea

Obesity is a condition that results from an imbalance between energy intake and expenditure. Recently, obesity has been linked to differences in the composition of gut microbiota. To examine this association in Papua New Guinea (PNG) highlanders, fecal samples were collected from 18 adults; nine obese participants were paired with their non-obese relative. Amplification of the 16S rRNA gene targeting the V1-V2 region was performed on DNA extracts for each participant, with high-quality sequences selected and used for operational taxonomic unit clustering. The data showed Firmicutes and Bacteroidetes were the two dominant phyla, while at genus level Prevotella was the most dominant genus in all of the samples. Nonetheless, statistical evaluation of potential association between nutritional status and bacterial abundance at both phyla and genus levels showed no significant difference. Further studies, ideally in both rural and urban areas, are needed to evaluate the role of the gut microbiome in the occurrence of obesity in PNG and other resource-limited settings.

Prevalence and risk factors of adverse birth outcomes in the Pacific Island region: a scoping review protocol

Introduction

Fetal growth restriction, preterm birth, low birth weight and stillbirth are adverse birth outcomes that are prevalent in low-income and middle-income settings such as the Pacific Island region. It is widely accepted that the excess burden of adverse birth outcomes is attributable to socioeconomic and environmental factors that predispose families to excess risk. Our review seeks to determine the prevalence of adverse birth outcomes in the Pacific Island region and to identify the risk factors of adverse birth outcomes in the Pacific Island region.

Methods

This scoping review will follow the five-staged Arksey and O’Malley’s framework and consultation with Solomon Islands’ health stakeholders. A preliminary literature review was undertaken to understand the scope of the review. We will use Medical Subject Heading and keyword terms for adverse birth outcomes to search CINAHL, Medline, Scopus, ProQuest and Springer Link databases for articles published from 1 January 2000. The subsequent searches will be undertaken via Google Scholar and the internet browser to world health organisation and regional health organisations for published and unpublished reports on non-indexed studies. All articles retrieved will be managed with EndNote software. Eligible studies will be screened using Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow chart for final selection. In the charting phase, we will extract the data into Excel spreadsheets. The results will be presented as numerical and thematic summaries that map risk factors and prevalence to the population and cultures of the Pacific Island region.

Ethics and dissemination

Formal ethical approval is not required as primary or administrative data will not be collected. However, we will seek ethics approval for the stakeholder consultation from the Research Office of Curtin University and the Solomon Islands. The findings of this study will be published in peer-reviewed journals and presented in national and regional conferences and disseminated to stakeholders.

Ethics approval

There will be no direct contact with human or patients in the case of the scoping review; therefore, no ethics will be required. However, we will seek ethical approval from the Research Ethics Office of Curtin University and the Health Research and Ethics Committee in the Solomon Islands for stakeholder consultation. Dissemination will be made through regional conferences and publication in peer-reviewed journals.

Stroke Epidemiology in Oceania: A Review

BACKGROUND AND PURPOSE

Oceania, comprising the regions Australasia, Melanesia, Micronesia, and Polynesia, is home to 42 million living in 8.5 million square kilometres of land. This paper comprises a review of the epidemiology of stroke in countries in this region.

METHODS

Information on epidemiology of stroke in Oceania was sought from data from the Global Burden of Disease (GBD) study (incidence, mortality, incidence:mortality ratio [IMR], prevalence, disability-adjusted life-years [DALYs] lost due to stroke, and subtypes), World Health Organization (WHO) (vascular risk factors in the community), and PubMed (incidence, prevalence, and stroke subtypes). Data were analyzed by region to allow inter-country comparison within each region.

RESULTS

In 2010, age- and sex-standardized stroke mortality rates were lowest in Australasia (29.85-31.67/100,000) and highest in Melanesia and Micronesia (56.04-187.56/100,000), with wide ranges especially in Melanesia. Incidence rates were lowest in Australasia (101.36-105.54/100,000), similarly high elsewhere. Standardized IMR (0.98-3.39) was the inverse of the mortality rates and mirrored the prevalence rates (202.91-522.29/100,000). DALY rates (398.22-3,781.78/100,0000) mirrored the mortality rates. Stroke risk factors show a variable pattern - hypertension is generally the most common medical risk factor among males (18.0-26.6%), while among females, diabetes mellitus is the most common in Micronesia and Polynesia (21.5-28.4%). Among the lifestyle factors, current smoking is the most common in Melanesia among males, while obesity is generally the most common factor among females. Ischaemic stroke comprises 70% of stroke subtypes. Trend data show significant falls in standardized mortality rates and DALYs in most regions and falls in incidence in almost all countries. There is significant economic impact, particularly due to young strokes; some ethnicities are at higher risk than others, for example, Maoris and Pacific Islanders.

CONCLUSIONS

Stroke is a major healthcare problem in Oceania. Variations in stroke epidemiology are found between countries in Oceania. Data are lacking in some; more research into the burden of stroke in Oceania is needed. With the expected increase in life expectancy and vascular risk factors, the burden of stroke in Oceania will likely rise. Some of the disparities in stroke burden may be addressed by great investment in healthcare.

Pacific Regional Infectious Disease Association (PRIDA): capacity-building for microbiology and infectious disease across the Pacific

PRIDA is an Australian based network of medical and scientific specialists, combining expertise in microbiology laboratory development, infection control, management of infectious diseases and antimicrobial stewardship. PRIDA focuses on grassroots support for Pacific and Southeast Asian sites through the establishment of long-term mentoring relationships with front line health care workers. With an emphasis on bench level training for scientists and bedside development for clinicians, PRIDA has advanced testing capacity, infection control and antimicrobial stewardship in the Solomon Islands, Timor-Leste, and PNG. Understanding the need to upskill HCWs in the Pacific, PRIDA has expanded into areas of formal education opportunities with development of online microbiology diplomas, for pathologists, physicians, and scientists. Concurrent design of multidisciplinary virtual video conferenced microbiology rounds provides teaching opportunities in real time and improvement in daily patient care. From its origin of volunteerism, PRIDA has attracted funding through partnership with larger organisations and are currently involved in sponsored AMR projects in the Pacific.

Gut Microbiome in Children from Indigenous and Urban Communities in México: Different Subsistence Models, Different Microbiomes

The human gut microbiome is an important component that defines host health. Childhood is a particularly important period for the establishment and development of gut microbiota (GM). We sequenced the 16S rRNA gene from fecal samples of children between 5 and 10 years old, in two Mexican communities with contrasting lifestyles, i.e., “Westernized” (México City, n = 13) and “non-Westernized” (Me’phaa indigenous group, n = 29), in order to characterize and compare their GM. The main differences between these two communities were in bacteria associated with different types of diets (high animal protein and refined sugars vs. high fiber food, respectively). In addition, the GM of Me’phaa children showed higher total diversity and the presence of exclusive phyla, such as Deinococcus-Thermus, Chloroflexi, Elusimicrobia, Acidobacteria, and Fibrobacteres. In contrast, the children from México City showed less diversity and the presence of Saccharibacteria phylum, which was associated with the degradation of sugar compounds and was not present in the samples from Me’phaa children. This comparison provided further knowledge of the selective pressures affecting microbial ecosystemic composition over the course of human evolution and the potential consequences of pathophysiological states correlated with Westernization lifestyles.

Risk of COVID-19 importation to the Pacific islands through global air travel

On 30 January 2020, WHO declared coronavirus (COVID-19) a global public health emergency. As of 12 March 2020, 125 048 confirmed COVID-19 cases in 118 countries had been reported. On 12 March 2020, the first case in the Pacific islands was reported in French Polynesia; no other Pacific island country or territory has reported cases. The purpose of our analysis is to show how travellers may introduce COVID-19 into the Pacific islands and discuss the role robust health systems play in protecting health and reducing transmission risk. We analyse travel and Global Health Security Index data using a scoring tool to produce quantitative estimates of COVID-19 importation risk, by departing and arriving country. Our analysis indicates that, as of 12 March 2020, the highest risk air routes by which COVID-19 may be imported into the Pacific islands are from east Asian countries (specifically, China, Korea and Japan) to north Pacific airports (likely Guam, Commonwealth of the Northern Mariana Islands or, to a less extent, Palau); or from China, Japan, Singapore, the United States of America or France to south Pacific ports (likely, Fiji, Papua New Guinea, French Polynesia or New Caledonia). Other importation routes include from other east Asian countries to Guam, and from Australia, New Zealand and other European countries to the south Pacific. The tool provides a useful method for assessing COVID-19 importation risk and may be useful in other settings.

Recent Advances on the Anti-Inflammatory and Antioxidant Properties of Red Grape Polyphenols: In Vitro and In Vivo Studies

In this review, special emphasis will be placed on red grape polyphenols for their antioxidant and anti-inflammatory activities. Therefore, their capacity to inhibit major pathways responsible for activation of oxidative systems and expression and release of proinflammatory cytokines and chemokines will be discussed. Furthermore, regulation of immune cells by polyphenols will be illustrated with special reference to the activation of T regulatory cells which support a tolerogenic pathway at intestinal level. Additionally, the effects of red grape polyphenols will be analyzed in obesity, as a low-grade systemic inflammation. Also, possible modifications of inflammatory bowel disease biomarkers and clinical course have been studied upon polyphenol administration, either in animal models or in clinical trials. Moreover, the ability of polyphenols to cross the blood-brain barrier has been exploited to investigate their neuroprotective properties. In cancer, polyphenols seem to exert several beneficial effects, even if conflicting data are reported about their influence on T regulatory cells. Finally, the effects of polyphenols have been evaluated in experimental models of allergy and autoimmune diseases. Conclusively, red grape polyphenols are endowed with a great antioxidant and anti-inflammatory potential but some issues, such as polyphenol bioavailability, activity of metabolites, and interaction with microbiota, deserve deeper studies.