Dengue Virus and Zika Virus Seroprevalence in the South Pacific Populations of the Cook Islands and Vanuatu.

Arboviral diseases are serious threats to global health with increasing prevalence and potentially severe complications. Significant arthropod-borne viruses are the dengue viruses (DENV 1-4), the Zika virus (ZIKV), and the chikungunya virus (CHIKV). Among the areas most affected is the South Pacific Region (SPR). Here, arboviruses not only cause a high local burden of disease, but the region has also proven to contribute to their global spread. Outpatient serum samples collected between 08/2016 and 04/2017 on three islands of the island states of Vanuatu and the Cook Islands were tested for anti-DENV- and anti-ZIKV-specific antibodies (IgG) using enzyme-linked immunosorbent assays (ELISA). ELISA test results showed 89% of all test sera from the Cook Islands and 85% of the Vanuatu samples to be positive for anti-DENV-specific antibodies. Anti-ZIKV antibodies were identified in 66% and 52%, respectively, of the test populations. Statistically significant differences in standardized immunity levels were found only at the intranational level. Our results show that in both the Cook Islands and Vanuatu, residents were exposed to significant Flavivirus transmission. Compared to other seroprevalence studies, the marked difference between ZIKV immunity levels and previously published CHIKV seroprevalence rates in our study populations is surprising. We propose the timing of ZIKV and CHIKV emergence in relation to recurrent DENV outbreaks and the impact of seasonality as explanatory external factors for this observation. Our data add to the knowledge of arboviral epidemics in the SPR and contribute to a better understanding of virus spread, including external conditions with potential influence on outbreak dynamics. These data may support preventive and rapid response measures in the affected areas, travel-related risk assessment, and infection identification in locals and returning travelers.

Climate-driven models of leptospirosis dynamics in tropical islands from three oceanic basins.

BACKGROUND: Leptospirosis is a neglected zoonosis which remains poorly known despite its epidemic potential, especially in tropical islands where outdoor lifestyle, vulnerability to invasive reservoir species and hot and rainy climate constitute higher risks for infections. Burden remains poorly documented while outbreaks can easily overflow health systems of these isolated and poorly populated areas. Identification of generic patterns driving leptospirosis dynamics across tropical islands would help understand its epidemiology for better preparedness of communities. In this study, we aim to model leptospirosis seasonality and outbreaks in tropical islands based on precipitation and temperature indicators. METHODOLOGY/PRINCIPAL FINDINGS: We adjusted machine learning models on leptospirosis surveillance data from seven tropical islands (Guadeloupe, Reunion Island, Fiji, Futuna, New Caledonia, and Tahiti) to investigate 1) the effect of climate on the disease's seasonal dynamic, i.e., the centered seasonal profile and 2) inter-annual anomalies, i.e., the incidence deviations from the seasonal profile. The model was then used to estimate seasonal dynamics of leptospirosis in Vanuatu and Puerto Rico where disease incidence data were not available. A robust model, validated across different islands with leave-island-out cross-validation and based on current and 2-month lagged precipitation and current and 1-month lagged temperature, can be constructed to estimate the seasonal dynamic of leptospirosis. In opposition, climate determinants and their importance in estimating inter-annual anomalies highly differed across islands. CONCLUSIONS/SIGNIFICANCE: Climate appears as a strong determinant of leptospirosis seasonality in tropical islands regardless of the diversity of the considered environments and the different lifestyles across the islands. However, predictive and expandable abilities from climate indicators weaken when estimating inter-annual outbreaks and emphasize the importance of these local characteristics in the occurrence of outbreaks.

Strengthening rural community water safety planning in Pacific Island countries: evidence and lessons from Solomon Islands, Vanuatu, and Fiji.

Pacific Island Countries (PICs) collectively have the lowest rates of access to safely managed or basic drinking water and sanitation globally. They are also the least urbanised, have dynamic socioeconomic and increasing climate-linked challenges. Community-based water managers need to respond to variability in water availability and quality caused by a range of hazards. Water Safety Planning (WSP), a widely adopted approach to assessing water supply, offers a risk-based approach to mitigating both existing and future hazards. WSP is adaptable, and making modifications to prescribed WSP to adapt it to the local context is common practice. Within the Pacific Community Water Management Plus research project, we used formative research and co-development processes to understand existing local modifications, whether further modifications are required, and, to develop additional modifications to WSP in Fiji, Vanuatu and Solomon Islands. The types of additional local modifications we recommend reflect the unique context of PICs, including adjusting for community management of water supplies and required collective action, community governance systems, levels of social cohesion in communities, and preferred adult-learning pedagogies. Incorporating modifications that address these factors into future WSP will improve the likelihood of sustained and safe community water services in Pacific and similar contexts.

Successful introgression of wMel Wolbachia into Aedes aegypti populations in Fiji, Vanuatu and Kiribati.

Pacific Island countries have experienced periodic dengue, chikungunya and Zika outbreaks for decades. The prevention and control of these mosquito-borne diseases rely heavily on control of Aedes aegypti mosquitoes, which in most settings are the primary vector. Introgression of the intracellular bacterium Wolbachia pipientis (wMel strain) into Ae. aegypti populations reduces their vector competence and consequently lowers dengue incidence in the human population. Here we describe successful area-wide deployments of wMel-infected Ae. aegypti in Suva, Lautoka, Nadi (Fiji), Port Vila (Vanuatu) and South Tarawa (Kiribati). With community support, weekly releases of wMel-infected Ae. aegypti mosquitoes for between 2 to 5 months resulted in wMel introgression in nearly all locations. Long term monitoring confirmed a high, self-sustaining prevalence of wMel infecting mosquitoes in almost all deployment areas. Measurement of public health outcomes were disrupted by the Covid19 pandemic but are expected to emerge in the coming years.

High SARS-CoV-2 attack rates in areas with low detection after community transmission established in Port Vila, Vanuatu, April 2022.

Objective: On 4 March 2022, the first community-acquired case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in Vanuatu, with community transmission occurring subsequently. It was expected that the number of notified SARS-CoV-2 cases would be an underestimate of the true infection rate of this outbreak; however, the magnitude of underreporting was unknown. The purpose of this study was to provide a population-based estimate of SARS-CoV-2 infection shortly after the first reports of community transmission, to understand the level of underdetection and undernotification in Vanuatu and thus to inform ongoing prevention and response activities. Methods: We conducted a cross-sectional SARS-CoV-2 prevalence study in two geographical administrative areas in Port Vila, Vanuatu in April 2022. All residents in selected areas were eligible. Trained teams conducted demographic and behavioural interviews and collected nasal specimens. Specimens were tested by polymerase chain reaction. The primary outcomes were the rates of SARS-CoV-2 attack (point prevalence) and cumulative attack, underdetection, notification and household secondary attack. Results: A total of 252 people from 84 households participated. Among 175 people who had a sample collected, 91 were SARS-CoV-2-positive (attack rate 52.0%). Most cases had not been detected before the study (underdetection rate 91.5%). More than half of previously detected cases were notified (notification rate 65.2%). Discussion: Within the first few weeks of community transmission, more than half of participants in the selected areas had evidence of SARS-CoV-2 infection; however, most infections had been undetected. This study provides important information about the rapid spread of novel infectious diseases in Vanuatu.

"Feeling at home in Vanuatu": Integration of newcomers from the East during the last millennium.

Several localities across the Vanuatu archipelago (Melanesia), so-called 'Polynesian Outliers', are inhabited by communities that display Polynesian linguistic and cultural features although being located outside the Polynesian Triangle. Several introductions of Polynesian genetic components to Central and Southern Vanuatu during the last millenium have resulted in the cultural distinctiveness observed among the Polynesian Outliers in Vanuatu. However, social, political or economic process surrounding the exchange of genes between Polynesian and local individuals remain unidentified. Recent bioanthropological studies suggest the existence of female mobilities from neighboring regions to Vanuatu but also to the Polynesian Outliers of Taumako (Solomon Islands) within patrilocal societies. We aim to examine the hypothesis that Polynesian biological affinities observed in ancient individuals from Vanuatu are gendered or sex-specific, and that some of the Polynesian migrations during the last millennium may have involved practices of exogamy. By reconstructing phenotypes and biological identities from 13 archaeologically-recovered human skulls (400-300 years ago) from "Polynesian-related" regions of Vanuatu, we provide new insights to better contextualize the settlement patterns of Polynesian individuals. Eastern-Pacific associated phenotype are observable in 4 women from the Eretok burial complex (Efate region) and the Polynesian Outlier of Futuna, who were buried in close proximity to individuals with Western-Pacific associated phenotype. We suggest that close integration of individuals from the East into the local Vanuatu society, as well as the practice of exogamy, might have been key processes contributing to the preservation of Polynesian cultural features in Vanuatu over the past millennium. Our finding are cross-referenced with oral records from these two areas, as well as the known genetic makeup of the Vanuatu Polynesian Outliers.

Management of saltwater intrusion using 3D numerical modelling: a first for Pacific Island country of Vanuatu.

Small island countries like Vanuatu are facing the brunt of climate change, sea level rise (SLR), tropical cyclones, and limited or declining access to freshwater. The Tagabe coastal aquifer in Port Vila (the capital of Vanuatu) shows the presence of salinity, indicating saltwater intrusion (SWI). This study aims to develop and evaluate effective SWI management strategies for Tagabe coastal aquifer. To manage SWI, the numerical simulation model for the study area was developed using the SEAWAT code. The flow model was developed using MODFLOW and the transport model was developed using MT3DMS. Whereby SEAWAT solved flow and transport equations simultaneously. The model was calibrated, and different scenarios were evaluated for the management of SWI. The SLR was also considered in the model simulations. The results indicated that increased population, pumping rates, and SLR affect the SWI rates. To manage the SWI, we introduced hydraulic barriers like barrier wells and injection wells which effectively managed SWI in Tagabe coastal aquifer. The results from this study are significantly important whereby, the water managers, site owners, and governing bodies can use the management strategies presented in this study to create policies and regulations for managing SWI rates in Port Vila. Additionally, the water industry, private businesses, and investors who wish to extract groundwater from the Tagabe can use this study as a reference for daily or yearly freshwater production rates without the risk of SWI.

A sweet deal for domestic industry: the political economy and framing of Vanuatu's sugar-sweetened beverage tax.

INTRODUCTION: The Government of Vanuatu introduced an excise tax on sugar-sweetened beverages (SSBs) in 2015. While lauded for its alignment with the WHO's Best Buys recommendations for addressing non-communicable diseases (NCDs), little is known about the tax's adoption process or whose interests it serves. METHODS: Using case study methodology, this study examined how and why Vanuatu's SSB tax was introduced. Policy documents, key informant interviews (n=33) and direct observations were analysed using theories of policy analysis, power analysis and postcolonial theory to map the policy's adoption, surrounding political economy and the ideas, interests and institutions that shaped the tax and its framing. RESULTS: The SSB tax emerged during a politically and economically unstable time in Vanuatu's history. The tax's links to the national health agenda were tenuous despite its ostensible framing as a way to combat NCDs. Rather, the tax was designed to respond to tightening economic and trade conditions. Spearheaded by several finance-focused bureaucrats, and with limited input from health personnel, the tax targeted less frequently consumed carbonated SSBs (which are mostly imported) without any revenue reinvestments into health. Driven by the desire to generate much-needed government revenue and instal domestic protections via selective implementation and carve-outs for local producers, the Vanuatu SSB tax did meet national objectives, just not the dual health and economic 'win-win' projected by the NCD Best Buys. CONCLUSION: Vanuatu's SSB tax adoption process reveals the limitations of decontextualised policy recommendations, such as the NCD Best Buys, whose framing may be overcome by local political realities. This research highlights the need for further political economy considerations in global health recommendations, since contextual forces and power dynamics are key to shaping both how and why policies are enacted and also whose interest they serve.

Adoption, Fostering, and Parental Absence in Vanuatu.

Alloparenting, wherein people provide care to children who are not their biological offspring, is a key aspect of human child-rearing. In the Pacific, many children are adopted or fostered by custodial alloparents even when both biological parents are still alive. From a behavioral ecology perspective, such behaviors are puzzling: why parent someone else's child at your expense? Furthermore, little is known about how these arrangements are made in Pacific Islander societies today, who provides care, and what kinds of outcomes fostered children experience. A better understanding of these proximate factors may help reveal the ultimate drivers behind custodial alloparenting. Here, we report findings from a survey carried out with the caregivers of 282 children in rural areas of Vanuatu, an island nation in Melanesia. Most fostered and adopted children lived with relatives such as aunts, uncles, and grandparents (87.5%) rather than unrelated caregivers, with a strong preference for maternal kin. The most common reasons for these arrangements were that the parents had separated (16.7%), were engaging in labor migration (27.1%), or a combination of both (27.1%). Results for investment in children's education and their educational outcomes were mixed, although children removed from crisis situations did more poorly than children removed for aspirational reasons. Our findings suggest that custodial alloparenting helps families adapt to socioeconomic transitions and changing marriage practices. Outcomes may depend on a range of factors, such as the reason children were transferred out of the natal home to begin with.

Development of teaching in ni-Vanuatu children.

Teaching is an important mechanism of social learning. In industrialized societies, 3-year-olds tend to teach through demonstrations and short commands, while 5-year-olds use more verbal communication and abstract explanations. However, it remains unclear whether this generalizes to other cultures. This study presents results from a peer teaching game with 55 Melanesian children (4.7-11.4 years, 24 female) conducted in Vanuatu in 2019. Up to age 8, most participants taught through a participatory approach, emphasizing learning-by-doing, demonstrations, and short commands (57.1% of children aged 4-6 and 57.9% of children aged 7-8). Contrary to Western findings, abstract verbal communication only became common in children aged 9-11 (63.6%), suggesting that the ontogeny of teaching is shaped by the socio-cultural environment.

The challenges in protecting public health interests in multisectoral governance in the context of small island developing states: the case of tobacco control in Fiji and Vanuatu.

BACKGROUND: The commercial determinants of health (CDoH) drive the rise of NCDs globally, and their regulation requires multisectoral governance. Despite existing recommendations to strengthen institutional structures, protecting public health interests can be challenging amidst industry interference and conflicting policy priorities, particularly in low and middle-income countries (LMICs) where the need for rapid economic development is pronounced. Small island developing states (SIDS) face even more challenges in regulating CDoH because their unique socioeconomic, political, and geographic vulnerabilities may weaken institutional conditions that could aid health sector actors in protecting health interests. This study aims to explore the institutional conditions that shape health sector actors' capability to protect public health interests in tobacco governance in Fiji and Vanuatu. METHODS: We employed a qualitative, exploratory case study design. We applied the administrative process theory to inform data collection and analysis. Seventy interviews were completed in Fiji and Vanuatu from 2018 to 2019. RESULTS: The findings show that the protection of health interests in tobacco governance were not supported by the institutional conditions in Fiji and Vanuatu. While the policy processes formally ensured a level playing field between actors, policies were often developed through informal mechanisms, and the safeguards to protect public interests from vested private interests were not implemented adequately. SIDS vulnerabilities and weak regulation of political parties contributed to the politicisation of government in both states, resulting in high-level government officials' questionable commitment to protect public health interests. The system of checks and balances usually embedded into democratic governments appeared to be muted, and policymakers had limited bureaucratic autonomy to elevate health interests in multisectoral policymaking amidst high-level government officials' frequent rotation. Finally, capacity constraints aggravated by SIDS vulnerabilities negatively impacted health sector actors' capability to analyse policy alternatives. CONCLUSIONS: Health sector actors in Fiji and Vanuatu were not supported by institutional conditions that could help them protect public health interests in multisectoral governance to regulate CDoH originating from the tobacco industry. Institutional conditions in these states were shaped by SIDS vulnerabilities but could be improved by targeted capacity building, governance and political system strengthening.

Low birthweight newborns in Vanuatu: A longitudinal follow-up study.

AIM: Medical care and technology have increased the survival of low birthweight babies (LBW), but especially in low- and middle-income settings the longer term thriving of such babies is not assured because of their fragility, limited services and difficult access after discharge from hospital. In Vanuatu, a Pacific nation of dispersed islands, improving LBW outcomes and survival remains a significant challenge. In this study, we prospectively document the survival, developmental and nutritional outcomes of a cohort of LBW over the first year of life. We also explored the mother's experiences of caring for an LBW baby in hospital and at home. METHODS: A prospective descriptive cohort study of 49 newborns weighing less than 2.5 kg, born between April and August 2019. Data were recorded on their hospital stay, and they were followed up at 6 and 12 months post-discharge and outcomes recorded. Developmental milestones were assessed using the Denver Developmental Screening Test, using milestones appropriate for corrected age. Qualitative interviews were conducted to identify experiences and challenges the mothers faced in caring for their LBW baby. RESULTS: The mean birthweight was 1800 g at 35 weeks gestation (between 2nd and 9th centile). At 6 months of age the median weight was 6.5 kg (9th centile) and at 12 months it was 7.8 kg (9th centile). Three infants died in the first 6 months post-discharge. By 12 months of age, the proportion of infants who had achieved milestones of social and emotional (90%), language and communication (97%), cognition (85%) and motor (69%) development. One had evidence of retinopathy, and 19 had clinical anaemia. Mothers identified several stressors that they attributed as risk factors for premature delivery and outlined the difficulties and isolation of caring for an LBW baby. CONCLUSIONS: It is vital that all LBW babies are followed up in the years after discharge: nutritional, developmental and general health outcomes were generally good; however, post-discharge deaths are more common in this group than in the general population. Equally important is the support for mothers of LBW babies to achieve better outcomes.

First Nations music as a determinant of health in Australia and Vanuatu: political and economic determinants.

This article reports on findings that indicate how First Nations musical activities function as cultural determinants of health. Drawing on early findings from a 3-year Australian Research Council funded project titled The Remedy Project: First Nations Music as a Determinant of Health, we detail Australian and Ni Vanuatu First Nations musicians' reported outcomes of musical activity using a First Nations cultural determinants of health framework. The broader findings indicate that our respondents see musical activity as actively shaping all known domains of cultural health determinants, and some surrounding political and social determinants. However, this paper focusses specifically on the political and economic determinants that emerged in analysis as the most dominant subthemes. We argue that this study provides strong impetus for continued investigation and reconceptualization of the place of music in cultural health determinant models.

This article looks at how making and performing music, recording music and listening to music helps the health of First Nations peoples in Australia and Ni Vanuatu. Music is an important part of the lives of First Nations peoples from these places and so research was done to try to understand why it is meaningful. Music can be used as an outlet for personal feelings, and can also be a way that groups of people can express common concerns. First Nations musicians talked about how music makes them feel, and how music is used to strengthen relationships between people, and between people and their culture. Musicians also talked about how music helps them express their political and economic goals. The findings backed up existing First Nations' models of health that say that health for First Nations People's needs to be thought about in a holistic way. The findings also showed that the relationship between music and health needs to be studied more so that we can better understand how it helps maintain links with the past, gives a guide for the present and opens options for the future.

Vocal input and output among infants in a multilingual context: Evidence from long-form recordings in Vanuatu.

What are the vocal experiences of children growing up on Malakula island, Vanuatu, where multilingualism is the norm? Long-form audio-recordings captured spontaneous speech behavior by, and around, 38 children (5-33 months, 23 girls) from 11 villages. Automated analyses revealed most children's vocal input came from female adults and other children's voices, with small contributions from male adult voices. The greatest changes with age involved an increase in the input vocalizations from other children. Total input (collapsing across child-directed and overheard speech, and across languages) was ∼11 min per hour, which was at least 5 min (31%) lower than that found in other populations studied using comparable methods in previous literature, as well as in archival American data analyzed with the same algorithm. In contrast, children's own vocalization counts were two to four times higher than previous reports for North-American English-learning monolingual infants at matched ages, and comparable to estimates from archival American data, consistent with a resilient language-learning cognitive system for this aspect of vocal development. The strongest association between input and output was with vocalizations by other children, rather than those by adults, which is consistent with research in anthropology but less so with current theoretical trends in developmental psychology. These results invite further research in populations that are under-represented in developmental science. RESEARCH HIGHLIGHTS: Combining long-form recordings with automated analyses, we estimated infants potentially exposed to ∼2.6 languages heard ∼11 min of speech per hour. Infants' input was dominated by vocalizations from female adults and from other children, particularly for the oldest infants in our sample. The strongest association between children's own vocalization counts and input counts was with those of other children, and not those with adults. Results invite further research on individual, group, and population variability in input quantity and composition, and its potential effects on vocal development.

Copying fideliy of functional and non-functional features in ni-Vanuatu children: A transmission chain study.

Observational learning plays a key role in cultural transmission. Previous transmission chain experiments have shown that children are able to maintain information across multiple generations through observational learning. It still remains unclear how the transmission of functional vs. non-functional information and the effect of being observed unfold across age in different communities. Here, we examine children's copying fidelity in observational learning of 5- to 13-year-olds from five different communities in Vanuatu, both individually (n = 263, 144 boys) and throughout a transmission chain of five to six children (n = 324, 178 boys). We additionally varied the functionality of the feature being copied (shape vs. color) and the copying context (observed vs. unobserved). Further, we also study developmental and cultural variation in the interaction of features and conditions. We find that children transmit the functional feature shape more faithfully than the non-functional feature color, both in the dyadic transitions as well as the transmission chains with an increasing tendency to do so as they get older. The age patterns show greater variation between communities for color than for shape. Overall, we find that being observed shows no uniform effects but influences transmission differently across communities. Our study shows that children are prone to passing on a functional feature across multiple generations of peers. Children copy non-functional features as well, but with lower fidelity. In sum, our results show children's high propensity and developing abilities for observational learning, ultimately allowing for effective cultural transmission.

Viruses Associated with Acute Conjunctivitis in Vanuatu.

The first manifestation of a viral infection may be conjunctivitis. There are limited data on the etiology of viral conjunctivitis in Vanuatu, a country in the South Pacific Ocean. Patients presenting to one of two Vanuatu health centers with presumed infectious conjunctivitis were eligible if symptom onset was within 14 days of screening. Conjunctival and anterior nasal swabs were obtained and subjected to unbiased RNA deep sequencing (RNA-seq) to identify DNA and RNA viruses. For samples collected from May to November 2021, RNA-seq identified a viral etiology in 12/48 patients. Human adenovirus species were the most common viruses (58%) detected, followed by human herpes viruses (cytomegalovirus, varicella zoster virus, and human herpes 7 virus). Rhinovirus C, Epstein-Barr virus, and bocavirus were also detected. In summary, the etiology for viral conjunctivitis in Vanuatu appears broad. Unbiased testing may be useful for disease surveillance.

Humanitarian aid and local responses: the aftermath of the rebuilding effort on Tongoa island, Vanuatu.

Cyclone Pam swept through the archipelago of Vanuatu on 13-14 March 2015, with wind speeds exceeding those recorded anywhere in the South Pacific since the 1980s. Southern and central parts of the country were particularly affected. Material damage on Tongoa, one of the most afflicted islands, was extensive, but no deaths were reported. During the storm, villagers found shelter in their kitchen, in what is considered locally as a 'lifeboat'. The aftermath was managed and mitigated by international aid organisations. On Tongoa, this included a 'Shelter Cluster' programme, under which villagers were given house rebuilding kits. Elaborating upon extensive ethnographic investigations on site between 2011 and 2018, this paper explores and reveals the ways in which this aid generated confusion among the local population. In a larger context of regular disasters triggered by natural hazards, locals have found endogenous ways of dealing with such extreme climatic events, for the most part without any external assistance.

Menstrual Health Experiences of People with Intellectual Disabilities and Their Caregivers during Vanuatu's Humanitarian Responses: A Qualitative Study.

Attention to menstrual health in humanitarian responses is increasing, but evidence related to people with intellectual disabilities and their caregivers is absent. This study begins to address that. We applied purposive sampling to select 17 women and girls (aged 15-31) with intellectual disabilities, their 17 caregivers in SANMA province, Vanuatu, and seven key informants. We used in-depth interviews, PhotoVoice and ranking, and observation and analysed data thematically using Nvivo 12. We found that caregivers wished to maintain the person's safety and privacy, especially when menstruating, which reduced evacuation options. People with intellectual disabilities support requirements sometimes increased after emergencies. This meant caregivers were less able to work and recover from disasters. Caregivers requested the distribution of more reusable menstrual materials and a greater choice, including adult-sized diapers for menstruation and incontinence. Key informants noted that menstrual health interventions must always be delivered to people with intellectual disabilities and their caregivers so that menstrual health knowledge and practices exist before emergencies. We found that men and women supported people with intellectual disabilities' menstrual health, thus challenging gendered assumptions about caregiving. Efforts to achieve menstrual health for this population within disaster preparedness plans must be included. If not, families will fall further into poverty every time a disaster hits Vanuatu.

DArTSeq SNP-based genetic diversity and population structure studies among taro [(Colocasia esculenta (L.) Schott] accessions sourced from Nigeria and Vanuatu.

Taro is a valuable staple food crop among resource-poor rural people in countries such as Nigeria and Ghana, among others. Characterization of genetic diversity is a prerequisite for proper management of breeding programs and conservation of genetic resources. Two hundred seventy one taro accessions obtained from Nigeria and Vanuatu were genotyped using DArTseq-based SNP markers with the objectives of investigating the genetic diversity and population structure. In the analysis, 10,391 SNP markers were filtered from the sequence and used. The analysis revealed higher transition than transversion types of SNPs in the ratio of 1.43:1. The polymorphism ranged from 0.26 to 0.29 for the markers, indicating moderate genetic diversity. A model-based Bayesian clustering analysis of taro accessions yielded five subgroups and revealed the admixture situation in 19.19% of all accessions in the study. Vanuatu taro accessions exhibited more genetic diversity than Nigerian taro accessions. The population diversity estimate (PhiPt) was relatively higher (0.52) for accessions originating from Vanuatu than for Nigerian accessions. Analysis of molecular variance (AMOVA) revealed that most variation existed among individuals within a population at 52%. Nei's genetic distance showed that relatedness is based on geographical proximity. Collection of taro genetic resources should give more emphasis to within regions to utilize diversity in taro breeding program. This study also demonstrated the efficiency of DArTseq-based SNP genotyping for large-scale genome analysis in taro. The genotypic markers provided in this study are useful for association mapping studies.