scholarly journals Worldwide survey reveals lower susceptibility of African Aedes aegypti mosquitoes to diverse strains of Zika virus

2018 ◽  
Author(s):  
Fabien Aubry ◽  
Daria Martynow ◽  
Artem Baidaliuk ◽  
Sarah H. Merkling ◽  
Laura B. Dickson ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Zika Virus ◽  
Large Scale ◽  
Pacific Islands ◽  
French Polynesia ◽  
Population Diversity ◽  
Potential Contribution ◽  
Response Curves ◽  
The Pacific ◽  
Low Passage

AbstractZika virus (ZIKV) is a flavivirus mainly transmitted to humans through the bite of infected Aedes aegypti mosquitoes. First isolated in Uganda in 1947, ZIKV was shown to circulate in enzootic sylvatic cycles in Africa and Asia for at least half a century before the first reported human epidemic occurred in 2007 on the Pacific island of Yap, Micronesia. Subsequently, larger ZIKV outbreaks were recorded in French Polynesia and other South Pacific islands during 2013-2014. In 2015, ZIKV reached Brazil from where it rapidly spread across the Americas and the Caribbean, causing hundreds of thousands of human cases. The factors that have fueled the explosiveness and magnitude of ZIKV emergence in the Pacific and the Americas are poorly understood. Reciprocally, the lack of major human epidemics of ZIKV in regions with seemingly favorable conditions, such as Africa or Asia, remains largely unexplained. To evaluate the potential contribution of vector population diversity to ZIKV epidemiological patterns, we established dose-response curves for eight field-derived Ae. aegypti populations representing the global range of the species, following experimental exposure to six low-passage ZIKV strains spanning the current viral genetic diversity. Our results reveal that African Ae. aegypti are significantly less susceptible than non-African Ae. aegypti across all ZIKV strains tested. We suggest that low susceptibility of vector populations may have contributed to prevent large-scale human transmission of ZIKV in Africa.

scholarly journals Transmission dynamics of Zika virus in island populations: a modelling analysis of the 2013-14 French Polynesia outbreak

2016 ◽  
Author(s):  
Adam J. Kucharski ◽  
Sebastian Funk ◽  
Rosalind M. Eggo ◽  
Henri-Pierre Mallet ◽  
W. John Edmunds ◽  
...  
Keyword(s):  
South America ◽  
Dengue Virus ◽  
Zika Virus ◽  
French Polynesia ◽  
Neurological Complications ◽  
Transmission Dynamics ◽  
Guillain Barre Syndrome ◽  
Island Populations ◽  
The Pacific ◽  
Guillain Barré

AbstractBetween October 2013 and April 2014, more than 30,000 cases of Zika virus (ZIKV) disease were estimated to have attended healthcare facilities in French Polynesia. ZIKV has also been reported in Africa and Asia, and in 2015 the virus spread to South America and the Caribbean. Infection with ZIKV has been associated with neurological complications including Guillain-Barré Syndrome (GBS) and microcephaly, which led the World Health Organization to declare a Public Health Emergency of International Concern in February 2015. To better understand the transmission dynamics of ZIKV, we used a mathematical model to examine the 2013–14 outbreak on the six major archipelagos of French Polynesia. Our median estimates for the basic reproduction number ranged from 2.6–4.8, with an estimated 11.5% (95% CI: 7.32–17.9%) of total infections reported. As a result, we estimated that 94% (95% CI: 91–97%) of the total population of the six archipelagos were infected during the outbreak. Based on the demography of French Polynesia, our results imply that if ZIKV infection provides complete protection against future infection, it would take 12–20 years before there are a sufficient number of susceptible individuals for ZIKV to reemerge, which is on the same timescale as the circulation of dengue virus serotypes in the region. Our analysis suggests that ZIKV may exhibit similar dynamics to dengue virus in island populations, with transmission characterized by large, sporadic outbreaks with a high proportion of asymptomatic or unreported cases.Author SummarySince the first reported major outbreak of Zika virus disease in Micronesia in 2007, the virus has caused outbreaks throughout the Pacific and South America. Transmitted by the Aedes species of mosquitoes, the virus has been linked to possible neurological complications including Guillain-Barre Syndrome and microcephaly. To improve our understanding of the transmission dynamics of Zika virus in island populations, we analysed the 2013–14 outbreak on the six major archipelagos of French Polynesia. We found evidence that Zika virus infected the majority of population, but only around 12% of total infections on the archipelagos were reported as cases. If infection with Zika virus generates lifelong immunity, we estimate that it would take at least 15–20 years before there are enough susceptible people for the virus to reemerge. Our results suggest that Zika virus could exhibit similar dynamics to dengue virus in the Pacific, producing large but sporadic outbreaks in small island populations.

scholarly journals Peptide-Based Subunit Vaccine Design of T- and B-Cells Multi-Epitopes against Zika Virus Using Immunoinformatics Approaches

2019 ◽  
Vol 7 (8) ◽  
pp. 226 ◽  
Author(s):  
Vivitri Dewi Prasasty ◽  
Karel Grazzolie ◽  
Rosmalena Rosmalena ◽  
Fatmawaty Yazid ◽  
Fransiskus Xaverius Ivan ◽  
...  
Keyword(s):  
B Cell ◽  
Zika Virus ◽  
Neutralizing Antibodies ◽  
Pacific Islands ◽  
Virus Disease ◽  
Peptide Vaccine ◽  
Human Leukocyte ◽  
T Cell Epitopes ◽  
B Cell Epitopes ◽  
The Pacific

The Zika virus disease, also known as Zika fever is an arboviral disease that became epidemic in the Pacific Islands and had spread to 18 territories of the Americas in 2016. Zika virus disease has been linked to several health problems such as microcephaly and the Guillain–Barré syndrome, but to date, there has been no vaccine available for Zika. Problems related to the development of a vaccine include the vaccination target, which covers pregnant women and children, and the antibody dependent enhancement (ADE), which can be caused by non-neutralizing antibodies. The peptide vaccine was chosen as a focus of this study as a safer platform to develop the Zika vaccine. In this study, a collection of Zika proteomes was used to find the best candidates for T- and B-cell epitopes using the immunoinformatics approach. The most promising T-cell epitopes were mapped using the selected human leukocyte antigen (HLA) alleles, and further molecular docking and dynamics studies showed a good peptide-HLA interaction for the best major histocompatibility complex-II (MHC-II) epitope. The most promising B-cell epitopes include four linear peptides predicted to be cross-reactive with T-cells, and conformational epitopes from two proteins accessible by antibodies in their native biological assembly. It is believed that the use of immunoinformatics methods is a promising strategy against the Zika viral infection in designing an efficacious multiepitope vaccine.

scholarly journals Potential of Black Soldier Fly Production for Pacific Small Island Developing States

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1038
Author(s):  
Matan Shelomi
Keyword(s):  
Large Scale ◽  
Organic Waste ◽  
Pacific Islands ◽  
Research Priorities ◽  
Small Island ◽  
Small Island Developing States ◽  
Black Soldier Fly ◽  
The Pacific ◽  
Crop Waste ◽  
Insect Biomass

Organic waste such as food waste and livestock manure is a serious concern in the Pacific Islands, where landfills are overflowing and illegal dumping of waste threatens the fragile ecosystems. Organic waste also attracts filth flies, some of which are vectors for pathogens that cause human disease. The black soldier fly, Hermetia illucens, has tremendous potential for the Pacific Islands. Capable of digesting almost any organic matter and converting it into insect biomass, black soldier flies are already being used around the world to process organic waste into larvae. The system can be adapted to large-scale municipal composting as well as small sizes for individual livestock farms or even urban households. The larvae can be fed live to fish or poultry, processed into feed comparable to fishmeal or soy meal, or even used to generate biofuel. Thus, the fly not only eliminates waste, but also can improve the sustainability of livestock production. The Pacific Small Island Developing States stand to benefit immensely from black soldier fly bioconversion facilities, used primarily as a means to compost organic waste; however, several knowledge gaps must first be addressed. We reviewed the state of black soldier flies in the Pacific and identified where their use shows the most promise. Research priorities for the field include fly surveys and bioconversion assays using Pacific crop waste.

scholarly journals How Did Zika Virus Emerge in the Pacific Islands and Latin America?

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
John H.-O. Pettersson ◽  
Vegard Eldholm ◽  
Stephen J. Seligman ◽  
Åke Lundkvist ◽  
Andrew K. Falconar ◽  
...  
Keyword(s):  
Latin America ◽  
Amino Acid ◽  
Zika Virus ◽  
Reverse Genetics ◽  
Pacific Islands ◽  
Vector Competence ◽  
Phylogenetic Analyses ◽  
Human Populations ◽  
Amino Acid Substitutions ◽  
The Pacific

ABSTRACT The unexpected emergence of Zika virus (ZIKV) in the Pacific Islands and Latin America and its association with congenital Zika virus syndrome (CZVS) (which includes microcephaly) and Guillain-Barré syndrome (GBS) have stimulated wide-ranging research. High densities of susceptible Aedes spp., immunologically naive human populations, global population growth with increased urbanization, and escalation of global transportation of humans and commercial goods carrying vectors and ZIKV undoubtedly enhanced the emergence of ZIKV. However, flavivirus mutations accumulate with time, increasing the likelihood that genetic viral differences are determinants of change in viral phenotype. Based on comparative ZIKV complete genome phylogenetic analyses and temporal estimates, we identify amino acid substitutions that may be associated with increased viral epidemicity, CZVS, and GBS. Reverse genetics, vector competence, and seroepidemiological studies will test our hypothesis that these amino acid substitutions are determinants of epidemic and neurotropic ZIKV emergence.

scholarly journals Observations sur la situation politique de la Polynesie Francaise au travers de quelques principies de bonne Gouvernance enonces par le PNUD 1997 et le Pacific Plan 2006-15

2008 ◽  
Vol 39 (4) ◽  
pp. 583
Author(s):  
Yves-Louis Sage
Keyword(s):  
Pacific Islands ◽  
Good Governance ◽  
French Polynesia ◽  
Political Life ◽  
The Political ◽  
Chronic Instability ◽  
Political Actors ◽  
The Pacific ◽  
Local Assembly ◽  
The Government

Since 2004, the political situation in French Polynesia has been marked by chronic instability. Waves of electoral reform initiatives undertaken by the government in order to improve political life have not been successful. This is not surprising since these reforms have been adopted without appropriate consultations with the population and often against the wishes of the local assembly. As a result, these reforms have in fact accentuated the problems they were supposed to resolve. This situation, criticised by a large majority of Polynesian voters, is the result of the violation by the principal political actors in French Polynesia of the principles of good governance developed by the United Nations Development Programme in 1997 and by the Pacific Islands Forum in the Pacific Plan 2006-15. Yet, these are not unsolvable problems should the political actors show the will to tackle them efficiently.

scholarly journals Structure in the variability of the basic reproductive number (R0) for Zika epidemics in the Pacific islands

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Clara Champagne ◽  
David Georges Salthouse ◽  
Richard Paul ◽  
Van-Mai Cao-Lormeau ◽  
Benjamin Roche ◽  
...  
Keyword(s):  
Pacific Islands ◽  
New Caledonia ◽  
Control Strategies ◽  
Virus Transmission ◽  
French Polynesia ◽  
Basic Reproductive Number ◽  
Effective Control ◽  
Reproductive Number ◽  
The Pacific ◽  
Seroprevalence Data

Before the outbreak that reached the Americas in 2015, Zika virus (ZIKV) circulated in Asia and the Pacific: these past epidemics can be highly informative on the key parameters driving virus transmission, such as the basic reproduction number (R0). We compare two compartmental models with different mosquito representations, using surveillance and seroprevalence data for several ZIKV outbreaks in Pacific islands (Yap, Micronesia 2007, Tahiti and Moorea, French Polynesia 2013-2014, New Caledonia 2014). Models are estimated in a stochastic framework with recent Bayesian techniques. R0 for the Pacific ZIKV epidemics is estimated between 1.5 and 4.1, the smallest islands displaying higher and more variable values. This relatively low range of R0 suggests that intervention strategies developed for other flaviviruses should enable as, if not more effective control of ZIKV. Our study also highlights the importance of seroprevalence data for precise quantitative analysis of pathogen propagation, to design prevention and control strategies.

scholarly journals Zika virus seroprevalence declines and neutralization antibodies wane in adults following outbreaks in French Polynesia and Fiji

2019 ◽  
Author(s):  
Alasdair D Henderson ◽  
Maite Aubry ◽  
Mike Kama ◽  
Jessica Vanhomwegen ◽  
Anita Teissier ◽  
...  
Keyword(s):  
Latin America ◽  
Zika Virus ◽  
French Polynesia ◽  
Cross Sectional ◽  
The Pacific ◽  
Before And After ◽  
Dynamics Of Population ◽  
High Level ◽  
Antibody Levels

SUMMARYBackgroundSerosurveys published following major outbreaks of Zika virus (ZIKV) have so far shown a high level of seroprevalence from samples collected within 12 months of the first confirmed case. A common assumption is that ZIKV infection confers long-term protection against reinfection, preventing ZIKV from re-emerging in previously affected areas for many years. However, the long-term immune response to ZIKV following an outbreak remains poorly documented.MethodsWe compared results from eight serological surveys, with sample sizes ranging from 49 to 700, before and after known ZIKV outbreaks in the Pacific region: five from cross-sectional studies of schoolchildren and the general population in French Polynesia over a seven-year period; and three from a longitudinal cohort in Fiji over a four-year period.FindingsWe found strong evidence of a decline in seroprevalence in both countries over a two-year period following first reported ZIKV transmission. In the cohort in Fiji, there was also a significant decline in antibody titres against ZIKV. However, the decline in seroprevalence was concentrated in adults, while high seroprevalence persisted in children.InterpretationThe observed patterns of long-term anti-ZIKV antibody levels following outbreaks in the Pacific could be an early indication of the dynamics of population immunity in Latin America. Given that ZIKV antibody levels can wane substantially over time, follow-up seroprevalence studies and prospective clinical trial designs in Latin America may need to be revised, and assumptions about the potential for ZIKV to re-emerge may need to be revisited.FundingPacific Funds, ANR, MRC, Wellcome, Royal Society.

scholarly journals Erratum for Pettersson et al., “How Did Zika Virus Emerge in the Pacific Islands and Latin America?”

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
John H.-O. Pettersson ◽  
Vegard Eldholm ◽  
Stephen J. Seligman ◽  
Åke Lundkvist ◽  
Andrew K. Falconar ◽  
...  
Keyword(s):  
Latin America ◽  
Zika Virus ◽  
Pacific Islands ◽  
The Pacific

scholarly journals Decolonisation Processes in the South Pacific Islands: A Comparative Analysis between Metropolitan Powers

1996 ◽  
Vol 26 (2) ◽  
pp. 355
Author(s):  
Paul De Deckker
Keyword(s):  
New Zealand ◽  
Great Britain ◽  
Pacific Islands ◽  
New Caledonia ◽  
Free Association ◽  
South Pacific ◽  
French Polynesia ◽  
The South ◽  
The Pacific ◽  
South Pacific Islands

The South Pacific islands came late, by comparison with Asia and Africa, to undertake the decolonising process. France was the first colonial power in the region to start off this process in accordance with the decision taken in Paris to pave the way to independence for African colonies. The Loi-cadre Defferre in 1957, voted in Parliament, was applied to French Polynesia and New Caledonia as it was to French Africa. Territorial governments were elected in both these Pacific colonies in 1957. They were abolished in 1963 after the return to power of General de Gaulle who decided to use Moruroa for French atomic testing. The status quo ante was then to prevail in New Caledonia and French Polynesia up to today amidst statutory crises. The political evolution of the French Pacific, including Wallis and Futuna, is analysed in this article. Great Britain, New Zealand and Australia were to conform to the 1960 United Nations' recommendations to either decolonise, integrate or provide to Pacific colonies self-government in free association with the metropolitan power. Great Britain granted constitutional independence to all of its colonies in the Pacific except Pitcairn. The facts underlying this drastic move are analysed in the British context of the 1970's, culminating in the difficult independence of Vanuatu in July 1980. New Zealand and Australia followed the UN recommendations and granted independence or self-government to their colonial territories. In the meantime, they reinforced their potential to dominate the South Pacific in the difficult geopolitical context of the 1980s. American Micronesia undertook statutory evolution within a strategic framework. What is at stake today within the Pacific Islands is no longer of a political nature; it is financial.

Metapopulation vicariance in the Pacific genus Coprosma (Rubiaceae) and its Gondwanan relatives

2017 ◽  
Vol 30 (6) ◽  
pp. 422 ◽  
Author(s):  
Michael Heads
Keyword(s):  
Large Scale ◽  
Distribution Patterns ◽  
French Polynesia ◽  
Oceanic Islands ◽  
Physical Contact ◽  
Central Pacific ◽  
Transform Faults ◽  
The Pacific ◽  
Igneous Provinces ◽  
High Level

Coprosma is perhaps the most ubiquitous plant genus in New Zealand. It belongs to the tribe Anthospermeae, which is distinctive in the family Rubiaceae through its small, simple, wind-pollinated flowers and its southern hemisphere distribution. The tribe comprises four main clades found respectively in South Africa, Africa, Australia and the Pacific. The high level of allopatry among the four subtribes is attributed here to their origin by vicariance. The Pacific clade, subtribe Coprosminae, is widespread around the margins of the South Pacific and also occurs on most of the high islands. Distributions of the main clades in the subtribe are mapped here and are shown to be repeated in other groups. The distribution patterns also coincide with features of regional geology. Large-scale volcanism has persisted in the central Pacific region since at least the Jurassic. At that time, the oldest of the Pacific large igneous provinces, the Shatsky Rise, began to be erupted in the region now occupied by French Polynesia. Large-scale volcanism in the central Pacific continued through the Cretaceous and the Cenozoic. The sustained volcanism, along with details of the clade distributions, both suggest that the Coprosminae have persisted in the central Pacific by survival of metapopulations on individually ephemeral islands. It is also likely that vicariance of metapopulations has taken place, mediated by processes such as the subsidence of the Pacific seafloor by thousands of metres, and rifting of active arcs by transform faults. It is sometimes argued that a vicariance origin is unlikely for groups on young, oceanic islands that have never been connected by continuous land, but metapopulation vicariance does not require physical contact between islands.

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