#Surveillance for #Eurasian-origin and #intercontinental #reassortant highly pathogenic #influenza A #viruses in #Alaska, spring and summer 2015 (BMC, abstract)

[Source: BioMedCentral, full page: (LINK). Abstract, edited.]

Short report / Open Access

Surveillance for Eurasian-origin and intercontinental reassortant highly pathogenic influenza A viruses in Alaska, spring and summer 2015

Andrew M. Ramey, John M. Pearce, Andrew B. Reeves, Rebecca L. Poulson, Jennifer Dobson,  Brian Lefferts, Kyle Spragens and David E. Stallknecht

Virology Journal / 201613:55 / DOI: 10.1186/s12985-016-0511-9

© Ramey et al. 2016

Received: 21 December 2015 – Accepted: 21 March 2016 – Published: 31 March 2016

 

Abstract

Background

Eurasian-origin and intercontinental reassortant highly pathogenic (HP) influenza A viruses (IAVs) were first detected in North America in wild, captive, and domestic birds during November–December 2014. Detections of HP viruses in wild birds in the contiguous United States and southern Canadian provinces continued into winter and spring of 2015 raising concerns that migratory birds could potentially disperse viruses to more northerly breeding areas where they could be maintained to eventually seed future poultry outbreaks.

Results

We sampled 1,129 wild birds on the Yukon-Kuskokwim Delta, Alaska, one of the largest breeding areas for waterfowl in North America, during spring and summer of 2015 to test for Eurasian lineage and intercontinental reassortant HP H5 IAVs and potential progeny viruses. We did not detect HP IAVs in our sample collection from western Alaska; however, we isolated five low pathogenic (LP) viruses. Four isolates were of the H6N1 (n = 2), H6N2, and H9N2 combined subtypes whereas the fifth isolate was a mixed infection that included H3 and N7 gene segments. Genetic characterization of these five LP IAVs isolated from cackling (Branta hutchinsii; n = 2) and greater white-fronted geese (Anser albifrons; n = 3), revealed three viral gene segments sharing high nucleotide identity with HP H5 viruses recently detected in North America. Additionally, one of the five isolates was comprised of multiple Eurasian lineage gene segments.

Conclusions

Our results did not provide direct evidence for circulation of HP IAVs in the Yukon-Kuskokwim Delta region of Alaska during spring and summer of 2015. Prevalence and genetic characteristics of LP IAVs during the sampling period are concordant with previous findings of relatively low viral prevalence in geese during spring, non-detection of IAVs in geese during summer, and evidence for intercontinental exchange of viruses in western Alaska.

Keywords: Alaska – H5N1 – H5N2 – H5N8 – Highly pathogenic – Influenza – Migratory bird – Yukon-Kuskokwim Delta

Keywords: Research; Abstracts; Avian Influenza; USA; Alaska; Wild Birds; H6N1; H6N2; H9N2; Reassortant Strains.

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#USGS Projects Large #Loss of #Alaska #Permafrost by 2100 (USGS, Nov. 30 ‘15)

[Source: US Geological Survey (USGS), full page: (LINK).]

USGS Projects Large Loss of Alaska Permafrost by 2100 [  ENVR   ]

Released: 11/30/2015 1:35:24 PM

Contact Information: U.S. Department of the Interior, U.S. Geological Survey, Office of Communications and Publishing, 12201 Sunrise Valley Dr, MS 119, Reston, VA 20192 / Jon Campbell, Phone: 703-648-4180 / Bruce  Wylie, Phone: 605-594-6078

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Using statistically modeled maps drawn from satellite data and other sources, U.S. Geological Survey scientists have projected that the near-surface permafrost that presently underlies 38 percent of boreal and arctic Alaska would be reduced by 16 to 24 percent by the end of the 21st century under widely accepted climate scenarios. Permafrost declines are more likely in central Alaska than northern Alaska.

Northern latitude tundra and boreal forests are experiencing an accelerated warming trend that is greater than in other parts of the world.  This warming trend degrades permafrost, defined as ground that stays below freezing for at least two consecutive years. Some of the adverse impacts of melting permafrost are changing pathways of ground and surface water, interruptions of regional transportation, and the release to the atmosphere of previously stored carbon.

“A warming climate is affecting the Arctic in the most complex ways,” said Virginia Burkett, USGS Associate Director for Climate and Land Use Change.

“Understanding the current distribution of permafrost and estimating where it is likely to disappear are key factors in predicting the future responses of northern ecosystems to climate change.”

In addition to developing maps of near-surface permafrost distributions, the researchers developed maps of maximum thaw depth, or active-layer depth, and provided uncertainty estimates. 

Future permafrost distribution probabilities, based on future climate scenarios produced by the Intergovernmental Panel on Climate Change (IPCC), were also estimated by the USGS scientists.  Widely used IPCC climate scenarios anticipate varied levels of climate mitigation action by the global community.

These future projections of permafrost distribution, however, did not include other possible future disturbances in the future, such as wildland fires. In general, the results support concerns about permafrost carbon becoming available to decomposition and greenhouse gas emission.

The research has been published in Remote Sensing of Environment.  The current near-surface permafrost map is available via ScienceBase.

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Current probability of near-surface permafrost in Alaska. Future scenarios.

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Current probability of near-surface permafrost in Alaska. Future scenarios. (High resolution image)

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Keywords: Research; USA; USGS; Updates; Permafrost; Alaska; Climate Change; Global Warming.

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