New avian flu virus jumps from birds to mammals, kills New England's baby seals

July 31, 2012

A novel avian influenza virus has acquired the ability to infect aquatic mammals and was responsible for an outbreak of fatal pneumonia that recently struck harbor seals in New England, according to scientists at the Center for Infection & Immunity (CII) at Columbia University's Mailman School of Public Health, the National Oceanic and Atmospheric Association, New England Aquarium, USGS National Wildlife Health Center, SeaWorld and EcoHealth Alliance.

This research is published in mBio.

Wildlife officials first became concerned in September 2011, when seals with severe and skin lesions suddenly appeared along the coastline from southern Maine to northern Massachusetts. Most were infants (less than 6 months), and a total of 162 dead or moribund seals were recovered over the next 3 months.

Pathogen screening was conducted in a subset of afflicted seals, using sensitive diagnostic tools developed at the CII, and a new strain of avian H3N8 was identified as a culprit.

"When initial tests revealed an avian influenza virus, we asked the obvious question: how did this virus jump from birds to seals?" says Simon Anthony, D.Phil, postdoctoral research scientist at the CII and the lead author of the study.

Based on full genome sequencing and phylogenetic analysis, seal H3N8 descended from an avian strain that has been circulating in North American waterfowl since 2002, which implies recent transmission from wild birds to seals.

Accordingly, seal H3N8 has acquired the ability to bind sialic acid receptors that are commonly found in the mammalian respiratory tract. Mutations in the HA and PB2 genes – required for cell entry and replication, respectively – suggest enhanced virulence and transmission in mammals, but these putative attributes require further investigation. Given these findings along with the long history of the spread of avian influenza to humans—most notably H1N1 and H5N1—seal H3N8 could pose a threat to public health.

"Our findings reinforce the importance of wildlife surveillance in predicting and preventing pandemics, says W. Ian Lipkin, director of the Center for Infection and Immunity and John Snow Professor of Epidemiology, at the Mailman School of Public Health. "HIV/AIDS, SARS, West Nile, Nipah and are all examples of emerging infectious diseases that originated in animals. Any of disease in domestic animals or wildlife, while an immediate threat to wildlife conservation, must also be considered potentially hazardous to humans."

Explore further: Oral interferon may prevent and control avian influenza virus infection

Related Stories

Oral interferon may prevent and control avian influenza virus infection

July 28, 2011
Avian influenza virus is a threat to the commercial chicken industry and, with its recent rapid spread across China, has also shown the ability for transmission from chickens to humans and other mammals. In an article in ...

Recommended for you

Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections

September 22, 2017
Group A Streptococcus bacteria cause a variety of illnesses that range from mild nuisances like strep throat to life-threatening conditions including pneumonia, toxic shock syndrome and the flesh-eating disease formally known ...

Ecosystem approach makes urinary tract infection more treatable

September 22, 2017
The biological term 'ecosystem' is not usually associated with urinary tract infections, but this should change according to Wageningen scientists.

Residents: Frontline defenders against antibiotic resistance?

September 22, 2017
Antibiotic resistance continues to grow around the world, with sometimes disastrous results. Some strains of bacteria no longer respond to any currently available antibiotic, making death by infections that were once easily ...

Individualized diets for irritable bowel syndrome better than placebo

September 21, 2017
Patients with irritable bowel syndrome who follow individualized diets based on food sensitivity testing experience fewer symptoms, say Yale researchers. Their study is among the first to provide scientific evidence for this ...

Superbug's spread to Vietnam threatens malaria control

September 21, 2017
A highly drug resistant malaria 'superbug' from western Cambodia is now present in southern Vietnam, leading to alarming failure rates for dihydroartemisinin (DHA)-piperaquine—Vietnam's national first-line malaria treatment, ...

A dose of 'wait-and-see' reduces unnecessary antibiotic use

September 21, 2017
Asking patients to take a 'wait-and-see' approach before having their antibiotic prescriptions filled significantly reduces unnecessary use, a University of Queensland study has shown.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.