Published Date: 2012-02-28 11:14:38
Subject: PRO/AH/EDR> Influenza (15): (Guatemala) bat, novel A lineage
Archive Number: 20120228.1055191
INFLUENZA (15): (GUATEMALA) BAT, NOVEL A LINEAGE
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
In this posting:
 CIDRAP report
 PNAS abstract
 CIDRAP report
Date: Mon 27 Feb 2012
Source: CIDRAP (Center for Infectious Disease Research & Policy) News [edited]
New influenza A virus found in bats
A research team today [27 Feb 2012] announced the discovery of a new influenza A virus in Guatemalan fruit bats, but in its current form the virus doesn't pose a threat to humans, according to the US Centers for Disease Control and Prevention (CDC).
The researchers, who included scientists from the CDC, reported their findings today in Proceedings of the National Academy of Sciences (PNAS) [The abstract is reproduced below as part . - Mod.CP]
Suxiang Tong, PhD, the study's lead author and head of the pathogen discovery program in the CDC's division of viral diseases, said in a CDC press release e-mailed to reporters that the discovery marks the 1st identification of an influenza virus in bats. "The study is important, because the research has identified a new animal species that may act as a source of flu viruses."
The bat influenza virus would need to go through several reassortment steps to infect humans, the CDC said. Early tests suggest the genes of the new virus are compatible with human influenza viruses.
However, Ruben Donis, PhD, a study coauthor and chief of the molecular virology and vaccines branch of the CDC's influenza division, added that initial tests show the virus found in bats would need to undergo significant changes to infect and spread easily among humans. "A different animal -- such as a pig, horse, or dog -- would need to be capable of being infected with both this new bat influenza virus and human influenza viruses for reassortment to occur."
The researchers found the new influenza A in only one species, little yellow-shouldered bats, which are common in Central and South America but are not native to the United States, according to the CDC.
In their search for novel flu viruses in bats, the research group captured 316 bats representing 21 different species at 8 locations in southern Guatemala in May 2009 and September 2010, according to the PNAS report. Using polymerase chain reaction testing, they found positive samples from 3 bats at 2 different locations, all of the animals little yellow-shouldered bats.
Genome sequencing found that the virus is different from known influenza A viruses, because its hemagglutinin can be classified as a new and different subtype, designated H17. The neuraminidase (NA) gene is different than all other known NAs. Scientists weren't able to grow the new virus in cell cultures or chicken embryos.
Serologic studies are under way to determine how common the virus is among bats in Central America and other regions, according to the study. Researchers noted that because the virus was found in 2 different locations at different times, the finding isn't likely to represent an incidental interspecies transfer.
"Bats may now be added to the list of mammalian hosts of influenza A viruses," the group wrote, adding that the finding expands the list of flu reservoirs and raises questions about how the virus is maintained in bat populations and what the findings mean for public health.
[Byline: Lisa Schnirring]
 PNAS abstract
Date: Mon 27 Feb 2012
Source: Proceedings of the National Academy of Sciences, USA (PNAS), online prior to print [edited]
[Ref: Suxiang Tong, et al: A distinct lineage of influenza A virus from bats. Published online before print, 27 Feb 2012; doi:10.1073/pnas.1116200109]
Influenza A virus reservoirs in animals have provided novel genetic elements leading to the emergence of global pandemics in humans. Most influenza A viruses circulate in waterfowl, but those that infect mammalian hosts are thought to pose the greatest risk for zoonotic spread to humans and the generation of pandemic or panzootic viruses. We have identified an influenza A virus from little yellow-shouldered bats captured at 2 locations in Guatemala. It is significantly divergent from known influenza A viruses. The HA [influenza hemagglutinin] of the bat virus was estimated to have diverged at roughly the same time as the known subtypes of HA and was designated as H17. The neuraminidase (NA) gene is highly divergent from all known influenza NAs, and the internal genes from the bat virus diverged from those of known influenza A viruses before the estimated divergence of the known influenza A internal gene lineages. Attempts to propagate this virus in cell cultures and chicken embryos were unsuccessful, suggesting distinct requirements compared with known influenza viruses. Despite its divergence from known influenza A viruses, the bat virus is compatible for genetic exchange with human influenza viruses in human cells, suggesting the potential capability for reassortment and contributions to new pandemic or panzootic influenza A viruses.
[Not an immediate threat, but indicative of the existence of novel sources of influenza A virus genetic variability potentially able to contribute to the evolution of new pandemic influenza viruses. - Mod.CP]
[Images of the little yellow-shouldered bat (_Sturnira lilium_) can be seen at http://www.rawstory.com/rs/wp-conten...utterstock.jpg
. - Sr.Tech.Ed.MJ]
A HealthMap/ProMED-mail map can be accessed at: http://healthmap.org/r/1Ifb.]
---------- Post added at 07:59 PM ---------- Previous post was at 07:58 PM ----------
I'd like some similar research for African bats.