While taking my stroll through the woods and fields at work this morning, a nice dark Merlin came cruising in along the tree line, broke up a flock of Mourning Doves, and then perched on the top of a distant tree for 20 minutes to preen. A very nice welcome back to work present for a Monday.
According to a new paper in the Journal of Virology, H5N1 avian influenza viruses may be widespread in Tree Sparrow populations in Asia. Just goes to show that we should be testing more than just waterfowl for the presence of avian influenza viruses. There are thousands of different variants of the hundreds of different HN subtypes in thousands of different bird species. If we are to ever really understand these viruses, we'll need widespread testing of as many species as possible.
Anyway, the Tree Sparrow article is:
"New Genotype of Avian Influenza H5N1 Viruses Isolated from Tree Sparrows in China" by Z. Kou, F.M.Lai et al, published in the Journal of Virology, December 2005, p. 15460- 15466, Vol. 79, No. 24.
Abstract: The 2004 outbreaks of highly pathogenic avian influenza H5N1 disease in China led to a great poultry loss and society attention. A survey of avian influenza viruses was conducted on tree sparrows (Passer montanus) collected in China in 2004. Four viruses were isolated from free-living tree sparrows. The results of the whole-genome analysis indicated that an H5N1 virus with a new genotype is circulating among tree sparrows. The hemagglutinin and neuraminidase genes of the new genotype were derived from Gs/Gd/96-like viruses and the nuclear protein gene descended from the 2001 genotype A H5N1 viruses, while the other inner genes originated from an unknown influenza virus. In experimental infection, all four viruses were highly pathogenic to chickens but not pathogenic to ducks or mice. The four tree sparrow viruses were different from the 2003 tree sparrow strain (genotype Z) in Hong Kong. The results suggested that H5N1 viruses might be distributed widely in tree sparrows.
Last year for Thanksgiving, I took my kids out to see wild turkeys west of Austin. This year, we're visiting family in Lexington, Virginia. We took a drive in the long-shot chance that we could find a turkey (its open season on wild turkey here in VA, so the birds should be pretty much hunkered down). We drove up to the Goshen Wildlife Management Area and there were hunters all over so we didn't do much more than drive around. Dropped back down to the Douthat State Park, where we did get out and we all got pretty good looks at a pair of Pileated Woodpeckers working the trees near the lake. Not exactly a wild turkey day, but a nice sighting to be thankful for on this Thanksgiving.
A new system was announced by the UN Convention on Migratory Species this week, but details so far seem to indicate that it is really just tracking migratory birds, not the viruses that they carry. We still need a solid plan for global monitoring of avian influenza viruses. The announcement this week that some of the ducks in Canada do have a low pathogenic variant of the H5N1 virus is more evidence that we have a lot to learn about the distribution and potential for spread of all of these avian influenza strains.
Meanwhile, there are also reports that live birds are regularly smuggled out of China into the United States. Smuggled domestic birds are probably a greater risk for spreading the highly pathogenic form of H5N1 than wild birds, both here in the United States as well as in Asia and Europe.
On Friday, I took my normal bird walk a little later than usual...but as I got down to the corner of teh corn field, a small flock of blackbirds flew up. I followed them to their perch in a nearby tree, and noticed that there were three Rusty Blackbirds in among the Red-wings. Several folks at work had never seen Rusty's before, so for the first time since I got it last month, I found a good use for my cell phone!
Half the office were able to come down to the field and see the birds before they flew off. A couple other folks were on a conference call and couldn't make it out until later. Sometimes there just isn't enough time in a day of bird conservation planning to actually go out and see a good bird!
So for the past month I've been looking to add Brown Creeper to my yard list at work, but these little guys can be hard to find. Yesterday, I went out to get something from my car, and on the way back to the house, a small bird flew onto the trunk of a nearby tree. It moved up the trunk in characteristic creeper fashion, and I got close enough to see that, yes, it was the little brown bird I had been seeking. Birds are great, often showing up at just the right moment!
Migration of land birds has really tapered off at work...morning walk today came up with 25 species, but nothing unusual. A Fox Sparrow was nice, and there are lots of chickadees and nuthatches using the feeders. Yesterday there were dozens of Bufflehead on Lake Galena at Peace Valley, so waterbirds are moving in. All the leaves are brown, skies are gray, and birds are moving on...
According to the BBC, last month's report of a parrot in the UK with H5N1 virus was a mistake. The positive bird flu virus test came from a mixed sample of tissue from a South American blue-headed pionus and a mesia from Taiwan. Apparently the mesia had the virus, not the parrot. More mesias from the same shipment ended up dying of bird flu in quarantine.
We've really got to do a better job of being careful with testing for H5N1 and other avian influenza viruses. Standard protocol right now is to mix samples from several birds--which can help identify if the virus is present, but doesn't give a precise (or in this case accurate) picture of virus in the bird population. If we are to figure out exactly which species has a particular bird flu virus, and how common infection is in a population, we can't be using pooled samples this way.
I've seen a private report out of Kuwait that the flamingo found there with H5N1 was one of several flamingos being held at a farm, and that the birds were imported ornamental birds rather than free-flying wild individuals. I'll report more on the origin of this bird if more news comes in...in the meantime another reminder to be careful with media reports--in this case, hard to make a direct implication of wild birds in the transmission of H5N1 avian influenza to Kuwait.
Birds Korea, the main bird conservation organization in Korea, is a source of interesting commentary on the current bird flu situation in Asia. Basically, there is just a lot that we don't know about the spread of H5N1 avian influenza, and these statements by Birds Korea highlight some of what we know and don't know about the virus--and makes the point that there are many other ways that the virus may be spread than through the migration of wild birds.
A report to the ProMed email list indicates that the wild duck that tested positive for H5N1 in Italy was carrying a low pathogenic variety of the virus, apparently not closely related to the highly pathogenic strains found to be killing domestic and wild birds in Asia. The duck was a young wild Mallard, killed and eaten by a hunter in the municipality of Mirandola, province of Modena, in the Emilia-Romagna Region.
This may indicate that low pathogenic (LPAI) versions of H5N1 are circulating in wild birds without causing illness in either wild or domestic birds. Widespread global testing of birds is needed to help determine the range of viruses and their effects in wild birds.
Senator Lieberman has a proposed bill to create a Global Network for Avian Influenza Surveillance. It was included in the Harkin-Specter amendment aimed at combating the growing threat of bird flu to Americans. The Senate passed the amendment, and if it makes it through the conference committee, the bill will:
• Increase the efficiency with which we can detect, verify, and report on the presence of deadly viruses and other infectious diseases in migratory birds,
• Create a database that identifies the avian flu and other viruses of interest in migratory birds so that they can be shared in as close to real time as possible.
• Track mutations or changes in the virus in wild birds,
• Utilize virus tracking information to guide domestic and global preparedness.
This looks like just the kind of start we need to be able to monitor avian influenza and other viruses that may impact the health of people and birds.
The widespread practice of reusing chicken manure as a fertilizer for fish farms, a practice promoted by aquaculturalists, may be responsible for transmitting H5N1 virus from infected poultry to wild birds. While we don't know enough yet about how widespread this practice is, and have mostly circumstantial evidence to support the case of viral transmission this way (the Mute Swan that died of H5N1 avian influenza in Croatia was found at a fish farm), there does seem to be a viable risk here to wild birds.
Again, there is a lot we need to learn about this virus and how it is transmitted. For now, transmission from wild birds seems to be the least of our worries (there haven't been repeated huge die-offs of wild birds in Asia, and no confirmed cases of domestic birds getting the virus from wild birds). Meanwhile, several outbreaks in wild birds may be caused by exposure to infected poultry, so poultry raising and marketing practices need to be more closely studied so we can get a better idea of what is really going on.
A New York Times story from yesterday discusses plans to monitor wild birds for avian flu in the United States. We still don't have the full plan yet, but the article has a photo of researchers in California taking a sample from a Yellow-billed Magpie. Also mentions thousands of birds sampled in Alaska, including species not previously mentioned as test subjects, including owls.
This morning I went in to work late after accompanying my son on a nursery school field trip to Green Lane Nature Center in Montgomery County outside of Philadelphia. Lots of fun walking around in the woods, learning about traditional Lenape native culture. Mostly just the common forest birds in the area, but I did get to see one of the lake's breeding Bald Eagles fly overhead at one point. Its always a good day when you get to see an adult Bald Eagle.
The Recombinomics website reviews the latest info on the Canadian H5 avian influenza detections in wild birds, and speculates that H5N1 may be in the U.S. already. The crippling final line of the status report is:
"Based on the data from Canada, it seems likely that H5 is well represented in the wild bird population in the US. It is unclear why such infections have not been detected and reported."
While it is probably more likely that the H5 influenza found in Canadian birds is H5N2, which is a fairly common LPAI H5 virus in Minnesota.
The answer is probably...um, because we're not really looking that hard for avian influenza viruses. If we were taking thousands of samples from birds all across the country, who knows what we'd find. The question really is, how badly do we want to really know how widespread these viruses are in wild birds? Is it enough to just wait for sick or dead birds to start turning up in parks and golf courses?
While we wait for the U.S. national surveillance plan, we can only hope that we will be offered a long-term, widespread system to detect and track all avian influenza viruses in wild birds--not just a short-term H5N1 detection sytem that will only tell us, too late, that the a dangerous virus has already arrived.
Dr. Reuven Yosef, Director of the International Birding & Research Centre in Eilat, Israel posted a note yesterday to the Pro-Med email list, with commentary on proscribed schemes for avian influenza virus monitoring in wild birds. The article reviews the migration pattern of bird species that may bring H5N1 bird flu to the Middle East from Central Asia. Most importantly, it recommends more widespread testing of apparently healthy wild birds:
"Further sampling should not be restricted to birds found dead or freshly hunted as suggested by existing action plans [WHO, EMPRES, EU surveillance guidelines, etc.], but instead be performed on a daily basis, from a wide range of species."
This morning there were 25 species in the woods near my office--including a late Palm Warbler and Eastern Phoebe. The warbler was feeding on the ground in the short mowed grass near the corn field, bobbing its tail up and down in characteristic fashion. Little guy should be headed for the West Indies, I'd think.
This morning it was very quiet in the woods outside my office, probably because a beautiful adult female Sharp-shinned Hawk was on patrol, cruising up and down the tree line and over the fields. On most mornings lately, I've been seeing over 20 species of birds. This morning, only a dozen or so were out, and the woods were almost completely silent--only a couple of Golden-crowned Kinglets were calling and one Winter Wren was singing deep in a tangled thicket.
Yesterday, news reports indicated that officials in British Columbia had found H5 viruses in 24% of 704 samples from wild ducks. Further testing will be conducted to find out if these viruses are the HPAI H5N1 virus, or some other H5 virus. Since these samples were taken from healthy birds, it underscores the importance of monitoring healthy birds for flu viruses, and we have to remember that without testing, we have no idea of the true situtation in respect to the circulation of avian influenza viruses.
The San Diego Union-Tribune has a good news story on this, with more details about the testing of young ducks in Merritt, BC.
The plan states that the government will "expand our domestic livestock and wildlife surveillance activities to ensure early warning of the spread of an outbreak to our shores" (p.7).
To do this, President Bush announced in his speech that "to strengthen domestic surveillance, my administration is launching the National Bio-surveillance Initiative. This initiative will help us rapidly detect, quantify and respond to outbreaks of disease in humans and animals, and deliver information quickly to state, and local, and national and international health officials. By creating systems that provide continuous situational awareness, we're more likely to be able to stop, slow, or limit the spread of the pandemic and save American lives."
Hopefully, this will be a long-term plan to monitor birds for more than just the current H5N1 strain of avian influenza, and will become a system for tracking the spread and evolution of all avian influenza viruses. But it probably won't.
The Financial Express today has a story on African efforts to monitor for H5N1 bird flu virus--including efforts in South Africa and Egypt.
In South Africa, the paper reports that "agriculture officials have been conducting random sampling of wild birds along the country's coastline and monitoring the health of domestic poultry."
In Egypt, "George Majid, Egypt's environment minister, said the government had been taking measures in co-operation with the American Navy Research Centre (Namro), based in Cairo, to take samples from migrating birds and conduct laboratory checks to ensure Egypt was free of the H5N1 virus."
News services are claiming that H5N1 may already be in Africa (something I pointed out here earlier). The most recent statement to this effect is in this Financial Express article and comes from Bernard Vallat, director general of the World Organisation for Animal Health.
This morning, while taking a bird walk break at work, there were over a dozen White-throated Sparrows in the woods. Where I grew up in Oregon, White-throated Sparrows are rare winter visitors; most people would be lucky to see one at all, and active birders may see only a few each winter.
While watching the birds this morning, and listening to them sing their whistled song, I got thinking about the first one I ever saw. It was the day that my grandfather died. He had been in the hospital for a few weeks after suffering a heart attack, when he died on my grandmother's birthday. It was the middle of October, and the family gathered at my grandmother's house to celebrate her birthday and mourn the passing of my grandfather.
At some point, the whole scene was a bit too much for a teenager, so I went for a walk down to the creek with my grandparent's dog Poco. Some sparrows in the brush caught my eye, and I quickly saw that it was a White-throated Sparrow. Up until that time, it was one of the rarest birds I'd found on my own--a bitter-sweet moment on a day of tender emotions.
I don't think of that day every time I see a White-throated Sparrow, but it is always there, just beneath the surface. Every bird that we come to know has a wealth of associations attached to it...just waiting for us to enjoy if we take the time to remember. Just another way that birds enrich our lives, by connecting us to the important people, places, and events of our personal histories.
A recent report out of Canada found 33 cases of H5 avian influenza in a national survey of wild ducks. Further tests will be conducted to identify the exact strain. Since the birds were healthy, researchers reported that they do not think the birds are carrying the highly pathogenic strain of H5N1. However, it is a misconception that ducks carrying H5N1 will appear sick.
While we will have to wait for further testing to see if the birds are carrying H5N1 for sure, H5 viruses of any type were previously thought to be rare in Canada. According to the Recombinomics website, "In Canada, there have been about 120 deposits at GenBank and only two are H5. One (H5N2) was detected in 1980 and the other (H5N9) was detected in 1966. Thus, there have been no H5 isolates reported in the past 25 years, although that is when most of the deposits from Canada were collected."
This nation-wide survey found 28 infected ducks in Quebec and 5 in Manitoba, and "will serve as a benchmark in future years". More information about the Canadian monitoring scheme can be found online here. . According to the operational proposal, so far the testing is just of Mallards and other wild ducks. Hopefully, future testing will include a wider range of wild bird species.