Posts Tagged ‘AI’

APHIS Issues Epidemiology Report for Avian Influenza Affected Poultry in Tennessee, Alabama, Kentucky, and Georgia

Friday, June 23rd, 2017

USDA APHIS logoThe United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) is releasing the epidemiology report for affected HPAI and LPAI poultry cases this spring. This kind of analysis helps to identify how the disease spread and how to help prevent it in the future. APHIS has made great strides in HPAI emergency response since the 2014-2015 outbreak. Rapid response times and a 24-hour depopulation goal of confirmed HPAI cases has helped minimize the spread of disease. Vigilant biosecurity practices remains a top priority to protect domestic poultry from the disease.

On March 4, 2017, APHIS’ National Veterinary Services Laboratories (NVSL) confirmed a case of highly pathogenic avian influenza (HPAI) H7N9 on a commercial broiler breeder farm in Tennessee. A second case of HPAI H7N9 in Tennessee was confirmed on March 15, 2017 on another commercial broiler breeder farm. This virus is NOT the same as the China H7N9 virus that emerged in 2013 and impacted poultry and humans in Asia. Additionally, APHIS found H7 low pathogenic avian influenza (LPAI) in six backyard flocks — three in Alabama, two in Tennessee, and one in Kentucky. APHIS also found H7 LPAI in six commercial broiler breeder flocks — one in Tennessee, three in Alabama, one in Kentucky and one in Georgia. Following these avian influenza findings, APHIS joined forces with the affected states and the poultry industry to complete a series of epidemiologic, genetic and wildlife investigations.

In the report, APHIS outlines the findings to date, which include:

  • The identification of a closely related 2016 H7N9 LPAI virus in a Blue Wing Teal in Wyoming that was likely a precursor to the 2017 H7N9. The Blue Wing Teal was part of a live-bird banding effort from Wildlife Services wild bird surveillance program.  
  • Results of genetic analyses determined that all H7N9 viruses detected from this event are of North American wild bird lineage.
  • The comparison of the HPAI and LPAI H7N9 viruses showed they are highly similar and therefore likely that the LPAI virus was first introduced into commercial poultry and later mutated to HPAI
  • Initial results from wild bird samples on infected premises have not confirmed Influenza A virus (IAV), however there is limited evidence from the samples that some birds may have been previously exposed to it.
  • Genetic and epidemiologic evidence suggests the possibility of more than a single introduction of virus from wild birds to commercial poultry with limited lateral spread from farm to farm.
  • Risk factors included rodents and wild mammals near barns, housing conditions, and biosecurity protocol breaches that could bring the virus from the environment into the barns.

APHIS will continue to collect and analyze data to help refine our prevention, detection, and response efforts based on the best available science and lessons learned. View the entire June 22, 2017 Report (PDF).

March 31, 2017 Update on Avian Influenza

Friday, March 31st, 2017

“H7 avian influenza has been identified in Georgia; you can find the link to the News Release here. Please refer to the USDA-VS newsroom link, Tennessee (TN), Alabama (AL) and Kentucky (KY) Department of Agriculture websites for updates on the AI status in their respective states.

While the case has been identified in a state that resides partially in the eastern flyway, the case was identified in the extreme western part of the state and is not yet a concern for impacting our flyway. Keep in mind this is a rapidly evolving situation and this can change at a moment’s notice.

Again, this is a great reminder to be vigilant about biosecurity and remind your producers to report unexplained sick birds.” — Maine State Veterinarian Justin Bergeron

chicken

What not to do! Unlike the bird in this picture, keep your birds separate from wild birds. Photo by Anne Lichtenwalner.

Please be aware that wildlife agencies also survey for Avian Influenza in wild birds, and that low pathogenicity AI does occur sometimes in wild birds in our region. It is difficult to do, but it is essential to keep your birds separate from wild birds: separate from water, feed, dust or feces that wild birds have contaminated. If you lose birds suddenly and would like our to test for AI, please let the state vet know and also contact the University of Maine Animal Health Lab at 207.581.2788.

March 20, 2017 Update on Avian Influenza

Monday, March 20th, 2017

flock of chickens

Photo by Donna Coffin

Avian influenza continues to be present in the US at low prevalence, and updates on the US and the international situation can be found at these sites:

The most recent isolation was from a bird swap in Alabama; this was apparently a low-pathogenicity strain (LPAI) from a guinea fowl. The USDA has issued a “stop movement” order to try to contain the situation in that area of Alabama. There is still concern about containment of a recent highly-pathogenic strain (HPAI) that was detected in Tennessee, and although an additional case of AI on a different Tennessee farm was determined to be LPAI, similarly stringent control measures were taken by state animal health officials.

Due to the large impact of either HPAI or LPAI on regional farms, it’s critically important to be very careful to prevent AI from spreading from wild waterfowl (that may carry AI, but not become sick from it) to your birds. Follow good biosecurity practices, and help protect both your own and others’ flocks by reporting unusual illness in your birds to your state’s livestock authorities.

Migratory Bird Patterns: Animation from Cornell Lab of Ornithology

Monday, March 6th, 2017

Canada geese

Photo by C. Eves-Thomas

Curious about why bird diseases may show up in a seasonal pattern? See Citizen Science Reveals Annual Bird Migrations Across Continents, courtesy eBird and the Cornell Lab of Ornithology, which helps illustrate how avian influenza may show up in the US in spring and fall. Wild birds are great travelers, and Avian Influenza virus may spread among them during their breeding seasons (when they aggregate). Because many of these wild birds may carry the virus, but not be ill with it, there is a risk that wild birds can make our domestic birds ill. Please help keep wild birds, and domestic birds, healthy by KEEPING THEM APART. This includes water and feed sources. We refer to this practice as biosecurity, and it’s a simple and powerful tool to prevent disease.

Initial Case of Highly Pathogenic Avian Influenza in the US: 2017

Monday, March 6th, 2017

March 5, 2017, Washington — The United States Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed the presence of highly pathogenic H7 avian influenza (HPAI) of North American wild bird lineage in a commercial chicken breeder flock in Lincoln County, Tennessee. This is the first confirmed case of HPAI in commercial poultry in the United States this year. The flock of 73,500 is located within the Mississippi flyway. Samples from the affected flock, which experienced increased mortality, were tested at Tennessee’s Kord Animal Health Diagnostic Laboratory and confirmed at the APHIS National Veterinary Services Laboratories (NVSL) in Ames, Iowa. Virus isolation is ongoing, and NVSL expects to characterize the neuraminidase protein, or “N-type”, of the virus within 48 hours.

APHIS is working closely with the Tennessee Department of Agriculture on a joint incident response. State officials quarantined the affected premises and birds on the property will be depopulated to prevent the spread of the disease. Birds from the flock will not enter the food system.

The Tennessee Department of Agriculture is working directly with poultry workers at the affected facility to ensure that they are taking the proper precautions to prevent illness and contain disease spread. As a reminder, the proper handling and cooking of poultry and eggs to an internal temperature of 165 ˚F kills bacteria and viruses.

As part of existing avian influenza response plans, Federal and State partners are working jointly on additional surveillance and testing in the nearby area. The United States has the strongest AI surveillance program in the world, and USDA is working with its partners to actively look for the disease in commercial poultry operations, live bird markets and in migratory wild bird populations.

USDA will be informing the World Organization for Animal Health (OIE) as well as international trading partners of this finding. USDA also continues to communicate with trading partners to encourage adherence to OIE standards and minimize trade impacts. OIE trade guidelines call on countries to base trade restrictions on sound science and, whenever possible, limit restrictions to those animals and animal products within a defined region that pose a risk of spreading disease of concern.

These virus strains can travel in wild birds without them appearing sick. People should avoid contact with sick/dead poultry or wildlife. If contact occurs, wash your hands with soap and water and change clothing before having any contact with healthy domestic poultry and birds.

All bird owners, whether commercial producers or backyard enthusiasts, should continue to practice good biosecurity, prevent contact between their birds and wild birds, and report sick birds or unusual bird deaths to State/Federal officials, either through their state veterinarian or through USDA’s toll-free number at 1.866.536.7593. Additional information on biosecurity for can be found at www.aphis.usda.gov/animalhealth/defendtheflock.

Additional background: Avian influenza (AI) is caused by an influenza type A virus which can infect poultry (such as chickens, turkeys, pheasants, quail, domestic ducks, geese and guinea fowl) and is carried by free flying waterfowl such as ducks, geese and shorebirds. AI viruses are classified by a combination of two groups of proteins: hemagglutinin or “H” proteins, of which there are 16 (H1–H16), and neuraminidase or “N” proteins, of which there are 9 (N1–N9). Many different combinations of “H” and “N” proteins are possible. Each combination is considered a different subtype, and can be further broken down into different strains. AI viruses are further classified by their pathogenicity (low or high); the ability of a particular virus strain to produce disease in domestic chickens.

https://www.aphis.usda.gov/aphis/newsroom/news/sa_by_date/sa-2017/hpai-tn

Update on Avian Influenza: November, 2016

Wednesday, November 30th, 2016

free range chickenThere are no US outbreaks of AI at the moment, but the situation in Europe and Asia is troublesome. The world Organization for Animal Health (OIE) keeps a running tally of where/when highly pathogenic avian influenza (HPAI; H5 and H7 serotypes) occurs. As of now, they list 12 European/Northern Asian countries with current (November 2016) reported outbreaks of H5N8 HPAI. The affected countries are Austria, Croatia, Denmark, Finland, France, Germany, Hungary, the Netherlands, Poland, Russia, Sweden, and Switzerland. There are also other non-European countries (India, Israel, Iran) with the same strain of HPAI. As well, other strains of HPAI are currently present in Algeria, (H7N1), Japan, and South Korea (H5N6). Activity to contain and control HPAI is ongoing, via eradication, cleaning, and confirmation of clearance. Migratory waterfowl are important as reservoirs of HPAI worldwide, but farm-to-farm spread has been thought to be due to human error, and occasionally due to airborne transmission from fields visited by waterfowl. As ever, prevention of spread by the use of biosecurity practices is paramount; see USDA’s Biosecurity for Birds to review.

2016 Maine: Heads-up! Avian Flu Still a Threat in the US

Wednesday, January 20th, 2016

By Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

chickens in barnWinter weather has finally arrived in Maine. Most of us probably have our poultry flocks indoors right now, so we might think that the threat of disease from wild birds is minimal. For now, we still don’t have any poultry cases of avian influenza in our region. However, the state of Indiana has not been so fortunate.

A strain of highly pathogenic avian influenza (HPAI), H7N8, was found on a turkey farm there last week. This strain is different from the strain that caused extensive losses in 2015, and is thought to have arisen from North American strains of the flu. According to the USDA, “This new ‘homegrown’ strain was first found in the highly pathogenic form on a large turkey farm in Dubois County, Indiana on Friday. Around 60,000 birds were immediately depopulated at the site.”

Subsequent rapid responses by the USDA APHIS, along with state agents, have screened and depopulated additional flocks in a control zone, with the goal of containment of the virus. These efforts included identifying backyard flocks in the region. About 900 sites within the control zone were investigated; only fewer than 30 had backyard chickens. These have all been tested and results are pending, but so far, none have been depopulated. However, a large layer chicken facility near the turkey flock was depopulated to help prevent spread of HPAI. There were 9 additional turkey farms in the area that tested positive for avian influenza, but the virus turned out to be a “low pathogenicity” strain (LPAI). Nevertheless, over 400,000 birds were depopulated to keep the virulent strain of HPAI from spreading. The USDA responses were swift, decisive, and so far, successful.

What does this mean for Maine farmers?

No real changes in recommendations: keep your biosecurity efforts up, even though it’s winter. Even though this strain, like the earlier strain of HPAI, seems to affect turkeys primarily, there is no guarantee that any species or type of bird is immune. We have strains of LPAI in wild birds throughout the US, and mutation of these strains into virulent HPAI is possible. Though we were not affected last year, we should be vigilant.

Keep your birds physically separate from wild birds, and from feed, water or pasture visited by wild birds. The wild species considered most likely to carry risk of HPAI are the “dabbling” ducks, but there is no guarantee that any species is free of AI. Please see earlier posts to assess relative risks of transmission of the virus.

Recent work on the risk of AI spread via feeds produced using grains that may have been harvested in AI-contaminated grain fields suggested that the risks of feed-transmitted AI are low. Pelleted feeds were considered to carry an even lower risk than was “mash” type feed. The highest risks are either contact (personnel, equipment, birds) with infected flocks, or direct contact with wild birds. Following basic poultry biosecurity works as protection against most poultry diseases. Help us keep HPAI and other poultry diseases out of your, and your neighbors’, flocks.

AI: Will Maine Encounter Avian Influenza from Southerly-Migrating Wild Birds?

Thursday, August 6th, 2015

By Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

It’s time to review biosecurity again, as the risk of getting avian influenza (AI) (and other diseases) from wild birds may increase this fall. The outbreak of highly pathogenic AI (HPAI) has calmed down, and Maine (and the East coast) escaped so far. After losses of more than 48 million birds, the US has had no new cases since the week of June 10th. Many of the affected commercial farms are completely cleaned up and restocking with new birds.

Canada geese in flightHowever, even now when the weather is warm, some wild bird species are readying for their southern migrations. As there was HPAI present in the wild migratory bird populations in other parts of the US and Canada this spring, there is certainly a good chance that southerly migrating birds could carry the virus into Maine this fall. Simple measures can decrease the chance of your birds getting infected.

  1. Don’t attract wild birds to your poultry areas. Make sure your feed is stored securely (clean metal garbage cans with tight-fitting tops work great for storage). Put feeders inside the hen house, and keep wild birds out by using bird netting. If you keep a wild bird feeder, put it as far away as possible from your poultry.
  2. Don’t bring disease to your poultry. Dirty boots, tools or even vehicle tires can carry infected manure from other farms, or wild birds, onto your property.
  3. Keep a “closed” flock. Restrict visitors’ contact with your farm, and be very careful if you visit other farms to avoid bringing infections with you. If you buy new birds, quarantine (3 weeks) and test them for parasites or disease before adding them to your flock. Better yet, buy all birds at one time, and clear out the old flock, clean/disinfect/fallow your poultry areas before bringing in new birds
  4. Simple sanitation: handwashing for people, and frequent cleaning of feeders/waterers/nests/bedding for poultry will greatly decrease the chance of disease. Use a simple mask if you are working in dusty areas, or with sick birds, to decrease your chance of getting sick or allergic.

It’s still not clear why so few “backyard” flocks (21 versus 211 commercial flocks) were affected with HPAI this year. We don’t know if this is a “real” effect, due to the low numbers of birds and diverse genetic backgrounds, or an “artifact” of reporting. Viruses can be picky: for instance, this particular virus was reported to be more pathogenic to turkeys than to chickens. Influenza viruses change relatively easily over time, and we won’t know till later what the “fall” version of the H5N8 HPAI virus, that was so problematic this spring, will be. Until then, poultry producers of any size category, from small urban flocks to large commercial flocks, should be focused on reducing the risk of disease with excellent biosecurity.

Read through the National Poultry Improvement Plan (NPIP) guide for more biosecurity ideas (http://healthybirds.aphis.usda.gov/). As well, if you would like to discuss your farm and specific ways you could increase biosecurity, please send an email to anne.lichtenwalner@maine.edu with “Poultry Biosecurity” in the subject line.

June 15, 2015, Avian Influenza Update

Tuesday, June 16th, 2015

chicksBy Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

In the news this weekend was the story that highly pathogenic avian influenza (HPAI) is now in Arizona … or is it? Apparently a source in Iowa sold gamebird products that were contaminated with HPAI, and these were “traced” to destinations that include Arizona, a state that is not on the USDA list for having HPAI. However, as of right now, there are no poultry operations apparently affected by HPAI in Arizona.

What does this mean, though? Someone purchased this disease, bringing it into the state. Normal movements of chicks across state lines should not be sources of disease; this is why NPIP has a program to keep hatcheries “on their toes” about important poultry diseases, including several forms of salmonella and mycoplasma, besides AI. This doesn’t mean that imported chicks are guaranteed to be disease-free, but just makes it much less likely you’ll be importing a problem with your new birds. Of course, if you don’t inquire about NPIP status when you purchase your new birds, you might be in for an unpleasant surprise if the birds arrive with a problem. States also require a certificate of health for shipments of chicks. This form indicates that the birds were healthy when shipped.

For now, Maine has NOT restricted movements of domestic birds (shows, sales, or import/export). As ever, it’s very important that the “buyer beware” when purchasing birds. Perhaps if our poultry-owning public is very actively spreading the word about biosecurity, and practicing what they preach, we won’t have an AI problem in our region. Perhaps this checklist for those purchasing birds would be helpful:

  • When choosing a hatchery, choose only those with NPIP salmonella/SE/AI/Mycoplasma free status.
  • Inquire to be sure the birds will be sent with a health certificate.
  • All new birds should be quarantined (kept separate from other birds) and carefully observed for at least 2 weeks after entry.
  • Consider testing meconium papers for salmonella when importing layers or broilers (this testing can be done at the University of Maine Animal Health Lab).
  • Consider necropsy if the mortalities exceed 5% of the flock within the first week (this testing can be done at the University of Maine Animal Health Lab).

HPAI Epidemiology Report: USDA APHIS

A new report from APHIS has summarized the ongoing HPAI outbreak’s origins. In general, there are no surprises; wild birds brought HPAI into the country, then poor biosecurity, along with the ability of the virus to either bind to dust, or to become directly windborne, contributed to rapid spread of HPAI within and between commercial operations. After high winds, they found more spread of HPAI up to 5 days later. It’s not just one factor, though; as they state, “genetic analyses of the HPAI viruses suggest that independent introductions as well as transmission between farms were occurring in several States concurrently.”

The examples of poor biosecurity are instructive: “For example, APHIS has observed the following:

  • sharing of equipment between an infected and noninfected farm;
  • employees moving between infected and noninfected farms;
  • lack of cleaning and disinfection of vehicles moving between farms;
  • reports of rodents or small wild birds inside the poultry houses.”

For those used to dealing with salmonella control, these are expected means of spread. These observations suggest that, despite there being a lot of guidance about using biosecurity, people at commercial farms are having trouble “getting it.” Good biosecurity is pretty basic (and pretty demanding, too). If backyard farmers take these kinds of things seriously, it may help all of us avoid this (and other) poultry diseases.

The Official Numbers from APHIS Veterinary Services as of June 15

As of June 15, there were 21 states that have had HPAI cases in any kinds of birds (wild or domestic) (AR, CA, IA, ID, IN, KS, KY, MI, MN, MO, MT, NE, ND, NM, NV, OR, SD, UT, WA, WI, WY). Of the 230 total farms with HPAI, 209 are commercial flocks and 21 are backyard flocks. By far the greatest number of commercial flocks were in Minnesota (108), with Iowa a close second (70), then South Dakota (10), Wisconsin (9), Nebraska (5), California (2), Missouri (2), North Dakota (2), and a single farm in Arkansas.

The impact on commercial poultry industry includes the loss of approximately 7.5 million turkeys and about 41 million layers and pullets. This represents about 3% of U.S. turkey inventory, almost 10% of U.S. layer inventory, and about 6% of U.S. pullet inventory. The broiler industry is relatively unaffected.

June 1, 2015: Update on Avian Influenza in the United States

Wednesday, June 10th, 2015

By Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

Since late last year, a real problem for poultry producers has arisen in the United States: highly pathogenic avian influenza (HPAI). In late 2014, following a cluster of cases in southwestern Canada, HPAI (contagious bird flu) was isolated from birds in backyard poultry flocks in Oregon and Washington. Since then, the disease rapidly spread from the northwest to other western, southwestern and Midwestern states. No HPAI has been found in the Eastern US so far, however.

wild ducks and geeseIn general, migratory wild birds — ducks and geese in particular — are the source of these viruses. If your flock is free-ranging, or if the feed or part of the flock’s enclosure is exposed to wild birds, your flock may be at risk. As well, being near larger poultry farms with HPAI, or near bodies of water where large flocks of wild birds congregate, appears to enhance the spread of HPAI to other flocks.

Wild birds migrate along “flyways”: these are generalized, vague “routes” that groups of birds tend to follow from south to north in spring, and back again in the fall. So far, HPAI seems to be showing up along the Western, Central and Mississippi flyways — but not yet on the Eastern flyway. It is unclear as to exactly why this is, but since HPAI can be carried by wild birds without killing them, it’s not unlikely that Maine could be at risk again in the fall. Some predictions have been made that suggest we will see increased risks of HPAI in the US for several years to come.

Most discussions of the current outbreak seem to indicate three things: that basic biosecurity helps to reduce spread of HPAI; that once a very large amount of virus is nearby (for instance, due to large, concentrated infected groups of birds shedding the virus) airborne spread may carry the virus as much as a couple of kilometers; and while heat will help to kill AI, warm weather is not going to wipe it out.

The good news is that there is no known human disease associated with the strains of HPAI currently in the US. However, other strains of bird flu in countries such as Egypt are causing problems, although there are only a low number of cases, and the disease is not spreading within the human population. In the US, where poultry workers are exposed to a high concentration of the virus, public health officials are advising that workers be careful to report any flu-like illness to their physician, just to be safe.

What does HPAI look like in birds? In general, it causes sudden death, and the symptoms can be a mixture of things: respiratory illness, which may or may not be accompanied by diarrhea. In the current outbreak, often birds die very suddenly without any particular illness. We strongly recommend that, if you have unexplained losses of birds or a severe decrease in productivity, you have your flock tested for HPAI. Contacting the Maine state veterinarian, Dr. Michele Walsh at 207.287.7615, is a good first step. The state may be able to pay for diagnostic work, including necropsy or blood testing for your birds.

As of the beginning of June, the USDA’s Animal and Plant Health Service (APHIS) estimates that over 200 poultry premises are affected with HPAI; with over 7 million turkeys and 40 million layers/pullets dead because of the disease or due to eradication efforts. The broiler industry is not yet considered to be affected by HPAI, but for the US turkey and layer industry the losses are getting close to 10% of the US industry. APHIS has spent over $150 million for active indemnity so far, and congress has authorized over $300 million to help defray HPAI losses to industry. Proportionately fewer backyard flocks are affected, and it is unknown if these are more resistant to the virus, or if fewer are reporting the problem. While it’s possible that the current strain affects commercial birds more severely, it’s prudent for all producers to reduce the risk by using excellent biosecurity.

Currently, the turkey and layer industries in Minnesota and in Iowa are epicenters of HPAI in the US. During mid-April to May, the number of active cases peaked at 36; in early June there are only 16 actively infected premises. APHIS has been able to depopulate turkey flocks within 36-48 hours of detection, speeding up their ability to disinfect farms and thus decreasing the likelihood of spread.

APHIS is depending heavily on composting to dispose of carcasses; it’s difficult to get landfills to accept large shipments of dead birds, and onsite burial is opposed by most farmers. APHIS just set up a large incinerator in Iowa to deal with carcasses; dead birds are contained in bags and “roll offs” until incinerated, which reduces viral load even prior to incineration.

While there are many EPA registered antiviral agents that may be effective against HPAI, APHIS seems to be relying most on Virkon, or on a hydrogen peroxide-based product. Disinfecting very quickly is probably an important factor in limiting spread. For very large farms, biosecurity must be very tight during the clean-up phase: it can take several weeks to completely clean up a large layer facility. Careful attention need to be paid to worker disinfection as they leave the worksite in order to avoid further spread of HPAI.

The question of HPAI vaccination is still being debated. APHIS is still accepting comments from industry, since use of a vaccine may not be protective. In general, the best approach is still the simplest one: biosecurity. Keep wild birds away from your birds. Key concepts:

  • AI virus is very concentrated:
    • 1 gram of manure could carry enough virus to infect 1 million birds
    • Disinfect boots/hands/tires
  • AI virus is very durable
    • Survives 1 week at 68° F
    • Survives 35 days at 40° F
    • Survives indefinitely when frozen
  • AI virus is primarily transmitted via feces, water, respiratory
    • Reduce aerosols: keep sick birds out of the house
    • Protect your face
    • Barriers between cages at shows/fairs: plexiglass
    • Clean boots, tires, floor of vehicle
  • Remember: Biosecurity is a series of multiple barriers, each reducing the risk of spread.

For more information and suggestions on biosecurity, please see the following: