The recent but now diminishing avian flu epidemic has resulted in Center for Disease Control (CDC) advisories that provide information about the infection and its effects. The CDC advisories’ findings and recommendations carefully draw explanations for the avian flu devastation to birds and offer advice to poultry producers and any humans possibly exposed to the virus.
This article relied considerably on the CDC Advisory, “Bird Infections with Highly-Pathogenic Avian Influenza A (H5N2), (H5H8), and (H5N1) Viruses: Recommendation for Human Health Investigations and Response,” and distributed on June 2, 2015.
“Between December 15, 2014 and May 29, 2015 the USDA confirmed more than 200 findings of birds infected with highly-pathogenic avian influenza (HHHPAI) A (H5N2), (H5N8) and (H5N1) viruses,” said the aforementioned advisory. The CDC considered the risk to human health in general to be low.
To be safe, the CDC said the risk to poultry producers, like turkey, chicken, and egg farmers and anyone in close proximity to infected birds or visiting a live poultry market could potentially be substantial even though no human infections with the current HPAI H5 viruses have been identified in the U.S. thus far.
The virus can mutate fairly easily in a process called reassortment, when the genetic material of two or more viruses combine. The current HPAI H5 viruses are not well adapted to humans but earlier strains of related viruses were lethal to humans in other countries.
Related strains of the viruses were first reported on duck farms in China in 2009-2010 and found mostly in 2014 in poultry and wild birds in the Korean Peninsula, Japan, England, the Netherlands, Germany and Italy. The first cases of the current HPAI H5 viruses in North America were reported in December 2014 on poultry farms in British Columbia.
Many fairs cancelled their poultry shows this summer to help prevent the spread of the avian flu.
For more information on the origin of HPAI H5 viruses in the U.S., the clinical symptoms in birds and suspected clinical presentation in humans, the CDC recommends: http://www.cdc.gov/flu/avianflu/hpai/hpai-background-clinical-illness.htm.
Symptoms of HPAI H5 viruses in birds include: sudden death; lack of energy, appetite and coordination; purple discoloration or swelling of various body parts; diarrhea; nasal discharge; coughing; sneezing; and reduced egg production or soft-shelled or misshapen eggs. The virus can spread quickly among birds and with deadly results.
In humans, HPAI H5 virus infections can start with the usual signs and symptoms of uncomplicated seasonal influenza, including fever, upper respiratory tract symptoms, myalgia and progress to lower respiratory tract illness. Atypical indicators have been reported; persons who have been exposed to HPAI H5 and who develop illness should report their exposures and symptoms to their physicians, who in turn should consult with public health departments.
The CDC advises that properly cooked eggs or poultry meat will not harm humans. The CDC recommends using personal protective equipment when working with infected or dead birds.
Forty-five million domestic chickens, turkeys or ducks in 15 states died of the flu or were killed to prevent the spread of the infectious viruses, according to Associated Press articles, the latest of which was reviewed here on June 11. Iowa lost 29 million birds, mostly egg-producing chickens, resulting in higher egg prices for consumers, said the Des Moines Register in a June 1, 2015 article.
As of June 12 this year, Minnesota lost nine million birds, mostly turkeys through euthanasia to stop the spread of the viruses (http://www.mprnews.org/topic/bird-flu). The number of new cases is dwindling as summer sun and warm temperatures become prominent.
The process of decontamination takes several weeks to months, depending on how quickly the dead birds are incinerated or buried and production facilities are disinfected. Production facilities are quarantined until approved by the USDA for repopulating.
At least one Minnesota turkey production unit repopulated its barns, and more turkey, egg and broiler producers are expected to follow suit in the affected states.
USDA livestock indemnity funds, which were approved as part of the 2014 Farm Bill, may be available to poultry producers. The indemnity program is supposed to pay for the loss of the poultry and for decontamination procedures.
Thus far, greater numbers of individual producer losses have been in confinement facilities and fewer losses among small producers, most of whom allow their birds to range freely or in pens outside their sheds.
The HPAI H5 viruses appear to spread from infected wild birds and neighboring production units through airborne dust and body excretions. Contaminated air that is sucked into poultry barns by ventilation system fans can spread the viruses rapidly.
It’s possible the viruses or variants will spread again as wild birds migrate this fall, next spring and thereafter and maybe through other vectors; there are no sure predictions at this point. It’s also possible that future avian flu strains could be more dangerous to humans than this outbreak.
The author is a psychologist and lives on a farm at Harlan, Iowa; contact him at: www.agbehavioralhealth.com.