Chicken (via Flickr/Tomasz Nowicki)
On Mar. 17, 2016, an 81-year-old woman in Hong Kong was admitted to the hospital for pneumonia and later transferred after testing positive for the H7N9 strain of avian influenza. She is currently stable. She visited a wet market while visiting Kaiping, Guangdong Province, and was exposed to recently slaughtered poultry.
Three other people, a 45-year-old man from Xuancheng and a 43-year-old mother and her 23-year-old son from Ji’an City, contracted H7N9 recently. The man is in critical condition, while the mother and son are stable.
Another case was reported in the Hubei Province with the H5N6 strain. A 35-year-old man checked into the hospital on April 12 and is in critical condition.
Other than the 81-year-old woman, it is unknown how these people were exposed. However, wet markets, where live or recently slaughtered poultry are sold, are prime suspects, particularly in cities where inhabitants are rarely in contact with farm animals.
The difficulty of controlling exposure in wet markets is well known. In February 2015, positive tests for H7N9 caused Guangzhou to ban live poultry from wet markets for five days. The ban was ineffective, as sellers illegally sold birds outside the market or in private homes and apartments.
Buyers cooperate, as they want freshly slaughtered animals and often disbelieve the warnings that have been issued by the government. The Chinese government needs to increase awareness of the dangers of avian influenza for the poorest segments of the population, who may have limited internet access and poor reading skills.
Mother and son cases
Poultry on family farms could be exposed because of only having bars between them and the wild birds (via Flickr/Joshua Berry).
In 2015, the first case of avian influenza was reported in April. This year, agricultural specialists are on high alert and want to prevent the disaster of last year. In one of the worst animal epidemics in recent years, 7.5 million turkeys and 42.1 million chickens died and taxpayers lost $950 million.
This Spring, wild waterfowl are expected to pass through the U.S. on their annual migration route back from the Southern Hemisphere. Government officials, industry leaders and farmers are working to tighten biosecurity measures before their arrival.
Some measures taken in Iowa, the epicenter of last year’s epidemic, include installing showers near the barns, requiring clothing changes and closing the barns to visitors. The farmers will also watch for symptoms of avian influenza, such as lethargy, decreased water intake and more birds dying suddenly. Despite this, contamination could still occur because completely preventing exposure from the outside is impossible.
Dust containing feces from wild birds is widespread, and in areas where biosecurity measures are not enforced or when workers choose not to follow procedures, outbreaks are likely to occur. However, preventing an outbreak from spreading to other farms should be easier this year because state agricultural departments are more prepared. They have taken measures to prevent the disaster of last year from reoccurring and plan to do everything in their power to take control of avian influenza epidemics this year.
Avian Influenza Season
Fresh and Live Chickens Sold at a Market in Laos (Photo via Flickr/Shankar s).
In Suzhou City, China, a 60-year-old man contracted the first known case of the H7N9 avian influenza strain of the year. He was diagnosed with pneumonia by several hospitals, but eventually testing by Hong Kong’s Public Health Laboratory Services revealed that he had H7N9. He was moved to Princess Margaret Hospital on Feb. 23, and his wife, son and others close to him are being monitored.
The man reported that he had no contact with live poultry, but it is known that he visited a wet market. These common, traditionally outdoor markets serve the poor in China, and they usually sell fresh meat, produce and live animals. However, some newer indoor wet markets may lack live animals.
It is unconfirmed whether the man visited a market with live poultry or not. Although he said that he had no contact with poultry, he may consider contact to be physical interaction with live birds and not realize there are alternate methods of contagion.
The most common way that avian influenza can pass to people is through accidental contact with bird feces. In addition, it is believed that inhaling aerosolized material in wet markets is one of the main ways that humans can get infected. Thus, this man could have been infected by the former or the latter.
Unfortunately, despite yet another case of avian influenza being attributed to wet markets, the practice of selling live poultry is likely to continue in China. Hong Kong’s government proposed central slaughterhouses for chickens in 2008 but was met with public backlash, as customers want to be able to inspect the birds which they buy. However, because of the number of cases of avian influenza contracted last year in China, it is possible that the government will institute new policies despite protests.
First Case of H7N9
(Wild geese in Stillwater. Picture by Rachel Higgins)
Outbreaks of various H5 avian influenza strains have occurred in France, Nigeria, Vietnam and Bangladesh. H5 strains, particularly H5N1, are dangerous, as they can spread to pigs, mutate and then pass to humans. Some strains can pass directly to humans and can be lethal for adults.
On Feb. 4, an outbreak of the H5N1 strain of avian influenza in crows was confirmed in Bangladesh and is believed to have spread from France. Although H5N1 is not the main strain in France currently, the country has been dealing with H5N2 since Jan. 28 and has lost thousands of birds.
In addition, Nigeria and Vietnam have both had recent outbreaks of H5 strains with the H5N6 strain in Vietnam concerning health officials. H5N6 is a strain that is also found in Laos, Hong Kong and China that can spread to people, although so far only China has reported human infection. Both Nigeria and Vietnam have lost thousands of poultry and are expected to lose more due to poor biosecurity.
Although the United States has not had an outbreak of H5 strains in recent years, it seems likely that it may spread to North America. Bird flu from Europe seems to be moving into Africa now, and the Asian strains are starting to appear in more countries. The most likely way for an H5 strain to come to North America is the migration route that passes through Alaska and then the Midwest.
Ducks and Canadian geese that fly along this path often carry various strains of avian influenza and are the main source of the virus in recent years. They can contaminate water sources with their feces, which indirectly infects poultry. Currently, only good biosecurity practice can prevent them from spreading the virus.
Outbreaks in Four Countries
Barns and Storehouses (photo via Flickr/Image Catalog and unsplash.com)
The Indiana outbreak on Jan. 15 caused around 450,000 birds to be euthanized and has caused the state to test birds up to 20 km away out of concern. Currently, there are no outbreaks of the high pathogenic strain (HPAI), but the low pathogenic strain (LPAI) is still common, despite Indiana culling even healthy birds as a preventative measure. In the coming months, biosecurity will be key in preventing farmers from Eastern Oklahoma and other areas from having an outbreak and should become a priority.
According to Dr. Josh Payne, OSU Extension’s poultry waste management specialist, contaminated food recently brought in from feed stores is a major source of contamination. Farmers may take care of their birds and then go into a feed store without properly decontaminating themselves or their equipment. If they have infected birds and handle the food or bring contaminated insects near it accidentally, the food can become contaminated and infect the birds of farmers who buy it.
Another major source of contamination is the farmers’ not wearing protective equipment such as masks, special boots, and gloves and not showering and changing clothes after work. Also, they are encouraged to wash their trucks if they have penetrated the inner perimeter of the farm where their birds are located.
Unfortunately, signals from the Deptartment of Agriculture have been mixed with regards to the minimum biosecurity measures that need to be taken. Due to this and the fact that instructions often seem more aimed at university-level agricultural specialists due to the language used, many farmers ignore the guidelines. Rewriting the guidelines for farmers who have a high-school education or less and prioritizing biosecurity requirements according to level of risk will help keep Oklahoma’s farms free from HPAI.
Detecting Avian Influenza
Healthy chicken (photo via Flickr/Bernard Spragg).
On Jan. 15, an outbreak of a new highly pathogenic avian influenza (HPAI) known as H7N8 appeared in Indiana. More cases were quickly confirmed on Jan. 16, and around 450,000 birds were euthanized. The new strain is believed to have mutated from one of the low pathogenic avian influenzas (LPAI) carried from Asia via Alaska by migratory birds.
When I recently attended a seminar given by an OSU poultry waste management specialist, Dr. Josh Payne, it quickly became evident why this occurred. LPAI regularly occurs throughout the world now, but due to the number of birds kept in close proximity on industrial farms, the mutation rate can accelerate. Tens or even hundreds of thousands of birds may pass this virus to each other continuously and what was originally a relatively mild disease can become dangerous in months.
Unfortunately, this is believed to have occurred in Indiana, where the LPAI was considered to be non-threatening until six months passed and birds began dying. These new losses indicate that biosecurity in many areas of the United States is still lacking. Although Dr. Payne indicated that people in Iowa had learned the value of biosecurity after the outbreak last summer, many producers and workers in other areas are still in denial.
The common attitude in Oklahoma seems to be that the virus will never come here when clearly LPAI is already here. In order to prevent damage to Oklahoma’s poultry industry, the level of biosecurity practices followed by workers should vary according to the level of the threat. A more cautious approach with regard to feed, trucks, wild birds, insects, and rats must be taken into consideration by producers, as these are prime sources of contagion.
Indiana Outbreak Facts