Reemergence of Human-Transmissible Strain in US Farm
- The United States has confirmed a case of H7N9 avian influenza in a commercial chicken breeding farm, according to the World Organisation for Animal Health (OMSA).
- The H7N9 strain, one of the primary sources of human infections, was detected in Noxubee County, Mississippi.
- The last recorded detection of this strain in the U.S.
H7N9 Avian Flu Detected in US Poultry; USDA Announces Billion-Dollar Investment
Table of Contents
- H7N9 Avian Flu Detected in US Poultry; USDA Announces Billion-Dollar Investment
- H7N9 Avian Flu Outbreak: Your Questions Answered
- What is H7N9 Avian Influenza?
- Where was H7N9 Detected in the US?
- When was H7N9 first detected, and when was the last detection in the US before this outbreak?
- How Serious is H7N9 avian Flu?
- How is the US Responding to the H7N9 Outbreak?
- What is the USDA Investment to Combat Avian Flu?
- What is the risk of human-to-human transmission of H7N9?
- What are the concerns surrounding H5N1 and H7N9?
- How do H7N9 and H5N1 compare?
Latest outbreak raises concerns amid ongoing H5N1 challenges.
H7N9 Avian Influenza Confirmed in Mississippi Chicken Farm
The United States has confirmed a case of H7N9 avian influenza in a commercial chicken breeding farm, according to the World Organisation for Animal Health (OMSA). This development occurs as the U.S. continues to grapple with an ongoing outbreak of H5N1.
The H7N9 strain, one of the primary sources of human infections, was detected in Noxubee County, Mississippi. the OMSA report stated, “La présence de l’influenza aviaire hautement pathogène (IAHP) H7N9 de la lignée nord-américaine liée aux oiseaux sauvages a été détectée dans un lot commercial de reproducteurs de poulets de chair dans le Mississippi.”
Confirmation of the analyses occurred last week. The last recorded detection of this strain in the U.S. was in August 2017. Additionally, the H5N9 strain was identified for the first time in the country in late January.
Response to the H7N9 Outbreak
Over 47,600 chickens where culled at the affected farm. the OMSA added, “le service d’inspection sanitaire des animaux et des plantes (APHIS) du ministère américain de l’Agriculture, en collaboration avec les responsables de la santé animale et de la faune sauvage des États, mène une enquête épidémiologique approfondie et une surveillance renforcée en réponse à cette détection.” This translates to the Animal and Plant Health Inspection Service (APHIS) of the U.S. Department of Agriculture,in collaboration with state animal health and wildlife officials,conducting a thorough epidemiological examination and enhanced surveillance in response to this detection.
Ancient Context of Avian Influenza Strains
The H5N1 and H7N9 strains, detected in 1997 and 2013 respectively, have been the primary causes of human cases of avian influenza, according to the Centers for Disease Control and Prevention (CDC).
The CDC notes that avian influenza A(H7N9) viruses were first detected in China in 2013. While human infections with A(H7N9) viruses are uncommon, they have resulted in serious illness.
The H7N9 strain can cause severe respiratory problems. Between 2013 and 2021, the H7N9 virus infected 1,668 people and caused 616 deaths, according to the Food and Agriculture Organization (FAO).
USDA Invests $1 Billion to Combat Avian Flu
Amidst these concerns, the U.S. Secretary of Agriculture Brooke Rollins announced a notable investment to combat the spread of avian influenza. On Febuary 26, 2025, the USDA committed up to $1 billion towards a extensive strategy to curb highly pathogenic avian influenza (HPAI), protect the U.S. poultry industry, and lower egg prices.
This financial commitment is in addition to existing funding allocated to indemnify growers for depopulated flocks.
Ongoing Concerns and Challenges
The United States is already facing a high circulation of the H5N1 strain of the virus in animals, including cattle, with some cases of transmission to humans, increasing fears of a future pandemic.
The country recorded its first human death linked to the H5N1 virus in early January. The few dozen human cases recorded in the United States, including the deceased, were caused by direct exposure to an animal, and no human-to-human transmission has been recorded.
H7N9 Avian Flu Outbreak: Your Questions Answered
The recent detection of H7N9 avian influenza in a U.S.poultry farm has raised concerns, especially amidst the ongoing H5N1 challenges. This Q&A article provides extensive information about the H7N9 strain, it’s potential impact, and the measures being taken to control its spread.
What is H7N9 Avian Influenza?
H7N9 is a subtype of the Influenza A virus that primarily affects birds. It can, however, infect humans and cause severe respiratory illness. The “N” in H7N9 stands for Neuraminidase,which is a protein found in the virus.
First detected in China in 2013
Circulates in wild birds and poultry.
Can cause severe respiratory problems in humans.
Where was H7N9 Detected in the US?
The recent case of H7N9 was confirmed in a commercial chicken breeding farm in Noxubee County, mississippi.
When was H7N9 first detected, and when was the last detection in the US before this outbreak?
H7N9 was first detected in China in 2013. The last recorded detection of this strain in the U.S. before the recent outbreak was in August 2017.
How Serious is H7N9 avian Flu?
H7N9 can cause serious illness in humans. According to the Food and Agriculture Institution (FAO),between 2013 and 2021,the H7N9 virus infected 1,668 people and caused 616 deaths which equates to a fatality rate of approximately 37%. The health.harvard.edu states, “H7N9 has caused outbreaks in china since 2013, leading to over 1,500 cases and a 40% fatality rate.”
How is the US Responding to the H7N9 Outbreak?
Following the confirmation of the H7N9 case in Mississippi, the following actions were taken:
Culling: Over 47,600 chickens were culled at the affected farm to prevent further spread.
Epidemiological Examination: The Animal and Plant Health Inspection Service (APHIS) of the U.S.Department of Agriculture, in collaboration with state animal health and wildlife officials, is conducting a thorough investigation.
Enhanced Surveillance: Increased monitoring is in place to detect any additional cases.
What is the USDA Investment to Combat Avian Flu?
The U.S. Secretary of Agriculture announced the USDA committed up to $1 billion towards an extensive strategy to curb highly pathogenic avian influenza (HPAI), protect the U.S. poultry industry, and lower egg prices. This is in addition to existing funding to compensate growers for depopulated flocks.
What is the risk of human-to-human transmission of H7N9?
While human infections with A(H7N9) viruses are uncommon, they have resulted in serious illness. As of March 2025, there has been no recorded human-to-human transmission of either H5N1 or H7N9 in the United States. The few dozen human cases recorded in the United States, including the deceased, were caused by direct exposure to an animal.
What are the concerns surrounding H5N1 and H7N9?
The US is already facing a high circulation of the H5N1 strain of the virus in animals, including cattle, with some cases of transmission to humans, increasing fears of a future pandemic.
The CDC and other health organizations are concerned about the potential for these viruses to mutate and become more easily transmissible between humans.
How do H7N9 and H5N1 compare?
| Feature | H7N9 | H5N1 |
| ———————– | ——————————————— | ——————————————— |
| First Detected | 2013 (China) | 1997 |
| Primary Host | Birds (wild birds and poultry) | Birds |
| Human Infections | Less common, but can cause serious illness. | Higher incidence of human infection. |
| Fatality Rate (Human) | Approximately 40% (based on past outbreaks) | 52% (across 23 countries) |
| US Detection (most recent)| March 2025 (Mississippi) | Ongoing circulation in animals and some human transmission |