Rev Virus Outbreak in Dutch Layer Hens

Reticuloendotheliosis Virus (REV) Detected in Dutch Poultry: Implications for U.S. Farmers

Discovery in Laying Hens Raises Concerns about Global Spread and Biosecurity Protocols.

Published: April 10, 2025

LEGHENNEN, netherlands—In July 2024, the Reticuloendotheliosis virus (REV) was identified in laying hens at a farm in the Netherlands. The Health service for Animals (Royal GD) confirmed the finding this week, sparking concerns among poultry farmers worldwide, including those in the United States, about potential global spread and the need for stringent biosecurity measures.

The initial discovery occurred when the Royal GD received laying hens for pathological examination due to diminished performance. Upon examination,”the adult laying hens had tumors (lymphomas) in various organs.” Subsequent testing confirmed the presence of REV.

This discovery is notably concerning for U.S. poultry farmers, who are already grappling with various challenges, including avian influenza outbreaks and rising feed costs. The introduction of REV could add another layer of complexity to poultry management and potentially impact the profitability of poultry operations.

Understanding Reticuloendotheliosis Virus (REV)

REV belongs to the retrovirus family, a group known for its ability to integrate its genetic material into the host’s DNA. While REV includes several subtypes differing in virulence, they all share the same serotype. This means that while some strains may cause more severe disease than others, they are all immunologically similar.

The virus is known to cause several syndromes in poultry, including lymphoid neoplasia (cancer of the lymphoid tissue) and Runting Disease Syndrome, characterized by stunted growth and poor feathering. Lymphoid leukosis, a neoplastic disease of poultry caused by avian leukosis virus, is characterized by B-cell lymphoma, occurring in chickens approximately 16 weeks of age and older.

The transmission routes are varied, adding to the difficulty of controlling the virus.REV can spread both vertically (from parent to offspring) and horizontally (through direct or indirect contact with infected birds). Iatrogenic transmission, caused by medical examination or treatment, is also possible, such as through contaminated needles or equipment. Wild birds act as a natural reservoir, further complicating eradication efforts.

The implications for the U.S. poultry industry are significant. REV could lead to increased mortality rates, reduced egg production, and higher veterinary costs.Moreover, the presence of REV could negatively impact consumer confidence in poultry products, potentially leading to decreased demand.

Consider the example of a hypothetical poultry farm in Georgia. If REV were to be introduced, the farmer could face significant economic losses due to decreased egg production, increased mortality rates, and the cost of implementing biosecurity measures. The farmer might also need to cull infected birds, further reducing their flock size and profitability. This scenario highlights the potential impact of REV on individual poultry farmers and the broader U.S. poultry industry.

Recent Developments and Further Spread

The Royal GD also detected the REV virus in the parent flocks of various breeding operations starting in December 2024, after the initial discovery in commercial laying hens in July 2024. This indicates that the virus may have been circulating undetected for some time.The discovery in parent flocks is especially troubling as it increases the risk of vertical transmission, potentially spreading the virus to future generations of chickens.

This finding raises questions about the effectiveness of current biosecurity protocols and the need for increased surveillance and testing. “From December last year, GD also demonstrated the REV virus in the supplying couples of different couples, after they first demonstrated the virus in July last year in the event of commercially held laying hens in the Netherlands.”

Practical Applications and Prevention Strategies for U.S. Farmers

Preventing the introduction and spread of REV requires a multi-faceted approach, including strict biosecurity measures, regular testing, and proper vaccination strategies.

Here are some key steps U.S. poultry farmers can take:

• Enhance Biosecurity: Implement stringent biosecurity protocols to prevent the introduction of REV onto farms. This includes controlling access to poultry houses, disinfecting equipment and vehicles, and providing protective clothing and footwear for workers and visitors.
• Regular Testing: Conduct routine testing of flocks for REV to detect the virus early and prevent further spread. Consider implementing a surveillance program that includes regular sampling and testing of birds.
• Source Healthy Birds: Purchase chicks and breeding stock from reputable sources that are certified REV-free. Request documentation to verify the health status of birds before purchase.
• Vaccination: Explore the availability and effectiveness of REV vaccines. Consult with a veterinarian to determine the best vaccination strategy for your flock. While a vaccine for REV isn’t readily available, research is underway to explore the potential of developing one.
• Monitor Flock Health: closely monitor flocks for signs of illness or reduced performance. Promptly investigate any unusual symptoms and consult with a veterinarian.
• Implement All-In/All-Out Management: Practice all-in/all-out management to reduce the risk of disease transmission between flocks. Thoroughly clean and disinfect poultry houses between flocks.
• Control Wild Bird Access: Implement measures to prevent wild birds from accessing poultry houses and feed storage areas. Wild birds can carry and transmit REV and other poultry diseases.

The USDA’s Animal and Plant Health inspection service (APHIS) provides resources and guidelines for poultry health management. U.S.poultry farmers should consult with APHIS and their state veterinary officials to obtain the latest data and recommendations for preventing and controlling REV.

For example, farms might consider implementing perimeter fencing to deter wild birds, using bird netting to cover ventilation openings, and implementing strict sanitation protocols to minimize the risk of contamination. These measures, while potentially costly, can definitely help prevent the introduction and spread of REV and other poultry diseases.

Addressing Potential Counterarguments

Some may argue that REV is not a significant threat to the U.S. poultry industry because it has not been widely reported in the country.However, the recent discovery in the Netherlands highlights the potential for global spread and the need for proactive measures.

Others may argue that the cost of implementing strict biosecurity measures is too high. However, the potential economic losses associated with an REV outbreak far outweigh the cost of prevention. Investing in biosecurity is a sound business decision that can protect poultry farms from significant economic damage.

US Poultry Industry: Key Data and Trends

Category	Data	Source
Total chicken Production (2024)	~45 billion pounds	National Chicken Council
Egg Production (2024)	~115 billion eggs	USDA Economic Research Service
Value of Poultry Production (2024)	~$45 billion	USDA Economic Research Service
Top Poultry Producing States	Georgia, Arkansas, Alabama, North Carolina, Mississippi	USDA National Agricultural Statistics Service

Conclusion

The discovery of REV in Dutch poultry serves as a wake-up call for the U.S. poultry industry. While the virus may not currently be widespread in the United States, the potential for global spread necessitates proactive measures to prevent its introduction and control its spread.

By implementing strict biosecurity protocols, conducting regular testing, and staying informed about the latest developments, U.S. poultry farmers can protect their flocks and livelihoods from the threat of REV. The time to act is now to ensure the long-term health and sustainability of the U.S.poultry industry.

archyde News – Covering global agricultural developments and their impact on the U.S.

What are some innovative preventative measures that could be implemented to bolster our defenses against REV?

Archyde News Interview: Dr. Emily Carter on reticuloendotheliosis Virus (REV) and the U.S. Poultry Industry

A Conversation on Prevention, Biosecurity, and the Future of Poultry Health.

Published: April 12, 2025

Introduction

Archyde News Editor: Welcome, Dr. Carter. Thank you for joining us today.The recent detection of Reticuloendotheliosis Virus (REV) in Dutch poultry has raised notable concerns. Can you tell us a bit about your background and your current role in poultry health?

dr. Emily Carter: Thank you for having me. I’m Dr. Emily Carter, a veterinary virologist specializing in avian diseases. I currently serve as the lead researcher at the National Poultry Health Institute, focusing on infectious diseases and biosecurity protocols to protect the U.S. poultry industry.

Understanding REV and It’s threat

Archyde News Editor: Could you explain what exactly REV is and why it’s a cause for concern for U.S. poultry farmers?

Dr. Emily Carter: Certainly. REV is a retrovirus, meaning it integrates its genetic material into the host’s DNA. It’s known to cause a range of issues in poultry, including tumors and Runting Disease Syndrome, leading to decreased egg production and higher mortality rates.The primary concern for U.S. farmers is its potential to spread rapidly and negatively affect profitability, as our poultry industry relies on continuous production and high biosecurity standards.

Biosecurity and Prevention Strategies

Archyde News Editor: The article highlights the importance of biosecurity. What are the most critical biosecurity measures U.S. farmers should be implementing right now to reduce the risk of REV introduction?

Dr. Emily Carter: Biosecurity is the first line of defense. Farmers must control access to poultry houses, ensuring all personnel and visitors use proper protective clothing and footwear, as well as thoroughly sanitizing vehicles. regular testing of flocks is crucial for early detection. Purchasing chicks and breeding stock from certified, REV-free sources is vital, and exploring potential vaccination strategies can provide an additional layer of protection. The key is a multi-layered approach.

Current Research and Future Outlook

Archyde News Editor: The article mentions that there isn’t a readily available vaccine for REV. Can you tell our readers about the ongoing research in this area?

Dr. Emily Carter: Research into REV vaccines is a high priority. Scientists are working on developing effective vaccines, but the nature of retroviruses makes this a complex undertaking, ofen requiring different approaches to vaccine development. The hope is to have an effective solution available within the next few years. However,this is just one part of the picture,as disease prevention is most effective when combined with robust testing and biosecurity protocols.

Challenges and Potential Impact

Archyde News editor: What are the biggest challenges the U.S. poultry industry faces in addressing REV? Moreover, what are the potential economic repercussions if the virus were to become widespread?

Dr. Emily Carter: The biggest challenge is awareness and ensuring all farmers understand the risks and implement preventive measures. The economic impact of an REV outbreak could be devastating.We’d see reduced egg production, increased mortality, higher veterinary costs, and potentially a decline in consumer confidence, wich could lead to decreased demand for poultry products. Early detection and swift action are key to mitigating these negative consequences.

Community Engagement and Open Discussion

Archyde News Editor: what is the single most crucial piece of advice you would give to poultry farmers concerned about REV?

Dr. Emily Carter: Stay informed. Keep up-to-date on the research,monitor your flocks closely,and always practice the highest levels of biosecurity. collaboration with your veterinarian and state agricultural agencies is critical for success. Ultimately, the future of the US poultry industry relies on adopting a disease prevention and rapid response model where farmers, veterinarian, and governmental agencies’ work together.

Reader Interaction

Archyde News Editor: Dr. Carter, thank you for sharing your insights. For our readers, what innovative preventative measures do you think could be implemented to bolster our defenses against REV?

(We invite our readers to share their thoughts and suggestions in the comments section below!)

Archyde News – Covering global agricultural developments and their impact on the U.S.