Illustration depicting a pig with advanced digital representation of the PRRS virus, showcasing efforts to protect animal health.

Unmasking the Silent Threat: How Scientists Are Fighting Back Against Swine Disease

Lena Kashyap in Health & Wellness December 2025 • 4 min read.

"New research reveals key insights into Porcine Reproductive and Respiratory Syndrome (PRRS) and offers hope for controlling this devastating illness."

Swine farming is a vital part of the global food system, providing a key source of protein for millions. But the industry faces constant challenges, and one of the most persistent is Porcine Reproductive and Respiratory Syndrome, or PRRS. This disease is a major threat to pig health and causes significant economic losses, impacting farmers and consumers alike.

For years, PRRS has plagued the swine industry, with containment proving incredibly difficult. The virus, which causes the disease, is persistent, meaning it can linger in pigs for extended periods, making it hard to control. Recent research, however, offers a glimmer of hope. Scientists are making progress in understanding the disease and identifying potential solutions.

A new study, focusing on the factors associated with the virus's presence in pigs, offers fresh insights. By examining the virus's behavior, the researchers aim to develop more effective strategies to manage and control PRRS. This article explores the key findings of the research, including the genetic factors at play and the potential for new treatments.

Decoding the Enemy: The Science Behind PRRS

Illustration depicting a pig with advanced digital representation of the PRRS virus, showcasing efforts to protect animal health.

PRRS is a complex disease, and understanding its mechanisms is the first step toward effective control. The virus primarily attacks the respiratory system and reproductive organs of pigs. This leads to a range of symptoms, including fever, loss of appetite, and respiratory distress. In pregnant sows, it can cause reproductive failure, resulting in significant economic losses for farmers.

The study focused on the level of the virus in the tonsils of pigs, as this is a primary site of PRRSV persistence. The research involved experimental infection of pigs with two different strains of the virus. The researchers then examined the factors that affect the virus levels, including the genetic makeup of the pigs, and the presence of other health factors.

Persistence: The PRRS virus can remain in a pig's system for over 150 days, making it a persistent threat.
Impact: PRRS leads to breathing problems and reduced reproduction, severely impacting pig health and the economy.
Focus: The study measured tonsil virus levels, which are key to understanding the virus's long-term presence.

The researchers found that the virus levels in the tonsils were linked to the pigs' immune responses, particularly the levels of serum viremia, or the presence of the virus in the bloodstream. Pigs with lower levels of the virus in their tonsils also had faster rates of clearing the virus from their blood. Additionally, the study looked at genetic factors and identified certain regions associated with virus levels.

Looking Ahead: The Future of PRRS Control

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1093/jas/sky446, Alternate LINK

Title: Identification Of Factors Associated With Virus Level In Tonsils Of Pigs Experimentally Infected With Porcine Reproductive And Respiratory Syndrome Virus1

Subject: Genetics

Journal: Journal of Animal Science

Publisher: Oxford University Press (OUP)

Authors: Andrew S Hess, Joan K Lunney, Samuel Abrams, Igseo Choi, Ben R Trible, Melanie K Hess, Raymond R R Rowland, Graham S Plastow, Jack C M Dekkers

Published: 2018-11-28

Everything You Need To Know

What is Porcine Reproductive and Respiratory Syndrome (PRRS) and why is it a significant concern?

Porcine Reproductive and Respiratory Syndrome (PRRS) is a devastating disease primarily impacting the swine industry. It poses a major threat to pig health, causing significant economic losses. The disease is caused by a persistent virus, meaning it can remain in pigs for extended periods, making containment incredibly difficult. PRRS attacks the respiratory system and reproductive organs of pigs, leading to symptoms like fever, loss of appetite, respiratory distress, and reproductive failure in pregnant sows.

How does the PRRS virus impact pigs, and what are the main health challenges it causes?

The PRRS virus directly attacks the respiratory system and reproductive organs of pigs. This leads to various health issues including fever, loss of appetite, and respiratory distress. In pregnant sows, PRRS causes reproductive failure, resulting in significant economic losses for farmers. The persistence of the virus is a major factor, as it can remain in a pig's system for over 150 days, making it a persistent threat to their health and increasing the challenges of control.

What key findings emerged from the recent study on PRRS, and what specific aspects were investigated?

The recent study focused on understanding the factors associated with the virus's presence in pigs, specifically measuring the virus levels in the tonsils, a primary site of PRRSV persistence. Researchers found that the virus levels in the tonsils were linked to the pigs' immune responses, particularly the levels of serum viremia (virus presence in the bloodstream). Pigs with lower levels of the virus in their tonsils also cleared the virus from their blood faster. Additionally, the study looked at genetic factors, identifying specific regions associated with virus levels, which provides a foundation for developing disease-resistant pigs.

How does the study's focus on tonsil virus levels contribute to a better understanding and potential control of PRRS?

The study's focus on tonsil virus levels is crucial because the tonsils are a primary site of PRRSV persistence. By examining the virus levels in this area, researchers can better understand how the virus behaves and how long it remains in the pig's system. The findings revealed connections between tonsil virus levels, immune responses (particularly serum viremia), and the genetic makeup of the pigs. This information provides a better understanding of the disease's mechanisms and opens up new avenues for developing more effective strategies to manage and control PRRS, such as identifying disease-resistant pigs.

What are the potential future implications of this research for the swine industry, and how might it lead to advancements in combating PRRS?

This research provides a foundation for future efforts to control PRRS. The identification of genetic factors and the association with immune responses opens up new avenues for developing disease-resistant pigs. The findings bring us one step closer to protecting the health of pigs and ensuring the stability of the swine industry. Future implications include the potential for targeted breeding programs to select for genetic traits associated with lower virus levels and improved immune responses. This could lead to a significant reduction in disease prevalence and economic losses, ultimately safeguarding the global food system that relies on swine farming.