H5N1 Testing in Cattle Veterinarians Suggests Asymptomatic Transmission of Avian Influenza

H5N1 Testing in Cattle Veterinarians Suggests Asymptomatic Transmission of Avian Influenza

H5N1 Testing in Cattle Veterinarians Suggests Asymptomatic Transmission of Avian Influenza


# Stealthy Dissemination of H5N1 Bird Flu Provokes Surveillance Worries

A new investigation by the **Centers for Disease Control and Prevention (CDC)** has indicated that three veterinarians involved with cattle have tested positive for previous infections of **H5N1 bird flu**. This revelation raises alarms regarding **unnoticed transmission** of the virus among both animals and humans, spotlighting possible flaws in monitoring efforts.

## **Unnoticed Infections Among Veterinarians**

The inquiry, carried out in **September 2024**, engaged **150 bovine veterinarians** from **the United States and Canada**. These veterinarians submitted **blood samples** and disclosed their exposure to cattle over the last three months.

Crucial findings from the analysis include:
– **Three U.S. veterinarians (2%) tested positive for H5 antibodies**, signifying past infection.
– **None exhibited symptoms** like respiratory issues, flu-like signs, or conjunctivitis (pink eye), typically seen in dairy workers infected with H5N1.
– **None of the three veterinarians interacted with cows confirmed or suspected to be infected** with H5N1.
– One veterinarian had engaged with **H5-positive poultry**, hinting at another potential exposure pathway.

## **Consequences for Public Health**

The results imply that **H5N1 might be spreading quietly** among animals and humans, raising alarms regarding **insufficient surveillance**. The fact that one veterinarian was based in **Georgia and South Carolina**, regions where no H5N1 cases in cows or humans had been reported, further emphasizes the probability of **unnoticed transmission**.

CDC researchers assert that these outcomes underscore the **necessity for systematic surveillance** of **dairy cattle, milk, and humans exposed to cattle** to guarantee early detection and appropriate risk evaluation.

## **H5N1 Outbreak in Dairy Farms**

This study emerges during a **widespread outbreak of H5N1 bird flu** across the U.S., which has impacted:
– **968 dairy herds across 16 states**
– **41 dairy workers** confirmed positive for the virus

Since September, the **U.S. Department of Agriculture (USDA)** has initiated a **national milk testing plan** aimed at detecting H5N1 in **bulk milk samples**. This initiative recently aided in identifying a **second spillover occurrence** of H5N1 from wild birds to cows, which has subsequently affected **multiple herds in Nevada** and caused at least **one dairy worker’s infection**.

## **The Necessity for Advanced Surveillance**

The inconspicuous transmission of H5N1 among veterinarians and dairy workers emphasizes the **urgent requirement for enhanced oversight and testing**. Experts caution that **undetected infections** could permit the virus to evolve, potentially heightening the risk of **human-to-human transmission**.

To alleviate this risk, health officials propose:
– **Routine testing of dairy workers and veterinarians** exposed to cattle
– **Broader surveillance of dairy herds** to promptly identify infections
– **Heightened public awareness and biosecurity practices** on farms

## **Final Thoughts**

The revelation of **unnoticed H5N1 infections** among veterinarians points to the **shortcomings in present surveillance efforts** and the **likelihood for silent transmission**. As the outbreak persists among dairy farms, **enhanced monitoring and early identification** will be crucial in averting additional spillover incidents and safeguarding public health.

For more details, visit the **[CDC’s official report](https://www.cdc.gov/mmwr/volumes/74/wr/mm7404a2.htm?s_cid=mm7404a2_w)** regarding the study.