Surveillance Study Highlights Risks of Animal Contact in Disease Outbreaks

A recent study published in Morbidity and Mortality Weekly Report reveals that limited knowledge about disease prevention among pet owners, particularly those with backyard poultry, is contributing to intestinal disease outbreaks across the United States.

Statistics on Enteric Illnesses

The research team led by the Centers for Disease Control and Prevention (CDC) estimates that the U.S. sees approximately 450,000 enteric illnesses, 5,000 hospitalizations, and 76 deaths linked to animal contact each year. These illnesses can be contracted through contact with animal feces, bodily fluids, or contaminated environments, food, or water.

Understanding Enteric Infections

Enteric infections typically target the lower digestive tract, causing symptoms such as diarrhea, nausea, and vomiting. Alarmingly, many cases remain unreported, underscoring the need for improved awareness and preventive measures.

Outbreak Trends from 2009 to 2021

From 2009 to 2021, a total of 557 animal-related enteric disease outbreaks were documented, resulting in 14,377 reported illnesses, 2,656 hospitalizations, and 22 deaths. While multistate outbreaks represented 29% of cases, they were responsible for a staggering 80% of illnesses, 88% of hospitalizations, and 82% of deaths.

The Role of Pathogens

Salmonella emerged as the leading cause of single-source outbreaks, accounting for 52% of cases. This pathogen alone contributed to 85% of associated illnesses, 91% of hospitalizations, and 77% of deaths. Other notable pathogens included Cryptosporidium, Escherichia coli, and Campylobacter.

“Strengthening the capacity of local, state, and territorial health departments to investigate and report animal contact outbreaks is critical to improving surveillance of animal contact outbreaks,” the authors state.

Primary Exposure Settings

Analysis indicates that the majority of single-location outbreaks occurred at private homes (40%) and farms or dairies (21%). Specifically, ruminants (such as cattle) were the most common source of single-animal outbreaks at 37%, followed closely by poultry (33%) and turtles (12%).

Poultry-Related Outbreaks

Poultry were linked to the highest number of outbreak-associated illnesses (66%), hospitalizations (70%), and deaths (83%). Notably, 84% of poultry-related outbreaks and 98% of illnesses occurred in private homes. The dominant pathogen-animal pairs included Salmonella with poultry, followed by Cryptosporidium with ruminants and Salmonella with turtles.

Recommendations for Preventive Measures

To mitigate these risks, the authors advocate for educational programs focused on proper animal-handling hygiene for ruminant farmers and owners of backyard poultry and turtles. The significant impact of multistate outbreaks highlights the urgent need for coordinated national responses and improved investigative resources at state and local levels.

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