Salmonella Risk in Backyard Chicken Farms

Lifestyle trend linked to ever-increasing rate of infection

Woman feeding chickens
Justin Mullet/Stocksy United

Backyard chicken farming in the United States has grown in popularity in tandem with the movement toward a more locally sourced, organic lifestyle. To many enthusiasts, chicken farming is more than just a hobby; it’s the very reflection of social responsibility, at once reducing carbon emissions while ensuring the animals are treated in a more humane, ethical fashion.

While many of these farms are fully compliant with local health and safety regulations, others fly well under the legal radar.

Oftentimes, the eagerness to embrace "natural" farming has led some to ignore traditional safeguards meant to protect themselves and their flocks from illness.

Salmonella Outbreak Linked to Backyard Farms

The increasing popularity of backyard chicken farming has been directly linked to a recent outbreak of Salmonella in 48 states. According to an advisement issued by the ​U.S. Centers for Disease Control and Prevention (CDC), 790 cases of salmonellosis have been confirmed in people who had come into contact with backyard flocks between January and June 2017. Of these, 174 cases were considered serious and required hospitalization.

These numbers suggest a significant increase in the number of cases attributed to backyard chicken farming. By comparison, a total of 53 outbreaks were confirmed from 1990 to 2014, resulting in 2,360 cases, 387 hospitalizations, and five deaths. The three-year total from 2015 to 2017 nearly matches those figures.

While the numbers still remain relatively low, it is this rate of increase that continues to worry public health officials.

Salmonella and Food Poisoning Symptoms

Salmonellosis is the name of the disease caused by Salmonella bacteria. The bacteria itself lives in the intestinal tract of humans and animals and is transmitted primarily through foods that have been contaminated with feces.

There are two main species of Salmonella—Salmonella bongori and Salmonella enterica—as well as numerous subtypes commonly associated with food poisoning. The symptoms of salmonellosis are similar to those of the stomach flu and can include:

  • Diarrhea
  • Fever
  • Stomach cramps
  • Vomiting

Symptoms typically appear 12 to 72 hours after exposure and can last anywhere from 4 to 7 days. Most cases resolve on their own without treatment.

However, in young children, the elderly, and persons with compromised immune systems, salmonellosis can lead to severe and even life-threatening illness. In these individuals, an infection can sometimes spread to the bloodstream causing a serious, all-body infection known as Salmonella septicemia. Treatment usually requires hospitalization and an aggressive course of intravenous antibiotics.

In the United States, salmonellosis strikes around 1.2 million people and causes nearly 400 deaths each year. The disease is responsible for more hospitalizations than any other foodborne germ, including E. coli, and impacts the national healthcare system by more than $365 million annually.

Salmonellosis Linked to Poor Farming Practices

Salmonella enterica is the bacterial type most commonly associated with poultry contamination.

While the handling and eating of poultry can cause illness, chicken eggs remain the predominant source of infection. According to the U.S. Department of Agriculture (USDA), S. enterica infection in hens hovers at around 10 percent, more than twice the rate seen in broilers.

Among backyard farmers, the improper management and handling of flocks are seen to be the major cause of Salmonella outbreaks. This seems especially true for those who keep smaller flocks either as pets or a source of fresh, home-grown eggs.

A survey conducted by University of California-Davis Department of Animal Science in 2014 demonstrated that, among home enthusiasts, there remains a widespread lack of awareness about poultry health issues.

According to the research, nearly 70 percent of owners allowed visitors into their coops while only 40 percent wore protective gear when cleaning. Both of these practices are considered unsafe. Even more concerning was the fact that many of the farmers knew little or nothing about common poultry infections such as ​avian flu or Marek’s disease (a deadly, tumor-causing virus considered epidemic in unvaccinated flocks).

Among the practices associated specifically with salmonellosis risk:

  • Failing to collect eggs at least daily, particularly in warm weather
  • Not refrigerating the eggs immediately after collection
  • Not washing hands after touching a chicken or cleaning a coop
  • Kissing or snuggling the chicken as pets
  • Failing to quarantine visibly ill chickens
  • Fertilizing gardens with fresh, uncured manure, the practice of which can contaminate crops

Salmonellosis in chickens is fairly obvious: they will be weak, have watery diarrhea, and develop a purple comb. Hens will have noticeably reduced egg production.

Washing or Not Washing Chicken Eggs

Another prime cause of Salmonella infection is the improper washing for chicken eggs. Many experienced farmers advise against washing as this can remove the gelatinous "bloom" that seals and protects the egg from bacteria. Instead, they endorse a light brushing or wiping to remove any excess grit followed by the immediate refrigeration at or below 40 degrees F.

Eggs are usually cleaner if collected immediately. Excessively dirty eggs are usually those that have been sitting in the nest for several days, and these should be discarded.

If you do decide to wash the eggs, you will need to ensure that the water is at least 90 degrees F. Warmer water temperatures cause the egg contents to swell and push dirt and contaminants from the shell’s pores. Using cold water, by contrast, opens the pores and invites contaminants in. The water should always flow around the eggs as you wash them. Never allow the eggs to sit in the water, submerged. After washing, dry the eggs thoroughly and refrigerate.

Tips for Preventing Salmonellosis

While salmonellosis can occur at any time of the year, the risk runs higher during the summer months when warmer temperatures provide the ideal environment for bacteria. Whether you have a backyard coop or keep chickens as gardening partners, there are several things you can do to keep yourself safe from Salmonella.

Chief among these is the reputation of the hatchery from which you source your birds. Never buy live poultry or chicks from anything other than a hatchery certified by the USDA National Poultry Improvement Plan (USDA NPIP). Avoid non-certified breeders, including specialty show breeders and other backyard farmers.

To avoid getting Salmonella from handling or managing your flock:

  • Clean your coop regularly, including floors, nests, and perches.
  • Change the food and water regularly, ideally every day.
  • Wear gloves and protective footwear when cleaning coops.
  • Always wash your hands after touching a chicken or collecting eggs.
  • Wash your hands outdoors rather than the kitchen sink.
  • Clean feeding bowls and all other farming equipment outdoors.
  • Do not eat or drink in the areas where the birds live or roam.
  • Do not allow birds in the house, especially where food is prepared.
  • Do not allow children or visitors to treat chickens as pets.
  • Do not give chicks to children as gifts.
  • Quarantine any sick bird and immediately contact your veterinarian.
  • Ensure that your flock is properly vaccinated against poultry diseases.
  • Cure chicken manure for at least 45 days before using as garden compost. During the curing process, avoid adding fresh manure to a cured or curing pile.

To prevent getting salmonellosis from fresh, homegrown eggs:

  • Collect eggs frequently, ideally once in the morning and once in the afternoon.
  • If you wash the eggs, do so outdoors rather than in the kitchen sink.
  • Discard any cracked or dirty eggs.
  • Do not keep eggs at room temperature for more than two hours.
  • Cook eggs thoroughly. Do not eat raw eggs.


Basler, C.; Nguyen, T.; Anderson, T.; Hancock, T.; and Barton Behrahvesh, C. "Outbreaks of Human Salmonella Infections Associated with Live Poultry, United States, 1990-2014." Emerg Infect Dis. 2016; 22(10):1705-1711.

Centers for Disease Control and Prevention (CDC). "Multistate Outbreaks of Human Salmonella Infections Linked to Live Poultry in Backyard Flocks." Atlanta, Georgia; issued July 13, 2017.

Elkhoraiba, C.; Blatchford. R.; Pitesky, M.; and Mench, J. "Backyard chickens in the United States: A survey of flock owners." Poultry Owners. November 1, 2014; 93(11):2920-2931.

U.S. Department of Agriculture. "Serotypes Profile of Salmonella Isolates from Meat and Poultry Products, January 1998 through December 2014." Washington, D.C.; updated August 11, 2016.

Whiley, H. and Ross, K. "Salmonella and Eggs: From Production to Plate." Int J Environ Res Public Health. March 2015; 12(3):2543-2556.