Rise in popularity of backyard poultry increases Salmonella risk
It is estimated that Salmonella causes 1.2 million illnesses, 23,000 hospitalizations and 450 deaths annually in the United States, according to the CDC.
Among the significant carriers of Salmonella, live poultry have become more commonplace among a wider range of people since the “local foods” movement has increased the popularity of households keeping backyard flocks. While this can be an educational experience for children and their families, there are risks associated with maintaining backyard poultry — particularly among young children.
According to a 2014 review published in Clinical Infectious Diseases, there were 45 outbreaks of human Salmonella infections linked to live poultry from mail-order hatcheries between 1996 and 2012. Experts expect that this will most likely increase with the rising popularity of backyard poultry flocks.
“Salmonella is found in the intestinal tract of many animals, including live poultry, although live poultry that has Salmonella in their tract may appear healthy,” Megin Nichols, DVM, MPH, from the CDC, said during an interview with Infectious Diseases In Children. “Over the years, backyard poultry ownership has increased and while that has increased, so have outbreaks of Salmonella. We are seeing an increase in the frequency of these outbreaks, and it is very important to keep in mind how people can protect themselves and their children from Salmonella while owning chickens.”
Infectious Diseases in Children spoke with several experts about the current status of poultry-associated salmonellosis, the specific risk to young children and how pediatricians and infectious disease specialists can better diagnose and manage Salmonella infections and outbreaks across the United States.
Photo courtesy of Shah SS
Backyard flock ownership rises
As the ownership of backyard flocks continues to grow in the U.S., increased live-poultry associated Salmonella infections and outbreaks are also rising — most notably in urban areas where zoonotic diseases from farm animals were once considered rare.
While the local foods movement encourages people to maintain their own backyard flocks, including chickens, ducks, geese and turkeys, as part of a greener, healthier lifestyle, it is imperative for advocates to be aware of the risks in handling live poultry.
“Raising poultry can be a very rewarding experience, however, it is always important to keep in mind that there are associated risks,” Nichols said.
In a 2014 review published in Clinical Infectious Diseases, researchers examined the history of live poultry-associated Salmonella infections across the U.S. between 1996 and 2012. The researchers found that despite the beneficial effect of interactions with animals, consumers were most often unaware of Salmonella risks associated with raising poultry.
“Because of the increasing number of households with backyard flocks, educational messaging about health risks associated with live poultry is especially important now, particularly in homes and settings with high-risk individuals and inexperienced flock owners,” the researchers wrote. “Human salmonellosis from contact with live poultry is a challenging, yet largely preventable public health problem.”
Children at increased risk
Populations at increased risk for serious illness from Salmonella infection include the elderly, those with immunocompromised conditions and young children. Because children lack fully developed immune systems and are more prone to kiss, cuddle and hold live poultry and then put their fingers or hands in or near their mouths prior to washing, they are at heightened risk for infection.
“Although salmonellosis can impact people of any age, children under the age of 5 years are one of the most common groups who experience live-poultry associated Salmonella infections,” Nichols said. “In recent outbreaks of salmonellosis linked to backyard poultry, a significant amount of ill people were children younger than the age of 10 years. In these outbreaks, between 30% and 38% were children, and this especially occurs around springtime and Easter.”
In a 2011 multistate Salmonella outbreak, 32% of 68 cases of Salmonella Altona and 75% of 28 cases of Salmonella Johannesburg occurred in children aged 5 years and younger across 24 states. Cases were linked to a single mail-order hatchery in Ohio between Feb. 25 and Oct. 10, 2011, according to findings published in MMWR.
During another multistate Salmonella Infantis, Newport and Lille infection outbreak in 2012 involving the same mail-order hatchery, 64 of the 194 cases occurred in children aged younger than 10 years, according to MMWR.
“Children under the age of 5 years should not handle live poultry,” Alicia Cronquist, RN, MPH, Foodborne Disease Program Manager at the Colorado Department of Public Health and Environment, said during an interview with Infectious Diseases in Children. “Adults should be especially vigilant about monitoring hand-washing with children of all ages. Whenever we have an outbreak in Colorado associated with live poultry, young children are always disproportionately affected — there are always more cases in young children than among any other age group.”
Human salmonellosis a reportable condition
PulseNet is the national molecular subtyping network for foodborne disease surveillance — a valuable tool in epidemiologic investigations including Salmonella infection cases and outbreaks, according to the CDC.
“The national network, PulseNet, helps state health departments to find a common source of infection,” Cronquist, who helps coordinate Salmonella and other enteric diseases for the state health department in Colorado, said. “We know that what gets reported to public health is just the tip of the iceberg. When a person becomes ill with a gastrointestinal illness and they are ill enough to visit their doctor, the doctor may request testing to determine which type of organism is making the person ill.”
Andi L. Shane, MD, MPH, MSc, associate professor of pediatric infectious disease and global health at Emory University School of Medicine and Children’s Healthcare of Atlanta, and a member of the Infectious Diseases in Children Editorial Board, said communication between the pediatrician and the local health department is an important step in the process.
“Health departments rely on pediatricians as they are often the first to recognize clusters of infections among families and in the community,” Shane said. “Pediatricians should obtain a stool specimen or rectal swab for culture and/or molecular diagnostic testing. While bacterial gastroenteritis can mimic viral etiologies, identification of the former is helpful both from clinical and epidemiologic perspectives, and is helpful in situations when antimicrobial therapy is indicated.”
If the stool testing comes back positive for Salmonella, it is reportable in all 50 states, and the laboratory and/or the physician’s office are required to notify their local public health department.
“This works a little differently in every state,” Cronquist said. “Specifically in Colorado, the report comes into a central reporting system, and the county health department where the person lives will call and ask the person a series of questions regarding their illness — primarily what a person does for a living and how the person became ill with Salmonella.”
In addition, a specimen of the sampled bacteria is sent to the state public health lab where more testing is conducted to determine the particular type of Salmonella.
Nichols suggested that all pediatricians should ask their patients and/or their families about any animals and pets that may be kept in the home.
“This information can be kept on file, and if the patient comes into the pediatrician’s office complaining of symptoms that may be associated with Salmonella, they are able to go back and reference that information,” she said. “If the family reported they own backyard poultry, then it could be beneficial to order a stool culture or perform additional testing.”
Dangers of treating live poultry as house pets
Between Feb. 3 and Oct. 14, 2014, PulseNet identified five clusters of Salmonella infections including 363 people infected with serotypes Infantis, Newport and Hadar.
According to information provided in MMWR, cases “were reported in 43 states and Puerto Rico, making it the largest live poultry-associated salmonellosis outbreak reported in the United States.”
Of the 69 purchases with hatchery source information, 84% came from the mail-order hatchery in Ohio previously implicated in other multistate outbreaks of Salmonella. Thirty-five percent of the 363 cases occurred in children aged 10 years or younger. Although no deaths were reported, 33% of cases were hospitalized. Moreover, 80% of 118 patients who provided supplemental information on live poultry exposure reported exposure to chicks, and 26% reported exposure to ducklings. Of particular note, 29% of all cases reported keeping live poultry inside of their home, and 27% reported having no direct contact with live poultry.
“This phenomenon of people having farm animals treated as pets, as they would a cat or a dog, changes the precautions people should take when interacting with them,” Samir S. Shah, MD, MSCE, director in the division of hospital medicine at Cincinnati Children’s Hospital, said in an interview with Infectious Diseases in Children. “There is real opportunity for the hatcheries that sell these chicks to educate consumers. For example, consumers should be encouraged to wash their hands after interacting with poultry and keep poultry feed or water dishes out of the kitchen because of the risk of cross-contamination.”
Shah said Salmonella outbreaks from raising backyard poultry seems to be occurring more frequently in urban areas, not just rural locations. “One factor that increases the potential for widespread outbreaks is the national distribution of these chicks — up to 100, 1-day-old chicks can be mailed via any post office in the United States,” he said. “Consumers are not always aware of the risks associated with live poultry. Baby chicks are perceived as pets rather than farm animals, and so people do not take the same precautions as they would if they were on a farm.”
Prevention of illness
“While there may be perceived psychosocial benefits to the raising of backyard poultry, this is an activity that is not appropriate for households where children under the age of 5 years or people with compromised immune systems reside,” Amelia B. Thompson, MD, MPH, of the division of pediatric infectious diseases at Emory University School of Medicine, told Infectious Diseases in Children. “If backyard poultry is part of a family’s activity, hand hygiene is the mainstay of prevention of transmission of pathogens. After contact with backyard poultry or any areas where they may have been roaming, thorough hand hygiene must occur. Live poultry should remain in the backyard, and families should not consider poultry to be domestic pets.”
Regarding prevention measures for mail-order hatcheries, the National Poultry Improvement Plan (NPIP) — established during the 1930s by the Agriculture Department — is a collaborative effort by industry, federal and state agencies that tests and monitors Salmonella infections in commercial and backyard poultry. The plan helps to guide both management and sanitation practices for mail-order hatcheries, according to the CDC.
An additional, voluntary Salmonella monitoring program, ratified by the NPIP in 2010, advises monthly environmental sampling of mail-order hatcheries for Salmonella. While some hatcheries are currently participating in the proposed guidance, the program is expected to become official this year. In the meantime, educational information on how to help prevent Salmonella infections and outbreaks can be found on the CDC website.
“Awareness of the risks and knowing how to mitigate the risks is key for prevention. If a patient has backyard poultry, they should appreciate that these are farm animals,” Shah said. “I would discourage patients from bringing the live poultry into their homes, which will increase the risk for transmission for any illness. Recognize that poultry is often not symptomatic, but they may be shedding Salmonella in their stool. The important thing is to minimize the risk for cross contamination. Do not clean feed dishes or water dishes inside the kitchen. Folks at home need to understand that these animals are not pets.”
Nichols said partnerships between pediatricians, ID physicians and parents are essential to help prevent Salmonella infections.
“Salmonella from backyard poultry is certainly preventable,” she said. “One of the most significant things we can do is to be vigilant. Parents and others should assume that any areas where live backyard poultry exist can be potentially contaminated with Salmonella.” – by Jennifer Southall
Basler C, et al. MMWR. 2015;64:258.
Behravesh CB, et al. Clin Infect Dis. 2014;doi:10.1093/cid/ciu067.
Forshey TM, et al. MMWR. 2012;61:195.
Forshey TM, et al. MMWR. 2013;62:213.
For more information:
Alicia Cronquist, RN, MPH, can be reached at the Colorado Disease Control and Environmental Epidemiology Division, 4300 Cherry Creek Drive South, Denver, CO 80246-1530; email: email@example.com.
Megin Nichols, DVM, MPH, can be reached at the Centers for Disease Control and Prevention, 1600 Clifton Road, MS A38, Atlanta, GA 30333; email: firstname.lastname@example.org.
Samir S. Shah, MD, MSCE, can be reached at the Cincinnati Children’s Hospital, 3333 Burnet Ave., Cincinnati, OH 45229-3026; email:email@example.com.
Andi L. Shane, MD, MPH, MSc, can be reached at Emory University School of Medicine and Children’s Healthcare of Atlanta, 2015 Uppergate Drive NE, Atlanta, GA 30322; email: firstname.lastname@example.org.
Amelia B. Thompson, MD, MPH, can be reached at Emory University School of Medicine, 2015 Uppergate Drive NE, Atlanta, GA 30322; email: email@example.com.
Disclosure: Cronquist, Nichols, Shah, Shane and Thompson report no relevant financial disclosures.
Given ‘local food’ trends, should discussions about child exposure to animals, zoonoses and associated risks be included in well-child visits?
Pediatricians have an opportunity to educate families on zoonosis prevention strategies during well-child visits.
Frequent exposure to animals is common in a child’s life. While this exposure most often involves a household pet such as a cat or dog, other unusual but possibly common exposures may exist as illustrated in this cover story. Risks of zoonotic infections exist with having animals and these risks can be mitigated by knowing what animals are occupying children’s households.
Since children have frequent well-child visits, this provides the pediatrician with an excellent opportunity to learn about the animals to which the child is exposed, and to educate families on the risk and to stress the importance of the most effective prevention strategy ̶ hand-washing.
As mentioned, caring for and raising live poultry put household members at risk for Salmonella infections. However, pet reptiles (lizards), amphibians (frogs) and rodents (hamsters) also put a child at risk for salmonellosis. Campylobacter infections, another diarrheal illness, can also be contracted from raising live poultry, as well as from puppies and kittens. Other diarrheal infections from exposure to less common household animals include Cryptosporidium (calves, lamb and goat kids) and E. coli O157:H7 (cattle, goats and sheep). Cat scratch disease, a frequent cause of lymphadenitis, most often occurs from kitten scratches. All of these illnesses can be prevented.
Hand hygiene is the key for preventing Salmonella and Campylobacter. Young children, especially those aged younger than 5 years, should be supervised while washing their hands after playing with animals. Food, drinks, pacifiers and other items that promote hand-to-mouth contact should not be allowed near these animals. While household animals provide fun and are important in a child’s life, they aren’t without risk. Knowing these risks and counseling families on how to decrease the risk of these infections is important.
For more information on helpful tips, visit www.health.state.mn.us/divs/idepc/dtopics/animal/index.html.
Jason Newland, MD, Med, FPIDS, is medical director of patient safety and systems reliability at Children’s Mercy Hospitals and Clinics. He can be reached at Children’s Mercy Hospitals and Clinics, 2400 Pershing Rd. #10,, Kansas City, MO, 64108; email: firstname.lastname@example.org. Disclosure: Newland reports no relevant financial disclosures.
Pediatricians routinely addressing zoonoses and animal exposure during well-child visits is impractical.
Parents need information about zoonoses and the risks associated with exposure to various animals, but asking pediatricians to routinely address these topics in well-child visits may not be practical. Without a doubt, the information is important. Not long ago, my partners and I treated a baby with Salmonella meningitis. The family of the baby had raised chickens but they weren’t aware of the potential risks. We have also seen cases of hemolytic uremic syndrome from E. coli O157:H7 linked to consumption of unpasteurized milk.
Kristina K. Bryant
According to the CDC, “tens of thousands of Americans” acquire a zoonotic disease each year, and children aged less than 5 years are particularly vulnerable. It would seem that the pediatrician would be the ideal person to teach families about the risks. However, the problem only becomes apparent when you start to do the math: The typical preventive health care visit lasts around 20 minutes, according to data collected by the American Academy of Pediatrics. If information about zoonoses is added to the anticipatory guidance provided at these visits, there will be less time to discuss other topics.
Can we realistically spend less time talking to parents of infants about safe sleep habits, choking hazards and car seat use? Should we reduce the time we spend counseling parents of school-aged children about bike helmets, water safety and seat belts? We also know that some topics currently addressed during well-child visits may not be getting the attention they deserve. For example, in one study of pediatric health care providers in Rochester, New York, the median time devoted to a discussion of vaccines during a well-child visit was only about two minutes!
The ideal solution would be longer well-child visits for which providers are fairly reimbursed. Until that happens, we need creative and effective ways to deliver anticipatory guidance about zoonoses to parents.
LeBaron CW, et al. Arch Pediatr Adolesc Med. 1999;153:1154-1159.
Kristina K. Bryant, MD, is professor in the department of pediatrics and infectious diseases at the University of Louisville. She can be reached at Gray Street Medical Building, 210 E. Gray St. Suite 802, Louisville, KY 40202; email: email@example.com. Disclosure: Bryant reports no relevant financial disclosures.