Multistate Outbreak of Human Salmonella Typhimurium Infections Linked to Live Poultry in Backyard Flocks (Final Update)

Introduction

CDC collaborated with public health and agriculture officials in many states and the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service, National Poultry Improvement Plan, and Veterinary Services to investigate an outbreak of human Salmonella Typhimurium infections linked to contact with chicks, ducklings, and other live baby poultry. Public health investigators used the PulseNet system to identify cases of illness that were part of this outbreak. In PulseNet, the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC, DNA “fingerprints” of Salmonella bacteria are obtained through diagnostic testing with pulsed-field gel electrophoresis, or PFGE, to identify cases of illness that were part of this outbreak.

A total of 356 persons infected with the outbreak strain of Salmonella Typhimurium were reported from 39 states: Alabama (2), Arizona (11), California (10), Colorado (44), Florida (6), Georgia (4), Idaho (3), Illinois (3), Indiana (10), Iowa (7), Kansas (19), Kentucky (4), Louisiana (10), Massachusetts (2), Michigan (1), Minnesota (5), Mississippi (6), Missouri (18), Montana (3), Nebraska (15), Nevada (1), New Hampshire (1), New Mexico (19), New York (17), North Dakota (6), Oklahoma (14), Oregon (12), Pennsylvania (1), South Carolina (1), South Dakota (10), Tennessee (3), Texas (41), Utah (13), Vermont (1), Virginia (1), Washington (19), West Virginia (1), Wisconsin (7), and Wyoming (5).

Among 348 persons for whom information was available, illness onset dates ranged from March 4, 2013 to October 12, 2013. Ill persons ranged in age from less than 1 year to 87 years, with a median age of 7 years. Fifty-seven percent of ill persons were children 10 years of age or younger. Fifty-one percent of ill persons were female. Among 240 persons with available information, 62 (26%) reported being hospitalized, and no deaths were reported.

Investigation of the Outbreak

Epidemiologic, laboratory, and traceback investigations conducted by officials in local, state, and federal public health, agriculture, and regulatory agencies linked this outbreak to contact with chicks, ducklings, and other live baby poultry. The majority of traceback investigations identified Privett Hatchery in Portales, New Mexico as the source of the poultry linked to this outbreak.

In interviews, ill persons answered questions about contact with animals and foods consumed during the week before becoming ill. One hundred and eighty-nine (76%) of 250 ill persons interviewed reported contact with live poultry (e.g., chicks, chickens, ducklings, ducks, turkeys, and goslings) before becoming ill. One hundred and forty-nine (95%) of 157 ill persons reported purchasing live poultry from 116 locations of 33 agricultural feed store companies. Ill persons also reported purchasing live poultry directly from mail-order hatcheries [4 (3%)], online [3 (2%)], as well as from another individual [2 (1%)], a farmers’ market [1 (<1%)], and a flea market [1 (<1%)]. One hundred and twenty-eight ill persons reported purchasing live poultry for one or more of the following reasons: eggs (58%), pets (41%), fun/hobby (21%), meat (9%), Easter present (5%), fair/exhibition (3%), school project (2%), pest control (2%), and to release to a lake or pond (2%).

Traceback investigations of live poultry purchased by ill persons from feed stores identified 18 mail-order hatcheries in multiple states. The majority of traceback investigations identified Privett Hatchery in Portales, New Mexico as the source of the poultry linked to this outbreak. Many mail-order hatcheries use a practice called drop shipping when one hatchery is not able to fill a customer’s order and a second hatchery is called upon to ship birds directly to the customer under the first hatchery’s name. Customers might not realize that the actual source of the purchased birds was a different hatchery than the one where the original order was placed.

Environmental samples that were collected during an investigation at Privett Hatchery yielded the outbreak strain of Salmonella Typhimurium. The outbreak strain was identified from a sample collected in a duck pen. One (2.5%) of 40 samples collected from this hatchery yielded the outbreak strain.

The owners of Privett Hatchery are fully cooperating with the New Mexico Department of Health, CDC, and the New Mexico Department of Agriculture to address this outbreak. Privett Hatchery is a participant in the U.S. Department of Agriculture National Poultry Improvement Plan (NPIP) program. The NPIP program is intended to eliminate certain strains of Salmonella that cause illness in poultry breeding flocks and hatcheries, but this program currently does not certify that these poultry are free from other strains of Salmonella that may cause human illness.

Contact with live poultry can be a source of human Salmonella infections. Poultry typically appear healthy and clean but can be carrying Salmonella germs that can make people sick. Many ill persons in this outbreak reported bringing live poultry into their homes or reported kissing or cuddling with the birds. These behaviors increase a person’s risk of a Salmonella infection from contact with live poultry. Always wash hands thoroughly with soap and water right after touching live poultry or anything in the area where they live and roam. Adults should supervise hand washing for young children. Additional recommendations are available. Because 18 different mail-order hatcheries supplied live poultry to the 116 feed store locations identified during this outbreak investigation, these recommendations are important and apply to all live poultry regardless of the age of the birds or where they were purchased.

Mail-order hatcheries, agricultural feed stores, and others who sell or display chicks, ducklings, and other live poultry should provide health-related information to owners and potential purchasers of these birds prior to the point of purchase. This should include information about the risk of acquiring a Salmonella infection from contact with live poultry. Agricultural feed store staff should clean and disinfect live poultry display areas routinely, especially before new live poultry are added to the display. Additional recommendations are available.

November 1, 2013

Final Case Count Update

A total of 356 persons infected with the outbreak strain of Salmonella Typhimurium were reported from 39 states. Since the last update on August 19, 2013, 41 new ill persons were reported from Alabama (1), Arizona (3), California (1), Colorado (7), Florida (1), Illinois (2), Kansas (3), Louisiana (1), Michigan (1), Minnesota (2), Montana (1), Nebraska (1), North Dakota (1), Pennsylvania (1), South Dakota (1), Tennessee (1), Texas (9), Utah (2), Wisconsin (1), and Wyoming (1).

Among the persons who reported the date they became ill, illnesses began between March 4, 2013 and October 12, 2013. Ill persons ranged in age from less than one year to 87 years, with a median age of 7 years. Fifty-seven percent of ill persons were 10 years of age or younger. Fifty-one percent of ill persons were female. Among 240 ill persons with available information, 62 (26%) were hospitalized. No deaths were reported.

This outbreak appears to be over. However, live poultry, including those kept in backyard flocks, are an important cause of human Salmonella infections in the United States.

August 19, 2013

Case Count Update

A total of 316 persons infected with the outbreak strain of Salmonella Typhimurium have been reported from 37 states. Since the last update on August 9, 2013, nine new ill persons have been reported from Arizona (1), Kansas (1), New Mexico (3), Oregon (2), Utah (1), and Wisconsin (1). This outbreak of human Salmonella Typhimurium infections is not related to the current outbreak of human Salmonella Infantis, Lille, Newport, and Mbandaka infections linked to live poultry.

Among the persons who reported the date they became ill, illnesses began between March 4, 2013 and July 28, 2013. Ill persons range in age from less than one year to 87 years, with a median age of 6 years. Fifty-nine percent of ill persons are 10 years of age or younger. Fifty percent of ill persons are female. Among 199 ill persons with available information, 51 (26%) have been hospitalized. No deaths have been reported.

Illnesses that occurred after July 22, 2013 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks.

Investigation Update

In interviews, ill persons answered questions about contact with animals and foods consumed during the week before becoming ill. One hundred and fifty-eight (81%) of 196 ill persons interviewed reported contact with live poultry (e.g., chicks, chickens, ducks, ducklings, turkeys, and goslings) before becoming ill. Ninety-seven percent of ill persons reported purchasing live poultry from agricultural feed stores. A total of 113 locations of feed stores representing 33 feed store companies were identified.  Ill persons also reported purchasing live poultry from a farmer’s market, a flea market, or directly from mail order hatcheries. Ill persons reported purchasing live poultry for backyard flocks to produce eggs or meat, or to keep as pets.

State health departments have tested samples collected from chicks in ill persons’ homes and retail locations. Samples collected by New Mexico, Vermont, and New York yielded the outbreak strain of Salmonella Typhimurium.

Traceback investigations of live poultry purchased by ill persons from feed stores identified 18 mail-order hatcheries in multiple states. The majority of traceback investigations identified Privett Hatchery in Portales, New Mexico as the source of the poultry linked to this outbreak. Many mail-order hatcheries use a practice called drop shipping when one hatchery is not able to fill a customer’s order and a second hatchery is called upon to ship birds directly to the customer under the first hatchery’s name. Customers might not realize that the actual source of the purchased birds was a different hatchery than the one where the original order was placed.

Environmental samples that were collected during an investigation at Privett Hatchery yielded the outbreak strain of Salmonella Typhimurium. The outbreak strain was identified from a sample collected in a duck pen. One (2.5%) of 40 samples collected from this hatchery yielded the outbreak strain. Additional laboratory testing is ongoing.

The owners of Privett Hatchery are fully cooperating with the New Mexico Department of Health, CDC, and the New Mexico Department of Agriculture to address this outbreak. Privett Hatchery is a participant in the U.S. Department of Agriculture National Poultry Improvement Plan (NPIP) program. The NPIP program is intended to eliminate certain strains of Salmonella that cause illness in poultry breeding flocks and hatcheries, but this program currently does not certify that these poultry are free from other strains of Salmonella that may cause human illness.

Contact with live poultry can be a source of human Salmonella infections. Poultry typically appear healthy and clean but can be carrying Salmonella germs that can make people sick. Many ill persons in this outbreak reported bringing live poultry into their homes or reported kissing or cuddling with the birds. These behaviors increase a person’s risk of a Salmonella infection from contact with live poultry. Always wash hands thoroughly with soap and water right after touching live poultry or anything in the area where they live and roam. Adults should supervise hand washing for young children. Additional recommendations are available. Because 18 different mail-order hatcheries supplied live poultry to the 113 feed store locations identified during this outbreak investigation, these recommendations are important and apply to all live poultry regardless of the age of the birds or where they were purchased.

Mail-order hatcheries, agricultural feed stores, and others who sell or display chicks, ducklings, and other live poultry should provide health-related information to owners and potential purchasers of these birds prior to the point of purchase. This should include information about the risk of acquiring a Salmonella infection from contact with live poultry. Agricultural feed store staff should clean and disinfect live poultry display areas routinely, especially before new live poultry are added to the display.

August 9, 2013

Case Count Update

A total of 307 persons infected with the outbreak strain of Salmonella Typhimurium have been reported from 37 states. Since the last update, 38 new ill persons have been reported from California (2), Colorado (6), Florida (1), Georgia (1), Iowa (1), Mississippi (1), Missouri (1), Nebraska (3), New York (2), Oklahoma (2), South Carolina (1), South Dakota (2), Tennessee  (1), Texas (4), Utah (5), Washington (2), Wisconsin (2), and Wyoming (1). This outbreak of human Salmonella Typhimurium infections is not related to the current outbreak of human Salmonella Infantis, Lille, Newport, and Mbandaka infections linked to live poultry.

Among the persons who reported the date they became ill, illnesses began between March 4, 2013 and July 23, 2013. Ill persons range in age from less than one year to 87 years, with a median age of 6 years. Sixty percent of ill persons are 10 years of age or younger. Fifty percent of ill persons are female. Among 193 ill persons with available information, 49 (25%) have been hospitalized. No deaths have been reported.

Illnesses that occurred after July 13, 2013 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks.

Investigation Update

In interviews, ill people reported purchasing live baby poultry (e.g., chicks, ducklings) from multiple feed stores and mail-order hatcheries. Ongoing traceback investigations to determine the ultimate source of Salmonella Typhimurium infected live poultry linked to this outbreak have been challenging because of the complicated distribution network for these birds.

July 2, 2013

Case Count Update

A total of 271 persons infected with the outbreak strain of Salmonella Typhimurium have been reported from 37 states. Since the last update, 47 new ill persons have been reported from Arizona (2), California (1), Colorado (7), Florida (2), Idaho (3), Indiana (3), Iowa (1), Kansas (3), Kentucky (3), Louisiana (3), Minnesota (1), Mississippi (1), Missouri (1), Montana (1), Nebraska (1), New Mexico (3), Oklahoma (4), Pennsylvania (1), Texas (2), Utah (1), West Virginia (1), Wisconsin (1), and Wyoming (1). This outbreak of human Salmonella Typhimurium infections is not related to the current outbreak of human Salmonella Infantis, Lille, Newport, and Mbandaka infections linked to live poultry.

Among the persons who reported the date they became ill, illnesses began between and March 4, 2013 and June 10, 2013. Ill persons range in age from less than one year to 87 years, with a median age of six years. Sixty-two percent of ill persons are 10 years of age or younger. Fifty-one percent of ill persons are female. Among 162 ill persons with available information, 43 (27%) have been hospitalized. No deaths have been reported.

Illnesses that occurred after June 4, 2013 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks.

June 6, 2013

Case Count Update

A total of 224 persons infected with the outbreak strain of Salmonella Typhimurium have been reported from 34 states. Since the last update, 78 new ill persons have been reported from Alabama (1), California (3), Colorado (8), Georgia (3), Illinois (1), Indiana (3), Iowa (3), Kansas (3), Kentucky (1), Louisiana (1), Massachusetts (2), Mississippi (1), Missouri (7), Montana (1), Nebraska (1), New Mexico (3), New York (7), North Dakota (4), Oregon (5), South Dakota (1), Tennessee (1), Texas (7), Utah (1), Washington (7), Wisconsin (2), and Wyoming (1). This outbreak of human Salmonella Typhimurium infections is not related to the current outbreak of human Salmonella Infantis, Lille, Newport, and Mbandaka infections linked to live poultry.

Among the persons who reported the date they became ill, illnesses began between and March 4, 2013 and May 20, 2013. Ill persons range in age from less than one year to 81 years, and 62% of ill persons are 10 years of age or younger. Fifty-one percent of ill persons are female. Among 141 ill persons with available information, 37 (26%) have been hospitalized. No deaths have been reported.

Illnesses that occurred after May 12, 2013 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks.

May 10, 2013

Case Count Update

CDC is collaborating with public health and agriculture officials in many states and the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA-APHIS) to investigate multiple outbreaks of human Salmonella infections linked to contact with live poultry. This outbreak of human Salmonella Typhimurium infections is not related to the current outbreak of human Salmonella Infantis, Lille, Newport, and Mbandaka infections linked to live poultry.

Public health investigators are using the PulseNet system to identify cases of illness that may be part of this outbreak. In PulseNet, the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC, DNA “fingerprints” of Salmonella bacteria are obtained through diagnostic testing with pulsed-field gel electrophoresis, or PFGE, to identify cases of illness that may be part of this outbreak.

As of May 7, 2013, a total of 146 persons infected with the outbreak strain of Salmonella Typhimurium have been reported from 26 states. The number of ill persons identified in each state is as follows: Arizona (5), California (3), Colorado (16), Florida (2), Indiana (4), Iowa (2), Kansas (10), Louisiana (5), Minnesota (2), Mississippi (3), Missouri (9), Nebraska (9), Nevada (1), New Hampshire (1), New Mexico (10), New York (8), North Dakota (1), Oklahoma (9), Oregon (5), South Dakota (6), Texas (19), Utah (3), Vermont (1), Virginia (1), Washington (10), and Wyoming (1).

Among the persons who reported the date they became ill, illnesses began between and March 4, 2013 and April 26, 2013. Ill persons range in age from less than one year to 70 years, and 66% of ill persons are 10 years of age or younger. Fifty-one percent of ill persons are female. Among 91 ill persons with available information, 27 (30%) have been hospitalized. No deaths have been reported.

This outbreak can be visually described with a chart showing the number of persons who became ill each day. This chart is called an epidemic curve or epi curve. Illnesses that occurred after April 14, 2013 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of 2 to 4 weeks. Please see the Salmonella Outbreak Investigations: Timeline for Reporting Cases for more details.

Investigation Update

In interviews, ill persons answered questions about contact with animals and foods consumed during the week before becoming ill. Eighty-three (94%) of 88 ill persons interviewed reported contact with live poultry (e.g., chicks, chickens, ducks, ducklings) before becoming ill. Seventy-three (97%) of 75 ill persons with available purchase information reported purchasing live baby poultry from various locations of 13 different agricultural feed store companies in multiple states. Ill persons reported purchasing live poultry for backyard flocks to produce eggs or meat, or to keep as pets.

State health departments have tested samples collected from chicks in ill persons’ homes and retail locations. Samples collected by New Mexico and Vermont yielded the outbreak strain of Salmonella Typhimurium.

Traceback investigations to determine the source of live baby poultry from homes of ill persons have identified multiple feed stores and mail-order hatcheries in multiple states. Investigations are ongoing to determine the source of the live poultry linked to this outbreak.

Contact with live poultry can be a source of human Salmonella infections. Some ill persons in this outbreak reported bringing the live poultry into their homes and kissing or cuddling with the live poultry. These behaviors increase a person’s risk of a Salmonella infection from contact with live poultry. Always wash hands thoroughly with soap and water right after touching live poultry or anything in the area where they live and roam. Adults should supervise hand washing for young children. Additional recommendations are available. These recommendations are important and apply to all live poultry regardless of the age of the birds or where they were purchased.

Mail-order hatcheries, agricultural feed stores, and others who sell or display chicks, ducklings, and other live poultry should provide health-related information to owners and potential purchasers of these birds prior to the point of purchase. This should include information about the risk of acquiring a Salmonella infection from contact with live poultry.

Initial Announcement

April 25, 2013

CDC is collaborating with public health and agriculture officials in many states and the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA-APHIS) to investigate multistate outbreaks of human Salmonella Infantis, Salmonella Mbandaka, and Salmonella Typhimurium infections linked to contact with chicks, ducklings, and other live poultry.

Public health investigators are using the PulseNet system to identify cases of illness that may be part of these outbreaks. In PulseNet, the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC, DNA “fingerprints” of Salmonella bacteria are obtained through diagnostic testing with pulsed-field gel electrophoresis, or PFGE, to identify cases of illness that may be part of this outbreak. The USDA-NPIP is a program that is intended to eliminate certain strains of Salmonella that cause illness in poultry breeding flocks and hatcheries, but does not certify that these live poultry are free from other strains of Salmonella that may cause human illness.

In interviews, ill people reported purchasing live baby poultry (e.g., chicks, ducklings) from multiple feed stores and mail-order hatcheries. Investigations are ongoing to determine the source of the live poultry in these outbreaks.

Contact with live poultry, including baby or adult birds, can be a source of human Salmonella infections. These birds typically appear healthy and clean, but can be shedding germs that can make people sick. Always wash hands thoroughly with soap and water right after touching live poultry or anything in the area where they live and roam. Adults should supervise hand washing for young children. Additional recommendations are available. These recommendations are important and apply to all live poultry regardless of the age of the birds or where they were purchased.

Mail-order hatcheries, agricultural feed stores, and others who sell or display chicks, ducklings and other live poultry should provide health-related information to owners and potential purchasers of these birds prior to the point of purchase.This should include information about the risk of acquiring Salmonella infection from contact with live poultry.

This investigation is ongoing and CDC will update the public when additional information is available.