Outbreak Investigation Updates by Date

Posted August 30, 2019 at 1:00 PM ET

July 19, 2019

CDC and public health officials in several states are investigating multiple multistate outbreaks of Salmonella infections with serotypes Agona, Alachua, Anatum, Braenderup, Enteritidis, Infantis, Manhattan, Montevideo, Muenchen, Newport, and Oranienburg linked to contact with backyard poultry.

Public health investigators are using the PulseNet system to identify illnesses that may be part of these outbreaks. PulseNet is the national subtyping network of public health laboratories coordinated by CDC. DNA fingerprinting is performed on Salmonella bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on Salmonella from ill people in this outbreak showed that they are closely related genetically. This means that the ill people are more likely to share a common source of infection.

As of July 12, 2019, a total of 768 people infected with the outbreak strains of Salmonella have been reported from 48 states. A list of the states and the number of cases in each is on the map of reported cases page.

Illnesses started on dates from January 1, 2019, to July 6, 2019. Ill people range in age from less than one year to 99 years, with a median age of 30 years. One hundred fifty-six ill people (24%) of 648 people with information are children younger than 5 years.  Fifty-seven percent are female. Of 419 people with information available, 122 (29%) have been hospitalized. Two deaths have been reported.

WGS analysis of 117 isolates from ill people predicted antibiotic resistance to one or more of the following drugs: amoxicillin-clavulanic acid, ampicillin, cefoxitin, ceftriaxone, chloramphenicol, ciprofloxacin, fosfomycin, gentamicin, kanamycin, nalidixic acid, streptomycin, sulfisoxazole, tetracycline, and trimethoprim-sulfamethoxazole. Testing of 5 isolates using standard antibiotic susceptibility testing by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory confirmed these results (fosfomycin and kanamycin were not tested by this method). If antibiotics are needed, this resistance profile may affect the choice of antibiotic.

WGS analysis of an additional 350 isolates from ill people did not show evidence of antibiotic resistance. Testing of 7 isolates using standard antibiotic susceptibility testing by CDC’s NARMS laboratory confirmed these results.

Five of the outbreak strains making people sick have been identified in samples collected from backyard poultry environments in four states. The sampling was from backyard poultry environments in ill people’s homes in California and Ohio and from poultry environments at retail stores in Michigan and Oregon. Additional testing in several states is being conducted.

In interviews, ill people answered questions about animal contact in the week before they became ill. Of 315 people interviewed, 237 (75%) reported contact with backyard poultry before becoming ill. Ill people reported buying poultry from various sources, including agricultural stores, websites, and hatcheries.

Backyard poultry from multiple hatcheries are the likely source of these outbreaks. Regardless of where poultry are purchased, they can carry Salmonella germs that can make people sick. Backyard poultry owners should always follow steps to stay healthy around their poultry.

This investigation is ongoing, and CDC will provide updates when more information becomes available.

June 13, 2019

CDC and public health officials in several states are investigating multiple multistate outbreaks of Salmonella infections with serotypes Agona, Anatum, Braenderup, Infantis, Montevideo, and Newport linked to contact with backyard poultry.

Public health investigators are using the PulseNet system to identify illnesses that may be part of these outbreaks. PulseNet is the national subtyping network of public health laboratories coordinated by CDC. DNA fingerprinting is performed on Salmonella bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on Salmonella from ill people in this outbreak showed that they are closely related genetically. This means that the ill people are more likely to share a common source of infection.

As of June 7, 2019, a total of 279 people infected with the outbreak strains of Salmonella have been reported from 41 states. A list of the states and the number of cases in each is on the map of reported cases page.

Illnesses started on dates from January 1, 2019, to May 24, 2019. Ill people range in age from less than one year to 92 years, with a median age of 25 years. Fifty-seven percent are female. Of 152 people with information available, 40 (26%) have been hospitalized. No deaths have been reported.

WGS analysis of 24 isolates from ill people predicted antibiotic resistance to amoxicillin-clavulanic acid, ampicillin, cefoxitin, ceftriaxone, fosfomycin, gentamicin, kanamycin, streptomycin, sulfisoxazole, tetracycline, or trimethoprim-sulfamethoxazole. An additional 35 isolates from ill people did not show evidence of antibiotic resistance. Testing of five outbreak isolates using standard antibiotic susceptibility testing by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory confirmed these results (fosfomycin and kanamycin were not tested by this method). This resistance may affect the choice of antibiotic used to treat some people.

One of the outbreak strains making people sick was identified in samples collected from backyard poultry in Ohio.  Additional testing in several states is being conducted.

In interviews, ill people answered questions about animal contact in the week before they became ill. Of 153 people interviewed, 118 (77%) reported contact with backyard poultry before becoming ill. Ill people reported buying poultry from various sources, including agricultural stores, websites, and hatcheries.

Backyard poultry from multiple hatcheries are the likely source of these outbreaks. Regardless of where poultry are purchased, they can carry Salmonella germs that can make people sick. Backyard poultry owners should always follow steps to stay healthy around their poultry.

This investigation is ongoing, and CDC will provide updates when more information becomes available.

May 16, 2019

CDC and public health officials in several states are investigating multistate outbreaks of Salmonella Braenderup and Salmonella Montevideo infections linked to contact with backyard poultry.

Public health investigators are using the PulseNet system to identify illnesses that may be part of these outbreaks. PulseNet is the national subtyping network of public health laboratories coordinated by CDC. DNA fingerprinting is performed on Salmonella bacteria isolated from ill people by using techniques called pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). CDC PulseNet manages a national database of these DNA fingerprints to identify possible outbreaks. WGS gives a more detailed DNA fingerprint than PFGE. WGS performed on Salmonella from ill people in this outbreak showed that they are closely related genetically. This means that the ill people are more likely to share a common source of infection.

As of May 10, 2019, a total of 52 people infected with the outbreak strains of Salmonella have been reported from 21 states. A list of the states and the number of cases in each is on the map of reported cases page.

Illnesses started on dates from January 12, 2019, to April 29, 2019. Ill people range in age from less than one year to 60 years, with a median age of 21 years. Fifty-six percent are female. Of 27 people with information available, 5 (19%) have been hospitalized. No deaths have been reported.

WGS analysis of four isolates from ill people predicted antibiotic resistance to amoxicillin-clavulanic acid, ampicillin, cefoxitin, ceftriaxone, or tetracycline. An additional five isolates from ill people did not show evidence of antibiotic resistance. Testing of outbreak isolates using standard antibiotic susceptibility testing by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory is currently underway. This resistance may affect the choice of antibiotic used to treat some people.

In interviews, ill people answered questions about animal contact in the week before they became ill. Of 33 people interviewed, 23 (70%) reported contact with backyard poultry before becoming ill. Ill people reported buying poultry from various sources, including agricultural stores, websites, and hatcheries.

Backyard poultry from multiple hatcheries are the likely source of these outbreaks. Regardless of where poultry are purchased, these birds can carry Salmonella germs that can make people sick. Backyard poultry owners should always follow steps to stay healthy around their birds.

This investigation is ongoing, and CDC will provide updates when more information becomes available.