Outbreak Investigations in Healthcare Settings

CDC works with health departments and federal agencies, such as the United States Food and Drug Administration (FDA)external icon, to protect patients and stop outbreaks from spreading in healthcare facilities. Often, these outbreaks are the result of either failures in infection control practices or contaminated equipment or medications.

During some outbreak situations, CDC sends experts to work side-by-side with facility and health department staff. For example, state health departments may contact CDC and request assistance through a process known as an Epi-Aid. Typically, these efforts include on-site assistance, laboratory support and additional consultation with experts at CDC headquarters. CDC advises the public about what they can do to protect themselves, provides recommendations to the medical and public health community about how to prevent future infections, and works closely with policymakers, regulatory agencies and industry to learn how to prevent similar outbreaks in the future.

In addition to formal Epi-Aid investigations, CDC routinely provides consultation and laboratory assistance to healthcare facilities and health departments that are working to solve outbreaks or investigate infection control breaches and other adverse events.

Epi-Aid Investigations Supported by CDC’s Division of Healthcare Quality Promotion

Contaminated Medical Solution

Summary: Bacterial contamination of organ preservation solution used in transplant surgery. Potentially contaminated products were removed from distribution by manufacturer.
Facility Type: Hospital
Infection Type: None
Pathogen: Pantoea agglomerans, Enterococcus casseliflavus
When: January 2017
Where: Iowa/ Texas
Related Education/Training Materials:
https://idsa.confex.com/idsa/2017/webprogram/Paper65426.html external icon

 

Transmission of Fungal Infection in Hospitals

Summary: Candida auris transmission at several healthcare facilities. Infection control practices were assessed and risk factors for infection were evaluated.
Facility Type: Nursing home/Hospital
Infection Type: Multiple
Pathogen: Candida auris
When: June 2017
Where: New Jersey
Related Education/Training Materials:
www.cdc.gov/mmwr/volumes/66/wr/mm6619a7.htm

 

Legionnaires’ Disease Cases

Summary: Several cases of hospital-associated Legionnaires’ disease associated with a single facility. Water management program deficiencies were identified as a possible contributing factor.
Facility Type: Hospital
Infection Type: Pulmonary
Pathogen: Legionella pneumophila
When: September 2017
Where: Georgia
Related Education/Training Materials:
www.cdc.gov/legionella/outbreaks.html
www.cdc.gov/legionella/about/index.html

 

Fungal Infections in Immunocompromised Patients

Summary: A cluster of mucormycosis infections in patients with hematologic malignancies, stem cell transplants, and solid organ transplants. Investigation involved environmental assessment. No single source of infection was identified.
Facility Type: Hospital
Infection Type: Multiple
Pathogen: Rhizopus species
When: November 2017
Where: Illinois
Related Education/Training Materials:
www.cdc.gov/fungal/diseases/mucormycosis/index.html

Sepsis at Hospitals

Summary:  An investigation was conducted to identify risk factors for septic shock and severe sepsis in 3 acute care hospitals by conducting a retrospective medical record review. Risk factors among adults included diabetes mellitus, cardiovascular disease, chronic kidney disease, and chronic obstructive pulmonary disease. The most common risk factor among children was cognitive deficits or cerebral palsy and among infants was congenital heart disease.
Facility Type: Hospital
Infection Type: Multi-organ
Pathogen: Multiple
When: January 2016
Where: New York
Related Education/Training Materials:
www.cdc.gov/mmwr/volumes/65/wr/mm6533e1.htm
www.cdc.gov/sepsis/basic/index.html

 

Elizabethkingia Infections at Multiple Facilities

Summary: Large outbreak of Elizabethkingia anophelis infections in southeast Wisconsin. Patients had various healthcare exposures but no common exposure was identified among the majority of patients and epidemiology did not suggest patient-to-patient transmission. After an extensive investigation, no healthcare or community cause of the outbreak was determined.
Facility Type: Multiple
Infection Type: Bloodstream
Pathogen: Elizabethkingia anophelis
When: January 2016
Where: Wisconsin
Related Education/Training Materials:
www.cdc.gov/elizabethkingia/about/index.html
www.dhs.wisconsin.gov/disease/elizabethkingia.htm external icon

 

Blood Transfusion Safety

Summary: In order to implement procedures to prevent transfusion-transmitted Zika virus, CDC assisted with an assessment of blood collection and utilization.
Facility Type: Inpatient/outpatient
Infection Type: None
Pathogen: Zika virus
When: February 2016
Where: Puerto Rico
Related Education/Training Materials:
www.cdc.gov/zika/transmission/blood-transfusion.html
www.cdc.gov/zika/index.html

 

Wound Infections at Nursing Home

Summary: An outbreak of group A Streptococcus wound infections at a nursing home. The investigation identified inconsistencies in hand hygiene and wound care practices as possible contributing factors.
Facility Type: Nursing home
Infection Type: Skin and soft tissue
Pathogen: Group A Streptococcus
When: March 2016
Where: Illinois
Related Education/Training Materials:
www.cdc.gov/groupastrep/index.html

 

Fungal Infections Among Oncology Patients

Summary: An outbreak of fungal bloodstream infections at an outpatient oncology clinic. During the investigation, practices in performing medication compounding and storage, reuse of single-use medications, and infusion practices were identified as possible contributing factors.
Facility Type: Outpatient oncology clinic
Infection Type: Bloodstream
Pathogen: Exophiala dermatitidis, Rhodotorula mucilaginosa
When: May 2016
Where: New York
Related Education/Training Materials:
www.cdc.gov/mmwr/volumes/65/wr/mm6545a6.htm
https://academic.oup.com/cid/article/66/6/959/4602217external icon

 

Antimicrobial Resistant Escherichia coli Infection

Summary: A patient was identified with Escherichia coli harboring mcr-1 following travel to the Dominican Republic. Colonization screening among contacts was performed and environmental swabs were collected. All colonization screening and environmental samples were negative for mcr-1 E. Coli.
Facility Type: Outpatient clinic; community
Infection Type: Gastrointestinal
Pathogen: Escherichia coli
When: July 2016
Where: Connecticut
Related Education/Training Materials:
www.cdc.gov/mmwr/volumes/65/wr/mm6536e3.htm
www.cdc.gov/drugresistance/tracking-mcr1.html

 

Outbreak of Surgical Site Infections

Summary: An outbreak of nontuberculous mycobacteria surgical site infections among plastic surgery patients. The investigation identified bacteria in the hospital water distribution system as the likely source.
Facility Type: Hospital
Infection Type: Breast
Pathogen: Nontuberculous mycobacteria
When: July 2016
Where: South Carolina
Related Education/Training Materials:
www.cdc.gov/hai/ssi/ssi.html

 

Bloodstream Infections at Hemodialysis Clinics

Summary: An outbreak of 58 Gram-negative bloodstream infections at three outpatient dialysis clinics of the same company. Wall boxes, the water source in the dialysis station, were found to be the source of the infections, and suboptimal practices in hand hygiene and vascular care were identified as possible contributing factor.
Facility Type: Outpatient hemodialysis clinic
Infection Type: Bloodstream
Pathogen: Various Gram-negative bacteria, predominantly Serratia marcescens and Pseudomonas aeruginosa
When: August 2016
Where: Illinois and Missouri
Related Education/Training Materials:
www.cdc.gov/dialysis/index.html

 

Cases of Resistant Bacteria at Hospital

Summary: New cases of carbapenem-resistant Enterobacteriaceae at a community hospital. CDC assisted with whole-genome sequencing on collected samples.
Facility Type: Hospital
Infection Type: Multiple sites of infections or colonization
Pathogen: Klebseilla pneumoniae, Escherichia coli
When: September 2016
Where: Kentucky
Related Education/Training Materials:
www.cdc.gov/hai/organisms/cre/index.html
www.cdc.gov/mmwr/volumes/66/wr/mm665152a5.htm

 

Hospital-Associated Outbreak of Fungal Infections in Colombia

Summary: Outbreak of Candida auris infections in Colombian hospitals. An investigation was conducted to determine clinical risk factors for developing C. auris infections and environmental sampling was performed.
Facility Type: Hospital
Infection Type: Multiple
Pathogen: Candida auris
When: October 2016
Where: Columbia
Related Education/Training Materials:
https://wwwnc.cdc.gov/eid/article/23/1/16-1497_article
https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciy411/4996781external icon

 

Cluster of Eye Infections Across Several Clinics

Summary: Cluster of epidemic keratoconjunctivitis cases across several ophthalmology and optometry clinics. Investigation identified contaminated surfaces as a possible contributing factor.
Facility Type: Ophthalmology/optometry clinics
Infection Type: Ocular (eyes)
Pathogen: Adenovirus
When: October 2016
Where: U.S. Virgin Islands
Related Education/Training Materials:
www.cdc.gov/mmwr/volumes/66/wr/mm6630a3.htm

 

Infections Caused by Waterborne Pathogen in Neonatal Intensive Care Unit

Summary: An outbreak of Pseudomonas aeruginosa infections within a neonatal intensive care unit. Investigation identified exposure to contaminated water during sink use, breast milk preparation, reprocessing of breast pump equipment, and humidifier use as possible contributing factors.
Facility Type: Hospital
Infection Type: Multiple
Pathogen: Pseudomonas aeruginosa
When: November 2016
Where: Maryland
Related Education/Training Materials:
www.cdc.gov/hai/organisms/pseudomonas.html

 

Outbreak of Drug Resistant Fungal Infections

Summary: An outbreak of Candida auris fungal infections, some with antifungal resistance. Healthcare-associated transmission of C. auris was identified for the first time in the United States. Patient colonization and contamination of the healthcare environment with C. auris was documented.
Facility Type: Nursing home/hospital
Infection Type: Multiple
Pathogen: Candida auris
When: October and December 2016
Where: New York
Related Education/Training Materials:
https://www.health.ny.gov/press/releases/2017/2017-05-05_c_auris.htmexternal icon
www.cdc.gov/mmwr/volumes/65/wr/mm6544e1.htm?s_cid=mm6544e1_e

Blood and Wound Infections in Nursing Home Patients

Summary: A cluster of group A Streptococcus bloodstream infections identified in residents of a nursing home. Inconsistencies in hand hygiene and wound care practices were identified as possible contributing factors.
Facility Type: Nursing home
Infection Type: Bloodstream and skin and soft tissue
Pathogen: Group A Streptococcus
When: March 2015
Where: South Carolina
Related Education/Training Materials:
www.cdc.gov/groupastrep/index.html

 

Hepatitis Cases After Unsafe Injections

Summary: Investigation identified reuse of syringes to access medication for multiple patients as a possible contributing factor.
Facility Type: Outpatient clinic
Infection Type: Hepatic (Liver)
Pathogen: Hepatitis C
When: March 2015
Where: California
Related Education/Training Materials:
www.cdc.gov/mmwr/volumes/65/wr/mm6521a4.htm?s_cid=mm6521a4_e
www.cdc.gov/injectionsafety/index.html

 

Hepatitis Cases in Dialysis Patients

Summary: Sixteen hepatitis C seroconversion cases at 9 dialysis clinics. The investigation identified lapses in infection control that may have contributed to transmission including hand hygiene, medication preparation and administration, cleaning and disinfection of environmental surfaces, and vascular access care.
Facility Type: Outpatient hemodialysis clinic
Infection Type: Hepatic (Liver)
Pathogen: Hepatitis C
When: March 2015
Where: New Jersey
Related Education/Training Materials:
www.cdc.gov/dialysis/index.html
www.cdc.gov/hepatitis/index.htm
https://www.ajkd.org/article/S0272-6386%2816%2900412-1/pdfexternal icon

 

Fungal Infections Among Bone Marrow Transplant Patients

Summary: A cluster of mucormycosis infections in a bone marrow transplant unit. The investigation identified patient exposure to a negative pressure medication administration room and construction practices near patient rooms as possible contributing factors.
Facility Type: Hospital
Infection Type: Pulmonary, skin and soft tissue
Pathogen: Mucor species
When: April 2015
Where: Colorado
Related Education/Training Materials:
www.cdc.gov/fungal/diseases/mucormycosis/index.html

 

Nontuberculous Mycobacteria Infections at Hospital

Summary: An outbreak of Mycobacterium avium complex infections among cardiac surgery patients. Investigation identified contaminated heater-cooler devices and device design and maintenance as the source of the infections.
Facility Type: Hospital
Infection Type: Multiple
Pathogen: Mycobacterium avium complex
When: July 2015
Where: Pennsylvania
Related Education/Training Materials:
www.cdc.gov/HAI/pdfs/outbreaks/CDC-Notice-Heater-Cooler-Units-final-clean.pdfpdf icon
https://wwwnc.cdc.gov/eid/article/22/6/16-0045_article

 

Fungal Infections in Organ Transplant Patients

Summary: An outbreak of mucormycosis infections in a cardiothoracic surgery intensive care unit. The investigation identified placement of immunocompromised patients in negative pressure rooms as a possible contributing factor.
Facility Type: Hospital
Infection Type: Pulmonary, skin and soft tissue
Pathogen: Mucor species
When: September 2015
Where: Pennsylvania
Related Education/Training Materials:
www.cdc.gov/mmwr/volumes/65/wr/mm6518a5.htm
www.cdc.gov/fungal/diseases/mucormycosis/index.html

 

Gastrointestinal Infections in Neonatal Intensive Care Unit

Summary: An outbreak of necrotizing enterocolitis (severe gastrointestinal infections) leading to five deaths in a neonatal intensive care unit. Inconsistencies in hand hygiene and formula preparation practices were identified as possible contributing factors.
Facility Type: Hospital
Infection Type: Gastrointestinal
Pathogen: Unknown
When: October 2015
Where: Illinois
Related Education/Training Materials:
https://rarediseases.info.nih.gov/diseases/9767/diseaseexternal icon

 

Group A Streptococcus Infections at Nursing Home

Summary: A Group A Streptococcus outbreak among staff and residents at one nursing home. The investigation identified inconsistencies in hand hygiene and personal protective equipment practices as possible contributing factors.
Facility Type: Nursing home
Infection Type: Skin and soft tissue
Pathogen: Group A Streptococcus
When: November 2015
Where: Illinois
Related Education/Training Materials:
https://www.ncbi.nlm.nih.gov/pubmed/29783026?dopt=Abstractexternal icon
www.cdc.gov/groupastrep/index.html

 

Cardiac Arrests During Hemodialysis

Summary: Unknown cause of cardiac arrest in 6 patients undergoing outpatient hemodialysis at three clinics. Case review and case-control study did not reveal risk factors associated with the event.
Facility Type: Outpatient hemodialysis clinic
Infection Type: Unknown whether infectious related
Pathogen: Unknown whether pathogen associated
When: December 2015
Where: Connecticut
Related Education/Training Materials:
www.cdc.gov/dialysis/index.html

Bloodstream Infections in a Nursing Home

Summary: A cluster of bloodstream infections identified in residents of a nursing home. CDC recommended enhanced environmental cleaning, better access to hand hygiene products, and stool testing of close contacts of case-patients.
Facility Type: Nursing home
Infection Type: Bloodstream
Pathogen: Salmonella
When: January 2014
Where: New York
Related Education/Training Materials:
www.cdc.gov/salmonella/index.html

 

Infections Among Cancer Patients

Summary: A cluster of Bacillus cereus infections identified in hospital patients with myeloid leukemia. Investigation identified dietary exposures as a possible contributing factor.
Facility Type: Hospital
Infection Type: Neurologic
Pathogen: Bacillus cereus
When: February 2014
Where: Massachusetts
Related Education/Training Materials:
www.cdc.gov/cancer/preventinfections/index.htm
https://academic.oup.com/ofid/article/2/3/ofv096/2460317external icon

 

Antibiotic Resistant Bacteria Found in Hospital Patients

Summary: A cluster of patients carrying a bacteria with carbapenem resistance. Investigation identified a contaminated medical device as a possible contributing factor.
Facility Type: Hospital
Infection Type: Multiple sites of infections or colonization
Pathogen: Plasmid-mediated AmpC-producing E. coli
When: February 2014
Where: Washington (state)
Related Education/Training Materials:
www.cdc.gov/hai/organisms/cre/index.html
https://www.ncbi.nlm.nih.gov/pubmed/external icon

 

First U.S. Case of Middle East Respiratory Syndrome Coronavirus (MERS-CoV)

Summary: A patient tested positive for MERS-CoV infection and was hospitalized after traveling from Saudi Arabia. CDC monitored possible contacts and updated guidelines for evaluating possible MERS-CoV patients.
Facility Type: Hospital
Infection Type: Pulmonary
Pathogen: MERS-CoV
When: May 2014
Where: Indiana
Related Education/Training Materials:
www.cdc.gov/mmwr/preview/mmwrhtml/mm6319a4.htm
www.cdc.gov/coronavirus/mers/index.html

 

Response to Novel Coronovirus in United Arab Emirates

Summary: Middle East Respiratory Syndrome Coronavirus (MERS-CoV) outbreak in United Arab Emirates. Infection control practices were assessed and case-control studies were conducted to investigate risk factors for transmission in hospital and community settings.
Facility Type: Hospital/community
Infection Type: Pulmonary
Pathogen: MERS-CoV
When: May 2014
Where: United Arab Emirates
Related Education/Training Materials:
https://wwwnc.cdc.gov/eid/article/22/7/16-0040_article
www.cdc.gov/coronavirus/mers/index.html

 

Pseudomonas aeruginosa Infections in Neonatal Intensive Care Unit

Summary: Deaths and infections among infants in a neonatal intensive care unit due to Pseudomonas aeruginosa. Investigation identified the hospital water system as a possible contributing factor.
Facility Type: Hospital
Infection Type: Bloodstream and pulmonary
Pathogen: Pseudomonas aeruginosa
When: September 2014
Where: California
Related Education/Training Materials:
www.cdc.gov/HAI/organisms/Pseudomonas.html
https://cste.confex.com/cste/2015/webprogram/Paper4719.htmlexternal icon

 

Bloodstream Infections in Patients Undergoing Dialysis Treatment

Summary: A cluster of 17 bloodstream infections among patients undergoing hemodialysis likely caused by contamination during reprocessing of reusable dialyzers.
Facility Type: Outpatient dialysis clinic
Infection Type: Bloodstream
Pathogen: Burkholderia cepacia and Stenotrophomonas maltophilia
When: September 2014
Where: California
Related Education/Training Materials:
www.cdc.gov/dialysis/index.html
https://cste.confex.com/cste/2015/webprogram/Paper4671.htmlexternal icon
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5441929/external icon

 

Ebola Importation and Transmission in the United States

Summary: Healthcare workers contracted Ebola while caring for a patient with the disease. CDC developed new guidance for infection control and for assessing risk of Ebola exposure.
Facility Type: Hospital
Infection Type: Multi-organ
Pathogen: Ebola Virus
When: October 2014
Where: Texas
Related Education/Training Materials:
www.cdc.gov/mmwr/preview/mmwrhtml/mm6346a11.htm?s_cid=mm6346a11_w
www.cdc.gov/ebola/

 

Fungal Infections among Hematologic Cancer Patients

Summary: A cluster of mucormycosis infections among hematologic cancer patients. Investigation identified construction in adjacent units as a possible contributing factor.
Facility Type: Hospital
Infection Type: Pulmonary and rhinocerebral (sinuses, oral and nasal cavities, or brain)
Pathogen: Mucor species
When: December 2014
Where: Kansas
Related Education/Training Materials:
www.cdc.gov/fungal/diseases/mucormycosis/definition.html