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Notes from the Field: Hepatitis C Outbreak in a Dialysis Clinic — Tennessee, 2014

Daniel Muleta, MD1; Marion A. Kainer, MBBS1; Loretta Moore-Moravian1; Andrew Wiese MPH1; Jennifer Ward MSc1; Sheila McMaster, MSN2; Duc Nguyen, MD3; Joseph C. Forbi, PhD4; Tonya Mixson-Hayden, PhD4; Melissa Collier, MD4

Outbreaks of hepatitis C virus (HCV) infections can occur among hemodialysis patients when recommended infection control practices are not followed (1). On January 30, 2014, a dialysis clinic in Tennessee identified acute HCV in a patient (patient A) during routine screening and reported it to the Tennessee Department of Health. Patient A had enrolled in the dialysis clinic in March 2010 and had annually tested negative for HCV (including a last HCV test on December 19, 2012), until testing positive for HCV antibodies (anti-HCV) on December 18, 2013 (confirmed by a positive HCV nucleic acid amplification test). Patient A reported no behavioral risk factors, but did have multiple health care exposures.

On April 16, 2014, the Tennessee Department of Health observed infection control practices at the clinic. Clinic officials reported that no changes to infection control protocols at the dialysis clinic had been made from the time patient A was identified to this date of observation. The health department observers noted that no visible blood was present on any surfaces, sinks were easily accessible, staff hand hygiene was performed consistently, and gloves and other personal protective equipment were used appropriately. Individual patient stations were disinfected after the previous patient left the station, with a 1:100 diluted household bleach solution, and surfaces were allowed to dry completely between patients. Medications were prepared for each patient in a separate, clean medication room at the time of administration; no multidose medication vials were carried into patient care areas. Blood for glucose testing was drawn from dialysis access sites with a syringe and tested by a glucometer in the laboratory. The glucometer was adequately disinfected between uses. Monthly trainings in infection control had been consistently provided to all staff members before the outbreak was identified.

Sixty-two dialysis patients were being treated at the clinic at the time of the investigation; all were retested for HCV. Nine (15%) patients, including patient A, were HCV-infected; specimens from patient A and five other chronically infected dialysis patients were positive for HCV genotype 1a (Figure), the remaining three were positive for genotype 1b. Genotype 1a is the most prevalent genotype in the United States (2). Patient B, who seroconverted in December 2010, had a history of injection drug use, which, at the time of diagnosis, was considered to be the source of exposure. Patient C was chronically infected and had tested positive for HCV upon admission at the dialysis clinic. Infection duration for all other HCV infected patients, including patient C, was unknown.

Quasispecies (HCV intra-genotype variants) analysis was performed from serum specimens collected from all nine patients found to be HCV positive. Patients A, B, and C were infected with genotype 1a; less than 5% nucleotide variation among intra-host HCV sequences was detected among the three patients, suggesting epidemiologic linkage of these infections (Figure). On separate occasions, patients A and B underwent dialysis on the same machine following patient C, during the most likely exposure periods (January–May 2013 for patient A and November 2009–June 2010 for patient B). Hospitalization events for patients A, B, and C during the likely exposure periods did not overlap in space and time. No other common exposures were identified.

No specific event or practice was identified at the dialysis center that could have led to HCV transmission. However, the limited infection control practice observation time or unreported changes in practice between the transmission event and Tennessee Department of Health infection control observations might have affected these observations. The laboratory findings, the common station use, and the absence of other shared exposures support infection of patients A and B during dialysis at the clinic.

Following CDC recommendations (3) for HCV screening of dialysis patients by performing anti-HCV testing every 6 months and reporting new anti-HCV seroconversions (4) to local health departments are important practices for dialysis clinics. More rigorous HCV screening regimens, combined with timely reporting of seroconversions to public health officials, will facilitate investigation and infection control improvement recommendations to prevent future infections. Even a single reported case of acute HCV infection in a hemodialysis patient warrants health department investigation, because it might represent intra-facility transmission.

1Tennessee Department of Health; 2End Stage Renal Disease Network 8, Ridgeland, Mississippi;3Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Diseases, CDC; 4Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC.

Corresponding author: Daniel Muleta,, 615-532-6633.


  1. CDC. Viral hepatitis—healthcare-associated hepatitis B and C outbreaks reported to the Centers for Disease Control and Prevention (CDC) 2008–2014. Atlanta, GA: US Department of Health and Human Services, CDC; 2015. Available at
  2. Messina JP, Humphreys I, Flaxman A, et al. Global distribution and prevalence of hepatitis C virus genotypes. Hepatology 2015;61:77–87.
  3. CDC. Recommendations for preventing transmission of infections among chronic hemodialysis patients. MMWR Recomm Rep 2001;50(No. RR-5).
  4. CDC. National Notifiable Diseases Surveillance System: hepatitis C, acute. Atlanta, GA: US Department of Health and Human Services, CDC; 2012. Available at

FIGURE. Nucleotide variation in hepatitis C quasispecies (E1-HVR1 region, 306 base pairs in length) among six patients* at a dialysis clinic — Tennessee, 2014

The figure is a diagram of a nucleotide variation in hepatitis C quasispecies (E1-HVR1 region, 306 base pairs in length) among six patients at a dialysis clinic in Tennessee during 2014.

* Patient C's hepatitis C test was positive on entry to the dialysis clinic; patients A and B seroconverted after beginning dialysis. Patients D, E, and F are other chronic hepatitis C-infected patients in treatment at the clinic, and were not genetically linked to the outbreak.

Alternate Text: The figure above is a diagram of a nucleotide variation in hepatitis C quasispecies (E1-HVR1 region, 306 base pairs in length) among six patients at a dialysis clinic in Tennessee during 2014.

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