Description of a Hepatitis C Outbreak in a Cancer Clinic

Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine.

Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians.

The summary below is from the full report titled "An Outbreak of Hepatitis C Virus Infections among Outpatients at a Hematology/Oncology Clinic." It is in the 7 June 2005 issue of Annals of Internal Medicine (volume 142, pages 898-902). The authors are A. Macedo de Oliveira, K.L. White, D.P. Leschinsky, B.D. Beecham, T.M. Vogt, R.L. Moolenaar, J.F. Perz, and T.J. Safranek.

What is the problem and what is known about it so far?

Hepatitis C virus (HCV) causes liver inflammation. The virus is most commonly transmitted when a person comes in close contact with infected blood, usually by being stuck with a needle, as in injection drug use, body piercing, or tattooing. Outbreaks of HCV infection are unusual, especially in health care settings. In 2002, officials in Nebraska learned of a possible HCV outbreak involving 4 patients. The only common factor among these patients was treatment at the same cancer clinic. The officials suspected that the patients somehow became infected from the treatment they received in the clinic.

Why did the researchers do this particular study?

To confirm that HCV was transmitted in the clinic, to determine how many people were affected, and to identify how it was transmitted.

Who was studied?

367 patients seen at the clinic between March 2000 and July 2001.

How was the study done?

The researchers took blood from each of the patients for HCV testing. They interviewed the patients and clinic staff and looked closely at the patients' medical charts to identify possible causes of infection.

What did the researchers find?

Slightly more than one quarter of patients became infected from treatment they received in the cancer clinic. All were treated on days when another patient who already had hepatitis C was also treated. The researchers discovered that a nurse often took blood from intravenous catheters using a disposable syringe. The nurse reused this syringe to take saline solution out of bags to flush the catheters. The nurse probably contaminated the syringe and saline solution with HCV from the patient who already had the infection and spread it to subsequent patients by flushing their catheters with contaminated saline. The outbreak ended when the nurse was dismissed and this practice was stopped.

What are the limitations of the study?

More than 200 patients had died of cancer before the study began, so the researchers could not identify all of the patients who were probably infected. Because the researchers did not take blood from clinic staff, they could not exclude the possibility that the infection was spread from workers to patients.

What are the implications of the study?

Reuse of disposable syringes in a cancer clinic caused a hepatitis C outbreak. The outbreak could have been prevented by using sterile syringes for each patient and not reusing contaminated syringes in saline bags. Careful adherence to simple infection-control standards can prevent many infection outbreaks. When those standards are violated, prompt recognition and correction of the violations are necessary to limit the spread of infection.