Investigation of Viral Hepatitis Infections Possibly Associated with Health-Care Delivery — New York City, 2008–2011

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are important causes of morbidity and mortality in the United States. Because HBV and HCV are transmitted efficiently percutaneously, possible transmission in health-care settings is of particular concern. Public health investigations of cases of HBV and HCV infection suspected to be associated with health-care delivery play an essential role in identifying unsafe practices and controlling health-care–associated viral hepatitis transmission. However, these investigations are resource intensive, and frequently overwhelm health department resources. Over many years, the New York City Department of Health and Mental Hygiene (DOHMH) developed a systematic approach to guide investigation and public health response to case reports of acute HBV or HCV infection in patients whose infection was potentially associated with health-care delivery. In this approach, the least resource-intensive investigation components are conducted for each case, and decisions to expand the investigation to more resource-intensive components are guided by the likelihood that a single case report represents a cluster of health-care–associated infections (HAIs). This report describes the DOHMH approach in the context of two single case reports. Components of this approach might be useful to other health departments that are developing their own approaches to this type of investigation.

Health care should provide no avenue for transmission of bloodborne pathogens, yet transmission of HBV and HCV in health-care settings is an increasingly recognized public health problem (1,2). During 2008–2011, a total of 31 outbreaks of HBV or HCV infection in health-care settings were reported to CDC. These outbreaks, reported from jurisdictions across the United States, resulted in approximately 250 persons acquiring HBV and/or HCV and the notification of approximately 88,000 persons potentially at risk for infection (2).

Outbreaks often are identified through the investigation of a single case report of acute HBV or HCV infection in which infection is suspected to be associated with health-care delivery (e.g., HAI). DOHMH investigates an average of 40 reports of persons with acute HCV and nearly 600 with acute HBV annually; for 10–20 of these reports each year, initial investigation determines that infection is potentially associated with health-care delivery. Because investigation of these reports has the potential to overwhelm available resources, beginning in 2001, DOHMH developed a systematic approach to guide investigation and public health response (Boxes 1 and 2). The least resource-intensive investigation components (i.e., interviews with the patients and their health-care providers) are conducted for each case. Decisions to expand the investigation to more resource-intensive components (e.g., site visits, active case finding, and broader notification of other patients) are guided by findings from the initial investigation.

The DOHMH approach is described in the context of the following two single case reports.

Case 1. In May 2007, a male resident of New York City aged 60–69 years contacted DOHMH to report his recent hepatitis C diagnosis. He and his gastroenterologist believed that he acquired HCV during an outpatient colonoscopy in February 2007; this was the index patient's only invasive procedure during the likely exposure period. Symptom onset occurred 32 days after the procedure and included influenza-like symptoms, anorexia, and joint pain. Laboratory tests revealed the presence of HCV RNA and elevated liver enzymes: alanine aminotransferase (635 IU/L [normal: 1–43 IU/L]) and aspartate aminotransferase (313 IU/L [normal: 1–40 IU/L]). The patient had no history of HCV testing. His liver enzymes were monitored routinely because of unrelated medications and had been normal during February 2006–November 2007. Following DOHMH's approach, a limited investigation was initiated (Box 1). No risk factors for HCV infection (e.g., injection drug use or blood transfusion before 1992) other than the colonoscopy were identified.

On May 29, 2007, DOHMH contacted the gastroenterologist who had performed the colonoscopy. The gastroenterologist and anesthesiologist who were involved in the index patient's procedure had valid medical licenses, without any disciplinary actions; neither was aware of other new hepatitis C diagnoses among their patients.

Records indicated that the index patient received 2 doses of intravenous propofol (1 dose = 6–8 cc). In a telephone interview conducted on May 29, 2007, the anesthesiologist stated that he routinely reused single-use propofol vials (including both 20 cc and 50 cc vials) for more than one patient. DOHMH advised the anesthesiologist to discontinue this practice immediately. According to the procedure log, six additional patients had undergone endoscopy procedures on the same day as the index patient; all received anesthesia. DOHMH matched the patient names and birth dates against its HCV surveillance database; two matches were identified. Both patients had HCV infections before the procedure date. One of these patients had an esophagogastroduodenoscopy (EGD) immediately before the index patient, increasing concerns that health-care–associated transmission had occurred. Accordingly, DOHMH proceeded with a full investigation (Box 2).

At the time of the initial investigation (May 2007), the anesthesiologist was no longer working in the gastroenterology practice where the procedures had occurred. Onsite investigation of the medical office where the anesthesiologist was currently practicing was delayed until December 2007 because of limited DOHMH resources and competing priorities. During the onsite investigation of the anesthesiologist, no obvious infection control lapses were identified. The anesthesiologist stated that he had stopped reusing single propofol vials for multiple patients since the telephone interview with DOHMH. During the observation of two procedures, the anesthesiologist was not observed to reuse needles or syringes to enter medication vials, even when obtaining additional doses for the same patient. In January 2008, DOHMH conducted an onsite investigation of the gastroenterologist's office; no infection control lapses were identified.

The remaining four patients who had had procedures on the same day as the index patient and the possible source patient were contacted; all tested negative for HCV antibodies, as did the anesthesiologist. An electronic database from the anesthesiologist's billing company was obtained, and 2,907 patients treated by the anesthesiologist during January 1, 2005–November 30, 2007 were matched against the DOHMH hepatitis C surveillance database in an attempt to identify additional clusters. A potential cluster was defined as two or more patients with a positive HCV test who had procedures on the same day, at least one of whom was first diagnosed with HCV infection after the procedure date. Such a cluster might indicate a separate transmission event that had occurred during procedures performed by the anesthesiologist. However, no additional clusters were identified.

Serum specimens from the index patient and the possible source patient were analyzed by the New York State Department of Health laboratory using methods described previously (3). Both patients were infected with HCV genotype 2b strains; the two strains also exhibited matching viral sequences. On the basis of the epidemiologic and laboratory findings, DOHMH concluded that health-care–associated transmission between these patients most likely occurred as a result of incorrect use of needles, syringes, or medication vials. Endoscopes were ruled out as a likely transmission vehicle because the index patient and source patient had different types of procedures with different types of scopes. Because no specific transmission mechanism or additional cases were identified, a decision was made not to notify additional patients beyond those who had been tested as part of the initial investigation.

Case 2. In April 2009, DOHMH was notified by an attorney regarding a case of acute HCV infection in a woman in her 40s after an EGD procedure in April 2006. Five weeks after her procedure, the woman was hospitalized and diagnosed with acute HCV infection. Although acute HCV is a reportable condition in New York City, the patient's health-care providers had not reported this case to DOHMH at the time of diagnosis. DOHMH interviewed the patient and her primary-care provider; no behavioral risk factors for HCV infection were identified. The patient had no previous history of HCV testing.

The anesthesiologist for the EGD procedure was the same anesthesiologist associated with case 1, and the procedure date was during a period when the anesthesiologist routinely reused single-use propofol vials for multiple patients. A different gastroenterologist had performed this procedure in a different outpatient practice. Given the absence of other risk factors, timing of symptom onset, and association with the anesthesiologist who was implicated in case 1, DOHMH revised its previous decision and proceeded to notify all 3,287 patients who received care from this anesthesiologist during January 1, 2005–July 30, 2008.* Patients were notified by mail with a recommendation to be tested for HBV, HCV, and human immunodeficiency virus.

Reported by

Katherine Bornschlegel, MPH, Catherine Dentinger, FNP, MS, Marci Layton, MD, Sharon Balter MD, New York City Dept of Health and Mental Hygiene. Anne Marie France, PhD, EIS Officer, CDC. Corresponding contributor: Anne Marie France, afrance@cdc.gov, 404-639-5313.

Editorial Note

Transmission of HBV and HCV has occurred in a broad range of U.S. health-care settings (1,2,4,5), and recognized transmission events likely represent only a small proportion of a larger problem (1,6). Public health investigations of case reports of acute HBV and HCV infections suspected to be HAIs play an essential role in identifying unsafe practices and controlling health-care–associated viral hepatitis transmission. In the two cases described in this report, transmission likely resulted from breaches in aseptic technique when preparing and administering parenteral injections. Similar breaches have been identified in the majority of outbreaks that involved patient-to-patient HCV transmission (4,6).

Despite the public health importance of investigations of HBV and HCV infections suspected to be HAIs, current capacity to fully investigate cases in a timely manner and identify and respond to outbreaks in health-care settings is lacking (7). Confirmation of health-care–associated transmission of HBV and HCV generally relies on 1) functioning public health surveillance and reporting, 2) thorough case investigation and successful identification of breaches in infection control during health care delivery, and 3) case finding to identify additional persons who might be infected. These activities are resource-intensive and pose numerous challenges. In many cases, despite intensive investigation, transmission associated with health-care delivery cannot be confirmed. Onsite assessments might not identify infection control breaches. For example, infection control breaches might be intermittent, especially if health-care providers are aware of proper technique but lapse when they are distracted or busy (8), or knowledge that an investigation is under way might lead to changes in practice. Additionally, in NYC, health-care providers are educated regarding appropriate infection control practices when first contacted by DOHMH, and are directed to immediately change any unsafe practices that are identified in initial telephone interviews. Finally, although single cases might be evidence of a larger problem, transmission also can represent an isolated event. Determining when to investigate a case report, how many resources to dedicate to the investigation, and when to notify persons of potential exposure, can be difficult for health departments. The DOHMH approach to investigating these case reports has provided a framework to guide public health investigation and response in the context of the resources available in NYC. In this approach, as illustrated by the cases described in this report, the least resource-intensive investigation components are conducted for each case, and decisions to expand the investigation to more resource-intensive components are guided by the likelihood that a single case report represents a cluster of HAIs.

Components of the DOHMH approach might be helpful to other health departments that are developing their own approaches to this type of investigation. In addition, CDC recently has developed a toolkit of recommended steps for the investigation of single cases of HBV or HCV infection suspected to be associated with health-care delivery (9). This toolkit, which was developed with input from DOHMH along with other state and local health departments, provides a useful framework for state and local health departments to develop an approach to these investigations that suits the resources available in their jurisdictions.

References

1. Thompson ND, Perz JF, Moorman AC, et al. Nonhospital health care-associated hepatitis B and C virus transmission: United States, 1998–2008. Ann Intern Med 2009;150:33–9.
2. CDC. Healthcare-associated hepatitis B and C outbreaks reported to the Centers for Disease Control and Prevention (CDC) in 2008–2011. Atlanta, GA: US Department of Health and Human Services, CDC; 2012. Available at http://www.cdc.gov/hepatitis/statistics/healthcareoutbreaktable.htm. Accessed May 9, 2012.
3. Gutelius B, Perz JF, Parker MM, et al. Multiple clusters of hepatitis virus infections associated with anesthesia for outpatient endoscopy procedures. Gastroenterology 2010;139:163–70.
4. Alter MJ. Healthcare should not be a vehicle for transmission of hepatitis C virus. J Hepatol 2008;48:2–4.
5. Fischer GE, Schaefer MK, Labus BJ, et al. Hepatitis C virus infections from unsafe injection practices at an endoscopy clinic in Las Vegas, Nevada, 2007–2008. Clin Infect Dis 2010;51:267–73.
6. Perz JF, Thompson ND, Schaefer MK, et al. US outbreak investigations highlight the need for safe injection practices and basic infection control. Clin Liver Dis 2010;14:137–51.
7. Trust for America's Health. HBV and HCV: America's hidden epidemics. Washington, DC: Trust for America's Health; 2010. Available at: http://healthyamericans.org/assets/files/TFAH2010HepBCBrief09.pdf. Accessed May 9, 2012.
8. Westbrook JI, Woods A, Rob MI, et al. Association of interruptions with an increased risk and severity of medication administration errors. Arch Intern Med 2010;170:683–90.
9. CDC. Healthcare investigation guide: recommended steps for investigating single cases of hepatitis B virus (HBV) or hepatitis C virus (HCV) that are suspected to be related to healthcare delivery. Atlanta, GA: US Department of Health and Human Services, CDC; 2012. Available at http://www.cdc.gov/hepatitis/outbreaks/healthcareinvestigationguide.htm. Accessed May 9, 2012.